Take off alternate - Landing distance req

[slr737]

We all agree that prior to departure, a pilot need to confirm that for the destination and alternate aerodromes is he able to meet the regulatory requirement, which means lands within 60% of the LDA.

What about a take off alternate? do we need to comply with the certified data (regulatory req) or can we use the operational (advisory) data?
Looking at EASA, it is said all alternate so it includes the take off alternate.

But for a take off alternate I would guess you would look at the One engine out performance which is by definition an advisory data. But if we need to look at a dispatch calculation for the take off alternate we would then have to multiply this by 1,67 in dry condition ?

thanks for your thought.

[B737900er]

You have asked and answered your own question friend.

[nick14]

depends in the operator, we have a performance department that factors the landing distances for us in normal ops. We have procedures for non-normal ie OEI.

[8che]

Why would you look at the one engine performance ? There are multitude of different reasons why you might need to return. For example our aircraft are approved for a planned full Cat 3b 75m with single engine. It is far more likely to need to return for a non engine related problem. If you need to return for any reason and the weather prevents it then you need a take off alternate. You may well return overweight or have electrical or hydraulic problems. The regulations only require you to dispatch with 1.67/1.92 for the destination and its related alternate as its presumed you will be at normal weights on arrival. That's why this requirement is in the landing section of the regulations not the take off section. A turn back to a take off alternate must therefore be assumed to be an enroute diversion and as such requires no factor for a non normal. The newest Performance tools will however include 15% for an enroute landing with no non normal.

[nick14]

Because that is the requirement:

CAT.OP.MPA.180

[despegue]

KISS guys...

Choose an aerodrome that is familiar with your ops., and you know has sufficient LDA. calculating this and that before the flight...come on!
Much more important to find a filed where the weather is going to be benign than worry about 1.67 etc.

[8che]

just read that again Nick....where is the requirement to check one engine landing performance ? What you refer to defines the maximum distance to the alternate. Nothing else and they should be set numbers in your companies OPS SPEC that goes into your PART A. The requirement for a take off alternate is simply weather and nothing to do with the reason for the return. Instead of just reading regulations think about the reasoning behind them. An engine failure requires land at the nearest suitable airport which is why distance is important.

[nick14]

And hence the requirement to ensure your LDA is sufficient for the OEI scenario.

I'm ready to be wrong but as I read that regulation and the stipulations further down there seems to be a requirement to ensure you can land?

[slr737]

8che,

unfortunately our aircraft are not catIIIb and as such cannot perform CAT III one engine out.
Yes you can have multiple scenario but the take off alternate is chosen to be within one hour one engine LRC. If you have an hyd problem, electrical problem you can still fly on 2 engine and as such will cover more ground that on one engine.

An enroute airport is still called alternate as per Air Ops and as such during dispatch you would still need to cover for the dispatch criteria either 1,67 or 1,92.

While I agree the take off alternate is mostly due to weather, landing on engine would be worst scenario as you need to land at the nearest suitable airport. You would not spend time lowering the fuel before landing. If you had flight control or gear problem, you would fly more longer as to reduce your landing weight by burning fuel (and such cover more ground to a suitable alternate)

But whatever scenario you take, the question was do we need to consider dispatch criteria or not. Looking at Air Ops and the reply from B737900Er, it is an alternate and as such you need to use those rules.

[LeadSled]

Folks,

As an old and far from bold pilot, with around 50 years in the business, such discussions as this really concern me!!.

All quasi-legalistic and ignores the real world, lulled into a very false sense of security because modern aircraft are so reliable, and serious non-normal situations may never be experienced by a pilot in a career --- outside of the sim.

And, believe me, real world emergencies never run like a sim. exercise --- that is when you find your personal proof of Murphie's Law.

The whole reason for "factoring" was/is because the "average" pilot cannot achieve the un-factored distances in the real world.

Not even close!!

So, if you commit yourself to a landing, and you have only the raw distance available, you are going to go off the end ---- and reverse thrust, which is not accounted for, is not going to save you.

If it is a "do or die" exercise, an uncontrollably fire, or minutes of fuel remaining, or some such dire situation, where running of the end is the least of your worries, so be it.

But for most situation, remember you are not a test pilot flying under test condition. So don't plan to be!!

Personally, I do not care what might be "legally" permitted, what phase of flight it might be, from pre-flight briefing to beer o'clock, except in extremis, as PIC I will want "real world" runway lengths available, 1.67 is good, more is better.

Tootle pip!!

PS: As my Christmas T-shirt says:"Common sense is now so uncommon, it should be re-classified as a superpower"

[Amadis of Gaul]

PS: As my Christmas T-shirt says:"Common sense is now so uncommon, it should be re-classified as a superpower"

Amen. And Amen again. Then Amen some more.

[B737900er]

Where can I purchase such a fine T-shirt?

[RAT 5]

An engine failure requires land at the nearest suitable airport which is why distance is important.

I'd always thought that takeoff altn' within 60mins was for the 'land at nearest suitable' and that can be for more than an engine failure on a 'twin'. (remember the 3 engine flight on a 4 donk a/c much debated on here) In a twin, if you are non-ETPS, do you not need to remain within 1hr of a suitable airfield. Is this not where the 60min rule comes from? In the event of other systems failure one might consider an airfield, even destination, as most suitable.
A non engine related problem might be departing with APU u/s and then losing another source of AC = 1 source only.

[No Fly Zone]

@LedSled came close, others noted that these events are most often weather related. WFT guys? If the weather at your departure point is so bad that you cannot return, whether on one engine or two, perhaps a better answer is to keep the SOB on the ground. Regardless of aircraft type, a cute little yellow Piper or the monster A380, if you don't like the weather, Do Not Fly! IIRC, that subject was addressed during Day ONE of my ground training many decades ago. :=

[slr737]

No Fly Zone,

Sems you are not working for an airline... Guess I'd like to see the face of your Chief Pilot or Director of Flight Ops if you call them "Guys wx is **** I'm not flying" while you could you have gone in accordance with the law.


Yeah I agree common sense is gone from a big part of the aviation community. But the law and regulation is something we can stick to it and as a Pilot, something I need to know and abide. Then you have common sense and airmanship.

But frankly, nowadays, my common sense is telling me to get a different job where we are at least considered a bit ! Now a pilot is just a glorify train driver and that's what my common sense is telling me ...

[8che]

Yes Nick you must be able to land. The point is you don't need 1.92 or 1.67 to do it.....just like every airfield you pass over within 1 hours flying distance when you go on your flight. The T/O alternate is no different you need to land ASAP hence the distance rule (not a performance rule) if you cannot return to departure airfield.

The clue is in the word DISPATCH. Dispatch requires all the regulatory extra bits and pieces..... but you cannot dispatch an engine failure. That's why you wont find any S/E performance with a factor in a QRH or OPT (Boeing) because that's all classed as ENROUTE performance. The regulator does not ask the manufacturer to produce this data so it doesn't exist. Knowing this are you seriously suggesting someone is regulatory required to get the back of a cigarette packet out and start adjusting the data to artificially increase the landing data for a T/O alternate because the incredibly expensive OPT/AFM software isn't correct ?

[LeadSled]

Sir737,
I worked for an airline (and a bloody good one) for 35 years, including Check and Training on Boeing heavy metal.

For those of you who cannot read, I say again: The factors are there because the average line pilot, flying the average line aeroplane, has no/nil/nada/zilch chance of producing anything like the unfactored results achieved in certification test flying. With very rare exceptions, you have never been trained in or demonstrated your competence in the specialized techniques used. How many of you even know, theoretically, what comprises those techniques.

To seriously suggest you can demonstrate them, to the test standard, in an emergency diversion, is delusional.

This factoring all came about (as did most certification airfield performence requirements) from hard won experience.

Take "1.92" ---- this is the factored length under FAR 25 + 15% = 1.92 of the raw test figures, for a wet runway ---- the 15% being (last time I noticed, a recommendation) because some aircraft didn't stop in the full factored distance.

This has become such a screw-up in Australia, that we had certain CASA FOIs (with nil experience on heavy aircraft, let alone any serious knowledge of certification standards) wanting the factored dry field length multiplied by a further 1.92 if the runway was wet. This left only three runways in the whole of Australia where you could land a Citation Mustang, if the runway was wet.

Tootle pip!!

[8che]

LeadSled, I currently do the same job you did,

There has never been any factored performance for Single Engine landing ......Period

[LeadSled]

8che,
Please re-read my posts, I made no specific reference to engine out condition, just the impossibility of any of us achieving the raw unfactored figures. Believe me, I have gone close, taking a B707-321C into Lasham.

As to engine-out field lengths (if any) --- any idea where they (or any "data" for other non-normal approach conditions) might come from??

As to what is manufacturer's "certified" data in an aeroplane performance manual -- that is a whole other can of worms, where those who have never bothered to acquaint them selves with the facts argue their misconceptions.

Tootle pip!!

[8che]

That's all very well but you are not attempting to answer SLR737's question.

RTFQ old chap.

[Dupre]

Disregarding the one engine scenario, slr737 raises an interesting question about landing performance requirement for takeoff alternate (even in good wx, where you can consider your departure airport).

To keep legal, do you have to demonstrate you can land in 60% of the LDA at your departure airport/takeoff alternate? And if so, at what weight are you required to demonstrate this at?

[RAT 5]

And if so, at what weight are you required to demonstrate this at?

Surely at the applicable relevant weight. Why anything else?

[Dupre]

because the applicable relevant weight may be above the max landing weight, if you are returning due to an abnormal condition. You were never intending on returning to departure airport until the abnormal happened.

But we are discussing the dispatch requirements in the ops room before we get onboard... Which brings us back to the first question, "do you have to demonstrate you can land in 60% of the LDA at your departure airport/takeoff alternate? "

[LeadSled]

That's all very well but you are not attempting to answer SLR737's question.

RTFQ old chap. 8che,
I have read the question, all right, and given a clear answer, you cannot "demonstrate" (as one poster puts it) that you can land in 60% of the factored LDA, because you are not an experienced and current test pilot, with a flight test aeroplane, using the rather brutal handling techniques that established the unfactored distances in the first place.

If you attempt to land where the actual landing distance available in only equal to the nominal unfactored distance, you will go off the end, with the consequent almost certainty of damage to your aircraft, which will almost certainly end you career if you are the PIC, and expose your passengers to entirely avoidable risks, which is what, in public, you will be canned for.

The "it was legal" defense doesn't work in real inquiries, let alone the court of public opinion.

Tootle pip!!

PS: I must have a look at the current figures for aircraft runway over-runs (not just Indonesia), but I think it will validate what I have said about landing performance, even when the runway in not obviously limiting.

[Dupre]

Just to be clear when I said "demonstrate" I was referring to calculating the required landing distance while sat in the dispatch office. Not demonstrating by any practical means.

[safetypee]

“… use of ‘factored’ data for landing at takeoff alternate …”

EU-OPS 1.400 requires that ‘Before commencing an approach to land, the commander must satisfy himself/herself that, according to the information available to him/her, the weather at the aerodrome and the condition of the runway intended to be used should not prevent a safe approach, landing or missed approach, having regard to the performance information contained in the Operations Manual.'

Many interpretations of this use the dispatch factors for the destination; the logic being that this is an equivalent level of safety.
With FOLD, the data may result in similar landing distance to the dispatch factored distances; however, if FOLD assumes reverse (check the small print) the slightly higher risk of a reverse failure in comparison to the dispatch case could be balanced by the infrequent use of FOLD for a landing at destination. FOLD is usually based on the minimum factor (15%) which can (should) be increased.

In principle the above applies for landing at the take-off alternate.
Assuming that this will be an abnormal operation then the assessment of ‘a safe approach and landing’ can be revised by the Commander – balanced by the necessities of the situation, e.g. use the minimum factor for urgent landing.
For increasing levels of emergency then ‘safe’ should be (continuously) reassessed; for an engine failure where FOLD could be invalided, then reference to the abnormal landing distances – landing with failures, should provide guidance for the landing distance required – with or without factors (check the small print).
As the risks increase the landing decision requires a well-balanced judgement (and thus justifiable after the fact); e.g. choosing the absolute minimum distance would consider an unfamiliar airport, landing at max weight, higher speed, etc, not just the failure, all of which could affect the accuracy of the assumed touchdown point in the data.

N.B. when last seen the Boeing ‘actual’ advisory data – pre OLD, has more limiting assumptions, thus less safety margin in the landing distance calculations (really read the small print). An interpretation of this ‘actual’ data is that after applying the minimum factor (15%), the resultant landing distance is only then something which can be achieved by an average pilot. However, when considering the safety aspects of an abnormal takeoff alternate landing, further factors will be required, particularly re the lack of reverse, etc.

Which manufacturers now publish FOLD?

[despegue]

Sorry, FOLD??
Never heard of this term, could you briefly explain what this is?

[Journey Man]

Despegue, aqui lo tienes http://www.skybrary.aero/bookshelf/books/2066.pdf

8che and slr737:

An alternate is an alternate and needs to be considered according to your applicable regulation. In EASA, this is governed by CAT.POL.230/235 for Perf A aircraft, which I presume slr737 is discussing. A takeoff alternate is no different.

There are many reasons why you may need to return after take-off, aside from OEI case. What weight would you plan for? An immediate return with a realistic circuit fuel burn would be sensible. Any more time aloft will only give you more favourable performance. If you have an unconfined fire or other such emergency, you may elect to return immediately regardless of the performance or structural limitations, should the situation dictate.

As with all of this, it's a planning criteria applicable up to the moment you begin the take-off run. After that, as safetypee points out, CAT.OP.MPA.300 applies. If you have planned things correctly during your preflight brief, you should have a good idea of where you're going in the event of certain triggers. i.e. a 'land as soon as possible' situation may warrant an overweight return to land; a 'land as soon as practicable' situation should warrant the take-off alternate which satisfied the dispatch requirements prior to take-off.

Consider your destination. Do you have to land within 60% of the LDA for a dry runway? No, you need to demonstrate that a realistic fuel burn will allow your theoretical landing performance to permit a landing within 60%. If you arrive at the destination heavier than planned (i.e. more favourable winds/flight level, direct routing, etc...), then what? You can still land, as long as the commander deems it's safe to do so prior to commencing the approach. Various companies have mandatory factors to help guide commanders with this decision. Factors are merely a guide, and no guarantee of achieving a safe landing as you can still royally balls up the TCH, Vref and flare.

LeadSled discusses the demonstrated landing performance. Your particular aircraft's configuration and the landing profile used to achieve this is in your AFM prior to the relevant performance. Read it. For the aircraft I've flown, they require maximum braking immediately after touching down and nailing the TCH and Vref speed, and glidepath angle. We generally don't do that. tends to spill the drinks, hence factoring is a good idea. Have a look at how an extra 10 knots on Vref affects your LDR. Or 10ft on TCH. All of this allows you to make an assessment of likely a safe landing can be achieved.

[flyburg]

I find this an interesting discussion and I have done some research of my operations manual and EU OPS.

The question, if I understood correctly, is: if we have to take into account N-1 landing minima, do we have to take into account at the planning stage N-1 landing distance requirements.

To me, not!

There are two regulations, sub part D and sub part F.

Sub part D talks about wx planning minima and stipulates that for a take off alternate you have to take into account N-1 limitations for the aircraft. So for example a B737(the one I fly) can't fly a N-1 cat 2/3, however, a EMB190 can fly a N-1 cat2/3. So for the first aircraft(B737) if the wx is below cat 1 I have to find an alternate that is above cat 1, for the second(emb 190) I don't.

Sub part F talks about performance requirements! Besides required enroute alternates, there is no requirement to take into account any N-1 conditions!!

So, to summarize, your take off alternate should have wx limits above N-1 limits for your airplane type(according part D) and comply with the general requirements(according part F) for being able to land within 60% of the runway with all engines!

My mind is scrambled with all the rules, but think about it! You can go to your destinations without having to take into account N-1 landing performance, your alternates don't have to comply with N-1 landing performance requirements! Why should your take off alternate have to?

It is only a WX requirement, related to N-1 limitations that have to be taken into account.

As a last argument, nowhere in my books, there is a dispatch chart for landing performance N-1(I sound like Yoda). Only FOLD charts!!

[c100driver]

It is actually very simple.

On the ground take-off is optional. All planned landing airports and alternates must meet dispatch landing distance.

Once airborne, landing is mandatory. All landings are en-route/advisory data.

From an IFALPA document that discusses the differences between certified and advisory.

Comparing Certified to Advisory data is, as the saying goes, like “comparing apples with oranges”. Certified data (that is factored dry test landing distance, with no reverse thrust, multiplied by 1.67 plus an additional .15 for wet runways) is used as a ight planning tool. Certified data allows you to determine the maximum takeoff weight which will allow the aircraft to land at the destination or alternate airport. FAA Advisory data is non-factored and assumes the use of reverse thrust in addition to all the conditions met or adjusted as referenced from the chart at the bottom of the PI page. Advisory data is provided to meet operational needs on varying runway conditions with the expectation that crews will assess landing performance based on actual weather and runway conditions at the time of arrival as opposed to those prevailing at the time of dispatch, when Certified data is used.

http://www.ifalpa.org/downloads/Level1/Briefing%20Leaflets/Aircraft%20Design%20&%20Operation/12ADOBL03%20-%20Certified%20vs%20advisory%20data%20on%20Boeing%20aircraft .pdf (IFALPA)

[slr737]

In my aircraft, we have the advisory data for OEI case and a lot of other advisory data for non normal.
If you want to make it dispatch, it is simple criteria of adding 1,67 or 1,92 to it.

The question is do we have to do it also for the take off alternate in whatever case we can think off.

Elsa air ops specify that in the dispatch case, you have to show that you can land within the 60% of the runway for the destination and ALL alternate. so for me it includes also the take off alternate.

So I would presume that you need to show that you can land also at the take off alternate within 60% in the normal configuration, like you would do for the destination or destination alternate.

However, we know that we take a take off alternate because we can't come back at the destination due to wx. OEI is one case where (on my aircraft) you cannot come back under CAT III conditions.

I would say that we need to demonstrate that we can land at the take off alternate within 60% under normal conditions. But nothing is really written!

However no one seems to have a "real" answer to it. So let's assume, like c100driver pointed out that yes we need the dispatch criteria under normal conditions. but if we have to divert because of a non normal then it becomes an inflight calculation and as such does not require the 60% rule.

Leadsled, yes we know that we won't make the landing distance written in the books. But it is also our duty to follow the rules and make it legal.
Legality has now became a real part of our job, compare to what you might have know flying the 707 back in the old days...

[c100driver]

It is not really that hard.

§121.197 Airplanes: Turbine engine powered: Landing limitations: Alternate airports.
No person may list an airport as an alternate airport in a dispatch or flight release for a turbine engine powered airplane unless (based on the assumptions in §121.195 (b)) that airplane at the weight anticipated at the time of arrival can be brought to a full stop landing within 70 percent of the effective length of the runway for turbopropeller powered airplanes and 60 percent of the effective length of the runway for turbojet powered airplanes, from a point 50 feet above the intersection of the obstruction clearance plane and the runway. In the case of an alternate airport for departure, as provided in §121.617, allowance may be made for fuel jettisoning in addition to normal consumption of fuel and oil when determining the weight anticipated at the time of arrival.

[c100driver]

The OEI case is a red herring and is specific to choosing a field that maybe Cat 2 or 3. In the case of a B737 without OEI cat2 or 3 then you have to use a airport that has cat1 minima. The landing distance that the chosen departure alternate has to meet before takeoff is the dispatch landing requirement. With the exception of some 4 engine aircraft that have certified AFM data for 3 engine ferry (i.e. intentional OEI) then the only certified data available is AFM all engine.

§121.195 Airplanes: Turbine engine powered: Landing limitations: Destination airports.
(a) No person operating a turbine engine powered airplane may take off that airplane at such a weight that (allowing for normal consumption of fuel and oil in flight to the destination or alternate airport) the weight of the airplane on arrival would exceed the landing weight set forth in the Airplane Flight Manual for the elevation of the destination or alternate airport and the ambient temperature anticipated at the time of landing.

(b) Except as provided in paragraph (c), (d), or (e) of this section, no person operating a turbine engine powered airplane may take off that airplane unless its weight on arrival, allowing for normal consumption of fuel and oil in flight (in accordance with the landing distance set forth in the Airplane Flight Manual for the elevation of the destination airport and the wind conditions anticipated there at the time of landing), would allow a full stop landing at the intended destination airport within 60 percent of the effective length of each runway described below from a point 50 feet above the intersection of the obstruction clearance plane and the runway. For the purpose of determining the allowable landing weight at the destination airport the following is assumed:

(1) The airplane is landed on the most favorable runway and in the most favorable direction, in still air.

(2) The airplane is landed on the most suitable runway considering the probable wind velocity and direction and the ground handling characteristics of the airplane, and considering other conditions such as landing aids and terrain.

(c) A turbopropeller powered airplane that would be prohibited from being taken off because it could not meet the requirements of paragraph (b)(2) of this section, may be taken off if an alternate airport is specified that meets all the requirements of this section except that the airplane can accomplish a full stop landing within 70 percent of the effective length of the runway.

(d) Unless, based on a showing of actual operating landing techniques on wet runways, a shorter landing distance (but never less than that required by paragraph (b) of this section) has been approved for a specific type and model airplane and included in the Airplane Flight Manual, no person may takeoff a turbojet powered airplane when the appropriate weather reports and forecasts, or a combination thereof, indicate that the runways at the destination airport may be wet or slippery at the estimated time of arrival unless the effective runway length at the destination airport is at least 115 percent of the runway length required under paragraph (b) of this section.

(e) A turbojet powered airplane that would be prohibited from being taken off because it could not meet the requirements of paragraph (b)(2) of this section may be taken off if an alternate airport is specified that meets all the requirements of paragraph (b) of this section.

[GlenQuagmire]

Where has the idea that manufacturers performance data is unachieveable come from? It's absolute rubbish to state that an average line pilot cannot achieve book figures. A manufacturer would be crucified in court if book figures were not achievable. Crossing the threshold at 50 feet on speed, closing the throttles, and performing a normal landing with maximum braking will produce at least the book figures and if a line pilot can't do that then he or she needs to find another job!

[latetonite]

A take off alternate is decided in the planning fase of the flight. So, performance dispatch is your requirement. Not inflight emergency.

[safetypee]

FOLD

http://www.scribd.com/doc/62707861/Safety-First-12

http://www.ukfsc.co.uk/files/Safety%20Briefings%20_%20Presentations/Airbus%20Safety%20First%20Mag%20-%20August%202010.pdf

http://crew.rj.com/wtouch/training_cockpit/Crew%20training%20publications/In_flight_landing_performance.pdf

Re #34 “Where has the idea that manufacturers performance data is unachieveable come from? It's absolute rubbish to state that an average line pilot cannot achieve book figures”.

The issue is not that the advisory distances are ‘absolutely’ unachievable, but that they are not achieved in operation.
There could be many factors apart from not touching down at the point assumed in the calculation (not 3000 ft or the first third – more often 1000 ft with little or no margin). The crew may not have sufficiently accurate data to use the chosen chart, e.g. wind, braking action; or not operate the aircraft as assumed by the manufacturer.

The FAA has recently issued SAFO 15 009 (www.faa.gov/other_visit/aviation_industry/airline_operators/airline_safety/safo/all_safos/media/2015/SAFO15009.pdf) which appears to acknowledge some of these issues above.
Also see the amended AC91-97A. (www.faa.gov/documentLibrary/media/Advisory_Circular/AC_91-79A.pdf)

[TypeIV]

Flaps up landings, hydraulic-, gear- and flight control problems are typically more common than OEI landings. Shouldn't we start multiplying their landing distances by 1.92 as well? :8

[Matey]

8che

With regard to the availability of your departure airfield following an engine failure in LVOs, your aircraft may well be approved for CAT 3 on one engine, but is it approved for autoland above Max Landing Mass? This is not the case on the B738 and would influence take off alternate selection following an engine failure at a mass above MLW in LVOs.

[8che]

No Matey its not which is why we can jettison fuel on the way to the alternate if needed.

On the 737 that's not an option so presumably some of the idiots on this thread will be factorising overweight landing performance before they take off !!

This is becoming tiresome

[LeadSled]

Leadsled, yes we know that we won't make the landing distance written in the books.????

But it is also our duty to follow the rules and make it legal.????

Legality has now became a real part of our job, compare to what you might have know flying the 707 back in the old days...Sir737,
Are you really serious in making that statement??

The requirement to operate legally has not changed, since a legal framework was put around aircraft, that goes right back to the 1920s, whatever the laws may be at the time.

"Legally" , what you have said above is that you have to operate your aircraft in a manner that fits the definition of reckless operation of an aircraft, next up the criminal scale from negligent operation of an aircraft.

To suggest that you must operate an aircraft in a manner that fits the definition of reckless to stay "legal", is, if I may say so, legal nonsense.

Planning to operate on a runway where you know, in advance, you cannot stop, if that runway is required, is recklessness.

In every country under whose legal framework I have operated ( been licensed as a pilot and/or operated aircraft on that registry -- UK/US/AU/NZ plus a few others) reckless operation of an aircraft is a most serious criminal offense.

That probably goes a long way to explaining the confused thinking in much of this thread, you all need to adopt a rather wider meaning of "legal", as I have alluded to in earlier posts, where is mention the LEGAL responsibilities of the PIC. Those legal responsibilities are not merely theoretical, they are an every day reality, as, every now and again, a pilot finds out the hard way.

Just meeting the dispatch requirements (however badly they are constituted) in no way constitutes a PIC meeting his or her legal responsibilities for the flight.

As for "the old days" (SFAR 422B), my comments apply up to and including the B747-400, a long way remove, in terms of certified performance and acceptable performance data, from the B707/DC-8 days.

By the way, I am still flying.

Tootle pip!!

PS: I have a very nasty suspicion that differently derived distances (certification amendment number at time of certification) are being mixed up here, and landing distanced based on different criteria are being conflated and confused.

[slr737]

Leadsled,
review what I have written and then make comment on what I have actually said !

And as to confirm what I've said ; We won't make the landing distance that is written in the book because that distance has been written using test pilot, using certain parameters (positive landing, ....) and landing within the required zone that under stress an average pilot will not make.

so nothing reckless here, except you maybe unable to read a whole topic before replying to it !

regarding legality, i'm sure all in this forum will say that since we all began flying a new set of rules has been created that restrict the operation of what we use to do before. this goes to locked door, always 2 in cockpit, use of FDM, ....
Of course, all those rules where written to increase safety

[latetonite]

Did anybody ever consider an TO alt airport with a 3000' runway?
See, that's the average required landing distance for a 65 T B737.

[LeadSled]

-----so nothing reckless here, except you maybe unable to read a whole topic before replying to it ! Sir737,
Believe me, I have read every post on this thread multiple times, with some amazement, starting with the strange idea that there was some time in recent air transport history, before which we did not have to comply with aviation law --- is close to the Top 10 in all time ridiculous statements on pprune.

As for recklessness, I have merely used you own words to point out what you have said is you/your company’s practice, in law, is as good a case of evidence of recklessness as I have seen in a while.

In this area, there is no significantly new law, just developments from time to time. What is relatively new is both Boeing and Airbus making much more data freely available as “advisory” information , as an aid to planning operations.

Please be clear, such advisory material does not replace the position of statutory requirement. One poster has helpfully posted the FAR Part 121 statutory requirements, which are quite clear, and are not superseded by any apparently less restrictive advisory material. Don't forget that, in some jurisdictions, the that head and tailwind components used in deriving the published landing field lengths are also factored, half the headwind and double the tailwind.

Read the very clear disclaimers in the Airbus information helpfully provided in links on this thread.

The EASA regulatory framework is fundamentally the same, as is EASA derivation of statutory landing field lengths.

The idea that, in pre-flight planning for a statutory eventuality, you can plan on the use of a runway that you cannot legally use ( land and stop within the confines of the runway), except in extremis when you have no choice but to land anywhere as fast as possible ---- which would be pretty much limited to a catastrophic fire or fuel exhaustion, is something I have not ever come across before. A mere engine or systems failure, even multiple system failures, short of the immediately foregoing, does not change the statutory requirement to have adequate runway available.

And, as a minimum, that will be 1.67 times the raw data, if that is your staring point

If, in fact, your company manuals apparently permit a lesser field length, the manuals are wrong, and should not have been approved, or (as is possible in Australia, the representative of the approving authority is seriously deficient in aviation knowledge) have been approved in error, or are being misinterpreted. Over a long career, I have seen all the above happen, but so far such gross errors (in my world) have been picked up (several times by me) before an avoidable disaster resulted.

As to my legal knowledge, those who know my actual identity would testify that my background legal knowledge is of a different order to the “average” professional pilot, including understanding statutory and case law on criminal negligence and criminal recklessness.

Hopefully it will be more helpful if we look at the background to all this, and it is clear to me that that there is considerable confusion of terms, with the role of much “advisory” information not clearly understood -- in the legal sense.

In other words, the use to which much “advisory” information can be put is being apparently seriously mishandled.

Not, probably, with criminal intent, but nevertheless, ignorance is not a defence in any court of law, much less the court of public opinion, to which politicians and some brands of airline management will respond.

For landing field length --- the ones that you have to use in all your normal planning, and the ones derived by either FAA FAR 25 certification, or the JAR/EASA equivalent, the “published” landing field length, is the raw data (obtained from test flying at certification) multiplied by 1.67. In reality, this has been expressed, for years, as the “demonstrated landing distance” being 60% of the published landing field length.

For clarity, I have not used acronyms.

Understand, very clearly, that whatever you are planning, whether pre-flight or inflight (except in an extreme emergency) the full 100%, not 60% of the landing field length must be available. The applicability of an additional 15% ( or raw data multiplied by 1.92) is (depending on the FCOM) usually at the discretion of the PIC.

However, as one of the links on a previous post so helpfully illustrates, the FAA has decided (along with EASA help) that 15% (1.92) is not enough under certain circumstances, FAA ARC has made recommendations, and a rulemaking is pending, the NPRM is not far away.

In my opinion, one area of confusion is what (at dispatch) “demonstrated 60%” means in practice. Legally it can mean only one thing, and I will use an example.

At the time the aircraft might arrive at an alternate ( to departure, destination or en-route), given all the circumstance, weight, met. etc., and the aircraft landing field length published is say, 5000 feet (easier than meters) that makes 60% a distance of 3000 feet. However, the statutory distance you must have is still 5000 feet minimum.

The alternate (for whatever purpose) at dispatch cannot be a 3000 ft runway. The only meaning in a dispatch guide of the reference to “60%” is to the raw number, you cannot use that in operational planning, or in flight.

In an extreme emergency, all bets are off, but otherwise statutory (“published” as in raw by 1.67) landing field length is the minimum.

Where Airbus and Boeing now publish all sorts of very helpful advisory information, which is a good guide to what the aircraft will actually achieve, in practice,(which hi-speed can I make) based on autobrake settings and use of reverse, for example, plus assumptions about real runway friction condition (and what other variables you might throw in) you will often see the result “factored” by 15%. That’s fine, as long as you understand that the resultant actual runway length available cannot be less than the statutory requirement.

These “recent” developments actually have a long history, going back to the BCARs and the UK ARB of the 1960s. The then UK flight test model sought to allow for the real world of line pilots flying line aeroplanes in line conditions.

The flight test guide required testing at a variety of Vref ++ over the 50’ fence, a variety of threshold crossing heights, and a variety of flare and landing techniques. The resulting landing field lengths were factored by “only” 15%.

In practice, the BCAR results (raw/demonstrated +15%) were almost the same as the FAA Flight Test Guide figures, and the FAA method of obtaining raw figures was more straightforward and more repeatable, if more brutal. I don’t know, but I have always assumed that JAA went along with the FAA. At the time, I was a little surprised when such practicality overrode the usual trans-Atlantic politics of differences for difference sake. This from an old mate of mine who, after the USAF, spent many years with McDonnell Douglas Flight Test at Longbeach, involved in both DC-10 and MD-11 certification in both US and in Europe.

This is a very long post, I hope some of you will read this far, this is a subject on which all pilots should be very clear.

Please understand that statutory landing filed lengths are the minimum, advisory information, including performance estimates in non-normal configurations, is very helpful, but except in an extreme emergency, you must meet the statutory requirement as a minimum.

You may, indeed, need much more, that is the role of the advisory material, but not less. The A-380, QF 32, at YSSS is a good example.

Tootle pip!!

[c100driver]

Please understand that statutory landing filed lengths are the minimum, advisory information, including performance estimates in non-normal configurations, is very helpful, but except in an extreme emergency, you must meet the statutory requirement as a minimum.

Once inflight the statutory landing distance requirement does not apply.

From the CASA documents (I am not an expert in the CASA regulatory structure so may have quoted the incorrect document).

CAAP 235-5(0) New performance provisions for CAO 20.7.1B and CAO 20.7.4

5.3 Actual landing distance
5.3.1 In response to recommendations of the FAA’s Take-off and landing performance assessment aviation rule making committee (TALPA ARC), the manufacturers of some jet-engine aeroplanes now supply actual landing distance information to help pilots make more accurate in- flight assessments of the landing distance required in unusual situations. Actual landing distance information takes into account: reported meteorological and runway surface conditions, runway slope, aircraft configuration, planned approach speed, thrust reversers and any other deceleration devices planned to be used for the landing. The FAA’s Safety Alert For Operators (SAFO 06012) contains useful information about the recommendations of the TALPA ARC.
5.3.2 Actual landing distance information is intended to show landing performance that can realistically be achieved by flight crews in commercial operations. This is distinct from landing performance demonstrated by test pilots during flight tests for aircraft type certification. The safety factor applicable to in-flight actual landing distance information is 1.15. The safety factor applied to aircraft type certification for pre-flight planning landing distance is 1.67. Pilots of jet-engine aeroplanes that do not have actual landing distance information should continue to make in-flight assessment of landing distance required using the manufacturers landing distance information with an applicable safety factor.
5.3.3 Two major manufacturers, Boeing and Airbus, have introduced a new reference for in-flight landing distance performance, catering for both normal and abnormal system operations. The new distances are referred to by Airbus as Operational Landing Distances (OLD) and In-flight Landing Distance (IFLD) whereas Boeing incorporates the actual landing distance in the Performance In- flight section of the Quick Reference Handbook. Both manufacturers have included this data in their respective performance applications. The actual landing distances are a realistic representation of operationally achievable landing performance. The representation of this information is generally “unfactored” unless otherwise stated. The CAO 20.7.1B amendment facilitates the adoption of manufacturers’ performance applications along with the application of the 1.15 safety factor.
May 2014
CAAP 235-5(0) New performance provisions for CAO 20.7.1B and CAO 20.7.4 5
FAA and EASA have adopted the in-flight landing distance factoring as policy, and along with ICAO are in the process of rulemaking.

[LeadSled]

c100driver,
In fact, that is close, but no chocolate frog.

The numbers derived from the tables that Boeing and Airbus produce will always ( I have never been able to see anybody demonstrate otherwise) produce a landing field length longer than the raw test flight figure factored by 1.67.

I think I said words to the effect that the landing filed length cannot be less than the statutory length, raw factored by 1.67.

Indeed, some of the recommendations that will be in the forthcoming FAA NPRM will turn some of these recommendations into statutory requirements, and in the case of wet/contaminated runway, looks like they will be greater than the raw figure factored by 1.92

As I alluded to, in a previous post, the "new" approach is very much like (but more conservative than) the BCARs of the 1960s/70s.

Here is the relevant CASA CAO 20.7.1b

11 Landing distance required 11.1 For subparagraph 5.1 (a), the landing distance for a jet-engined aeroplane is:
(a) for an aeroplane engaged in regular public transport operations when landing on a dry runway, or in charter operations when landing on a dry or wet runway — 1.67 times the distance required to bring the aeroplane to a stop on a dry runway; or
(b) for an aeroplane engaged in regular public transport operations when landing on a wet runway:
(i) 1.92 times the distance required to bring the aeroplane to a stop on a dry runway; or
(ii) the distance set out in the flight manual or operations manual for operations conducted on wet runways.
11.1.1 For the purposes of subparagraph 5.1 (a), the landing distance required in relation to a propeller driven aeroplane that is engaged in regular public transport, or charter, operations is:
(a) for a landing at a destination aerodrome:
(i) when the runway is dry — a distance equal to 1.43 times the distance required to bring the aeroplane to a stop; or
(ii) when the runway is wet — a distance equal to 1.67 times the distance required to bring the aeroplane to a stop; and
(b) for a landing at an alternate aerodrome — 1.43 times the distance required to bring the aeroplane to a stop.
11.1.2 Subject to paragraph 11.2, the landing distance required under paragraph 11.1 or 11.1.1 must be determined using information set out in the flight manual.
11.2 For a landing on a contaminated runway, the landing distance required is:
(a) subject to paragraph 11.3, the distance set out in the flight manual or the operations manual for operations conducted on contaminated runways; or
(b) the distance approved by CASA for operations conducted on runways covered by slush, snow or a depth of water.
11.3 For subparagraph 4.1 (d) and paragraph 5.1, an aeroplane engaged in private, or aerial work, operations must be operated so that compliance with the landing requirements is demonstrated using data set out in:
(a) the flight manual; or
(b) the manufacturer’s data manual; or
(c) the approved foreign flight manual.
Note The data contained in some manufacturers’ data manuals is unfactored and makes no allowance for degraded aircraft performance.
11.5 This subsection does not apply in the case of an emergency.


Critical to the reading of the above is the status of the information currently presented. It is a very legalistic approach in Australia, and the differences between certified, acceptable and advisory information is absolutely critical in determining legal compliance. All AFM "data" has to be "accepted" (in reality, approved) by CASA for use under an FCOM, it makes for some very interesting "discussions".

Tootle pip!!

[c100driver]

Here is the current one from the CASA website.

The note at the bottom says that it include the Legislative Instrument from May 2014 (what ever that means in Aussie speak)

note 11.2


11 Landing distance required
11.1 When determining the maximum weight for take-off of a jet-engined aeroplane of maximum take-off weight greater than 5 700 kg for the purpose of subparagraph 4.1 (d), the landing distance required is:
(a) for an aeroplane engaged in regular public transport operations when the appropriate weather reports and forecasts, or a combination, indicate that the runways will be dry at the estimated time of arrival, or in charter operations — 1.67 times the distance required to bring the aeroplane to a stop on a dry runway; or
(b) for an aeroplane engaged in regular public transport operations when the appropriate weather reports and forecasts, or a combination, indicate that the runways may be wet at the estimated time of arrival:
(i) 1.92 times the distance required to bring the aeroplane to a stop on a dry runway; or
(ii) the distance set out in the flight manual or operations manual for operations conducted on wet runways.
11.2 When determining the maximum weight for landing of a jet-engined aeroplane of maximum take-off weight greater than 5 700 kg for the purpose of subparagraph 5.1 (a), the landing distance required is 1.67 times the distance required to bring the aeroplane to a stop on a dry runway or, if actual landing distance data is supplied by the aircraft’s type certificate holder, 1.15 times the actual landing distance.

[c100driver]

As an interesting aside the regulators Airline Inspectors (ex airline pilots) believed the rule to be observed as per despatch inflight, however the performance specialists who wrote the rule within the regulator have told me that the rule is specific to prior to takeoff only.

Before departure, takeoff optional. plan conservative.
Inflight, Landing mandatory. actual plus 15%

[LeadSled]

c100,
I have been doing some homework since my last post, just to make certain that I have my facts straight --- something I had drummed into me from an early age by a barrister/politician father.

The results are most interesting.

Re. Australian CAO 20.7.1b ( my post was from the Comlaw web site, the "law", which CASA web site is not) and it looks like the only aircraft able to use the amendment is the A380, probably the QF A-330 in the near future. The latter based on answers to questions to a C&T mate of mine at QF. It is not clear what Virgin are doing.

In both the US and EASA-land, the operational landing field length remains the "certified" or "published" length, being the test flight figures factored by 1.67, or as more correctly expressed in both EASA or FAA regulations, the demonstrated field length is 60% of the published length.

Until there is a suitable rule-making to authorize something like CASA CAO 20.7.1b, landing field lengths LEGALLY remains the certified length.
In the CASA case, it seem there is a disconnect between the Australian Type Acceptance Certificate based Certificate of Airworthiness details, and the adoption of the "advisory" figures as the certified figures. That will now be looked into. Remember, in the Australian legal framework, a CAO does not outrank a regulation.

EASA has indicated (presumably under the terms of the Trans Atlantic Mutual Cooperation Agreement) that they will follow the FAA, which has not got to even an NPRM, as far as I can determine.

It follows that all the "Advisory" information is just that, advisory, and does not supersede the current (traditional) certified landing field lengths.
If you read a bunch of the Airbus publications on the subject, it actually says this, and warns that Advisory is just that, advisory.

Once the law changes, not much will really change, because the length required (was advisory, now "acceptable data" +15%), once you have taken all the factors into account, will be much the same as now, except for wet or contaminated runways, which will be longer than now, as, not only will the equivalent of the present 1.92 factor be mandatory (no Captain's discretion) but the increment for wet or contaminated will actually increase in most circumstances.

Just because words appear in an FCOM or a dispatch manual say it, or an FOI and other specialists have varying interpretations, one thing is certain, it is not the law until it is the law. Then it is what is in the statute books, as it is, not as somebody thought it was going to be.

FAR Part 121 is particularly clear on the subject, the relevant para. is somewhere on this thread.

What will not happen, under any circumstances, and which is where this thread started, will anybody be able to plan, pre-flight or in-flight, to use a runway that is only 60% of the present certified landing distance, or anything like it.

It seems that confusion reigns supreme, a lot of people, and some NAAs have jumped the gun, and misunderstandings abound.

I have seem this often enough in Australia, where FOIs start demanding amendments to FCOMs, "because the law is changing", and then it doesn't happen, or the new "rules" vary very substantially from the CASA PR and internal training of FOIs. CASR Part 61 is a classic example of an complete shambles, which bears only a fleeting ( and probably accidental) resemblance to the explanatory memoranda and early FOI training.

Tootle pip!!

[c100driver]

Firstly my commiserations of having to put up with the total mess of incomplete, incompetent and contradictory information masquerading as Civil Aviation Regulations of Aussie. They are a total shambles and it is no wonder that PPrune has so many conflicting discussions on what is correct.

While trying to check some of the comments I have found "legal documents" that are unsigned in comlaw, explanatory statements that explain what the law is meant to say! (why could they just not write it correctly in the first place)

However I did find that the CAR's authorise the director to issue any directions via a CAO. So in this case the director can in-fact over rule (redefine?) the content of the rule.

Whilst attempting to research the facts I did come across an exemption to Tiger for the use of IFLD plus 15% IAW CAO 20.7.1B. Because the com law and CASA websites were written by a 5 year old child with learning disability I have not bothered to look for the rest of the airline exemptions though I suspect that they are all there.

The FAA 121.195 only mentions "prior to takeoff" in respect of landing distance it never mentions landing distance requirements inflight.

[LeadSled]

The FAA 121.195 only mentions "prior to takeoff" in respect of landing distance it never mentions landing distance requirements inflight.

C100driver,
Because the required pre-flight planning is required to cover, in this case, what happens in flight, as well.

The issue that surprised me, is that FAA and EASA have not yet legislated to recognise the "proposed" system, and EASA is waiting for FAA to move.

As to a CAO (or, for that matter, a regulation) being used to "over-ride" a provision of the Act., or a CAO over-riding a provision of a regulation, in Australia, that has a long and inglorious history, it quite contrary to any known legal principle, in the first instance, as for CAR/CASR versus CAO or other legal instrument, what a mess --- the is no legal certainty.

At least, under the Legislative Instruments Act, each and every case requires a Legal Instrument, that LI can be rejected by the Parliament, to that extent the "whatever" has been passed by Parliament, it is not a decision by a public servant.

Hence the expression:"inadvertent criminals", or "pilots and engineers are just criminals who haven't been caught yet".

There is reasonable legal certainty with what Qantas is doing with the A380, as certain as is possible in the legal shambles we live and work under in AU.

Tootle pip!!