Air Canada A320 accident at Halifax

[peekay4]

I know several US Part 121 and 135 ops authorized for ops spec C073, using MDA for DA. I would say it is not an uncommon authorization to have in the US especially for regionals & charters serving smaller airports having non-precision approaches.

By now the Transportation Safety Board must have a pretty good idea of why AC624 crashed...

[Groucho]

"By now the Transportation Safety Board must have a pretty good idea of why AC624 crashed"

Exactly. All this talk about MDA/DA/'hard floors'/'add 50ft'/'Dive and drive' is really irrelevant here.

The a/c hit the ground BELOW the threshold elevation and short of it. Regardless of 'limits', there was either a lack of visual reference and/or some sort of performance issue, either of which will already be known.

[7478ti]

There have been many accidents following this erroneous "visual reference" profile over the past 5 decades. In fact, it is important to note that even FAR25.1309 [see the preamble] was largely instituted due to the two famous fatal accidents very similar to this one, that took place at KBFD, both CV580s, at the same airport, both winter nights, two weeks apart. The first was AL736 on Christmas eve, Dec 24, '68 and the second AL737 Jan 6, '69. These two accidents were key events in the direct chain that led to RNP's creation, assuring that every SIAP has a safe vertical and lateral path defined all the way to the TDZ, all the time,... as well as a safe path back out from the TDZ, in the event of some factor like "loss of visual reference".

As to the MDA being used as a DA, Theo VanDeV at KLM clearly showed during AWO HWG deliberations over two decades, ago why this policy to set MDA=DA is safe and appropriate, without needing any 50' additives, but some states and authorities have nonetheless been slow to take advantage of the increased safety of using VNAV paths with MDA=DA, in lieu of "dive and drive", by still assessing a completely unnecessary 50' additive penalty.

[Retired DC9 driver]

The Inquisitor wrote
The methodology of getting to MDA may have 'evolved', but it is STILL a hard floor - unlike a DA, you do NOT go below it unless you have the required visual references. It is not the altitude at which you initiate the MAP.Actually, in the Airbus if you have the "magic" working properly, and have set the FPA properly at the FAF, and crossed the FAF at the proper altitude, when you reach MDA without the visual reference there should be no hesitation, it's a Go Around. You should have been in a perfect position to "see" the runway, stabilized on the correct approach path to touch down with correct Threshold Crossing Height.
So in that sense MDA is the altitude at which you initiate a MAP, in a constant descent, if you can't see the runway, ie a Decision Altitude.
Whereas on the DC-9 you got down to MDA, inside the FAF stabilized (but early!) so you could level off, and sit there, peer out, at MDA looking for the runway..

[L39 Guy]

Aterpster,

I agree with you 100%. As an individual that is involved with procedure design and has design many and flown hundreds of LPV approaches, LPV is a vastly superior system than GLS/RNP. I state that for the following reasons:

Procedure Design
- the design criteria affords a very tight final, tighter than RNP (even 0.1 in close). There are a handful of places in the world where RNP 0.1 would yield lower approach limits than LPV
- the vertical path of RNP, being barometric altimetry driven, is subject to all of the barometric altimetry problems in both warm weather (a flight path angle that is steeper than the nominal path) and cold weather (flatter than the nominal path). As well, there are temperature restrictions at both ends of the temperature spectrum
- GLS may solve the barometric altimetry issue however it creates many others (discussed shortly)
- LPV uses satellite-derived height, thus eliminating all of the limitations of barometric altimetry
- how would it work at airports and not just the ones where airlines go exclusively? For each runway end there would be an GLS/RNP approach for the airliners and an RNAV (GPS and LPV) for the bizjets and GA aircraft?


Financial
- North America is covered with WAAS coverage; my understanding of the European Galileo satnav system is that it will have the qualities (accuracy, integrity, etc) to support Cat 1 ILS like approaches, ie LPV/APV
- with WAAS the navigation source is free; with Galileo it will come with a small licensing fee
- Galileo will have worldwide coverage
- GLS means, last time I heard, a $3 million per airport investment in the ground infrastructure; the investment in the aircraft to either install new multimode receivers or modify the existing ones is massive (last I heard about $250K per box)
- naturally, Honeywell, Boeing, Airbus and the others would love to have the airports and airlines pony up that kind of dough
- it is interesting to note that a brand new, certified WAAS receiver from Garmin is about $14K; upgrading an existing box to WAAS is $3K. Why Honeywell and the others can't do it for something similar (or even double) is beyond me.
- $3 million per airport times how many airports? Big, big dough.
- Given that there is no operational benefit there is no financial benefit from the cost to the industry of GLS boxes on the ground and expensive MMR's in the aircraft

With the knowledge the industry has with LPV/APV and with Galileo on the threshold of operational capability, the only logical and financially responsible solution is LPV/APV - airlines should be pushing the avionics providers to get with the program and upgrade the existing GPS's and FMS's to a WAAS/Galileo capability that would provide the best operational capability with the lowest (by a large margin) implementation cost to the industry.

[scud]

And as I understand it:

New terminal = investment by the airport authority
New navaid = cost to NavCanada

Considering the transition to RNAV GNSS approaches, there's going to be very little appetite to invest in net-new ILS equipment, even though a large fraction of commercial aircraft in Canada cannot perform precision GPS approaches.

Around 1998, Nav Canada conducted a cost-benefit analysis concerning the installation of an ILS for runway 05 in Halifax. The request came from an operator who's 767 suffered a major tail strike a couple of years before, that cost 10 million dollars to fix. That was due to crossing the FAF at the minimum crossing altitude, giving a flight path angle of about 1.2 degrees to MDA, and coming in a little slow near the VRef.

The result was that Nav Canada's cost for an ILS would have been about 2 million dollars, plus another 2.5 million to the Halifax Airport Authority for upgraded approach lighting and landscaping, because the localizer antenna would have to otherwise be placed in a ravine, and there was a service road where the glide-slope antenna would be situated. Both agreed that the cost-benefit was positive: 4.5 million dollar investment compared to another potential (or worse) 10 million dollar loss to an air carrier. The airline in question balked at being responsible for such an outlay, despite the fact that they understood that the system would pay and not the airline directly. Nav Canada put the project on the back burner due to lack of airline interest.

Typical of airlines in Canada, at least at the time: our pilots are heroes, except whey they become :mad: when they crash an airplane.

[scud]

As to the MDA being used as a DA, Theo VanDeV at KLM clearly showed during AWO HWG deliberations over two decades, ago why this policy to set MDA=DA is safe and appropriate, without needing any 50' additives, but some states and authorities have nonetheless been slow to take advantage of the increased safety of using VNAV paths with MDA=DA, in lieu of "dive and drive", by still assessing a completely unnecessary 50' additive penalty.

"dive and drive" has nothing to do with adding 50 feet. It is irrelevant in this context because "dive and drive" is seldom used anymore. Use of a DA or MDA in this case both involve approaches along a predefined flight path angle using the aircraft vertical nav capability.

The issue of whether to add 50 feet is related to the accuracy of the approach, navigation equipment and the regulatory limitations of the operator.

A DH assumes that a decision to land or go-around will be made no later than at that height, and it is permissible for the aircraft to dip down below that height in case of a go-around because of its inertia. It is predicated on the aircraft being exactly at the MAP location, as guaranteed by the precision approach system (ILS) for example, so that adequate clearance above obstacles is maintained.

An MDA assumes a lower degree of precision, in which case the MDA is the lowest altitude the aircraft can descend, taking into consideration the highest obstacle within a certain radius of the MAP (plus the path from the FAF); the exact location of that obstacle in not considered in the approach. The typical height above this highest obstacle is 250 feet. Because of this uncertainty, the aircraft must never be allowed to descend below MDA unless visual, because of the potential but uncertain proximity to this highest obstacle. This is why 50 feet is added: to allow for the dip in altitude due to inertia and reaction time when deciding to do a go-around, assuring remaining above MDA.

RNAV approaches can either use DA or MDA, depending on the operator certification and the accuracy of the nav equipment. If you look at a GNSS approach plate, you may see 2 sets of minimums: one for LNAV/VNAV and the other LNAV only. Under the former you will find a DA and under the latter a MDA. 50 feet must be added to the MDA, unless doing a 'dive and drive' descent, which is still legal but not SOP. Some major operators in Canada are not approved for LNAV/VNAV, despite having such limits on the approach plate.

[peekay4]

Incidentally the blanket exemption (http://www.tc.gc.ca/CivilAviation/Regserv/Affairs/exemptions/docs/en/2509.htm) in Canada allowing the use of MDA as DA (without adding 50ft) will expire at the end of this month -- April 30, 2015.

I believe large jet operators may still request exemption, but it will be interesting to see if the blanket exemption gets extended or not.

[YRP]

- it is interesting to note that a brand new, certified WAAS receiver from Garmin is about $14K; upgrading an existing box to WAAS is $3K. Why Honeywell and the others can't do it for something similar (or even double) is beyond me.


Maybe off topic, but the cost is largely NRE (development cost). From working in the electronics industry on even smaller product developments, without the same reliability / robustness targets as aviation, the development costs can be pretty big.

For a general aviation Garmin box, the manufacturing cost is sub $1K. The rest is engineering work.

The market is much smaller for commercial airline avionics. They are going to sell/upgrade between 1000 and 10,000 units (at a guess) for any given product. Those have pretty high standards for reliability/certification and a lot of integration with other a/c systems.

If you add up the engineering work (design, verification, certification) and divide it across the possible market, and add probably not a small amount of liability insurance, those cost figures are probably not unreasonable.

[AJW709]

On the investment case (or not) for ILS upgrades at YHZ it's interesting to compare to YYT (St John's, Newfoundland), another place with a surfeit of interesting weather conditions which will install Cat III ILS next year (becoming only the 4th or 5th airport in the country with Cat III ILS & the first to use LED approach lighting. (Source:http://stjohnsairport.com/wp-content/uploads/2015/03/Accessibility-and-Safety-Initiative-FAQs.pdf)

It strikes this SLF as odd that Halifax, as an arguably busier airport than St John's, hasn't put in the same investment in addition to the shiny new terminal/car parks/hotel.

[peekay4]

GPS/WAAS equipment cost is just a fraction of the total cost. What's expensive is the actual cost to retrofit each and every individual aircraft. It's not like you one simply unplug old equipment and swap in new ones.

You need a team of engineers a full week per aircraft at a minimum. If you stick to the OEM providers (Honeywell, etc), just the labor costs alone would be in the $ hundreds of thousands per aircraft. Then you have to add the cost of flight testing, cost to upgrade the simulators, cost to re-train all the pilots (and update all the training materials, manuals, job aids, etc), cost to train the mechanics, cost to provision spares, project management costs...

Plus it might not make sense to just upgrade to GPS. You'd probably package the upgrade to also add ADS-B, maybe CPDLC, even a HUD. Perhaps even more exhaustive upgrades are justified for older aircraft (older A320s still have CRTs).

Pretty soon you're easily past $1 million per aircraft...

[ASRAAM]

I might have missed it but no one seems to have mentioned the flight directors. I would assume that during the instrument approach the autopilot was in use, either as a fully managed approach or in nav/FPA. Once visual the FDs should have been turned off. It's worth giving some thought as to what would have happened if they had been left on. For example if an FPA of 3 degrees was set but not followed because the crew were now visual and aiming at the runway. The situation would be somewhat similar to the Korean 777, except of course for all those airbus protections..... Until 100RA. Thoughts anyone?

[RESA]

I suspect that there was a major error in the execution of the approach . . . I just wonder why nobody questions why the entire undercarriage was left behind at the “frangible localiser array”? I don’t recall a snow-bank ever eviscerating an aircraft . . . totally removing the under carriage?

What’s under that snow . . . not just dirt ?

[Mudman]

If you look at the google street (https://www.google.ca/maps/@44.863709,-63.530008,3a,39.4y,64.74h,86.59t/data=!3m4!1e1!3m2!1sQ7iQNpHS7LNMNV5w636Ziw!2e0) view of the area the ground slopes quite steeply below the array. The array sits on a concrete pad. I'd expect that below the dirt and gravel is a substantial concrete foundation. Given most footings and foundation walls around here have to be at least 3'- 4' deep to be below the frost line to prevent upheaval I imagine that is what took the gear off. Also being winter the ground was frozen solid almost as hard as concrete.

https://www.google.ca/maps/@44.863709,-63.530008,3a,39.4y,64.74h,86.59t/data=!3m4!1e1!3m2!1sQ7iQNpHS7LNMNV5w636Ziw!2e0

This Transport Canada Photo shows how far in front of the array the aircraft made first contact. Well below the level of the array. Anyone who has backed into a snowbank or slid of the road into one knows that snow and ice can be surprisingly unyielding.

https://farm8.staticflickr.com/7601/16992279831_42d43f360f_b.jpg

[L39 Guy]

The WAAS upgrade is a matter of upgrading the chip in the receiver (to do a 5 Hz update rate rather than a 1 Hz), the antenna (using the same cabling) and the software. All that is being done is the GPS sensor in a multi-sensor MMR is being upgraded to incorporate the WAAS correction which, by the way, is on the same frequency as the USAF/GPS satellites; Galileo, incidentally, uses the frequency and is interoperable with GPS/Glonass/WAAS.

Doing upgrades for other items such as CPDLC, etc is beside the point. It is important to note that in order to be ADS-B compliant after 2020 in the US, a WAAS position will be required so, unless the air carriers snivel for an exemption, they will be upgrading to WAAS anyways.

With WAAS grade receivers, precision approaches to virtually every runway in North America becomes possible and with Galileo every runway in the world.

Compare this alternative with upgrading MMR's for Local Area Augmenation System (LAAS) which will require VHF receivers, software, certification, etc and at least $3 million per airport for the LAAS box to get the same results as WAAS/Galileo for airline only type aircraft and the choice is clear.

[scud]

GPS/WAAS equipment cost is just a fraction of the total cost. What's expensive is the actual cost to retrofit each and every individual aircraft. It's not like you one simply unplug old equipment and swap in new ones.

You have to include the costs to the airport infrastructure, such as High intensity runway and approach lighting, centre-line lighting, not counting imbedding all these in-pavement and such issues such as CAT II and CAT III hold short lines, especially if taxiways have to be redesigned for that. Plus, there has to be increased lighting for taxiways, such as the 'greens' centreline taxiways. And for airports that have never had CAT II/III systems, an huge stand-by generator to power the whole thing. Then, once an airport has imbedded runway and taxiway lighting, snowblough blades have to be converted from steel to plastic, so as to not rip them out during snow clearing operations.

In the case of Halifax, the cost to the airport authority for the improved infrastructure to accommodate a CAT I for 06 was similar to the cost of the ILS itself to Nav Canada.

[aterpster]

L39 Guy:

With WAAS grade receivers, precision approaches to virtually every runway in North America becomes possible and with Galileo every runway in the world.

Not exactly. That's why the U.S. has a lot of LP approaches now, and more all the time. Some runways don't have the clear zones for a vertically guided approach (APV in FAA-speak).

And, ICAO has yet to anoint LPV as a precision approach.

[aterpster]

scud:

The U.S. now has many LPV approaches down to 200 and 1 with only edge lights (which are usually there anyway) and precision runway markings.

[peekay4]

L39 Guy:
The WAAS upgrade is a matter of upgrading the chip in the receiver (to do a 5 Hz update rate rather than a 1 Hz), the antenna (using the same cabling) and the software.
That's assuming WAAS upgrade is the only thing that's required. Which is the wrong assumption in most cases.

In reality, a large number of A320s (and even A330s/A340s) do not have even vanilla GPS installed as part of the navigation system! No GPS units. No MMR. These A320s depend solely on radio updating (VOR/DME) or manual IRU alignment before takeoff.

(I believe the Air Canada aircraft involved in this accident was not equipped with GPS.)

Also, some of these aircraft have dual FMS which are not GPS compatible. Total upgrade price == very costly.

[L39 Guy]

My, this is a tough audience. Allow me to clarify a few points in order of responses:



Scud: for a non-precision approach (i.e. minimums as low as 250 ft) there is no requirement of sophisticated lighting, hold short lines, etc. For 99% of the runways out there particularly at airports with an existing CAT II or CAT III ILS, LPV can provide approach limits to 250 ft with the only improved airport infracture is insuring the Glideslope Qualification Surface (GQS) - the region between DA and the runway is free of obstacles above a protected surface (I won't burden you with the calculation of this surface but it is roughly a 2 degree slope for a 3 degree Flight Path Angle (FPA). In Halifax's case, all four runway ends have LPV approaches with limits between 250 and 259 ft (DA value rounded up to the next highest 10 ft - TDZE). Neither Runway 05 or 32 have fancy lighting. The problem in this case is that the AC A320's don't have GPS and even if they did, they and virtually every other transport category aircraft (Airbus, Boeing, etc) don't have WAAS making these procedures unable.
aterpter: agreed about the strict ICAO definition precludes LPV from being called that. Notwithstanding that, however, for all intents and purposes LPV is a precision approach for the operator - limits as low as 200 ft, 6 sec time to alert, "glideslope-like" vertical guidance (better than the ILS in my opinion). For the pilot it looks and feels just like an ILS despite what ICAO might say. As far as the clear zones, see my comment above about GQS and I agree - we run into this issue in Canada too.
peekay4: the origin of my comments was to state that RNP/GLS is an inferior option from an economic, operational and procedure design perspective compared to RNAV with WAAS/LPV/APV. It's great business for Honeywell who would dearly love to install a GLS box at every airport and charge a grazillion dollars for avionics upgrades. You are absolutely correct that many FMS's in B737-300/400/500 and Airbus 319/320/330/330/340 do not have GPS hence cannot even do a simple RNAV approach. My point remains that a better option for the reasons above is to have these aircraft equipped with GPS/WAAS rather than GLS, assuming they are going to be upgraded. ADS-B in the US in 2020 is going to drive it for any aircraft that will be flying in that airspace. Having said all of that, it is shameful that a major international airport like Halifax with its location in a valley, with the maritime weather they get and the winds they get do not have a proper ILS to all four runway ends; 250 ft minimums if the proper approach lighting is a far cry better than having to do a LOC/DME approach

[JammedStab]

L39 Guy:

That's assuming WAAS upgrade is the only thing that's required. Which is the wrong assumption in most cases.

In reality, a large number of A320s (and even A330s/A340s) do not have even vanilla GPS installed as part of the navigation system! No GPS units. No MMR. These A320s depend solely on radio updating (VOR/DME) or manual IRU alignment before takeoff.

(I believe the Air Canada aircraft involved in this accident was not equipped with GPS.)

Also, some of these aircraft have dual FMS which are not GPS compatible. Total upgrade price == very costly.

Depending on what we see in the final report, there is a chance that we will get to see the price paid for not making this "costly" upgrade.

The last operator that crashed a jet in Canada were saving themselves money by waiting to upgrade their GPWS to TAWS standard. Several lives lost.

[peekay4]

With their extensive insurance policies, I would guess that AC's out-of-pocket expenses for this incident will be much less than the cost to upgrade their sizable fleet of non-GPS aircraft.

[aterpster]

L39 Guy:

2.aterpter: agreed about the strict ICAO definition precludes LPV from being called that. Notwithstanding that, however, for all intents and purposes LPV is a precision approach for the operator - limits as low as 200 ft, 6 sec time to alert, "glideslope-like" vertical guidance (better than the ILS in my opinion). For the pilot it looks and feels just like an ILS despite what ICAO might say. As far as the clear zones, see my comment above about GQS and I agree - we run into this issue in Canada too.

No doubt that LPV is better than many CAT I ILSs. The LPV G/S is extremely stable, unlike some CAT 1 ILs. But, LPV lacks the integrity to go below 200 feet. Technically I agree. Practically, I think it is all B.S.

Ah, ICAO and the FAA and their PBN stuff.

[Big Pistons Forever]

Seem to me the hull value of an A 320 would pay for a fleet wide GPS WASS sensor upgrade.

What would have been the cost if the jet was just a few feet lower and smoked the berm head on instead of bouncing over it, an event that almost certainly will produce lots of casualties ? Hundreds of Millions of dollars ? Not to mention the damage to reputation and forward bookings.

Sadly stinting on upgrades which will provide an obvious increase in approach precision and thus safety because it requires an upfront investment, has become ops normal for the bean counter, short term profit focused airline management at pretty much every airline in the world.

[peekay4]

Again, Air Canada will not bear the cost of hull replacement. Their insurance will cover that.

American Airlines paid $400 million to upgrade their 757/767 fleet with GPS. That's over $2.5 million per aircraft (120 of them), plus another $100 million in additional costs.

Rightly or wrongly, I'm sure AC's bean counters have thoroughly gone through the cost vs. benefit analysis of an upgrade.

[underfire]

Incidentally the blanket exemption in Canada allowing the use of MDA as DA (without adding 50ft) will expire at the end of this month -- April 30, 2015.
Thankfully.
Most have no concept of the difference, nor how far above MDA their actual DA is (it sure as hell isnt 50 feet, but at least the 50 feet + ROC gives some hope, and hopefully most obstacles are in the missed)

[oblivia]

With their extensive insurance policies, I would guess that AC's out-of-pocket expenses for this incident will be much less than the cost to upgrade their sizable fleet of non-GPS aircraft.

Indeed, AC (and whoever else owns the plane) has probably made a substantial profit on this hull and will have already received the cheque! Airlines insure planes at their full value at the time of purchase, so old birds like this one tend to be worth far less than the policy covering them. And insurers pay out in full within 72 hours of a loss, with policies that cover any and all risks.

BA got paid immediately and in full, for example, when a perfectly serviceable 747 was stranded in Kuwait after the Iraqi invasion. It was the oldest hull in the fleet and earned the company a nice profit. The Iraqis later burned it, long after the cheque had cleared.

The reason for this amazing level of insurance is, of course, the industry's remarkable safety record...

[fox niner]

Reading the statements made above, I would almost start to believe that airlines would actually welcome a hull loss once in a while to boost their profitability.

[oblivia]

In the case of losses where people die, it can actually a bit embarrassing for airlines to report a windfall profit while the victims wait years for the minimum possible payout the insurer can get away with. The MH370 victims' families will probably get far less (in total) than the airline was paid within three days of its disappearance—and they'll likely wait the best part of a decade to find out.

Even so, I don't think any airlines set out to have accidents for insurance purposes, but I'd be happy to hear stories from pilots who've been asked to write off an airframe. How does that conversation go...?

[YRP]

I find it hard to belief that insurance companies would insure for significantly more than the current value. At best they might use a year or two out of date values. Paying a claim for more than the value is betterment and is very undesirable.

Look at it from the insurance cost point of view. If AC insures a plane at twice its value, it has to pay twice the premiums (for hull insurance rather than liability). AC isn't going to want that any more than the insurance company.

Gambling on loss rates is exactly the opposite of the point of insurance.

[Numero1]

What do you professionals think of this?


Air Canada Flight 624 class action statement filed in Halifax - Nova Scotia - CBC News (http://www.cbc.ca/news/canada/nova-scotia/air-canada-flight-624-class-action-statement-filed-in-halifax-1.3041345)

[peekay4]

Indeed, AC (and whoever else owns the plane) has probably made a substantial profit on this hull and will have already received the cheque! ...
BA got paid immediately and in full, for example, when a perfectly serviceable 747 was stranded in Kuwait after the Iraqi invasion. It was the oldest hull in the fleet and earned the company a nice profit. .
I believe this is incorrect. Unfortunately people compare aviation insurance to their more familiar car (auto) insurance policy, and make wrong conclusions.

Cars rapidly depreciate. The old joke is, as soon as you drive a new car off the lot, you've lost 50% of the car's value. So car insurance works with this concept in mind. In case of a total loss, the payout is based on Actual Cash Value, which takes into account the age of the car, wear and tear, mileage, etc. All these things are subtracted from the car's replacement value (depreciation).

In aviation, things work very differently. The replacement value of an airplane doesn't follow your typical depreciation scale. Even a Cessna 172 sold for $20k back in 1975 might be worth $45k today.

So in aviation, instead of using Actual Cash Value, the payout is based on a fixed Agreed Value. I pay $X dollars premium, and the insurance company agrees to pay me $Y dollars if there's a loss. There is no depreciation involved.

People conclude: wow, if I crash a 30 year old plane, the insurance company will still pay me $Y dollars, which must be way above the depreciated value of the airplane!

But we've already shown that that's wrong, with the Cessna example. At the time of the claim, the replacement cost of the airplane might actually be greater than the Agreed Value.

Companies like Air Canada (or British Airways) do not like to under-insure or over-insure. If they under-insure, then they have to shoulder tons of expenses if there's an accident. If they over-insure, then they are overpaying their premiums.

So periodically, airlines will get experts to re-appraise every aircraft in their fleet, and re-adjust their insurance requirements accordingly. So if the value of an aircraft drops over time, they will re-insure the aircraft at a lower Agreed Value, and pay less premiums.

Thus in reality the delta between the Agreed Value and the replacement value of the aircraft isn't very large, unless either the airline or the insurance company hasn't been doing their job.

[oblivia]

That makes more sense. I was trying to find the article where I'd read all this stuff. It's here:

The big money surprise about Malaysia Airlines - Fortune (http://fortune.com/2014/05/01/the-big-money-surprise-about-malaysia-airlines-flight-370/)

But on re-reading I'm pretty sure it's gotten things a bit back to front.

[peekay4]

The article quotes an "expert" stating "he knows no airline" which doesn't insure all risks at "full replacement value".

But we can easily find actual airline insurance terms from SEC filings by doing a simple Google search (https://www.google.com/search?client=safari&rls=en&q=site%3Asec.gov+airlines+%22agreed+value%22&oq=site%3Asec.gov+airlines+%22agreed+value).

You'll see insurance agreements related to numerous past and current airlines, including Delta, United, Skywest, American Airlines, Aloha, etc.

All of them use "agreed value" as I described above, and not "full replacement value".

The only exception I know is if an airline self-insures. Otherwise "agreed value" is standard practice world-wide.

[BeechNut]

In aviation, things work very differently. The replacement value of an airplane doesn't follow your typical depreciation scale. Even a Cessna 172 sold for $20k back in 1975 might be worth $45k today.

So in aviation, instead of using Actual Cash Value, the payout is based on a fixed Agreed Value. I pay $X dollars premium, and the insurance company agrees to pay me $Y dollars if there's a loss. There is no depreciation involved.

This is exactly my experience with insuring my own aircraft (a 1979 Beech Sundowner 180). Although the market for GA aircraft has tanked in my part of the world and the Agreed Value has declined.

The caveat here is that the insurance company will balk if you ask to insure for an Agreed Value greatly above the true market value of the aircraft. They don't want to pay out for much greater than true market value (at my end of the scale the premium difference on a $10k delta in agreed value is fairly small). And of course I don't want to pay excessive premiums, so it's in both of our best interests to assess a fair Agreed Value.

Two things have affected the Agreed Value on my aircraft: one, the market (which has been pretty poor since 2008); the other, as I run down the time to TBO on my engine.

While I don't know if I can extrapolate this to airliners, I'm pretty sure that as an aircraft approaches a major check, it's market and hence agreed value adjusts accordingly. Since I bought my aircraft, I've reduced the agreed value as my engine approaches TBO.

[Ian W]

There is one major difference that should be highlighted between ILS, GLS and LPV (and variants). With ILS the aircraft is following a glidepath beam from antennae on the ground, with GLS the aircraft is following a glidepath based on GPS alt corrected by Ground Augmentation - both of these are accurate glidepaths to the runway elevation. However, with LPV the glidepath is based on a distance/altitude calculation and the aircraft glidepath is 'barometric aided' in other words your vertical displacement from the runway elevation is based on your altimeter setting, you are not flying a ground referenced glidepath but an altimeter referenced glidepath. So the altimeter setting needs to be checked and rechecked. (unless you want to fly an EGPWS aided approach of course)

In ASRS missetting the altimeters in the aircraft is one of the most common incident reports. So from experience of the reporters to ASRS, LPV has far more potential risk than ILS or GLS, particularly if the crew are lulled into a false sense of security as the LPV presentation can look so much like a normal ILS

[Jet Jockey A4]

Not sure I understand your comment.

Maybe I’m wrong (not as tech savvy as others on this forum) or was thought wrongly but this is the way I understand the different GPS/RNAV approaches…

As far as I know with the LPV approach you are not using a "barometric altimeter" to fly the assumed G/S like you would on a LNAV or LNAV/VNAV approach.

The LPV approach uses a GPS/WAAS derived altimetry to fly a very precise angular type G/S like an ILS and never changes regardless of the altimeter setting set on the altimeter nor does it change with the OAT, so there is no need to actually change the crossing altitudes over the various fixes on the approach like on a LNAV/VNAV approach to keep the proper ground clearance.

If you were to fly a LPV approach and you didn't set the proper altimeter setting (whether high or low) or if you did not "TEMP COMP" you would still be on that "proper and correct" G/S (like on an ILS) but your crossing altitudes over every fix on that approach would be either higher or lower than is written on the approach chart. You should still mentally do the “TEMP COMP” to have a correct idea of the “new” crossing altitudes over the fixes to double check but it does not need to be programmed in the FMS unlike a LNAV/VNAV approach.

Finally, you still need to readjust your DA (or MDA) to a higher minimum in the colder temperatures to keep that correct ground clearance.

[peekay4]

From a vertical guidance perspective:

LNAV -- no vertical guidance. Does not require WAAS.

LP -- no vertical guidance. Requires WAAS.

LNAV/VNAV -- with vertical guidance, using baro-VNAV systems. WAAS may be used instead of baro-VNAV.

LPV -- with vertical guidance, using WAAS. (WAAS required).

GLS -- with vertical guidance, using GBAS.

[YRP]

This is exactly my experience with insuring my own aircraft (a 1979 Beech Sundowner 180). Although the market for GA aircraft has tanked in my part of the world and the Agreed Value has declined.

The caveat here is that the insurance company will balk if you ask to insure for an Agreed Value greatly above the true market value of the aircraft. They don't want to pay out for much greater than true market value (at my end of the scale the premium difference on a $10k delta in agreed value is fairly small). And of course I don't want to pay excessive premiums, so it's in both of our best interests to assess a fair Agreed Value.


Slightly off topic because this likely does not apply to airlines (possibly excepting Qantas :) ):

The other factor for GA aircraft is that you really do not want to overinsure your aircraft. The insurance company decides on write-off vs repair based on a certain percentage of the insured value. If you overinsure, they could decide to repair a plane that should have been written off. You are left owning a plane worth much less than it was previously because of the damage history. Some insurance policies have a "value correction" clause to avoid this situation.

[peekay4]

It's been 30 days now since the crash... hopefully the Annex 13 preliminary report be made available soon.

I'm a bit surprised that we haven't heard anything more about this crash. Often, (but not always), lack of news points to the dreaded "pilot error". Navigation equipment malfunction, windshear, etc., tend to get leaked to the media.

[L39 Guy]

JetJockey A4, you are correct. Both lateral and vertical positioning with WAAS/LPV is based upon satellite derived values including elevation. It is insensitive to altimeter settings, non-standard atmospheres (both hot and cold), etc.

In fact, whereas barometric altimetry is advertised to be +/- 50 ft (16m), WAAS vertical position accuracy is typically in the 0.5 m range.

With the imminent implementation of Galileo, not just North America, Japan and India but the entire world will have this augmented satellite navigation source thus permitting an "ILS-like" approach with localizer-like and glide-slope-like qualities to any airport in the world.

With GLS, a separate roughly $3 million box will be required near the airport - it too will provide the same level of accuracy, integrity, etc as WAAS/Galileo but will also require significant avionics improvements including VHF radios for the datalink, etc.

Hands down, WAAS/Galileo and LPV/APV is a far better solution for the aviation community anywhere in the world and for any size and type of aircraft.

[Geosync]

To bring the insurance conversation back full circle, the basic foundation of insurance is that it deals with "pure risk", which is the chance of loss or no loss, but no chance of gain. As others have mentioned, insurance companies aren't dumb, they typically won't over insure an aircraft. Does it happen? Sure, now and then, but typically no. In the airline world polices have deductibles just like your homeowners, or your Cessna 172 policy and they usually are between $1,000,000 and $500,000 dollars depending on model, body type, etc. So the airline will eat that first chunk of money before insurance kicks in. If there are upgrades to the aircraft the value is adjusted. If there is damage that is being repaired, the value is lowered until the repairs are complete. So in the end, the insureds typically don't make a profit in the event of a total loss, insurance has plenty of checks and balances that naturally prevent that. Has it happened? Yep, I've seen it(and believe me, the fallout isn't pretty for the underwriters) but it is rare. And if there is suspected fraud involved, insurance companies will do a deep investigation; they have lawyers on staff and they'll hire outside counsel if need be. Chances are the insurance companies has been doing this much longer than the insured has been around, so they're not to be messed with.

[GlobalNav]

Quoted: "From a vertical guidance perspective:

LNAV -- no vertical guidance. Does not require WAAS.

LP -- no vertical guidance. Requires WAAS.

LNAV/VNAV -- with vertical guidance, using baro-VNAV systems. WAAS may be used instead of baro-VNAV.

LPV -- with vertical guidance, using WAAS. (WAAS required).

GLS -- with vertical guidance, using GBAS."

Nice summary. Still, all provide guidance in the instrument segment to some minimums - MDA, DA or DH - and the pilot must make a decision to continue descent and operate into the visual segment to land.

The pilot must be capable of making a safe decision and skillfully use the flight visibility and visual references to visually control the airplane to land. The main problem, as I see it, is safely conducting the visual segment which means, to begin with, not accepting less than then necessary visual cues. The safety of every instrument approach, except Cat III autoland, requires this.

[slast]

The pilot must be capable of making a safe decision and skillfully use the flight visibility and visual references to visually control the airplane to land. The main problem, as I see it, is safely conducting the visual segment which means, to begin with, not accepting less than then necessary visual cues. The safety of every instrument approach, except Cat III autoland, requires this.

That is 100% correct and is the nub of the matter. And the decision must be that those "necessary visual cues" to continue below DH have ALREADY "been in view for sufficient time for the pilot to have completed an assessment of the aircraft position and rate of change of position, in relation to the desired flight path."

But we know that this assessment is very difficult in the vertical plane, and needs sight of at least a point of "low relative motion" (i.e. the aiming point). That is in no way guaranteed to be visible by DH, and is not even theoretically available in limiting conditions. Unfortunately the industry has for decades glossed over this inconvenient fact and trained pilots to believe that far less visual reference will be OK.

That means that the pilot's actual ability to "visually control the airplane to land" may have been fatally compromised without him even realising it. 99% of the time we get get away with it, but every now and again some unfortunate individual does not and is held responsible for making a "pilot error".

[scud]

1.Scud: for a non-precision approach (i.e. minimums as low as 250 ft) there is no requirement of sophisticated lighting, hold short lines, etc. For 99% of the runways out there particularly at airports with an existing CAT II or CAT III ILS, LPV can provide approach limits to 250 ft with the only improved airport infracture is insuring the Glideslope Qualification Surface (GQS) - the region between DA and the runway is free of obstacles above a protected surface (I won't burden you with the calculation of this surface but it is roughly a 2 degree slope for a 3 degree Flight Path Angle (FPA). In Halifax's case, all four runway ends have LPV approaches with limits between 250 and 259 ft (DA value rounded up to the next highest 10 ft - TDZE). Neither Runway 05 or 32 have fancy lighting. The problem in this case is that the AC A320's don't have GPS and even if they did, they and virtually every other transport category aircraft (Airbus, Boeing, etc) don't have WAAS making these procedures unable.

L39 guy, you're misconstruing my point.

The only cost-effective alternative for Air Canada's A320 fleet for runway 05 in Halifax, that would have prevented this accident would have been the installation of an electronic Glide Slope. That's because Air Canada's A320 fleet does not have GPS (I know because I've got over 4000 hours on them), and therefore unable to do LPV approaches that would have given them a precision type of approach (with a reliable glide path). The cost of installation of a Glide Slope, plus the addition of enhanced approach and runway CAT I lighting is still far more cost-effective than the installation of GPS/WAAS/LAAS on a fleet of over 40 aircraft, not to mention the other types that don't have GPS (none of the 767's... and yes, I've got over 4000 hours on those too).

The point being is that, you can have all manner of LPV/GLS equipped airplanes, but it's not cost effective at all if you can't reduce the DH below 250 feet because you don't have at least CAT I approach and runway lighting. That was my point.

[peekay4]

As others have mentioned, insurance companies aren't dumb, they typically won't over insure an aircraft. Does it happen? Sure, now and then, but typically no. In the airline world polices have deductibles just like your homeowners, or your Cessna 172 policy and they usually are between $1,000,000 and $500,000 dollars depending on model, body type, etc.
Geosync you might be surprised that both of the above assertions are not universally true for aviation insurance.

First, since aviation insurance uses "agreed value", it's very common for insurance companies to de facto "over insure" an aircraft. And they don't really care, since the insured is paying enough premium to cover the "agreed value". In other words, over insurance hurts the aircraft owner, not the insurance company. It's up to the aircraft owner to periodically get a new appraisal and reduce the "agreed value" if necessary.

The insurance company sure wont complain collecting higher premiums!

YRP also brings up a very important point above. If the aircraft is "over insured", then the insurance company may elect to repair a substantially damaged aircraft instead of simply writing it off and paying out the full agreed value. This can be highly detrimental to the aircraft owner.

In the airline industry this becomes important because, as you know, a large percentage of airliners are leased. (E.g., I believe the accident Air Canada aircraft was leased).

In a dry lease arrangement, the lessee is typically required to insure the aircraft with an "agreed value" not exceeding the aircraft's replacement value, to prevent over insurance. Otherwise, in case of an accident the lessor (owner) might get stuck with a "repaired" aircraft with a substantial damage history and severely diminished value. Again, this restriction to prevent over insurance is from the aircraft's owner, not from the insurance company.

Regarding deductibles, many aircraft insurance these days are written with ZERO deductibles. Remember that deductibles were designed for things like car insurance where there tends to be frequent but relatively small claims -- fender benders, cracked windshields, dings on doors, etc. Aircraft insurance is the exact opposite: there's rarely have a claim, but when there is one it's usually catastrophic.

So compared with car insurance, deductibles play a smaller role in aviation insurance. Sometimes there is a fixed deductible and the insurance company will not give an option of a higher deductible in exchange for a reduced premium. And if there is a deductible, the deductible has to be very high (over 10% of the agreed value) to make the premium reduction worth the extra risk.

[slast]

In the context of visual cues, by chance I was just reading this in the report of the Air France Toronto over-run in 2005, page 122: may turn out to have some relevance....

"Much has been written on the issue of pilot decision-making processes regarding landing. Nevertheless, this occurrence and others give a clear indication that there are still risks associated with this task. The Board believes that the ability to capture and interpret cues that are essential in the decision-to-land process is inadequate, especially when the cues are
ambiguous or not immediately compelling. Consequently, pilots will continue to land in deteriorating weather once the landing decision has been made, in spite of cues that indicate that a go-around or balked approach should be executed.

Therefore, the Board recommends that:
The Department of Transport mandate training for all pilots involved in
Canadian air transport operations to better enable them to make landing
decisions in deteriorating weather. (A07-03)

[JFZ90]

https://fortunedotcom.files.wordpress.com/2014/05/140430115037-mac19-graph.jpg?quality=80

One observation of that insurance article - their own article contradicts the assertion that payouts are always at "replacement value".

The chart shows the hudson A320 having a payout of only $24M. I recall a new A320 is around €100m a pop, so thsi is far far away from the real replacement value.

(I'm assuming the hudson A320 was scrapped, not repaired, surely....?)


EDIT - turns out it is in a musuem.

http://upload.wikimedia.org/wikipedia/commons/thumb/1/14/N106US_aviation_museum.jpg/1024px-N106US_aviation_museum.jpg

[Retired DC9 driver]

slast,
regarding the Air France over-run, in CYYZ, an ICAO standard run out zone in Toronto would have likely saved the A-340 aircraft from breaking up at all. Fortunately a very professional in-flight crew evacuated all the passengers before the fuselage was consumed by fire.
Previously a DC-9; following a blown tire and rejected TO had an overrun in the same area. When the DC-9 went into the ravine, two passengers were killed when the fuselage buckled, but there was no fire..

[slast]

Hi DC9, after 30+ years as an IFALPA rep, you certainly won't find me arguing against the implementation of ICAO SARPS !
My thought was though it will be long while before the final report comes out, it's odds-on that the enquiry into this (Halifax) will find reason to question the crew's decision making, whatever the other contributory causes - they almost always do. And the individual crew members are already facing several class action lawsuits.
The report into the AF accident made a lot of play about decision making in changing conditions:
On the other hand, a decision to continue and land when the visible cues are very faint at best at DH is a stressful one for a pilot. Should visual cues then diminish or disappear after the decision to land has been made, the first feeling or impression on the part of pilots is one of incomprehension, followed by a period of inaction, where they wonder what just happened,
and where they wish that things will get back to normal soon. This lack of reaction while waiting for the runway environment to re-appear is because the brain becomes task saturated at that very moment, unless the pilot has been trained to react instinctively and immediately to the threat. Naturally, the correct action must be an immediate go-around. The Board believes that, if more training could be done in this respect, the rate of these types of accidents would decrease.
So I wondered if anything changed in AC's training after that (or anyone else's, come to that). I suspect not much.

[Fargoo]

JFZ90 - List price for an A320 is $94 Million.

I'd be surprised if an operator with a big fleet pays anywhere near that figure.

Press release | Airbus, a leading aircraft manufacturer (http://www.airbus.com/presscentre/pressreleases/press-release-detail/detail/new-airbus-aircraft-list-prices-for-2014/)

[peekay4]

By the way the blanket exemption in Canada allowing the use of MDA as DA (without adding 50ft) has been extended for five years -- until April 30, 2020.

Exemption from Paragraph 602.128(2)(b) of the Canadian Aviation Regulations - Transport Canada (http://www.tc.gc.ca/CivilAviation/Regserv/Affairs/exemptions/docs/en/2923.htm)

This exemption authorizes pilots-in-command of IFR aircraft operated by holders of an air operator certificate or a private operator registration document to descend below the minimum descent altitude (MDA), when conducting a non-precision approach [...] following a stabilized constant descent angle (SCDA) non-precision approach.

[Jet Jockey A4]

Thanks for the info!

[RatherBeFlying]

I had a good look at both the DC-9 and the A340 that had come to rest in the ravine.

My suspicion remains that EMAS would reduce takeoff weight because of reduced runway length.

Just before AF overran I was watching Buffalo weather radar as a line of cells propagated down the Bruce Peninsula down to YYC and my office in Port Credit.

Traffic came to a stop on the expressway under a downburst.

AF might have gotten across its downburst, but I seriously doubt it would have made it through the tailwinds on the other side.

[ATC Watcher]

Slast, a few questions if I may : you said earlier that none of the AC 320s are GPS equipped, meaning they are not RNP/RNAV capable right ?
So the vertical nav on that APP as purely visual , right ?
Do the AC A320s have HUDs ?

[slast]

I think your message should be addressed to SCUD, not me - although I was A320 qualified, I am not current and not Air Canada. If SCUD answers I would also be interested to know what crew callouts would have been are required on this approach.

[Retired DC9 driver]

ATC watcher
That approach in YHZ would be flown as a "coupled/selected" approach. Coupled to, and tracking the LOC , descending to FAF altitude before the FAF. When in ALT *star*, capturing the FAF crossing altitude, the PF selects FPA of zero, and winds up the altitude selection to MA altitude.. Then at .3 before the FAF he selects the desired FPA or flight path angle and the aircraft will start descending as it passes the FAF.
Now the aircraft is descending at that FPA.
At MDA (no +50 feet required now?) the aircraft should be in a stable, landing configuration to continue the landing if visual..disconnect the autopilot and land

So I wouldn't call it a "visual" approach except below MDA. Don't really understand your question.
No HUD on the AC A-320s, just the 787 to my knowledge..but I am retired now

[ATC Watcher]

Ooops, Slast, sorry , indeed the questions were for Scud , your 2 posts ( 297 and 298) were clsoe to one another and I mixed up.:ooh:

Retired DC9 : thanks, I am trying to understand how they were conducting that APP (as I suppose AC flying to Halifax and using that runway would be rather common )
HUDs: some old A320s were equipped with HUDs (an option, Air inter in France had them if I remember correctly ) I was asking if some of AC 320s have the option.

[Retired DC9 driver]

ATC watcher,,,
Re HUDs; I corrected my post..

Note for peekay4, just so all understand this exemption,
regarding the "descent below MDA" on a non precision approach. CARs says later in the document
"This exemption is required in order to accommodate the altitude loss below MDA that will likely occur during a missed approach, following a stabilized constant descent angle (SCDA) non-precision approach".

so you could descend below MDA still in IMC conditions under this exemption, but only during the execution of a Go Around..In the past, the 50 foot "buffer" would ensure, that even during a GA in IMC,the aircraft would never descend below MDA.

[alf5071h]

Re “I wondered if anything changed in training after that’, #303 (also #297, #300)
It might be better to consider if we could have expected any change in training.
While investigators and regulators continue to spout a ‘need for more training to improve decision making, judgement, etc’, but fail to provide guidance as to what and how should be trained, the industry is left to its own ideas.
This should not be surprising as there are few accident/incident reports which identify specific aspects of decision making – to continue or discontinue an approach – that have weaknesses and might be addressed by training.

At the time of deciding all decisions are good (valid), as judged by the decision maker; only subsequent events might classify the decision – good, less-so, poor, ‘wrong’, but all of this is in hindsight, and based on the judgement of the reviewer.
A significant problem in low visibility approaches is determining what the decision maker actually sees – perceives, and then how this is used, which may depend on training and experience. This point identifies a weakness in safety thinking, such that even if the decision maker is a highly trained / experienced pilot, the perception of an ‘incorrect picture’ can result in choosing an inappropriate action. We cannot assume that training and experience will always provide adequate perception and thus accident avoidance.
Vice-versa an inexperience pilot, perceiving a ‘correct picture’, can equally choose an appropriate course of action based on minimum training and experience.

The industry should heed the thoughts of James Reason where improving human performance – training, etc, is difficult and cannot be assured to be used in every situation. Solutions offering greater safety benefit can come from improvements in working conditions – the wider working environment, and protecting humans from their own fragility.
In low visibility this could be improving what might be seen, to perceive the visual scene (approach accuracy, guidance and autos, approach lighting), and/or ensure that pilots are not exposed to conditions where a decision could be unacceptably wrong (revise the approach minima). The point about ‘acceptability’ considers that the decision process is continuous and that choices of action can be changed, and even poor decisions are not necessarily ‘unsafe’, because the risks are contained.

The industry should stop trying to improve the human. Instead look at the working environment and pressures of operation; reconsider the assumptions made about operations, how operations, infrastructure and equipment have changed since regulations were formulated and minima published.

[CanadianAirbusPilot]

Retired DC9 knows the scoop. At AC on a NPA you still add 50 feet to MDA. Everything else he wrote is bang on.

[JammedStab]

16 June 2015 - Aviation news release - Transportation Safety Board of Canada (http://tsb.gc.ca/eng/medias-media/communiques/aviation/2015/a15h0002-20150616.asp)

News release


Ground contact prior to runway threshold of Air Canada Flight 624 during approach to Halifax Stanfield International Airport (A15H0002)

The occurrence

On 29 March 2015, an Air Canada Airbus A320-200 aircraft (registration C-FTJP, serial number 233), was being operated as Flight AC624 from Toronto, Ontario, to Halifax, Nova Scotia, with 133 passengers and 5 crew on board.

The aircraft was flying the localizer approach procedure to land on Runway 05 at the Halifax Stanfield International Airport. A localizer approach only provides pilots with lateral guidance to align the aircraft with the runway for landing. During the approach, the engines of the aircraft severed power transmission lines, and then the main landing gear and rear fuselage impacted the snow-covered ground about 225 metres before the runway threshold. The aircraft continued through a localizer antenna, then impacted the ground in a nose down attitude, about 70 metres before the threshold. It then bounced and slid along the runway, coming to rest on the left side of the runway about 570 metres beyond the threshold.

The passengers and crew evacuated the aircraft; 25 people sustained injuries and were taken to local hospitals. The aircraft was substantially damaged. There was no post-crash fire.

Investigation team work

The Investigator-in-charge, Doug McEwen, is assisted in this investigation by TSB investigators with backgrounds in flight operations, aircraft performance, aircraft systems, aircraft engines, human performance, and air traffic control. Representatives from Air Canada, Airbus, NAV CANADA, Transport Canada, France’s BEA (Bureau d'Enquêtes et d'Analyses pour la sécurité de l'aviation civile), the RCMP, Halifax International Airport Authority, and the Halifax Regional Police department are also providing assistance.

Work to date

A large number of technical and operational documents, weather reports, air traffic control communications, and incident reports have been gathered and are being reviewed by investigation team members. Numerous interviews have been conducted with passengers and individuals from various organizations.

The flight data recorder (FDR) and cockpit voice recorder (CVR) have been examined. With assistance from external specialists, the TSB has retrieved information from the aircraft's Digital Access Recorder, which records additional flight and aircraft parameters. Further analysis of this recorded data will be conducted.

What we know

Weather

Prior to landing, the crew received an updated weather report at 12:15 am Atlantic Time which included: windspeed 20 knots gusting to 26 knots from the north north west; 350° true; with a forward visibility of ½ statute mile in snow and blowing snow. The vertical visibility was 300 feet above the ground, temperature of minus 6°C, dewpoint minus 7°C, and altimeter setting of 29.63 inches of mercury.

The aircraft

Preliminary examination of the FDR indicates the aircraft was correctly configured for landing, the airspeed was consistent with a normal approach speed, and the altimeters were set to 29.63 inches of mercury. No mechanical deficiencies were identified with the aircraft's engines, flight controls, landing gear and navigation systems. During the review of the aircraft's maintenance records, no discrepancies were noted. Approximately 4900 litres of fuel was recovered from the aircraft.

Post-impact damage

The forward right and both rear exits were not used during the evacuation. No discrepancies were noted during the initial examination of these exits. Examination of the aircraft revealed that the right side cabin floor in seat rows 31 and 33, and the floor adjacent to the flight attendant fold-down seat near the rear of the cabin were punctured from below by aircraft structure. No pieces of the localizer antenna structure penetrated the cockpit.

Next steps

Work will include:
•Recreating the accident flight profile as closely as possible to add to the understanding of the challenges encountered by the pilots of AC624.
•Completing a detailed site survey illustration, examining relevant aircraft components and developing an animation of the aircraft's flight profile.
•Evaluating pilot training and experience, human performance aspects, crew resource management, industry standards and company operating procedures.
•Reviewing flight attendant training and experience as well as company procedures and regulatory requirements.
•Examining survivability issues such as cabin and cockpit crashworthiness, passenger evacuation, and airport emergency response.
•Reviewing non-precision localizer approaches utilizing a stabilized constant descent angle.
•Conducting additional interviews as required.
•Ongoing examination of aircraft structural damage.

Approach-and-landing accidents

The TSB Watchlist identifes approach-and-landing accidents as one issue which poses the greatest risk to Canada's transportation system. These accidents include runway overruns, runway excursions, landings short of the runway, and tail strikes. The TSB has called on operators, regulators, and air navigation service providers need to take more action to prevent approach-and-landing accidents, and to minimize the risks of adverse consequences if a runway overrun occurs.

Communication of safety deficiencies

Should the investigation team uncover a safety deficiency that represents an immediate risk to aviation, the Board will communicate without delay so it may be addressed quickly and the aviation system made safer.

The information posted is factual in nature and does not contain any analysis. Analysis of the accident and the Findings of the Board will be part of the final report. The investigation is ongoing.


The TSB is an independent agency that investigates marine, pipeline, railway and aviation transportation occurrences. Its sole aim is the advancement of transportation safety. It is not the function of the Board to assign fault or determine civil or criminal liability.

For more information, contact:
Transportation Safety Board of Canada
Media Relations
Telephone: 819-994-8053
Email: [email protected]

[RatherBeFlying]

the FDR data would have been released by now:=

[hawk37]

Weather

Prior to landing, the crew received an updated weather report at 12:15 am Atlantic Time which included...a forward visibility of ½ statute mile in snow and blowing snow.

See as the visibility on the approach plate is 1 mile for all categories (loc dme rwy 05), and the pilots were given 1/2 mile, do airlines in Canada have any sort of approach ban based on visibility?

[clunckdriver]

"Rather be Flying," that must have been some system to cover from Calgary VOR to the Bruce penilsular!

[HeloSammy]

Hawk 31, See post #231

http://www.pprune.org/8933482-post231.html

[peekay4]

New TSB photos show AC 624 interior damage.

Article: CBC News | Nova Scotia (http://www.cbc.ca/news/canada/nova-scotia/air-canada-flight-624-interior-damage-shown-in-new-photos-1.3249212)

https://c1.staticflickr.com/1/409/18931751725_1170a30197.jpg

https://c2.staticflickr.com/6/5618/21631987689_bbe115d01d_z.jpg

https://c1.staticflickr.com/1/712/21818876875_333f1e8823_z.jpg

[wanabee777]

About a month later was the Asiana A320 accident at Hiroshima.

Also touching down short.

Asiana A320 Skids After Landing at Hiroshima, Japan; 23 Hurt - NBC News (http://www.nbcnews.com/news/world/asiana-a320-makes-hard-landing-hiroshima-japan-three-hurt-n341201)

http://wpmedia.news.nationalpost.com/2015/04/asiana-airbus-a320-side.jpg?w=940&h=673

[CEA330Driver]

Spot on! I'm sure Air Canada follows Airbus recommendations like most carriers do. Below MDH you have to be visual and on profile to continue the descent to land - otherwise a Go-Around is mandatory.

[peekay4]

One year ago today:

One year later: AC624 passengers still recovering from Halifax crash landing | Globalnews.ca (http://globalnews.ca/news/2606059/one-year-later-ac624-passengers-still-recovering-from-halifax-crash-landing/)

Still no TSB report on this "hard landing"...

[Zeffy]

Transport Canada can be sued by passengers of Halifax plane crash, judge rules (http://www.cbc.ca/news/canada/nova-scotia/halifax-plane-crash-lawsuit-transport-canada-1.3894398)

[vmandr]

Transport Canada has no duty of care to Canadian air travellers in general, she ruled

Strange statement from a 'judge' (if was made as it appears in the article).
WTF ? I like to ask what, then, is the purpose of existence of Transport Canada ?
to collect fees ?

And BTW the Canadian transport system - not just air - is also being used by other, not 'Canadian' travelers too.

[Jet Jockey A4]

It's Air Canada's fault! As such they should be the only ones getting sued but we know in the real world everyone is going to get sued that is involved in some way with this accident.

1- This accident could have been easily avoided if Air Canada had installed the proper equipment in their aircrafts (older 320s).

2- The pilots screwed up (for whatever reasons) causing an accident, end of story. Again since they are Air Canada employees, it's Air Canada's problem.

[peekay4]

Strange statement from a 'judge' (if was made as it appears in the article).
WTF ? I like to ask what, then, is the purpose of existence of Transport Canada ?
to collect fees ?

The judge is correct. In general a regulator's duty of care is to the public at large (collectively), not to specific individuals. Such is the law in Canada and probably the rest of the world.

In this case, Transport Canada can still be sued only in their role as the owner & landlord of Halifax airport (as part of the Canadian National Airport System). Transport Canada would have been immune had the accident occurred at an airport that's not owned by them.

[vmandr]

JJ4

Agreed !

peekay4

As in every other accident, i believe in the case of 'the fish rots/stinks from the head down'.
the regulator's oversight is stipulated/defined in legislation. 'public' and 'collective' are vague, legal terms. however when part of the 'public' - one or more individuals - are hurt, have every right to sue. (if they'll win against the State is a different thing).
And yes, same law / principle for the rest of the world.

Since they have oversight of all transport activities, they cant be immune, regardless, me thinks.

[cooperplace]

Hmmm....sounds remarkably familiar, but I can't put my finger on it;

1. Legacy carrier with a local reputation for arrogance,
2. Overrun/crash (the 'c' word),
3. PR department refusing to acknowledge the 'c' word,

The only thing missing will be the spending of 10's of millions of dollars in fixing what appears to be a write-off.

is it the Q word that you're looking for?

[peekay4]

however when part of the 'public' - one or more individuals - are hurt, have every right to sue
No, there is no such right. Otherwise anyone can sue the government for every wrongdoing by any regulated entity. That would be nonsense.

In general, governments enjoy sovereign immunity. This comes from a very long heritage in common law, where in the old days "a king can do no wrong" (rex non potest peccare). In more modern times, a suit could only go forward if the government has waived its right to immunity in limited circumstances, as codified in statutes (e.g., in Canada, in the Crown Liability Act).

Also, in this specific case, Transport Canada as the regulator does not have a "proximate" (close and direct) relationship with any individual passenger, but only to the public collective. Without this proximity, there is no "duty of care" -- as the judge correctly observed -- and so there is no right to sue. See the Supreme Court case of Kamloops v. Nielsen.

It would be different if the suit had alleged some sort of operational error by Transport Canada, but that's not the case here. Equipping certain approaches with ILS vs VOR is a policy question, not an operational one, and government entities are generally immune to liability from broad policy decisions. For reference see the Supreme Court judgement in Just v. British Columbia.

The reason Transport Canada can be named as part of the suit is only because of their dual role as the airport's landlord -- so they may be liable, like any other landlords.

[vmandr]

Enlightening peekay.

In general, governments enjoy sovereign immunity
I guess only till the next ...elections ;)

one way or another i am driving towards the 'head of the fish' which blames everyone and never gets blamed itself. ie Sweden in that CRJ accident. nice text, screened by lawyers, recommendations to everyone but themselves (maybe with exception of Swedish SAR).
all 'authorities' the same.

[EdmontonCTR]

If Transport Canada owes no duty of care to air travellers, I guess they can cancel all future audits and furlough their Aviation safety inspectors that oversee and monitor Air Canada! :ugh:

[SMT Member]

Some here some to misinterpret what is the legal obligation of the regulator vs that of the operator.

The direct duty of care towards air travellers lies with the operator. That is enshrined in the regulations you are bound to follow when offering airline services.

Therefore, the regulator has a 'duty of care' only to ensure the airlines operating under their licenses are following the rules, including rendering duty of care as stipulated in the regulations.

It's the airline who have an obligation to offer support directly to anyone involved in an incident, just as e.g. a train operator would be. If the operator does not live up to all of their responsibilities, it is up to the regulatory agency to beat them into shape, ultimately by curtailing or withdrawing their operating license if they refuse to follow the regulations. But it is never the job of the regulator to offer duty of care to passengers in any direct sense.

[grizzled]

peekay4

Though your comments about suing governments in Canada are generally correct they do not apply to suing government entities operating as "regulator". There are many examples of Canadian federal regulatory agencies being sued -- including at least a dozen suits against Transport Canada in its regulatory role since 2000. ALL have been settled out of court (for obvious reasons, if you understand precedent and confidentality).

Feel free to PM me if you want to discuss this further.

[AJW709]

Air Canada lawsuit accuses Airbus of negligence in Halifax crash landing | CTV News (http://www.ctvnews.ca/business/air-canada-lawsuit-accuses-airbus-of-negligence-in-halifax-crash-landing-1.3347461)

[alph2z]

From article and TV report:


... The document (statement of claim) said it did not advise that in certain conditions, the plane's flight path angle could be affected by external forces.

It also claims Airbus failed to incorporate a warning system to alert pilots to a deviation from the planned flight path angle.

"(Airbus) failed to provide adequate and/or accurate information as to how pilots should correct a deviation in the flight path in circumstances where manual intervention was required," ...


... Air Canada's lawsuit against Airbus says the flight crew correctly configured the aircraft for landing, including entering the correct flight path angle into the flight computer.

"Since the aircraft was correctly configured for approach and landing and the approach was stable, the aircraft should have intercepted the threshold to runway 05 at an altitude of 50 feet," the claim said.

"Instead, the aircraft descended at a steeper angle than expected and touched down short of the runway."

[9 lives]

The document (statement of claim) said it did not advise that in certain conditions, the plane's flight path angle could be affected by external forces.

So, Air Canada is suing Airbus, accusing that Airbus did not advise them about gravity?

It also claims Airbus failed to incorporate a warning system to alert pilots to a deviation from the planned flight path angle.

Isn't the PNF the warning system? Air Canada already pays for one on every flight!

"(Airbus) failed to provide adequate and/or accurate information as to how pilots should correct a deviation in the flight path in circumstances where manual intervention was required," ...

I have not read an Airbus Flight Manual, I wonder if it has a picture of the side stick explaining "pull back for nose up". I suppose placarding requirements may be more basic than I realized!

As a Canadian pilot, I'm embarrassed by these claims attributed to Air Canada. Sorry rest of the world :rolleyes:

[tubby linton]

A non precision approach in selected guidance should use distance and crossing altitudes as depicted on the approach chart as the vertical guidance., but the altitudes may needs correcting for temperature variations. . If the latter is the case then the required flight path angle needs adjusting. This is what pilots have done for years in all types and is called airmanship.It is nothing to do with a specific manufacturer.
Altimeter Temperature Error Correction - SKYbrary Aviation Safety (http://www.skybrary.aero/index.php/Altimeter_Temperature_Error_Correction)
The descent rate required will also be influenced by the ground speed of the aircraft whilst commencing the approach but again this is instrument flying basics.

[JammedStab]

Looking through another forum a while back, I saw a post stating that this was one of their non-gps aircraft. Therefore, more likely to have a slight error in the calculated vertical path.

To be honest with you, I have found that the calculated path on these VNAV approaches corrected by GPS to be amazingly accurate right down to 50 feet. And who out there has not been in a situation of extremely murky minimums with the pilot just barely able to have the required visual reference and then continuing inside on instruments for at least a few more seconds until the picture is clearer.

But if the path is incorrect, and the references you saw at minimums were actually something else, you could be headed toward something else beside the threshold plus 50 feet.

Is this plausible?

[FlightDetent]

Somehow I feel it is the (financial) damage control team trying to pull a crazy stunt. Most likely there thousands AirCanada employess embarrased too.

[PJ2]

If the latter is the case then the required flight path angle needs adjusting. Agreed, but not because of the higher altimeter reading.

A corrected baro altitude places the airplane at the correct FAF crossing height, albeit at a higher altimeter reading. So for practical purposes the geometry is not steeper, it is the same.

If the airplane has GPS or temperature-compensated baro-VNAV, in a Managed RNAV approach, a correct descent path is calculated and flown either by the pilot, (following the flight directors) or the auto-flight system.

If the aircraft doesn't have GPS or a compensated baro-VNAV, a Selected FPA requires correction because the air, being at the same cold temperature all the way down, has a reduced pressure gradient resulting in a reduced altitude change and shallower descent. So the FPA has to be corrected and made slightly steeper.

[©hris]

Somehow I feel it is the (financial) damage control team trying to pull a crazy stunt. Most likely there thousands AirCanada employess embarrased too.

:O

Yup, I certainly am.

In other...possibly related news, our COO (who flies the 787 too) is leaving effective end of April.
Air Canada Announces Departure of Klaus Goersch (http://www.stockhouse.com/news/press-releases/2017/04/03/air-canada-announces-departure-of-klaus-goersch)

[CONF iture]

Shame on AC to proceed with such a ridiculous lawsuit.
It was a very challenging situation for the crew to shoot that non precision approach with low visibility, strong gusty crosswind, and then most probably turbulence all over the place. Whatever the cold temperature correction and the associated flight path angle correction, the crew failed to go around at the minimum altitude.

[Grizzz]

Air Canada lawsuit accuses Airbus of negligence in Halifax crash landing | CTV News (http://www.ctvnews.ca/business/air-canada-lawsuit-accuses-airbus-of-negligence-in-halifax-crash-landing-1.3347461)

[roybert]

This is just Air Canada doing a little CYA to help off set all the money that will be awarded to the passengers.

[Chuck Ellsworth]

"Instead, the aircraft descended at a steeper angle than expected and touched down short of the runway."

I understand that Air Canada is now changing their SOP's to demand their pilots be in their seats and watching the Airbus magic box fly the airplane in case the magic box gets it wrong and tries to land short...in which case the pilots are required to take over and fly it to the runway.

[BluSdUp]

Has any major airline ever done this before?
Airbus and Boeing takes one on the chin every so often , and improves.
Going to court claiming neglect is rather pommpus!
" We have flown this aircraft for some time now, and we dont fully understand it. This crew shure did not. oh , and can sommeone PLEASE explain what the NON in non-precision is all aboot, eeh!"

Did Bob and Dough McKenzy just join AC. " Take off, Eeh!!"

[aterpster]

I understand the carrier can modify an AB to have a "Boeing Switch" in a prominent place on the pedestal panel.

[FlightDetent]

It is a standard fit. The marking is little obscured, however, labelled "TOGA".

[Chuck Ellsworth]

When they touched down before the runway and started clearing the approach lights out of the way did the automatic voice prompt say " Retards " :E

[Kewbick]

Oui, certainement..

[olster]

As a former Airbus instructor I find it a bit 'disappointing' to say the least that these accidents keep happening. A bit of application in terms of really learning and understanding the systems / automation coupled with professional discipline should keep you safe. But yet, still it happens...

[pfvspnf]

If an Asian carrier does it , poor standards, low hour pilots , not enough time in the bush. When AC does it , let's blame airbus for screwing up an NPA

[J.O.]

I know whose pilots I'd want at the helm on a dark and stormy night with an NPA between me and my destination.

[Jet Jockey A4]

Do tell, inquiring minds want to know!

[YRP]

I know whose pilots I'd want at the helm on a dark and stormy night with an NPA between me and my destination.

Ken Borek's? :E

[pfvspnf]

Maybe the lot that made a good positive touchdown in Jamaica

[peekay4]

"The Transportation Safety Board of Canada (TSB) will hold a news conference on 18 May 2017 to make public its investigation report (A15H0002) into the 29 March 2015 collision with terrain involving Air Canada Flight 624 at the Halifax Stanfield International Airport, Nova Scotia."

When: 18 May 2017 10:00 a.m. Atlantic Daylight Time (9am Eastern / 1pm UTC)
Where: Four Points by Sheraton, Halifax, Nova Scotia

The event will be broadcast live on TSB's YouTube channel (http://www.youtube.com/TSBCanada).

Link: TSB Media Advisory (http://www.bst-tsb.gc.ca/eng/medias-media/avis-advisory/aviation/2017/a15h0002-20170516.asp)

[Jet Jockey A4]

I suspect the report is going to say the ground came out of nowhere and hit Air Canada's Airbus 320. )-:

[standbykid]

I suspect the report is going to say the ground came out of nowhere and hit Air Canada's Airbus 320. )-:

Apparently pax should 'dress for the weather'.

[+TSRA]

http://www.tsb.gc.ca/eng/rapports-reports/aviation/2015/A15H0002/A15H0002.pdf

Here is a link to the accident report from TSB.

[andrasz]

On first read a rather well prepared report with no window washing. What I find rather sobering is the number of uncovered shortcomings both on the side of the airport and the operator, many of which were not a contributing cause and would have remained unnoticed were not for the accident.

[peekay4]

Archived news conference (presentation starts at the 24:25 minute mark):

9x5xXWP_k4E?t=24m25s

[grizzled]

On first read a rather well prepared report with no window washing. What I find rather sobering is the number of uncovered shortcomings both on the side of the airport and the operator, many of which were not a contributing cause and would have remained unnoticed were not for the accident.

And that, dear friends, is the inevitable result of a lack of oversight. A problem we are seeing more and more in countries that used to have well-funded, well staffed and well trained regulators. Transport Canada is one of many that have been decimated in this current world of reduced regulatory capability. They are so far behind in their "surveillance activities" of service providers (airports, airlines, and Nav Canada) that this same issue (undiscovered shortcomings) will become the norm in accident reports.

Ironically, exactly the opposite result from what is intended in today's SMS focussed world...

[PJ2]

I don't know how one "likes" a post here, but grizzled's post is +1! Oversight AND inexperience...SMS is not a DIY safety tool. It still requires regulatory validation and verification. Well said, grizz.

[Jwscud]

I am genuinely surprised that nobody in the Airbus training department thought the way they were flying NPAs was dangerous.

I find it crazy that nobody was checking the vertical profile after the FAF by any means, and that this was:

1. SOP for the fleet
2. Not in accordance with the FCOM
3. Not picked up by any form of audit

I am reminded of comments after Gemini 8 "The crew reacted as they were trained, and they reacted wrong because we trained them wrong" - the most sobering part for me is that the crew flew the approach as per SOP, were slightly late picking up how wrong the visual picture looked in :mad: weather and ended up drilling it in.

[Denti]

I have to say, that was the first thoughts i had myself. How can a company have a set of SOPs that is against its own FCOM? What kind of audit did they have that they didn't notice something as dangerous as not checking a vertical profile on a non precision approach?

If they were really trained that way, the fault does not lie with the chaps in the front row, although i would have thought that basic airmanship is more common on the north american continent.

[FlyingStone]

I have to say, that was the first thoughts i had myself. How can a company have a set of SOPs that is against its own FCOM?

Many operators just take plain vanilla Boeing/Airbus FCOM and write the differences between the company SOP and the manufacturer SOP in a separate document (like OM B). Easy to implement, nightmare to study.

Otherwise, really looks like a strange thing, not checking DME vs. altitude table during non-precision approach, especially when flying with selected guidance in bad weather. Perhaps it's time for the Airbus to finally step up and come up with a way to fly LOC-only approaches with managed vertical guidance.

[iceman50]

Perhaps it's time for the Airbus to finally step up and come up with a way to fly LOC-only approaches with managed vertical guidance.

They do now in the A350, possibly an upgrade for earlier models! Does Boeing in all its marks?

[Denti]

Many operators just take plain vanilla Boeing/Airbus FCOM and write the differences between the company SOP and the manufacturer SOP in a separate document (like OM B). Easy to implement, nightmare to study.

FCOM plus OM/B? That sounds like a nightmare indeed. On our boeing fleet the fompany adapted the boeing FCOM and published it as OM/B, on the airbus they never did that and we just use the airbus documentation, but even in those golden times where we had company SOPs that differed a lot from the OEM ones they were incorporated into the airbus documentation, published by airbus.

Otherwise, really looks like a strange thing, not checking DME vs. altitude table during non-precision approach, especially when flying with selected guidance in bad weather. Perhaps it's time for the Airbus to finally step up and come up with a way to fly LOC-only approaches with managed vertical guidance.

Indeed. That was one of the not so nice surprises when transitioning from the 737 to the A320 family that the bus couldn't even fly a managed LOC approach, something we did for many years already on the 737 with IAN. And one of the reasons why i always comment that the A320 is a generation behind the 737NG on the avionic front.

[Volume]

which were not a contributing cause and would have remained unnoticed were not for the accident. This is what we call "evidence based oversight" now...
If no problem is visible, there is none.

[+TSRA]

I find it crazy that nobody was checking the vertical profile after the FAF by any means, and that this was:

...
3. Not picked up by any form of audit

Audits, unfortunately, ignore quite a bit of the technical minutiae. In almost every audit I've ever had the pleasure to be a part of, when it came to any technical discrepancy, the non-pilot auditor was apt to ignore it as they didn't understand it (most common in my experience). Instead, what they should do is point out everything that could be misunderstood by a layperson.

It becomes especially dangerous when the auditor questions a company representative and the question is answered sufficiently that the auditor feels there is no issue. On more than a couple of occasions, I would have to ask the auditors to put in every question they had into the findings report on the theory that just because I could answer their question, did not mean a line pilot could.

Also, auditors are people too. They are often all looking for the same things, but one can only be so effective cross-referencing manuals all day.

[peekay4]

Having been on both sides of the audit game:

1. Audits can't check for everything. It would be impossible from a time/effort perspective and the purpose of an audit is not to QA. At most, an audit can check for a sample of possible issues, selected semi-randomly (risk-weighted).

2. As such, audits tend to focus on broad processes and controls. E.g., does Air Canada have X process in place to mitigate against risk Y, and if so where is the evidence?

3. The unfortunate reality is that item 2 often devolves into chasing documentation (paperwork) against a checklist of risk items.

It's not an auditor's job to go through Air Canada's manuals/SOPs line by line to see if there are gaps (that's Air Canada's job). The auditor is there to check if there are specific controls in place, and that those set of controls -- as a whole -- are generally adequate and effective.

[Jwscud]

When I say "audit" I mean both airlines I have worked for have had guys from different fleets/management positions or external guys come and sit on the jumpseat and in the sim and watch what was going on.

On the line, they looked for both procedural compliance and areas of procedural weakness. That's more what I was getting at. What the report doesn't say is what the other AC fleets did for NPAs - was this an airline wide practice or just the Airbus fleet?

[Semaphore Sam]

What a wonderful idea, a DME vrs. Altitude graph, right on the approach plate! When I first saw that, on one of the first constant descent NPA approach charts, I thought it was brilliant (and it was!) back in the 80's. However, in Canada especially, there is the issue of low temperature; to be accurate, you'd have to calculate an additive to each DME point, based on surface temperature, and altitude above the field for each fix. I surmise that TC, having been faced with that problem, just decided it wasn't worth the hassle of adjusting each fix for temperature (at, say, -42, or whatever) for each fix, and shuffled it under the rug. If you just check the altitude vrs. DME, without temperature compensation, as a procedure, you could be really low; to check each fix could take 10-15 minutes in a holding pattern. TC probably said, "Why bother? Don't want that can of worms! Just let's not reference DME vrs. Altitude." Sam

[PEI_3721]

Safety Audits differently.
http://www.safetydifferently.com/safety-audits-differently/


Should we do a safety audit or do safety differently.
http://www.safetydifferently.com/should-we-do-a-safety-audit-or-do-safety-differently/

[mcdhu]

But why would you not check the vertical profile whether required by SOPs or not.
Isn't there an element of self preservation in all of us pilots.

[Jwscud]

Alternatively, your forward thinking company could produce an App that allows you to stick the temperature, QNH AND the altitudes and produce a set of corrected altitudes in seconds. Or a rough and ready table on the winter ops guide. I have worked for airlines that have done both.

It really is isn't difficult. It takes 5 minutes away from reading the paper in the cruise. Checking your vertical profile in IMC is a business of life or death. With the switchover to paperless flight decks it surely can't be long before LIDO, Jepp, Navtech insert a function into their approach plates for you to enter the QNH and temperature and automatically display the correct crossing altitudes.

[birmingham]

Great quote:

"Spurway [spokesman for the Halifax Stanfield International Airport] said the incident was not a crash because it is believed the plane was under control as it came in. He said there's no indication what caused the hard landing and he did not know the condition of the plane."

Air Canada flight leaves runway in Halifax, 25 sent to hospital - Nova Scotia - CBC News (http://www.cbc.ca/news/canada/nova-scotia/air-canada-flight-leaves-runway-in-halifax-25-sent-to-hospital-1.3013979)

Using that definition everybody could die and still a crash wouldn't have occurred.

Let's look at the pictures again

http://i.imgur.com/tOHY2aS.png

Nah - no crash I was mistaken!

If the spokesman actually believes his own statement I think he should take a short break to regain perspective!

[peekay4]

Alternatively, your forward thinking company could produce an App that allows you to stick the temperature, QNH AND the altitudes and produce a set of corrected altitudes in seconds. Or a rough and ready table on the winter ops guide. I have worked for airlines that have done both.

It really is isn't difficult. It takes 5 minutes away from reading the paper in the cruise. Checking your vertical profile in IMC is a business of life or death. With the switchover to paperless flight decks it surely can't be long before LIDO, Jepp, Navtech insert a function into their approach plates for you to enter the QNH and temperature and automatically display the correct crossing altitudes.
Cold temperature correction wasn't an issue here. The crew properly corrected the FPA and MDA according to Air Canada's cold wether SOP. But the flight path diverged due to winds, and the crew didn't verify distance vs. altitude.

[H Peacock]

I'm with mcdhu here, how could any competent crew fly any approach without monitoring both the lateral profile and the vertical profile. Okay, they saw the localiser neatly aligned, but did they honestly just sit there and make absolutely no effort to monitor the vertical profile?

I've used FPA before - albeit not on a Bus, but did these guys ever wonder how the automation was positioning the aircraft. Did they really just hit the mode button and expect to be on profile all the way to MDA?

[safetypee]

Why the apparent lack of monitoring of the vertical profile ...?
Perhaps this is a symptom of reducing exposure to NPAs because of the availability of 'precision like approaches', which is related to automation dependency - the skills of monitoring are degrading.

Extracts of a study into "Loss of manual flying skills" suggest that this is due to the lack of recency in monitoring the flight path and increased mental workload, irrespective of automatic or manual flight.
In addition, modern aircraft offer the crew more technical options and facilities, e.g. FPA, which require thought about which one, and when to use them, including hazards they might generate.
A dominant mantra of the ALAR Tool Kit was to monitor altitude against distance - altitude first because that's the life saver. Yet with the availability of advanced displays and navigation features, simple cross checks may be overlooked or never be part of flying awareness (weak training).

"The majority of the cognitive demands were associated with the vertical profile and energy management aspects of the approach task rather than the lateral aspect, suggesting that the former is a more cognitively complex activity.

... the vertical profile and aircraft energy is heavily dependent on mental computation and can demand significant working and long term memory capacity if an efficient model, simplified through heuristics (rules of thumb), is not available."

Continued learning (professionalism) may also feature; lack of exposure, fewer opportunities to learn / refresh knowledge, and even a complacency of not requiring to learn because the automatics will provide the answer.

"... at under certain conditions pilots are slower to acquire this knowledge structure, or perhaps learning simply fails to occur at all."

Note that this is not about auto / manual flight skills, it is the willingness and ability to employ mental skills associated with forming and retaining a good mental model, planning ahead, and knowing what systems to use, when and why - which are the important parameters to monitor.

The study concludes -

"Subjective data and anecdotal evidence suggested that pilots of highly automated airliners may be vulnerable to the loss of their manual flying skills. However, there was insufficient objective data to support this safety concern and guide any remedial action. ...

The cognitive task analysis study revealed the dominant role of cognition (mental activity) in manual flying skill. Expert pilots reported using highly refined mental model structures and heuristics (rules of thumb) in order to predict the performance of their aircraft in its dynamic environment. The study found that the level of refinement of these models is closely linked to the performance achieved in manual flight. Pilots reported using advanced meta information gathering meta-cognitive (the method of our thinking) skills to isolate elements of the control problem, reducing its complexity, and narrow their information scan and reducing cognitive workload . ... expertise was closely linked to mental model structure. "

Where operators allow more manual flight practice, then the tasks must also be mentally challenging.

The Loss of Manual Flying Skills in Pilots of Highly Automated Airliners (https://core.ac.uk/download/files/23/138808.pdf)

[slast]

I am a bit puzzled by several aspects of this report, but can someone confirm that the chart on page 5 is correct?

It has an INDICATED altitude scale on the left which presumably means what the altimeters were showing, including the 2200 ft adjusted Split Crow crossing altitude. It then shows a calculated MDA of 813ft ASL - presumably Above Sea Level, and the Threshold Elevation at 449 ft ASL.

Working on the basis of 2 degC/1000ft lapse, for -6C at (roughly) 500ft field elevation, the sea level temp would be -5C, so the air mass temperature was ISA-20.

Applying the PANS-OPS approximation rule of thumb of 4% per 10 degrees below ISA, the correction would be 8%.

Shouldn't the threshold elevation shown also be corrected to 485' on the INDICATED altitude scale, and the calculated FPA be crossing the threshold higher as well? In fact doesn't it also need to be a bit higher to take the FPA to the intended touchdown point which is actually 463 feet AMSL = 500ft indicated???

[Chu Chu]

On page 2 of the report, it says that the cold weather correction to the MDA was 23 feet. This equals 8% of the difference between the MDA and the threshold elevation. So maybe the altimeter was set to the actual field pressure, and the cold weather correction at the threshold was zero?

[Locked door]

Hi Slast,

Ref cold weather temperature corrections, you need to know that the definition of QNH (the altimeter setting in America and Canada). By definition there is no temperature error at airfield elevation, but an increasing one the higher above airfield elevation you get. Even in Denver if the OAT was -60 Celsius, your altimeter would read correctly at airfield elevation.

https://www.skybrary.aero/index.php/Altimeter_Pressure_Settings

Airfield QNH is obtained by correcting a measured QFE to sea level using ISA regardless of the temperature structure of the atmosphere. As your altimeter is calibrated using ISA, it will indicate altitude correctly at the airfield reference point. At other altitudes, the indicated altitude is likely to be in error, depending on the temperature of the atmosphere.

[slast]

Thanks LD, I knew there had to be a flaw in my logic! Its a long time since I've had to think about how QNH is derived at cold/high airports. Senior moment etc....

[lederhosen]

There have been a number of accidents over the last few years where the autopilot has been used below minimums on a non precision approach. The Turkish airlines crash in Nepal is a classic example. If the pilots had been flying manually, they would probably have been forced to recognise sooner that they did not have enough visual reference to land safely. This is where the over reliance on automation bites. I fly quite a number of non precision approaches using vnav lnav and in good weather it can be startling how far off the papis and extended centreline the aircraft can be just above mdh. We get lulled into a false sense of security by the reliability of the autopilot. The only positive aspect seems to be that in the Air Canada and Turkish cases at least, the aircraft crashed onto the airfield with not too many casualties.

[Fortissimo]

And that, dear friends, is the inevitable result of a lack of oversight. A problem we are seeing more and more in countries that used to have well-funded, well staffed and well trained regulators.



I heard the Head of TSB Canada speak at a conference last year. She commented that they were seeing an increasing incidence of ineffective regulatory activity in all domains, citing examples of deficiencies in an operator's management, training and SOPs where the regulator was aware but had failed to intervene.


She also said that SMS worked where there was an ability to identify problems, the capability to fix them, and the organisational commitment to do so, but that it all needed to be overlaid with balanced regulatory oversight.


It is always worth remembering that 'oversight' has two meanings: one refers to supervision, the other refers omission. Some NAAs appear to be elevating the latter concept to an art form.

[underfire]

I fly quite a number of non precision approaches using vnav lnav and in good weather it can be startling how far off the papis and extended centreline the aircraft can be just above mdh.

That is why there is the NA below. Especially relevant when ICAO lets you go to 2.5 GPA at NA below.

Hopefully, when you say being far off of extended centerline, you mean vertically, not horizontally.

[RAT 5]

If you just check the altitude vrs. DME, without temperature compensation, as a procedure, you could be really low; to check each fix could take 10-15 minutes in a holding pattern. TC probably said, "Why bother? Don't want that can of worms! Just let's not reference DME vrs. Altitude." Sam

But why would you not check the vertical profile whether required by SOPs or not.
Isn't there an element of self preservation in all of us pilots.
mcdhu

I'll admit to not having read the whole thread, or not yet the whole TSB report. For interest I'll be seeing an AC mate from B767 fleet and ask him about their type SOP's. But the above comment raises the question that is becoming more common; what should you do, from an airmanship point of view, outside SOP's? In today's diluted training environment it is a very disturbing discussion. I flew for an airline that included the SBY ILS in the approach checks. i.e. switch in ON. It was then removed from the checklist so some pilots then concluded it was no longer necessary to switch it on for approach. Trained Monkey stuff. Those of us of longer tooth decided that airmanship dictated it was still a good idea. Indeed we'd been doing it before it was ever on the checklist. It somehow became an adopted procedure and we never knew why it was removed. However, even some 'still quite raw' new generation LTC's suggested it was no longer necessary during Line Checks of some of us dinosaurs. That led to interesting debates along the lines of "show me where it says I MUST NOT switch it on."
In more general terms it does disturb me that many training dept's are generating type rated LST passing pilots and them grooming them into company SOP obedient a/c operators. There is less and less the creation of type rated airman who operate according to company SOP's. It did make me laugh at an airline who trumpeted that they had comprehensive ultra-safe well proven SOP's that were binding: they then also suggested that airmanship was an SOP, but there was considerable lack of evidence of that amongst new generation crews on the line. They were either ignorant of the concept or felt too inhibited to apply any discretion.

Apologies for thread creep. Much has been thrashed out previously, but this is not about manual skills, rather management & operational skills. Is it that SOP's are diluting self-preserving airmanship techniques?

[sinnic]

On first read a rather well prepared report with no window washing. What I find rather sobering is the number of uncovered shortcomings both on the side of the airport and the operator, many of which were not a contributing cause and would have remained unnoticed were not for the accident.

Been a lurker for a while but it's time to ask: have I understood this report correctly?

The crew set up an approach for some of the nastiest conditions imaginable. They hit the button at the FAF to have George drive all the way down to the ground on a calculated FPA. Georges let the airplane get low but nobody noticed because the SOP said they didn't have to check.

They let Georges continue way below minimum disconnect height, as they thought they might see something, they had a "conversation" about what they COULD see when well below MDA. Eventually they decided things weren't right, in just enough time to write the aircraft off without actually killing anyone. Since the minimum altitude shown is 50 ft below the threshold, it seems to have been only by a huge amount of luck that this wasn't 138 fatalities and not AC's initially claimed "hard landing"!

But hey, according to this report it was all in accordance with the local laws and the airline's own SOPs, so, no big deal! You don't need to see an actual timeline of crew or automatic callouts, or other flight parameters. The report provides over 20 paragraphs about the Captain's snoring/potential fatigue problem, which it turns out not to have been an issue, but only 2 about why the aircraft deviated from the planned flight path to cause the accident. It simply says "the wind did it".

But the Airbus explanation chart that says wind changes cause distinct individual variations before returning to parallel the initial path. The rather poor quality trace provided seems to show steadily increasing divergences all the way from the start.

Then there's a whole lot of stuff about the lights and what might theoretically have been visible in those conditions, but although they survived without major injuries, not a word about what the pilots recalled actually seeing.

Am I the only one wondering whether if this had been in Asia or some other regions, this report would have been greeted with a certain amount of derision by many ppruners??

[CONF iture]

They were nasty conditions, and the crew was waiting to see what they wanted to see ...
Going below a published minimum without proper visual references.
Minimum that was already pretty low for the approach type in service and the added complexity of the temperature corrections and proper fix and distance confirmation through a remote DME.

A reminder for all of us.

[c_coder]

Street view from 05 end of runway.

https://www.google.ca/maps/@44.89619,-63.496295,3a,90y,268.3h,84.12t/data=!3m4!1e1!3m2!1sV6nira3KO_5Q4QUaUHkjjw!2e0

The southern boundary of YMML doesn't have above ground power lines. And public lighting to the south and west of Essendon airport is a special type, with shorter, more closely spaced poles. Both locations seem to have given thought to the possibility of an aircraft coming in low.

Additionally it seems to be a pretty obvious failure mode to have a non-redundant power feed which your aircraft rely on, in a location where the same aircraft can damage the lines.

[RAT 5]

Spoke to an AC buddy on a different type. They start descent in whatever mode and only check the 4nm v ALT, not all the DME's all the way down. He seemed to suggest that, after this event, the 'visual reference' had been modified and if 'lights' can be seen they can continue below DA on autopilot. Sadly our conversation was distracted and I never cleared up that point. Are there those in the know? It seemed in quite a few scenarios AC's procedures differ quite a bit from common EASA ones. It seems there is also a dodgy culture shift westwards.

[pattern_is_full]

The southern boundary of YMML doesn't have above ground power lines. And public lighting to the south and west of Essendon airport is a special type, with shorter, more closely spaced poles. Both locations seem to have given thought to the possibility of an aircraft coming in low.

Additionally it seems to be a pretty obvious failure mode to have a non-redundant power feed which your aircraft rely on, in a location where the same aircraft can damage the lines.

Well, at CYHZ, the airport is "uphill" from the road and power lines, on a hilltop about 15m above the road. You would have to be below runway elevation to impact those power lines - as was the AC airplane.

In which case, the power lines are the least of your problems....

https://www.flightglobal.com/assets/getasset.aspx?itemid=60703

In effect, these power lines are "buried" - about 5m below the tarmac elevation.

[Retired DC9 driver]

Post on this, May 18th from ACPA
https://acpa.ca/newsroom/acpa-media-releases/air-canada-pilots-association-responds-to-tsb-inve.aspx

[Jet Jockey A4]

Typical BS...


It's time AC joins the 21st century and equips its aircrafts with the proper equipment.

If a privately owned single engine aircraft can be equipped with WAAS/SBAS then surely a modern airliner like an Airbus 320 can be equipped with WAAS/SBAS.

Ground based nav aids are most likely going to be phased out at some point and satellite based approaches are going to become more and more the norm IMHO.

[RatherBeFlying]

Meanwhile in the back, there were well over a hundred GPS units in smartphones.

Mind at our recent provincial glider contest, people's smartphones were a couple miles off. Can't always count on them.

The glider mounted GPS loggers worked just fine - for under $1000.

[slast]

I am surprised there has been no comment about this aspect of the AC624 accident report. If you read it in detail, 138 people missed almost certain death by less than a second, and escaped only because by good luck that the runway is at the top of a slope. They were well below runway level for several seconds, and it just avoided being the worst civil air accident in Canadian history.

Pretty clearly, the immediate cause of the accident was continued descent below MDA without the pilot having enough visual cues to either reach the runway safely or determine that the aircraft was not properly placed to do so. But there's nothing in the analysis, causes or risk findings about the fact that apparently Canada does not adhere to ICAO standards regarding visual references.

Annex 6 etc is very simple: at DH/MDA the visual cues "should have been in view for sufficient time for the PILOT to HAVE MADE an assessment of the aircraft position and rate of change of position, in relation to the desired flight path". The assessment process ENDs when the aircraft reaches DH/MDA.

But the CAR visual reference requirement is different: ".... visual aids that, when viewed by the pilot of the aircraft, ENABLE THE PILOT to make an assessment of the aircraft position and rate of change of position, in order to continue the approach and complete a landing", and any one of the listed items will meet that requirement.

If you can START an assessment at DH/MDA, presumably it can have two possible conclusions - the flight path is satisfactory, or it is not. In the latter case, surely you have to go around - but by definition you are below the height at which a safe instrument go-around can be made.

From this report it not only seems entirely acceptable under CAR to have a decision process STARTING at the MDA, but in effect to have it made by committee of 2, and not just "the pilot" who will be doing the landing. The report consistently refers to "the flight crew" (both pilots) rather than the pilot (actually responsible for making the landing) making these assessments below MDA.

A short recap: at MDA, the F/O says he can see some lights. The Captain commits to landing and then STARTS making his own assessment. A debate occurs, with both talking about what they can see. The F/O becomes unhappy and calls for a go-around, with which the Captain subsequently concurs. The go-around starts from a height when the aircraft should be in the flare, only 15 feet above runway level, but is actually well short of the runway.

This seems to be in accordance with CARS and the conflict with Annex 6 doesn't get a mention in the report. The fact that AC did not include the words about assessing the flight path doesn't seem to materially affect the outcome - what else would you use the cues for? (Though this omission seems to be another item that had slipped through TC's supervision.)

The report also says AC has now removed the "lights only" call, which presumably leaves only ""no contact" or "runway in sight". Since typical DH/RVR ratios don't expect the runway to be in sight at DH, (e.g in Cat 1 at 200ft the aircraft is 3000 ft from the threshold with 550m/1800ft RVR), what does the PM now call if only approach lights are visible? "No contact" or "runway in sight"? Neither of which is true?

[Capn Bloggs]

Since typical DH/RVR ratios don't expect the runway to be in sight at DH, (e.g in Cat 1 at 200ft the aircraft is 3000 ft from the threshold with 550m/1800ft RVR), what does the PM now call if only approach lights are visible? "No contact" or "runway in sight"? Neither of which is true?
The call should be "Visual", which means Visual Reference has been achieved ie the required number of approach lights. Whether the PF continues for the landing or does a GA is up to them.

[slast]

Capn Bloggs, you say "The call should be "Visual" " - my emphasis. Can you clarify for me whether this is an opinion or is it what the AC procedure wording says? Do you have the actual AC text that is associated with it ?
Thanks, Steve

[Capn Bloggs]

Slast, just an opinion. :ok:

[Capn Bloggs]

Slast, the apparent AC text is at the bottom pf page 44:

During a non-precision approach, when the aircraft reaches the MDA, a PM is required to make a call of “Minimums” followed by either “No contact,” “Lights only,”70 or “Runway in sight.” The response by a PF is to call either “Go-around, flaps” or “Landing.”

Air Canada does not provide any specific training on or definition of what “Lights only” entails.

When a PM calls, “Lights only,” a PF expects that the PM has acquired visual references in order to continue with the approach. The typical response is for the PF to call, “Landing,” and to continue with the approach..

[slast]

Thanks... I had that, but under Safety Action by Air Canada on P 78, 4.1.1 (a) "The “lights only” call has been removed from standard operating procedures." Hence my query. See also RAT 5's post 391, previous page.

[JCO7]

I am surprised that there has been no mention of the monitored approach concept. Obviously it is not AC SOP but do other North American operators apply it?

Marginal Wx or any non-precision approach - FO flies, Captain monitors and acquires requisite visual cues approaching minimums, while PF (FO) remains on instruments. At minima, FO/PF calls "decide" and either the Capt has the required visual cues in which case he says "continue" or "landing" and assumes flying control or he says "go around" and the FO executes the go-around.

The benefit is that when landing the Capt already has the visual cues and the PF does not now have to start assessing visual cues after minimums. Conversely if the visual reference is not there, the FO is already on instruments and in a better position to execute the go-around.

It seems from the report that the PM called "lights only" at minimums, which was then followed by further assessment by both pilots as to what they could or could not see - all below minimums. I'm sorry but the decision to continue or go-around must be made at minimums and based on solid visual reference. There should be no decision-making and discussion process happening under minimums.

I also note that no additive to MDA was mentioned. It is fairly standard to add say 50 feet to MDA on a constant descent final approach. The value of 50' is actually in the Boeing documentation for Boeing operators. This allows a go-around to be executed at minimums (MDA + 50') without breaching the MDA - which is a "hard floor".

Lastly, was there perhaps a culture during ILS approaches of continuing despite adequate reference knowing that the airplane will deliver the aircraft correctly to the runway and you will eventually see what you need to see?
Obviously with that mindset during a non-precision approach you will come short (no pun intended) due to the aircraft not "knowing" where it is relative to the glidepath.

[gwillie]

.....it just avoided being the worst civil air accident in Canadian history..........

Well........perhaps second-worst......unless charters are not included in "civil air" category............https://en.wikipedia.org/wiki/Arrow_Air_Flight_1285

[slast]

You're right, Arrow Air was a civil aircraft charter, but all passengers were US military personnel, so I think this would have caused greatest Canadian loss of life. However you look at it, a major catastrophe was only avoided by luck.

[slast]

JC07,
I thoroughly endorse your comments, but have kept away from that subject so far. Some readers will be well aware of my views on it. However, FYI there was an AC accident in similar conditions (snow / low vis / night / minimal lighting ) in which the TSB picked up that point. See pages page 47 and 48 of the report, which is accessible at
1997 CRJ Go-around LoC on rejected landing Fredericton Canada | PicMA (http://www.picma.info/?q=content/1997-crj-go-around-loc-rejected-landing-fredericton-canada)

Some years later Transport Canada published an Advisory Circular on the subject, and modified its Approach Ban criteria to allow operators using PMA procedures to have lower visibility limits.
http://www.picma.info/sites/default/files/Documents/Background/Transport%20Canada%202006%20AC%200239%20PMA.pdf

Remarkably, given the references it does make to other accident reports, this report makes no mention of either of these documents, nor of the Canadian Airlines B767 accident on the same runway, also at night in snow and poor visibility, where the runway slope was a significant factor.

As far as the 50' height loss is concerned, that was taken into account. Report page 2: "The MDA was calculated at 813 feet ASL, based on the published MDA of 740 feet ASL plus a cold temperature correction of 23 feet, plus 50 feet added to the corrected MDA, as required by Air Canada’s Flight Operations Manual (FOM)."

813 ft indicated altitude corresponds to an ISA altitude of 790 ft, vs. the true MDA of 740, which gives the required 50 ft height loss allowance . But according to my plot of the altitudes, the F/O call of "minimum, lights only" came after the aircraft had passed the calculated/indicated MDA where a decision should have made, and marginally below the true MDA. The callout takes approximately 1.5 second and the Captain's response of "Landing" was about 20 ft below true MDA, as he started assessing the cues. So there can be no doubt that had the Captain called for a go around instead of landing, it would still have been from well below MDA and obstacle clearance criteria would have been infringed.

[RatherBeFlying]

On an ILS with the glideslope flown within tolerances, descent past DH is within terrain margins, indeed, all the way to TDZ.

On a CDA with substantial headwind, the aircraft can drift back into a zone where terrain clearance margins are not defined. But in this case, the aircraft ended below the runway. There may well have been an influence from the quite considerable downslope wind, but this is not addressed by TSB.

In the tailwind CDA case the aircraft is blown towards the threshold and airspace with designed in terrain margins.

[FlightDetent]

It is CDFA. A stands for angle, so the wind effect should be negligable. Provided we check during the final descent and adjust the flightpath appropriately.

[tubby linton]

A actually stands for approach not angle https://www.skybrary.aero/index.php/Continuous_Descent_Final_Approach

[FlightDetent]

Ouch. Thanks, I deserved that.

[slast]

On an ILS with the glideslope flown within tolerances, descent past DH is within terrain margins, indeed, all the way to TDZ.

On a CDA with substantial headwind, the aircraft can drift back into a zone where terrain clearance margins are not defined. But in this case, the aircraft ended below the runway. There may well have been an influence from the quite considerable downslope wind, but this is not addressed by TSB.

In the tailwind CDA case the aircraft is blown towards the threshold and airspace with designed in terrain margins.

There is a thread on Airbus Flight Path Angle in Tech Log started in Jan 2014. This says that in essence it calculates Vertical speed against groundspeed to maintain the selected FPA (more complicated in practice obviously). So nominally head and tailwinds should be accounted for. However there are obviously greater inaccuracies and tolerances in a non-precision CDFA than a precision approach - there is a clue is in the name! ;)

However the explanations given in the report for the developing deviations do not make sense. If you look closely at Fig 1 and Fig 15, the "perturbations" go in opposite directions.

[Capn Bloggs]

We have a similar system our aeroplane and while it does a good job at maintaining 3°, if it is "bumped off" the nominal 3° path by whatever, it stays "bumped off". You have to put it back on the charted slope. If you don't, you'll end up going in short or long. You must closely monitor the profile and intervene with FPA adjustments to maintaining the charted slope, especially when limiting steps are involved.

My impression is that too many think that these "wonderful" CDFAs are simply "point 3° from the FAF and all will be OK". Not so.

[slast]

There is a detailed critique of the accident report available from a link right at the bottom of this page:
2015 A320 snowstorm CFIT Halifax Canada | PicMA (http://picma.info/content/2015-a320-snowstorm-cfit-halifax-canada)

[slack]

FPA approaches on the bus into poor gusty winds weather are :mad: :mad:. I never did them. The warm terminal building at the alternate was just fine thank you.

[rigpiggy]

Those power lines will interfere with an ils signal, as they traverse the extended centerline. Therefore the presence of those power lines preclude the installation of an ils on rwy 05.

Why did they then have an ils on 05 prior to the mk airlines accident? I may be mistaken it has been a number of years

[rigpiggy]

We have a similar system our aeroplane and while it does a good job at maintaining 3°, if it is "bumped off" the nominal 3° path by whatever, it stays "bumped off". You have to put it back on the charted slope. If you don't, you'll end up going in short or long. You must closely monitor the profile and intervene with FPA adjustments to maintaining the charted slope, especially when limiting steps are involved.

My impression is that too many think that these "wonderful" CDFAs are simply "point 3° from the FAF and all will be OK". Not so.

Basic math. nm x 300'= altitude above tdze. GS/2x10 ergo 5 nm at 1500 130 knots gs -650 fpm. Very very close easy math

[RAT 5]

Except: it is height above TDZE. And, it is 320'/nm for 3 degrees, and it is GS/2X10+50 for V/S on 3 degrees. The DME v ALT tables on approach charts confirm this. One is a simple rule of thumb, and the other is accurate, but not too difficult.

[Capn Bloggs]

GS/2x10 ergo 5 nm at 1500 130 knots gs -650 fpm. Very very close easy math
Ace, if you set 3° at 1500ft/5nm, you cream it in 1/3 of a mile short of the threshold. My point was: calculate all you like, the FPA will NOT hold you on the 3° approach path if you get bumped off it (as the report says); closely monitor the charted profile and change the FPA to adjust. Do not "point and shoot" because you think it's "very very close".

[rigpiggy]

Not so much, because you are supposed to level off at the MDA, and only descend from there with required visual reference.
RNP Y05 .30 is 455 above tdze and the LOC 05 is 357.

Yes you can be more exact, however reading the dme and a quick crosscheck should have shown the error.

[FlyingStone]

Is anybody still doing "dive and drive" with jets these days?

[slast]

An undetected incorrect instrument flight path angle was NOT the cause of the accident, despite the implications of the TSB report.

On any instrument approach the exact position of the aircraft relative to the desired (perfect) flight path will vary. Depending on the degree of precision it could be closer or further away from it.

Cat 3 = very close indeed, Cat 1 precision fairly close, non-precision LOC further away, non precision NDB further still. Minimum instrument flight height (DH/MDA) naturally goes up as accuracy decreases. A Continuous Descent Final Approach NPA as used by the AC crew (whether or not using the autopilot/FPA mode etc.) drastically reduces the position scatter compared to "dive and drive, but use the same MDA.

This accident occurred when the crew descended below that minimum safe height (MDA) without having completed a visual confirmation that the aircraft's actual position and velocity (rate of change of position) showing that they were NOT going in short of the runway.

Such a descent is prohibited under ICAO Annex 6 but IS allowed under Canadian rules because Canada has a much less stringent definition of required visual reference, as already described post 396 (http://www.pprune.org/rumours-news/558968-air-canada-a320-accident-halifax-20.html#post9824550)

When the very idea of DH/MDA was being introduced into ICAO by the FAA, correspondence with the US NTSB made it clear that "We see nothing in the definition of Decision Height which permits the decision to be made after the aircraft has descended below the prescribed height while the Captain attempts to locate the runway." But that is exactly what the Air Canada crew were doing, quite legitimately, under CARs.
For full explanation see this (http://www.picma.info/sites/default/files/public_html/sites/default/files/Documents/Events/Report%20critique%201_3_2.pdf)

[fox21]

Is anybody still doing "dive and drive" with jets these days?

Bingo, I was wondering the same. Rarely used FPA to the MDA.

[RAT 5]

Slast: I agree with your sentiments. Crew actions at & below MDA were very dangerous. I've read the final paragraphs of the report including the consequential actions by AC. What still seems to be missing is an SOP requirement to X-check ALT v DME during descent from FAF. They seem to have adopted most of TC's recommendations, but that one was not mentioned. It is very scary to read about the inside workings of AC & TC. The discrepancy between AC's FCOM & SOP manual were glaring, yet approved. That casts shadows on the quality of TC's oversight and true understanding of what they were approving; and AC's own in-house FLT Ops dept that they could produce two such differing documents. It also is scary that they could produce such lax SOP's for such a critical manoeuvre. Their whole philosophy seems gash compared to those we use in EU. One would naturally think that AC was of the same quality standard as all other national carriers in EU & USA. Apparently they operated well below. The airmanship mindset in FLT OPs is surprising.
In EU there is an approach ban based upon VIS/RVR. In Canada they could even make an approach, in some circumstances, with a reported vis 50% of that charted?? They could continue below MDA with a call only of "LGHTS". What lights? It could be the carpark of motorway?? They had no SOP to monitor the ALT v DME during descent towards the concrete stuff?? Astonishing. (And a friend on B767 tells me it's the same there and they don't use FPA). The captain is PF in bad weather, rather than monitored approach. (a matter of debate, I know). They had an SOP allowing them to continue below MDA if lights were seen in the belief that the runway would become more visible. OMG. There was no calculation of DA/MDA taking into account the length of the ALS, so that the height above the runway at MDA coincided with the visibility and lighting system. This can encourage press-onitis below MDA if a LIGHT is seen in the belief that more lights will become visible. Considering the harsh conditions that Canada can present I would have expected ultra-cautious procedures, even if that resulted in more GA's even diversions.

It was all an astonishing eye-opener, and if I read the conclusions correctly the vertical path monitoring by raw data is still not in SOP's. It does make one wonder about the thinking in FLT OPs & TC that this behaviour could be promoted. It also make one wonder about the individual pilot's self survival instincts. The hairs on the back of my neck are very twitchy if nothing is seen at +100. To continue below MDA, still without the runway/full approach lights not in sight, would be beyond my courage. It's like driving down the road at a speed where the braking distance is greater than the visibility, in the hope that no other nutter is out there in such bad Wx.
One wonders what other scary gems are hidden in AC's SOP's. Is it a coincidence that their name is in lights a few times quite recently on what seem to be basic airmanship hiccups?

Does anyone on the inside have any more information about changes in operating culture? Is Canada going to move closer to FAA & EU procedures/philosophies/techniques.

[BluSdUp]

I am considering Canada in maybe a two to five years.
I have to do some research , and I am with you Rat 5. Something seems off in some of the incidents with Canadian Ops.

The WestJet in the Caribbean is another NPA incident I find interesting.

I have the greatest respect for Canadian pilots, dont get me wrong, but I have seen some local CAAs in Europe loosing the plot the last 15 to 20 years.

You would think Canada with ICAO in Montreal would be a beacon of proper , safe procedure.

Looking forward to some enlightenment from Canada.

[Jet Jockey A4]

I don't know what the big deal is when it comes to a landing minima in Canada.

To continue an approach below a specified DH or MDA for that approach in Canada the visual requirements are "black and white" and very clear as follows...

Landing Minima (TC AIM October 12, 2017)…

CAR 602.128 specifies that landings are governed by published DH/MDAs.

Pilots of aircraft on instrument approaches are prohibited from continuing the final approach descent below DH or descending below MDA, as applicable, unless the required visual reference (see requirements below) has been established and maintained in order to complete a safe landing.

When the required visual reference is not established or maintained, a missed approach must be initiated. Pilots must be cautioned that the missed approach segment that provides for obstacle clearance originates at the published MAP. The published MAP on a precision approach is coincidental with the DH. Obstacle clearance will not be assured for missed approaches initiated beyond the MAP.

Certain published approaches that contain multiple lines of minima may have step-down altitudes that are lower than a published line of minima. Pilots should not descend to a stepdown altitude that is lower than the altitude on their selected line of minima.

The visual references required by the pilot to continue the approach to a safe landing should include at least one of the following references for the intended runway, and should be distinctly visible and identifiable to the pilot by:

(a) the runway or runway markings;
(b) the runway threshold or threshold markings;
(c) the touchdown zone or touchdown zone markings;
(d) the approach lights;
(e) the approach slope indicator system;
(f) the runway identification lights;
(g) the threshold and runway end lights;
(h) the touchdown zone light;
(i) the parallel runway edge lights; or
(j) the runway centreline lights.


So just seeing the ground or some lights while on the approach is a non starter.

It is of my opinion that the crew of that Air Canada flight saw "something" and decided to continue their descent below MDA without meeting any of the above requirements or did not control their aircraft and allowed it to descend below the MDA into the ground.

[RAT 5]

Thanks JJ A4. What you've written is IAW EU Ops and makes sense. It is dated October 12 2017. Were these the requirements at the time of the crash, or updated from the report? The call of "lights only', or "ground contact" early in an approach had always been taught to me as an absolute No No. It risked, as in the case, continuation bias, yet it was an AC SOP. The report says they think they saw the first 2 approach lights and during the analysis of what they were seeing decided to continue. We do not know if these '2 lights' were 2 single centreline lights, or 2 bars of approach lights. I would have thought that 2 single lights would be difficult to assess as approach lights, whereas 2 bars would be confirmation. Single lights do not allow assessment of position, attitude, bank angle, create of closure: a horizontal bar does; and if you can see a horizontal bar you can also see centreline lights of the approach light system. Thus there needs to be a wider definition of 'approach lights'. In EASA I believe it says at least 1 horizontal bar. This allows you to determine roll attitude. Remembering that the rules are written for many types of a/c and operation, i.e. even hand flown twin pistons. 'Runway centreline lights' even needs expanding e.g. how many? Surely if you can see centreline lights you must be able to see Threshold lights as well; and therefore centreline lights on their own do not define a runway. Centreline lights need to be in combination with other lights.
It seems you are local to Canada. What is the now published requirement to confirm the vertical profile inside FAF?

[Jet Jockey A4]

The AIM manual is updated twice a year and this version is the latest one from October 12th 2017 with the new one due in April 2018.

Unfortunately I don't have access to older versions to see if or when the standards were changed (it could have been years ago).

I will try to find other info on your questions but may take awhile because I'm on a flight through Europe at this time.

The approach lighting on RWY 05 consist of HIRL, CL, SSALR, and a PAPI on the left side. The opposite side (RWY 23) is a CAT II runway with much better lighting.

If the approach to that runway as not changed since the accident, then the approach that night to RWY 05 was a LOC only approach (no G/S) but with a DME. The MDA was 820' (357') and the MAP was at 1.7 DME (taken from another DME freq.) which brought the MAP to the threshold of RWY 05.

However if you the crew had decided to do a constants descent from the final fix to RWY 05 they would have done their missed approach a lot sooner than the 1.7 DME point.

[slast]

RAT 5, thanks, your comments are very appropriate.

JJA4, with all respect, the problem with Canadian minima is not the list of visual references, which is pretty common. It is what decision the rules expect the pilot to make.

The concept of Decision Height (ICAO and elsewhere) is that the pilot must answer Yes or No to the question "Has what you have already seen on the ground confirmed that you are in the right place and going in the right direction?", and continue or go around as appropriate. This is also written into for example the Airbus FCTM.

But Canada's rule (CAR 100.01(1) definitions) doesn't ask that. It poses a very different question: "is what you can see on the ground right now going to allow you to find out if you are in the right place and going in the right direction?". So the crucial decision is delayed to some undefined point in the future. ICAO requires the pilots assessment to finish at DH. Canada allows it to START there.

Under CAR, below DH the pilot has ceased to have sufficiently accurate instrument information to avoid obstacles, but as in this case he/she may still be assessing from visual information whether its position and velocity are satisfactory. The pilot eventually concluded that its position and trajectory were NOT safe and that a go-around was required, but by that time the aircraft was only just above the touchdown zone elevation and well below the altitude at which a go-around can safely be carried out. IMHO this difference was a direct cause of the accident.

In this case, when it was reached, well below the DH/MDA, the pilots' subsequent decision was "no our position and rate of position are not satisfactory, we need to go around", by which time it was too late to avoid ground impact.

While the report makes considerable play of Canadian non-compliance with ICAO and EASA rules regarding CVR power supplies, it makes no mention of the (far more serious) fact that CAR 100.01(1) is in direct conflict with both ICAO Annex 6 and EASA wording intended specifically to prevent this situation arising.

[IcePack]

If they became visual what caused the undershoot? Back in the day a VC8 touched down on the grass to the left of the RWY. (All 3 u/c) snaked about a bit till it got back on the hard surface. Well neither pilot could explain why they had let the aircraft touch down in that position only mitigation was they saw the RWY late. (250’) something within humans that despite what they are seeing they see what they want to see.

[slast]

An unoffical diagram from the information in the report.
http://www.picma.info/sites/default/files/images/Profiles%202_0.png

[slast]

The approach lighting on RWY 05 consist of HIRL, CL, SSALR, and a PAPI on the left side....
If the approach to that runway as not changed since the accident, then the approach that night to RWY 05 was a LOC only approach (no G/S) but with a DME. The MDA was 820' (357') and the MAP was at 1.7 DME (taken from another DME freq.) which brought the MAP to the threshold of RWY 05.
For clarification, I expect your data is current but at the time of the accident the runway had left-side PAPI, high-intensity threshold, end, centre-line, and edge lighting, but only a medium-intensity omnidirectional approach lighting system (ODALS) extending 1500 feet from the threshold with 5 lights spaced approximately 300 feet apart, which flash sequentially every second (60 times per minute).

The runway also has a significant up-slope from the threshold to the TDZ. The MDA was 740ft (277) with a temperature correction.

So since the accident the approach lighting has been upgraded and the MDA raised. Can you tell me what the current visibility minima are? It's also my information (not confirmed) that the Captain has left the company.

[Retired DC9 driver]

RAT 5, thanks, your comments are very appropriate.

JJA4, with all respect, the problem with Canadian minima is not the list of visual references, which is pretty common. It is what decision the rules expect the pilot to make.

The concept of Decision Height (ICAO and elsewhere) is that the pilot must answer Yes or No to the question "Has what you have already seen on the ground confirmed that you are in the right place and going in the right direction?", and continue or go around as appropriate. This is also written into for example the Airbus FCTM.

But Canada's rule (CAR 100.01(1) definitions) doesn't ask that. It poses a very different question: "is what you can see on the ground right now going to allow you to find out if you are in the right place and going in the right direction?". So the crucial decision is delayed to some undefined point in the future. ICAO requires the pilots assessment to finish at DH. Canada allows it to START there.

I disagree, and I have flown this approach into YHZ, with a certain Airline ;)

On a Coupled/Selected approach, you fly the selected Flight Path Angle to minimums (+50 ' in this case) plus low temperature corrections at the FAF and MDA.. No contact at minimums then , immediate Go-Around. The 50 foot additive protects you from descending BELOW the published MDA during the GA.

So (as I would fly it) Coupled/Selected ; descending on the 3.5 degree FPA and coupled to the LOC, at minimums, ie. published MDA + 50 feet, it was auto pilot disconnect, " Landing" , or "Go around flaps" call by Captain who would be flying. Depending on whether the runway is visible for a safe landing, aircraft alignment with center line, amount of crab, etc.. Because you are descending on a constant 3.5 degree FPA, at minimums, it is treated the same as minimums on an ILS ie a Decision Height. You have the visibility to land or not.

PNF calls would be "One Hundred above" then "Minimums" , "runway in sight" or "no contact" . Runway in sight call is made anytime runway is visible, on the approach, whereas "no contact" is a call made at minimums.


IMHO, what this Airport needs is an ILS on Runway 05
my 2c worth

[Jet Jockey A4]

RAT 5, thanks, your comments are very appropriate.

JJA4, with all respect, the problem with Canadian minima is not the list of visual references, which is pretty common. It is what decision the rules expect the pilot to make.

The concept of Decision Height (ICAO and elsewhere) is that the pilot must answer Yes or No to the question "Has what you have already seen on the ground confirmed that you are in the right place and going in the right direction?", and continue or go around as appropriate. This is also written into for example the Airbus FCTM.

But Canada's rule (CAR 100.01(1) definitions) doesn't ask that. It poses a very different question: "is what you can see on the ground right now going to allow you to find out if you are in the right place and going in the right direction?". So the crucial decision is delayed to some undefined point in the future. ICAO requires the pilots assessment to finish at DH. Canada allows it to START there.

Under CAR, below DH the pilot has ceased to have sufficiently accurate instrument information to avoid obstacles, but as in this case he/she may still be assessing from visual information whether its position and velocity are satisfactory. The pilot eventually concluded that its position and trajectory were NOT safe and that a go-around was required, but by that time the aircraft was only just above the touchdown zone elevation and well below the altitude at which a go-around can safely be carried out. IMHO this difference was a direct cause of the accident.

In this case, when it was reached, well below the DH/MDA, the pilots' subsequent decision was "no our position and rate of position are not satisfactory, we need to go around", by which time it was too late to avoid ground impact.

While the report makes considerable play of Canadian non-compliance with ICAO and EASA rules regarding CVR power supplies, it makes no mention of the (far more serious) fact that CAR 100.01(1) is in direct conflict with both ICAO Annex 6 and EASA wording intended specifically to prevent this situation arising.

To me, like I said before the rules are clear. I have not read CAR 100.01 (1) most likely in ages and I don't really care for it because we use the rules written below. If you are a lawyer or try to interpret the rules in a different way so be it. I know by applying strictly the rules below I won't get into trouble.

CAR 602.128 specifies that landings are governed by published DH/MDAs.

Pilots of aircraft on instrument approaches are prohibited from continuing the final approach descent below DH or descending below MDA, as applicable, unless the required visual reference (see requirements below) has been established and maintained in order to complete a safe landing.

When the required visual reference is not established or maintained, a missed approach must be initiated.


The visual references required by the pilot to continue the approach to a safe landing should include at least one of the following references for the intended runway, and should be distinctly visible and identifiable to the pilot by:

(a) the runway or runway markings;
(b) the runway threshold or threshold markings;
(c) the touchdown zone or touchdown zone markings;
(d) the approach lights;
(e) the approach slope indicator system;
(f) the runway identification lights;
(g) the threshold and runway end lights;
(h) the touchdown zone light;
(i) the parallel runway edge lights; or
(j) the runway centreline lights.


Well in my book it is very clear and in our company it is very well understood that at DH or MDA if the above conditions are not met a Go-Around must be initiated immediately.

[Retired DC9 driver]

Well in my book it is very clear and in our company it is very well understood that at DH or MDA if the above conditions are not met a Go-Around must be initiated immediately.I agree....as I stated above.

[jack11111]

Slast, Is there anyway I can get your excellent Chart in a form I can expand?

(referring to post #430)

[Jet Jockey A4]

An unoffical diagram from the information in the report.
http://www.picma.info/sites/default/files/images/Profiles%202_0.png


From the conversation in the cockpit that you provide on the chart it seems to me they did not have the required light to continue below the MDA... They should have initiated an immediate Go-Around.

Again, and I said this at the beginning of this thread, it is a real shame Air Canada never equipped their older A320s with GPS so that this crew could have used GPS/WAAS do to a LPV approach. Doing a LOC approach in these weather conditions with a baro type VPath that may have been improperly programmed was looking for trouble.

[Jet Jockey A4]

I just pulled the approach plate for CYHZ and it's new from just a few days ago (2017-10-17)...

The changes stated on the approach plate are D-ATIS, lighting and visibility.

I must assume since the accident they may have improved the lighting system for RWY 05. Also as you pointed out, there are new/higher minimums for that approach but the visibility is still the same at 1 mile. The rest of the approach remains the same with the same DME being used to dictate the MAP at 1.7 DME which again is the threshold of RWY 05.

NOTE: In Canada with our "Visibility Approach Bans", Air Canada (and others qualified) could start the approach with less than the 1 mile visibility required on the approach plate.

[RAT 5]

I'm still curious if AC have now included in their SOP's a DME v ALT check inside the FAF? Jeppe has the table on the charts, why not use it; especially on cold weather correction days? I still say, in response to JJ, that the term "Approach lights" needs an expanded definition. It is far too lax & simple and easy for someone to say,"I saw the lights." Yeah, but what kind of lights? JJ says that the visual criteria for landing is black & white; but if you read the list everything mentioned is within the runway it self, even the Approach Slope indicators. All the lights are in the runway surface, except 'Approach Lights'. The runway lights are identified by their position and title and thus we know what they are, where they are and what colour. "Approach Lights" is too vague and a real sucker clue, especially given the variety of approach lighting systems and layouts possible.

[Jet Jockey A4]

I can't speak for AC's SOPs and what they say but any professional pilot even if it is not written in their SOP would use the info provided on the Jepp plate and that includes the DME v Alt info provided and he would also be cross checking the altitudes over the FAF to make sure his temp correction he applied is correct... This is called airmanship.

I now understand what you meant about your "approach lights" comment but I have not found anything that would make it clearer.

If the chart posted above is correct, the PM's first call when he initially saw lights was "lights only", not "approach lights".

What did he see? Random lights on the ground or the actual approach lights for the runway?

[slast]

Slast, Is there anyway I can get your excellent Chart in a form I can expand?

(referring to post #430)
Hi Jack
It's page 3 of this critique of the entire TSB report.
http://www.picma.info/sites/default/files/images/Report%20critique%201_4.pdf.
If you want a graphic source file to manipulate etc I can supply it, send me a PM.

Any comments especially errors and corrections please let me know.

[slast]

From the conversation in the cockpit that you provide on the chart it seems to me they did not have the required light to continue below the MDA... They should have initiated an immediate Go-Around.


The chart is my best attempt to correlate the information in the report, since the TSB did not see fit to do so. The report contains several contradictory statements about this point. The analysis says "As the aircraft reached the calculated MDA, both crew members observed some approach lights. These cues meet the criteria for required visual reference per the Air Canada Flight Operations Manual, the Transport Canada Aeronautical Information Manual, and the Canada Air Pilot general pages."

But earlier it states "At 0029:27, a radio altimeter automated audio call (automated call) of “400” was made, indicating that the aircraft was 400 feet above the terrain. Almost immediately after this call, the aircraft crossed the calculated MDA at 1.2 nm from the threshold. The PM observed some approach lights and called, “Minimum, lights only,” when the aircraft was about 1.0 nm from the threshold. The PF immediately called, “Landing,” and began to observe some approach lights. By this time, the aircraft had crossed the published MDA (740 feet ASL) and was 0.3 nm farther back than the published distance. The autopilot remained engaged as the aircraft continued descending, and there was no reduction in the descent rate."

[Jet Jockey A4]

I understand this is your best attempt at making this graph which looks good to me.

So in conclusion using your graph...

- The crew did not program the right flight path into the aircraft's FMCs because they were below the temperature corrected flight path.

- You can't rely on the radar altitude call out at 400' or 100' because of the terrain. In fact when the auto calls at 400' and 100' were given they were actually a lot closer to the ground then one would expect.

- The PM's call of "minimums, lights only" came at or slightly below the uncorrected cold temperature MDA, perhaps 50 to 60 feet below what the corrected MDA was on that night.

- The captain's call of "landing" came at an even lower uncorrected MDA.

- At approximately 150' above ground, both pilots have a "conversation" about the approach lights.

- Autopilot disconnect happens at less than 50' above ground. It would be interesting to know the A320's autopilot minimum descent limits are on a non precision approach.

- The captain's G/A initiation starts below the RWY's threshold altitude with the known consequences.

I am not an expert in crash analysis but it sure looks to me that the crew busted minimums without having the proper visual clues to continue below the MDA. This might have been further compounded by several technical errors from them in the way they programmed the FMCs (I'm not qualified on the A320) and did not apply the temperature corrected altitudes at least at the MDA.

[Musician]

- The crew did not program the right flight path into the aircraft's FMCs because they were below the temperature corrected flight path.
That seems unlikely.

From the TSB report: "As the aircraft descended, the actual flight path diverged from the desired profile as a result of wind variations. The divergence continued to increase throughout the approach. The airspeed was constant, and the vertical descent speed ranged between 700 and 800 feet per minute (fpm)."

The report analyses the calculations of the crew and finds them correct; the crew computed and presumably set a FPA of 3.5° (for an actual angle of 3.08°), but the FDR shows their actual path vs. indicated altitude was 3.77°. On a normal visual approach, the pilot will compensate as she flies the approach from MDA when the autopilot is turned off, so it's not usually an issue. TSB report Section 1.18.2 discusses the Airbus FPA guidance mode and the possible deviation.

The interesting part is that the airplane flew an actual 3.50° descent. Since the ADIRS also uses inertial inputs to determine height, and these are not affected by temperature, it is possible that the unit did actually do as programmed and steered the plane down an actual 3.5° slope, effectively ignoring the barometric deviation; this would be contrary to published documentation. (Undocumented behaviour is not uncommon in the software realm.)

The report also mentions in 1.18.3 that Airbus intially got the procedures wrong, as was discovered in 2009, and it was supposedly corrected by Air Canada and Airbus under Transport Canada's supervision.

I'm sure somebody at Airbus knows if my theory (ADIRS working inertial and non-barometric) or the TSB's "wind perturbation" theory is correct.

[slast]

JJA4, I will try to confirm your conclusions or otherwise, but a major problem is that we can only go by the TSB report which raises MANY unanswered questions that I cover in the critique referenced previously.


- The crew did not program the right flight path into the aircraft's FMCs because they were below the temperature corrected flight path.
The flight path was programmed according to AC's procedures, as far as I can tell. However there are questions about what the temp-corrected angle should have been; the descent initiation point; a rounding error (exact angle could not be set); and how "wind variations" could have affected the FPA actually flown. Also in my opinion although it seems nuts not to have any crosschecks on the way down, the way Air Canada implemented temperature corrections made this difficult. Overall one can only say that the crew seem to have actually conducted the instrument descent in accordance with the SOPs they had been given. (Report para 1.18.3). There is no question the the flight path achieved did not bring the aircraft to the correct point, and this was not detected by the crew. But who was responsible for that is not clear.

You can't rely on the radar altitude call out at 400' or 100' because of the terrain. In fact when the auto calls at 400' and 100' were given they were actually a lot closer to the ground then one would expect.
Correct. The terrain profile on my chart was a screen grab from the TSB presentation crosschecked against Google Earth.

The PM's call of "minimums, lights only" came at or slightly below the uncorrected cold temperature MDA, perhaps 50 to 60 feet below what the corrected MDA was on that night.
Correct as possible without FDR/CVR

The captain's call of "landing" came at an even lower uncorrected MDA.
Likewise.
At approximately 150' above ground, both pilots have a "conversation" about the approach lights.

Autopilot disconnect happens at less than 50' above ground. It would be interesting to know the A320's autopilot minimum descent limits are on a non precision approach.Disconnect was about 30ft above threshold elevation, 16 ft above touchdown zone elevation. The minimum autopilot height was MDA -50 but the report does not say whether the MDA had been entered in the FMC or whether the crew observed the "disconnect A/P" warning - one of the many failings in the report.

The captain's G/A initiation starts below the RWY's threshold altitude with the known consequences.
Close to or below. Certainly below the TDZ elevation.

I am not an expert in crash analysis but it sure looks to me that the crew busted minimums without having the proper visual clues to continue below the MDA. This might have been further compounded by several technical errors from them in the way they programmed the FMCs (I'm not qualified on the A320) and did not apply the temperature corrected altitudes at least at the MDA.
But the report is quite specific that "the crew" had the legally required visual reference at the MDA. The crew actually followed the law and their procedures and still crashed! But nobody was killed. I wonder if that is why the report has been able to get away with not even mentioning any of the implications of that astonishing fact. This time, it wasn't all the crew's responsibility - so whose was it?

[RAT 5]

But the report is quite specific that "the crew" had the legally required visual reference at the MDA.

Sure? How is that visual reference defined? If it is simply 'approach lights' that IMHO is insufficient; unless it assumes that there pilots are responsible for determining that 'approach lights' are not car park or highway lights. If so, that requires the pilots to know exactly what type of approach lights they expect to see at MDA and how much of then defines 'approach lights'. Because here is not correlation between MDA and approach light length and viability, it is difficult to assess what you might see at MDA. So to define what is legal and what is not is beyond grey area; it is deep in the most & fog of uncertainty. That is not what you need so close to invisible ground. 'Hoping' that the lights you see will guide you to a safe landing on the runway should not be the name of our game. We and the pax need more certainty.

[Musician]

The TSB seems quite certain as to the legality. From section 2.5 of the report: "As the aircraft reached the calculated MDA, both crew members observed some approach lights. These cues meet the criteria for required visual reference per the Air Canada Flight Operations Manual, the Transport Canada Aeronautical Information Manual, and the Canada Air Pilot general pages."

[Jet Jockey A4]

Thanks for the info Musician but I am really confused by the FMCs in the Airbus.

Seems like a very complicated system just to have some sort of VPATH during an approach. It reminds me of the Air France A320 crash during an approach in France near Strasbourg IIRC... tell me it wasn't the same type of error here?

Maybe the TSB is convinced that both pilots saw the approach lights but I remain a skeptic especially if the graph provided slast is correct in its time lines.

Does anyone with Airbus 320 experience know what the minimum altitude for autopilot use (AFM limitation) is on this type of approach (non precision) for the A320?

[RAT 5]

Does anyone with Airbus 320 experience know what the minimum altitude for autopilot use (AFM limitation) is on this type of approach (non precision) for the A320?

An earlier poster said MDA -50'. I think. I doubt this was similar to the Air Inter Strasbourg crash. That was a mix up between FPA & V/S. There was a huge difference between FPA 3degrees & 3000fpm. In this case they were only a few feet too low, but enough.

I read that AC was threatening to sue Airbus for designing a system that did not bring the aircraft to the threshold as advertised. After reading the report that seems a stretch as to where blame should lie.

[J.O.]

The A320 FCOM limits autopilot use to MDA minus 50’ on a non-precision approach. If I recall correctly, a NPA procedure that is flown fully managed (approach path computed and flown by the FMGC) will lead to the autopilot disconnecting automatically at MDA minus 50’, but this does not occur when the approach is flown with a pilot-selected flight path angle.

[Jet Jockey A4]

Thank you.

[slast]

RAT 5, I entirely agree with your sentiments. However as I have been banging on about for some time, it seems Canada DOES allow descent below MDA solely on approach lighting (unspecified) having been visible at DH/MDA, because this will "enable" the flight path to be assessed. Whereas elsewhere (Annex 6 etc) the cues must have been in view for sufficient time for the pilot to HAVE MADE that assessment. That is also (I believe) in the Airbus FCTM - DH/MDA marks the end of any assessment. In Canada you can BEGIN it there. Of course if you then assess it as NOT satisfactory you are in trouble, being below the safe go-around height.

Re the autopilot, not only is the FM limit as already stated by J.O. (MDA-50ft), but "an amber message DISCONNECT AP FOR LDG is displayed when, during a Non Precision Approach, the AP/FD remains engaged at Minimum minus 50 ft, or ‐ 400 ft AGL (if no minimum entered)."

In this case, there is no record of whether the crew entered the MDA in the MCDU. If it was, then it would have been 813' indicated, 790' true, vs the actual MDA of 740'. This message should have come on at the actual MDA, which also ties in with the a 50ft addition to the published MDA when using a CDFA, as in this case. If it was NOT set, it would have come on at 400ft AGL simultaneously with the 400 auto callout, which because of the sloping terrain was actually only about 300ft above the TDZ.

This message should therefore have been visible but there is no record of whether either crew member observed it, and if so made the required callout.

[J.O.]

DISCONNECT AP FOR LDG

That feature is an option that was not always installed on older variants of the A320. I’m not sure if it was installed on the accident aircraft.

[slast]

Aha! interesting. The accident aircraft was the first one delivered to AC.

[FlightDetent]

The older ones actually should be even more intuitive. At FMS inserted MDA -50 ft, the AP should trip off and FDs revert to basic HDG-V/S modes. Mode announciators boxed on FMA, FD bars flashing, and audio triple click.

In your graph (lot of meticulous work behind it!) do I read it correctly that the vertical axis reference is corrected ALT, thus the corrected profile line is different from the geometrical path green line?

Secondly, to leech on your research further: Does the report mention anything about the V-DEV indicator (yo-yo / doughnut) and indications displayed on the PFD?

Thanks.

[slast]

The older ones actually should be even more intuitive. At FMS inserted MDA -50 ft, the AP should trip off and FDs revert to basic HDG-V/S modes. Mode announciators boxed on FMA, FD bars flashing, and audio triple click. Thank you. I flew the very earliest delivery A320s (to BAW 1989) and still have the manuals I think so will check what they say when I get home.
In your graph (lot of meticulous work behind it!) do I read it correctly that the vertical axis reference is corrected ALT, thus the corrected profile line is different from the geometrical path green line?
So you know what you are looking at, and please say if you think my methodology is wrong so I can correct it:
Far left GREEN scale is just a measured tape covering the range needed, placed to match threshold elevation.
Next to it is a RED scale which is the green one geometrically stretched to cover the temperature correction, and moved so that field elevation matches correctly. Thanks to Locked Door post#382 for correcting my error on this.
Right hand GREY scale is same gradations as GREEN i.e. true feet but zeroed at touchdown zone elevation.
Green solid "nominal flight path" is from 2000ft msl at the FAF Split Crow to the ideal aiming point and PAPI location.
Yellow solid line is the 3.08 degree VDA from Split Crow, which is slightly below the ideal, but seems to cross the threshold "at about 50ft" - the threshoild being 14ft lower than the TDZ.
Red dashed line is the planned descent path, using the temperature adjusted crossing height at the FAF to the TDZ. The plan was to fly as close as possible to this by setting the FPA to -3.5deg in accordance with AC's table.
Red solid line represents as best I can fit it the aircraft flight path. Descent from FAF was started slightly early. So at for example 4 DME from I-HZ, the aircraft should have been ideally at 1250 ft true alt (green scale). But because of Air Canada cold temp adjustments were in 100ft increments (presumably up), this aircraft should have had an altimeter reading of 1350 ft. (red scale) at this point. However if my analysis is right, the altimeter reading (red scale) would actually have been 1250 ft, the charted value for 4 DME, although the aircraft was actually 60 ft low.
Inset chart shows a blown-up section of the report's FDR readouts.
Secondly, to leech on your research further:
leech away! My objective to stop accidents where pilots are personally blamed for making predictable errors that could easily been prevented, if the airline had made suitable procedural changes and/or provided better training, so any comments that might ensure this stuff is correct are welcome.
Does the report mention anything about the V-DEV indicator (yo-yo / doughnut) and indications displayed on the PFD?
Thanks.
Not that I've seen. It misses lots of information as noted in the critique.

[767-300ER]

That seems unlikely.

Since the ADIRS also uses inertial inputs to determine height, and these are not affected by temperature, it is possible that the unit did actually do as programmed and steered the plane down an actual 3.5° slope

FPA uses baro-inertial vertical speed and therefore FPA is affected by non-standard temperatures and consequntly requires temperature correction.

[RAT 5]

FPA uses baro-inertial vertical speed and therefore FPA is affected by non-standard temperatures and consequntly requires temperature correction.

With various errors possible, FPA, baro-altimeter,......it is still surprising that AC SOP's did not include a vertical profile check via ALT v DME, especially as the table is on the chart. I also find it surprising that the self-survival instincts of a pilot would not do it anyway. I've asked the question about whether it is now an SOP; no reply yet.
I hope this was not a case of a pilot NOT doing something of basic airmanship nature because it was not an SOP. It doesn't say you are not allowed it do it, just that it is not mandatory to do it. That philosophy reminds of one company that removed the SBY ILS from the Approach checklist so the more lazy guys interpreted this as it was not necessary to select it on. That struck me with sadness as it indicated that the trained monkey syndrome was too prevalent. I'm not saying that was the case in AC, just asking.

[mccauleyprop]

Slast, I would like to commend you on such a detailed critique of the Canadian TSB report on AC624.
I must admit, I would not have ever thought, that the Canadian TSB would ever "sugar coat" their findings! I have always had the utmost respect for their findings, and now this revelation has me questioning their motive in not reporting in detail the actual events.

[Gilles Hudicourt]

I was also shocked on how much information the TSB report glossed over.

I did not read all the thread here, but I did spend some hours going over the report with a fine comb some weeks ago. From memory here is what I have found. Sorry if I repeat what others have already mentionned.

1) The report does not mention if the accident aircraft had or did not have GPS.
2) The report does not mention if the pilots made an accuracy check, as the required of A320s that have no GPS
3) The report does not mention if the pilots had "Accuracy High" in the Prog page.
4) The report does not mention if the pilot had tuned the DME frequency.
5) The report does not mention if the pilots had tuned the NDB frequency
6) The report does not mention how the pilots determined they had reached the final descent point (FAF)
7) The report mentions that second "Gate" by quoting the Air Canada procedures, but never mentions how the crew implemented or failed to implement that procedure.


Air Canada's Stable Approach Policy is built around an Arrival Gate concept whereby a flight shall not continue the approach unless the required criteria for each Arrival Gate are met. There are two Arrival Gates for every approach; the first is the FAF (or FAF equivalent), the second Arrival Gate is at 500 feet AGL (or 100' above minimums, whichever is higher). A Go-around is mandatory if the criteria for each Arrival Gate is not met.
For non-precision approach, at the first Arrival Gate (FAF), the aircraft must be on the inbound course and on the descent profile defined by the FPA, the vertical speed, or the flight management guidance system.

No flight shall continue an approach past the FAF Arrival Gate unless it is being flown in a way that ensures the Stable Approach Criteria will be met by the 500 foot Arrival Gate.

At the second gate (500 feet AGL or 100 feet above the MDA), no flight shall continue unless the following stable approach criteria are met:
Established on the correct vertical approach path


8) The report avoids stating that the crew went below minimums but only suggests it by stating that the MDA was passed at 1.2 NM and that the PM called lights only at 1.0 NM.

Almost immediately after this call, the aircraft crossed the calculated MDA at 1.2 nm from the threshold. The PM observed some approach lights and called, "Minimum, lights only," when the aircraft was about 1.0 nm from the threshold.

At a ground speed of about 130 kts, 0.2 NM is roughly six second after, and about75 feet below the MDA. Not much, but much longer that I expect from my PM when I'm flying an approach to minimums.

9) The report fails to mention if the crew had entered the CYHZ05 in the PROG page as is normal procedure for these aircraft.

10) The report fails to mention what waypoint was in the database after the FAF. Was it a threshhold, a MAP or some other point ? That would give an idea of what the yoyo would have indicated, and if that might have influenced the crew.

11) The report fails to mention what data was used to create figure 1. Was it the FMS data ? If it was, was the IRS based FMS data valid ? If it was, how do we know it was ? This brings us back to point 2 and 3 above.

12) The report failed to indicate if the crew selected a LOC05 in the FMS, anf if they manually entered a corrected altitude at the FAF in the FMS, or if they just computed it for the FAF without changing the FMS provided FAF (uncorrected) crossing altitude.

13) The report states that the crew computed a corrected MDA of 813 feet. But the report fails to indicate if the crew entered that corrected MDA in the FMS or the regular MDA.

14) The actual communications between the two pilots are not provided, but are just paraphrased. The real verbatim exchange would have provided an insight of what actually went wrong......

There are many other things I have issues with, but what I described above is enough for me to have lost the blind faith I had in the TSB .....

It's a shame they did this, for they shot themselves in the foot. This report will be the proof that lawyers will produce in the future to question the credibility of the TSB when they will be tasked with a more important and complex investigation, one with say, hundreds of lost lives. Will Canada have to outsource their investigations because of this ?

I still think they are competent and would have been capable of writing a good report. Why they produced this half baked report, we'll leave to speculation.

[Gilles Hudicourt]

I noted that several people asked why this runway does not have an ILS.

There are terrain features that prohibit the installations of an ILS, and one of those is if the terrain on the runway axis a certain distance before the threshold is nor fairly flat for a certain distance, in order for the Radio altimeter, which does not measure the height of the aircraft above the runway, but the height of the aircraft above the terrain directly below it, to be able to activate certain features such as flare mode, or changes flight laws, elevator trim, auto thrust etc. Even a dinosaur like the 737NG has such RA dependent features.

Such features would not work correctly if the terrain half a mile before the threshold was significantly higher or lower than the runway threshold.

I remember in a distant past flying ILS approaches in aircraft that did not even have a RA, but the aircraft I now fly prohibits ILS approaches if both RA are U/S.

[Retired DC9 driver]

Italics are mine
Gilles Hudicort wrote
"12) The report failed to indicate if the crew selected a LOC05 in the FMS (it's a MCDU), and if they manually entered a corrected altitude at the FAF in the FMS, or if they just computed it for the FAF without changing the FMS provided FAF (uncorrected) crossing altitude. You would enter it in the MCDU at time of briefing, and then the PF checks the MCDU data entry including this change.

13) The report states that the crew computed a corrected MDA of 740 feet. But the report fails to indicate if the crew entered that corrected MDA in the FMS or the regular MDA."All part of the briefing after entering it in the MCDU and on a Non-Precision approach you add the 50 foot additive. PF cross checks all the data entry into the MCDU as part of his approach briefing.
The TSB report said the pilots did brief the approach, so these entries into the MCDU would have been done at that time, and cross checked by the PF. . DME would be set up to verify FAF passage too, and LOC up on PFD for raw data info. All standard SOPs.
from the TSB report;
"Air Canada’s Airbus A320 Quick Reference Handbook was revised to include the FPA and chart of approach altitude corrections for cold temperatures. The chart was designed to identify the applicable altitude correction (in 100-foot increments) to be added to the FAF and the degree correction to be added to the FPA based on the approach altitude height above the aerodrome and the temperature in degrees Celsius. The Quick Reference Handbook also includes a chart for the cold temperature corrections for the MDA. The investigation determined that the FPA calculated by the flight crew was in accordance with the QRH." which included the cold temperature corrections for FAF and MDA .
I find it hard to believe that Gilles would think none of this was done.:rolleyes:

Finally, as stated in the TSB report,
"For a flight in FPA guidance mode, Air Canada’s practice was that, once the aircraft was past the FAF, the flight crews were not required to monitor the aircraft’s altitude and distance from the threshold, nor to make any adjustments to the FPA."
At Air Canada, the use of the distance/altitude table on the Jeppesen chart as a monitoring tool is not cited during pilot training for LOC/non-precision approaches"
Last Wx report was;
"wind 340°T at 22 knots, with gusts at 28 knots, visibility ¾ sm in light snow and drifting snow, broken cloud at 700 feet AGL, overcast cloud at 1000 feet AGL, temperature −6 °C, dew point −6 °C, and altimeter 29.62 in. Hg."
They were busy with that kind of weather..
So I doubt they would have been cross checking DME versus altitude inside the FAF, but that is speculation on my part.

[Gilles Hudicourt]

I find it hard to believe that Gilles would think none of this was done

I don't think anything, except that report glosses over a number of important and highly relevant things which should have been spelled out.

Here is an example of what I mean:

The cabin crew then made a passenger announcement, which included instructing passengers to stow their carry-on baggage, put their seat backs upright, and fasten their seat belts. The cabin crew subsequently confirmed that these actions had been taken.

I find it hard to believe the cabin crew would not have done these actions which they do during every flight. Yet it is mentioned in the report. It does NOT leave the reader to ASSUME they were done as they should have been.

For a flight in FPA guidance mode, Air Canada’s practice was that, once the aircraft was past the FAF, the flight crews were not required to monitor the aircraft’s altitude and distance from the threshold, nor to make any adjustments to the FPA.

Which is one of the many contradictions of the report, for in the same report one can read:

The following Air Canada documents are available to flight crew:
• The TC-approved Aircraft Operating Manual (AOM), which contains the SOPs, is based on information about the operational, technical, procedural, and performance characteristics of the aircraft in the Air Canada Flight Crew Operating Manual (FCOM).
Flight crews use the AOM for all aircraft operations.
• The FOM contains information that applies to all flight operations, except when superseded by an AOM.
• The Flight Crew Training Manual (FCTM) is designed as a reference document to provide pilots with practical information on how to operate the Airbus aircraft.

The Air Canada FCTM indicates that the flight crew should monitor the aircraft’s position along the vertical flight path while conducting a non-precision approach, by referring to the distance indicated on the distance measuring equipment, the altimeter reading, and the time.

And the report (not me) later quotes the same Air Canada FOM:

No flight shall continue an approach past the FAF Arrival Gate unless it is being flown in a way that ensures the Stable Approach Criteria will be met by the 500 foot Arrival Gate.

At the second gate (500 feet AGL or 100 feet above the MDA), no flight shall continue unless the following stable approach criteria are met:
• Flaps and landing gear are in the landing configuration; and
• Landing Checklist completed; and
• Indicated airspeed with plus 10 knots to −5 knots of target airspeed (Airbus-target airspeed is Ground Speed Mini when active); and
• Thrust stabilized, usually above idle, to maintain the target approach speed along the desired flight path; and
• Established on the correct vertical approach path and where applicable, remaining within ½ scale deflection of the guidance used for an
instrument approach or, for a visual approach, established on the correct approach slope as indicated by visual approach slope indicators (i.e.
VASIS [visual approach slope indicator system], PAPI or HGS [head-up guidance system]); and
• Rate of descent not in excess of 1000 fpm unless required to maintain the published constant descent path (e.g. glideslope, VASIS, calculated
descent rates, etc.). If an approach requires a rate of descent greater than 1000 fpm, a special briefing should be conducted; and
• Established on the correct lateral approach path and where applicable, remaining within ½ scale deflection of course deviation indications for
VOR [very high-frequency omnidirectional range], localizer approaches and five degrees of track for NDB [non-directional beacon] approaches.

How does one verify that one is on the correct vertical path by 500 AGL or 100' above the MDA when doing a a LOC approach ?

[RAT 5]

Finally, as stated in the TSB report,

"For a flight in FPA guidance mode, Air Canada’s practice was that, once the aircraft was past the FAF, the flight crews were not required to monitor the aircraft’s altitude and distance from the threshold, nor to make any adjustments to the FPA."
At Air Canada, the use of the distance/altitude table on the Jeppesen chart as a monitoring tool is not cited during pilot training for LOC/non-precision approaches"

What is Airbus recommended procedure regarding this? I've only flown Boeing, and a whole mess of other a/c, and I would never fly an NPA without using all the help I could get. Not monitoring ALT v DME was used in the 'dive & drive' type profile of ages gone by. Using FPA only would be like, in a less sophisticated a/c, setting a V/S at FAF and starting the watch and hoping. Why would you do that when you could make it safer monitoring ALT v DME? I'm curious if there are other Flt Ops who advocate that NPA technique and how that SOP can be approved the the CAA? There has to be a risk involved and this day of TEM why introduce any risk, especially when the statistics for CFIT show NPA's are the riskiest approaches. It doesn't seem common sense. I know what I'd do on such an approach. SOP does not say you are NOT allowed to use the ALT vDME table.

And, was it not reported some months ago that AC was making a claim against AirBus that the FPA system did not bring the a/c to the threshold as advertised? What happened about that? Surely the TSB report would have to investigate if the crew flew the profile according to Airbus procedures including any aspect of temp corrections and entries into MCDU.

Last Wx report was;
"wind 340°T at 22 knots, with gusts at 28 knots, visibility ¾ sm in light snow and drifting snow, broken cloud at 700 feet AGL, overcast cloud at 1000 feet AGL, temperature −6 °C, dew point −6 °C, and altimeter 29.62 in. Hg."
They were busy with that kind of weather..
So I doubt they would have been cross checking DME versus altitude inside the FAF, but that is speculation on my part.

If the automatics were in control of the a/c what would make them busy? Are you suggesting that in calmer weather they would have had time to do so even though it was not an SOP?

[wiedehopf]

I noted that several people asked why this runway does not have an ILS.

There are terrain features that prohibit the installations of an ILS, and one of those is if the terrain on the runway axis a certain distance before the threshold is nor fairly flat for a certain distance, in order for the Radio altimeter, which does not measure the height of the aircraft above the runway, but the height of the aircraft above the terrain directly below it, to be able to activate certain features such as flare mode, or changes flight laws, elevator trim, auto thrust etc. Even a dinosaur like the 737NG has such RA dependent features.

Such features would not work correctly if the terrain half a mile before the threshold was significantly higher or lower than the runway threshold.

I remember in a distant past flying ILS approaches in aircraft that did not even have a RA, but the aircraft I now fly prohibits ILS approaches if both RA are U/S.

Only problem would be with Cat II/III because they have a decision altitude based on the radar altimeter. Cat I ILS uses the barometric altimeter for minimums. Thus you can have dropping terrain approaching the runway.

And with Cat I there is of course no autoland. You say several features would not work, so how do they work on a visual approach to the same runway?

While i'm not saying an ILS could definitely installed at the location i would not be surprised if the non-existent ILS was just due to cost.

Edit: google says it is due to cost.

"The Halifax airport, and every other airport in the country, has financial constraints," Williams said. "They don't have an unlimited supply of money. And let me tell you, passengers would be the first to complain about increased costs if the airlines were required to pay for it."
http://www.cbc.ca/news/canada/nova-scotia/air-canada-flight-624-wreckage-to-be-moved-off-halifax-runway-1.3015771

[Retired DC9 driver]

RAT 5 wrote
"Using FPA only would be like, in a less sophisticated a/c, setting a V/S at FAF and starting the watch and hoping." As I understand it, the FPA or Flight Path Angle is Inertial based,; it certainly isn't just a V/S you set. As the ground speed varies, the aircraft position relative to the desired FPA is adjusted by the autothrust to maintain the correct FPA. The idea of a Continuous Descent Approach, is that the aircraft is configured in the landing configuration and continuous descent, at Vapp and the FPA places you in a position relative to the runway for a Threshold Crossing Height of 50. With no thrust changes , or changes in rate of descent you should be at the MDA in a position to see the runway, disconnect autopilot and continue to landing..
In the old "Dive and Drive" LOC approaches, you would have a Missed Approach Point defined by a DME value or cross radial. Once you are past the FAF descending to MDA, then increase power to level off, and at the MAP (Missed Approach Point) if runway is not in sight, it's a Go Around.

[Retired DC9 driver]

Gilles wrote
"How does one verify that one is on the correct vertical path by 500 AGL or 100' above the MDA when doing a a LOC approach ?" In this case, an Airbus on LOC 05 to YHZ,
by correctly setting the published FPA at 0.3 DME from the FAF, then pull the knob. Check the FMA at the top of your PFD, that you are in FPA mode and proper angle is displayed.
This assumes you crossed the FAF at the correct altitude, coupled to the LOC . A Coupled/Selected approach.
No offense Gilles, but sometimes I wonder if the people on this thread are actually pilots, familiar with the automation in Airbus and Boeing aircraft.

see page 1.6.2 in the TSB report as to how the PFD, with FMA above should be displayed on this Coupled/Selected approach. Note the "Bird" ; Velocity Vector is displaced to the side by the crosswind.

ps. there is a small purple circle icon on right side of PFD that displays the FPA "path" (where the larger diamond would be a G/S indication). So that small icon VDEV displays if the aircraft is following the FPA vertical path correctly. The VDEV on the PFD is not to be used as a vertical descent aid.

[fireflybob]

Irrespective of company procedures or manufacturer "advice" I am staggered that any professional pilot would not be cross checking/monitoring any charted DME check heights on a non precision instrument approach.

[Capn Bloggs]

Gilles wrote
"How does one verify that one is on the correct vertical path by 500 AGL or 100' above the MDA when doing a a LOC approach ?" In this case, an Airbus on LOC 05 to YHZ,
by correctly setting the published FPA at 0.3 DME from the FAF, then pull the knob.

...No offense Gilles, but sometimes I wonder if the people on this thread are actually pilots, familiar with the automation in Airbus and Boeing aircraft.

A bit harsh, there DC9. What you have described might put an aeroplane on the correct path just after the FAF (you did cross the FAF in a 3° descent, I hope, so there was no balloon into the final descent...), but certainly doesn't ensure you will remain on that path. Unless you have an FMS-generated VNAV path to follow/coupled to, you'd better be following the DME profile down to the MDA (as FFbob noted) because what you've described is simply a point-and-shoot exercise, with you hoping you'll pop out with 2W/2R on the PAPI.

To Rat you said:
As the ground speed varies, the aircraft position relative to the desired FPA is adjusted by the autothrust to maintain the correct FPA.
No it doesn't. If the aeroplane is bumped off the 3° path for some reason, it won't go back to it, it will simply re-set the flight path to 3°. The report describes this issue on page 65 and is something that any Airbus or Boeing driver should understand... :cool:

Further, I'm not an Airbus pilot but I very much doubt that the autothrust would control the vertical path: throttles control the speed, the pitch control controls the vertical path/FPA. That is what happens on my auto-jet. Just like they fly coupled ILSs. You get low, the stick comes back to correct. You get fast, the throttles come off.

[FlyingStone]

No it doesn't. If the aeroplane is bumped off the 3° path for some reason, it won't go back to it, it will simply re-set the flight path to 3°. The report describes this issue on page 65 and is something that any Airbus or Boeing driver should understand... :cool:

This should be the highlight of the whole topic here. Misunderstanding of the automation. People think because they do a nice LOC/FPA approach during their type rating with ISA conditions in still air in the sim FPA is great, set -3.0 degrees and pull 0.3 nm before FAF and that's it. Yep, unless it's -30C or +45C and bumpy as hell.

The only half bullet-proof tool for NPA is a VNAV coupled approach, with all the altitudes corrected for cold temperature. And even then, one should crosscheck with DME table until visual or there's no more entries in the table.

[slast]

Irrespective of company procedures or manufacturer "advice" I am staggered that any professional pilot would not be cross checking/monitoring any charted DME check heights on a non precision instrument approach.
Unfortunately not as simple as it sounds as the chart DME heights also need to be cold-temp corrected.

It appears that Air Canada got the approval of Transport Canada for a chart in the QRH (not shown in the report) that gave low temp corrections for FAF altitude and the MDA, rounded up to the nearest 100ft, and for the FPA itself. The numbers were apparently correctly extracted for these. But there is no mention of DME altitude corrections, which could be different for each approach and not easily amenable to 100 ft rounding since they would actually become less than 100ft as the aircraft descends.

Once the descent was started the aircraft was ALWAYS below the intended flight path. But using the indicated altitudes against the basic chart values would have produced the following indications:

6 DME indicated alt 2080 = 140 ft HIGH when actually 40ft LOW
5 DME indicated alt 1650 = 70 ft HIGH when actually 70ft LOW
4 DME indicated alt 1240 = 10ft LOW - near correct but actually 110ft LOW
3 DME indicated alt 840 = 80 LOW when actually 150 ft LOW.

Which brings to mind the question of what procedures AC used to deal with this situation for older aircraft, without a FPA facility?

[RAT 5]

Which brings to mind the question of what procedures AC used to deal with this situation for older aircraft, without a FPA facility?

And also, for an operator that spends a good deal of its time in winter operating in sub-zero temps, how can they devise what appears to be a less than ideal method for its crews to conduct NPA's in said nasty conditions. One would have thought they were expert in winter ops: and how can that apparently less than ideal method have been approved by an equally supposed winter op experienced XAA? And if their methods are less than ideal, what have they done about it, and been required to do about it PDQ. It's already getting cold up there.
Is all that off target or am I misunderstanding?

[Retired DC9 driver]

Well I guess I have stirred up some discussion :)
Ok, I correct my previous statement, for RAT and Capt Bloggs
"As the ground speed varies, the aircraft position relative to the desired FPA is adjusted by the autothrust and pitch to maintain the correct FPA."

[fireflybob]

Unfortunately not as simple as it sounds as the chart DME heights also need to be cold-temp corrected.

slast, I agree and as RAT 5 has alluded to above I rather assumed that an operator that spends much of it's time in sub-zero temps would do this as a matter of course.

[J.O.]

On top of all the very valuable discussion which has helped my understanding of how it happened, I still struggle with the notion that a "non-precision" approach had such a ridiculously low MDA. It helped to set this crew up for failure, IMHO.

[Gilles Hudicourt]

Unfortunately not as simple as it sounds as the chart DME heights also need to be cold-temp corrected.

It appears that Air Canada got the approval of Transport Canada for a chart in the QRH (not shown in the report) that gave low temp corrections for FAF altitude and the MDA, rounded up to the nearest 100ft, and for the FPA itself. The numbers were apparently correctly extracted for these. But there is no mention of DME altitude corrections, which could be different for each approach and not easily amenable to 100 ft rounding since they would actually become less than 100ft as the aircraft descends.

Once the descent was started the aircraft was ALWAYS below the intended flight path. But using the indicated altitudes against the basic chart values would have produced the following indications:

6 DME indicated alt 2080 = 140 ft HIGH when actually 40ft LOW
5 DME indicated alt 1650 = 70 ft HIGH when actually 70ft LOW
4 DME indicated alt 1240 = 10ft LOW - near correct but actually 110ft LOW
3 DME indicated alt 840 = 80 LOW when actually 150 ft LOW.

Which brings to mind the question of what procedures AC used to deal with this situation for older aircraft, without a FPA facility?

The way I see it is to comply with that "Second Gate" they have in their procedures, the AC crew could have chosen one of the DME fixes from the chart that most closely matched a point that was either at 500 feet AGL, or 100 feet above the MDA, computed it's cold temperature corrected indicated altitude, and used it to evaluate where they were relation to the required slope. If too low, as AC does not allow FPV corrections after the FAF, then they would have called for a Go Around, as per the SOP.

The crew might have done all of this mind you. We just don't know, for the TSB authors, or the lawyers that later edited the original report, decided it was not necessary to include this information in the report.