Non-Precision Approaches. What does your airline recommend?

[downfourgreen]

Well folks, one more crash and many fatalities during a non-precision approach and nobody knows when authorities will review that outdated procedure to set up a new safer standard in order to avoid future incidents and accidents during the 21st century :(.
Several airlines still recommend to fly exactly the approach chart profile view and its steps, ROD, etc. and everybody knows how hard and dangerous those techniques are for a low speed single engine airplane and I don’t need to tell you how demanding task is to align an MD-11 or any wide-body airplane just a few miles on final during a rainy and windy night at weather minimuns.
I know that some airlines have strict standard procedures for non-precision arrivals with many recommendation and rules to follow based on profile and constant-rate descents after FAF to the MDA or TCH, runway alignments, etc.
Can someone give me a feedback about those operation criteria, including training, wind and rate of descent limits, RNP, etc., beside the Jepp’s charts with a VNAV profile and VDPs?
Thank you fellows...
DN4GR

"While my guitar gently weeps..." G.Harrison

[ 27 November 2001: Message edited by: downfourgreen ]

[Hand Solo]

Don't know how Jepp charts depict NPAs but in my compnay the objective is to fly a constant 3 degree approach path (or the relevant slope). This generally means not levelling at intermediate step altitudes and possibly delaying the final descent beyond the initial approach fix in order to achieve a continous smooth descent through the FAF down to MDA. Training for NPAs is covered in the initial conversion course and recurrent sims, wind limititations are either the aircrafts limits or the (lower) limits of the Captains nerves! Descent rates for all approaches are restricted to less than 3000fpm when descending below MSA+3000, with type specific restrictions on autopilot descent modes to prevent high rates of descent & long engine spool up times close to the ground. Aircraft should be on the stable on the final approach profile by 1000 Radio or a go-around should be considered. If the aircraft is not stable on the profile by 500 radio a go-around is mandatory. On the Airbus we fly the final approach in track/flight path angle mode with the autopilot engaged in bad weather. The 'non-landing' pilot flies the approach with the 'landing pilot' calling out distance to go and height above or below the profile, plus any other pertinent information. The approach is terminated at the MDA if visual contact is not made. It is not permissilbe to fly level at MDA until the Missed Apporach Point is reached.

[411A]

Dive (within reason) and drive...has worked for me for over thirty years in several heavy jets.
The constant descent idea is OK...but sometimes it just does not work.
Some companies just do NOT get the message.
Training is the KEY.

[shakespeare]

411A.

I could not disagree with you more strongly. One sure fire method of upsetting a assymmetric non-precision approach is to use the "step down method". With every thrust change as the a/c levels off there has to be a corresponding input of rudder and then another pitch down to the next step = more power changes and rudder inputs and so it goes on. I have never seen an unstable approach flying a constant rate descent. Auto-pilot in or out!

JAR OPS requires this method to be taught in recurrent sim sessions, and if performed correctly, it is in my opinion by far the safest and most efficient way to fly a non-precision approach.

Irrespective of whether it has a 3 degree or 4 degree profile, VOR/DME, NDB/DME, constant rate works every time. Interestingly enough, if you take away the DME forcing the lads to use the tear drop procedure from overhead the navaid, they don't need to use step down at all. If it works here it should work on a straight in approach, and it does!

The trouble in many airlines is that pilots have not recieved thorough non-precision approach training, and as a result don't have a good understanding of flying the procedures correctly.

As you said, "TRAINING IS THE KEY".

[ 29 November 2001: Message edited by: shakespeare ]

[sabenapilot]

On aircraft with a FPA (Flight Path Angle) on the autopilot, European JAR-OPS requires that it is used iso the usual V/S mode.

This means you simply track the radial inbound and set the published FPA (for instance 3.7%). The plane will then descent on a virtual glideslope towards the runway once its horizontal path intersects with the virtual glidslope.
During the approach you'll see the autopilot will modulate the V/S in function of the (normally deceasing) GS and you'll skim the tops (if any) of the intermediate stepdowns.

When apporaching the MDA, no level flight till the MAP is made; instead the MDA must be considered as a DA and a go-around must be executed! This poses no big problem (for instance a too early immediate left turn), because of the design of the FPA mode, which will make sure the MDA will always be reached very shortly before (0.2NM at the max) or on the MAP itself (at the very latest).

Also note that in this FPA technique no VDP (Visual Descent Point) is to be used by the crew, but rather do they use the normal call outs and procedures as for a precision approach.

Quite clever from Airbus, isn't it?
BTW, does anybody know if you can do this FPA technique on the B737NG or B777 as well?

[moggie]

I have to agree with all of you - except 411A.

What do you fly, 411A, and who for? I for one would hate to be on it with your "dive and drive" approach. The bigger the aeroplane the less safe that style becomes - large adjustments to ROD near the ground are asking for trouble.

Hand Solo's SOP sounds just like the one I spend most of my time teaching pilots for a very big airline and I can tell you that the secret to a safe NPA is a stabilised descent rate and small adjustments - especially if dealing with aeroplanes at the lower-tech end of the market. It's all about situational awareness and mutual monitoring on NPA's and stepped approaches push up the workload, reducing SA and the ability of the Non-Handling Pilot to monitor what is going on.

Yes, a pilot should be able to handle a stepped approach, by why make life difficult.
They always say that the superior pilot uses his superior judgement to avoid getting into positions that require the use of his superior skill.

In addition, the airlines that I train for apply a factor to the MDA to turn it into a DA so that the same decision making and handling methods are used for precision and non-precision approaches. This formalises the procedure that you would have to go through anyway and does not reduce the likelihood of getting in.

[downfourgreen]

A nice debate.
In accordance with FAR and ICAO PANS OPS criteria, an airplane is not authorized to fly below MDA until reaching the required visual reference or begin a missed approach prior to the published missed approach point.
Therefore, based on your opinions I have some doubts and would like some help:
Almost everybody agrees that a constant-rate descent is safer and comfortable than a step down approach, but I’m little confused when, for example, an airplane has to reach a significant high MDA (e.g. 600ft AGL). During a profile descent, the pilots are waiting for visual cues to complete their approach, if the crew complies with JAR-OPS I understood that they should reach MDA at point where the airplane could complete a stabilized approach (3 degree, 800 fpm, at least), and in case of no visual contact or not stabilized they must start a go-around promptly, without stopping at MDA. However, if the MAP is over the VOR, some miles ahead, how and where do the pilots begin the missed approach maneuver? Don’t they need to keep the airplane at MDA until MAP (FAR and ICAO rules)?
How do you define the initial point to start a final descent based on a 3-degree profile angle until MDA when no information is provided on approach chart? Is it only an FMC calculation?
Thanks in advance

[FlapsOne]

In my company (737)- notional 3 degree (adjusted if necessary to make or not below step heights) flown in VS. MDA +50' is then used as Company Decision Alt. If no vis ref at Co DA then go around as if on precision approach.

We do not fly a 737 level at MDA to MAP. The thought of doing that with one donk out is horrifying!

[TechFly]

Tks to everybody for apporting their pilot techniques!

I think Moggie was giving two keywords: Situational Aw. & Monitoring.

As we all know sometimes it is possible to reach the same objective with different ways.

In this case I prefer to adhere for a constant descent (as close as possible to the std 3° angle) trying to figure out the VDP with reference to "Dist. from RWY" vs. "cloud base".

PNF will give the deviations from the published std profile (in terms of ft).

For what is concerning the MAPt I look at it in particular for the separation from obstacle in case of a GA with an engine failure.

Looking for your comments.

Cheers.

Fly safe & enjoy life.

[411A]

FlapsOne, better stick to the UK. If you came to the USA and could NOT fly level at MDA (and not the +50 nonsense)with an engine out, you would FAIL your FAA type ride.
Its called airmanship...and handling ability...and if you ain't got it, don't apply.

[Softons_Mum]

Using the continuous 3 degree descent procedure, u treat the MDA as a DA - if the required visual reference is not there you go around. In terms of if the missed approach point if it is some distance ahead, you continue the tracking as required to reach the missed approach point whilst climbing away, then follow the standard missed approach when reaching the specified point...or as directed by ATC .... ;)

[Softons_Mum]

in terms of 411as method of flying level - it may well be practical (or required - some procedures require a visual level segment after reaching the missed approach fix) - however in many cases it is not practical - why fly level along the MDA to the missed approach point if you know that you cant descend safely to the runway with appropriate rates of descent and speeds when you reach that point? in most companys i would say that it would be viewed very poorly doing greater than 1000fpm below 1000 feet.......

[LevelFive]

DN4GR,
For non-precision approaches – ceiling less than 1,000feet or visibility less than 3 statute miles, the first officer must fly using the autopilot while the captain seeks visual reference with the runway, or the captain can manually fly using the HGS system. FLAPS must be 40 by the final approach fix. Max descent rate 1,200 fpm. Minimum descent rate 1,000 fpm. The captain does the landing. Sim check is get down, drive in and descend as soon as runway is in sight. Wind limits – 70 kts peak gust headwind, max crosswind 35 kts, max tailwind 10/15 kts depending on model.

[2daddies]

411A,
Mate, I promise you that I can fly at MDA + 50 - 0 (and don't give me any of that "I can maintain an altitude to within 10 feet" rubbish - you bloody well CANNOT and you know it!) with one-engine inoperative and without falling into a slanging match about our respective country's standards I'm sure you'll find that if I can pass an Australian Multi-Engine Command Instrument Rating test AND a base-check with my airline I can pass an FAA equivalent - it's what I get paid to do.

My point though is: why dive and drive if you don't have to? It's can be uncomfortable for passengers (descent rates/markedly changing engine note) , it makes speed, energy and configuration management difficult, it places unnecessary power demands on the engines and quite frankly the closer I get to the ground the more reluctant I am to dive towards it - distractions and mistakes happen and if you make an error in a nice constant 3 degree descent chances are you'll have A LOT more time to fix it than if you're driving down to the next step at 3000 fpm (not to mention avoiding triggering the GPWS).

Airmpanship encompasses many elements of flying - but basically don't do something if there's an easier and SAFER way of getting the job done!

[ 30 November 2001: Message edited by: 2daddies ]

[ 30 November 2001: Message edited by: 2daddies ]

[411A]

You missed the point entirely 2daddies.... the FAA wants to see a NP approach flown to the missed approach point, NOT a miss upon reaching MDA. If you cannot do this, level at MDA, with an engine out, it's pink slip time, simple as that. It's called maximum time at MDA to be able to see the runway or approach lights. Diving at 3000 ft/min is certainly not required, 800-1000 generally works fine. If an airline wants to impose additional restrictions, that is up to them, I mentioned the FAA requirement for the rating. Does not necessarly apply to everyday plain vanilla line ops. Those of us trained long ago use the dive&drive method because it works, for us anyway. For the more "junior" guys, new to line ops, the constant descent method may well be better suited. Different strokes for different folks :D

[CaptA320]

411A I agree that in the old days, in fact not so long ago at all the method of flying a NPA was the dive and drive, most of us were trained in this method throughout our initial training. However this has changed as the constant rate of descent procedure has been found to be both safer and more comfortable for pax. When I did my intitial pilot training there was no such thing as CRM...get my point.
The issue here is not if a pilot has the ability to fly MDA+50, despite the fact that most of us had to display that in order to get our ATP tickets, line flying has little to do with an FAA check ride. Major airlines around the world have recognized that the "stablized" approach not only increases situational awareness but also is safer.
The constant rate of descent method is no so widely recognized that Jepps decided to publish on their charts the dme crossing altitudes for the portion beyond the FAF.
The way we train pilots is two fold.
If the chart has the published dme/altitude profile then it is recommended to be used in conjunction with the published gradient which should be converted to FPA.
If the chart does not have published dme altitudes then the crew should calculate the profile of descent by first looking at the VOR (lets say), calculating its displacement from threshold (when on threshlod what should my dme read) then knowing we want to cross the threshold at 50 feet work back to platform altitude based of the gradient.
So if the VOR is 1 mile before the threshold and threshold elevation is 60 and platform altitude for the approach is 2000ft with a gradient of 5 it would be as follows.

At threshold (-1DME) we should be at 110ft at the VOR we should be at 410ft, at 1DME 710ft, at 2DME 1010ft, at 3DME 1310, at 4DME 1610ft, at 5DME 1910, at 5.3DME 2000ft.
Now this profile must be compared with the chart to ensure it complies with any DME/Altitude restrictions, it also complies with the FAF (FAF cannot be less that 5.3DME) and at MDA the pilot must have obviously visual contact to continue.

[sabenapilot]

411A,
you say: the FAA wants to see a NPA flown to the missed approach point, NOT a miss upon reaching MDA.
In other words: If you reach the MDA before your MAP, you have to fly level at MDA till the MAP before starting the missed approach.


First of all:
purely technically speaking (based on European JAR-OPS); after descending to the MDA on a NPA, you do NOT have to stay level at MDA till the MAP! An MDA is nothing more then a MINIMUM, so there is no rule wharsoever preventing you from already starting to climb up again. However, you are correct on that you have to stay on the appraoch track till the MAP. Only then are you allowed to initiate any turn (if the missed approach calls for that of course...)

Second remark:
I do not know what plane you fly, but it clearly is no airbus with FPA (Flight Path Angle), because then you'd know this discussion of yours is purely theoretical...
FPA allows you to fly a continuous descent NPA, skimming all tops of any intermediate stepdowns (when used correctly), and reaching your MDA at any selected point!
If you use your MAP for this selected point, then your MDA is nothing more then a virtual DH and a go around MUST be flown upon reaching the altitude.
If you work out and use a VDP however, then you may indeed continue your approach by flying level to the MAP, but as the subsequent descent from that MDA at MAP is no longer on your smooth and continuous descent profile, you will easily end up with all kinds of unpleasant audio warnings like: SINK RATE, TOO LOW... TERRAIN etc.. Not really something I'd like to hear on a NPA appoach in poor visibility (only RWY lights in sight, no RWY itself for instance...)
BTW- If Airbus stongly advises against any level flight at MDA on a NPA approach for all these reasons, then why try to be sharper then these highly qualified guys?

[411A]

Well sabenapilot, the level flight required at MDA is a REQUIREMENT for the FAA rating, what the airline ops specs says about this (in normal line flying) is quite another. If the individual airline wants to treat an MDA as a DA, that is their option. Seems quite unnecessary to me. And, so is the +50' business added to MDA...more European nonsense. Either you can fly accurately, or you cannot, rather simple really... :rolleyes:

[RatherBeFlying]

In these wonderful days of FMCs, you can project a straight slope back from the screen height at the threshold to stay above all the step-down fixes and convert the MDA to a DH -- just make sure you key it in right and monitor those step-down fixes.

The first instrument approaches were non-precision approaches. NDBs were new fangled technology and the criteria were designed around the DC-3 -- and still are except that the circling minima were given widened bands as approach speeds increased.

On my very first IFR flight test, as the stopwatch ran out the time on an NDB approach, I lifted my hood at the MAP to find the runway half a mile off to my left after what looked to me like a good tracking of the course -- and passed! I'd really want to know very well the guy who swung the compass before doing an NDB for real -- today you take along a GPS.

[411A]

Yes, and those GPS approaches can be very accurate...why is it that this very useful aid has not found wider acceptance in the EU?

[ 01 December 2001: Message edited by: 411A ]

[Hand Solo]

Because its controlled by the American military and they can't be trusted not to turn it off when we need it. Thats why. Could make life very difficult if they invoked SCATANA mark 2 and shut off the GPS.

[BEagle]

Whereas at DA a decision is made (which will involve the aeroplane descending briefly below DA before go-around is achieved), as we all know, at MDA the aeroplane must not descend further until the appropriate visual references are achieved.

So for those youngsters not trained to fly level at MDA and who therefore treat MDA as DA, an extra factor must be built in to ensure that the aeroplane does not descend below MDA when go-around is initiated. Hence for those who insist on using the DA technique on a non-precision approach, an extra 50 ft at least must be added to MDA to compensate.

Trainig and practice are needed to fly a 'dive and drive' - but commercial pressures rarely allow such luxuries these days.

[ 01 December 2001: Message edited by: BEagle ]

[Kingpilot]

411a-

The Flight safety foundation has done a tremendous amount of work on the CFIT problem and have identified the "dive and drive" technique as contributing to the high risk of NPAs. They recommend a constant rate of descent, even if it lessens the chances of getting in. The FSF is, I believe, US based, so this is not just a European thing. Both you and the FAA need to roll with the times here. If you are interested take a look at www.flightsafety.org (http://www.flightsafety.org) for plenty of excellent research into CFIT and Approach and landing accidents. Look for the flightsafety digest from a couple of years back, it is a .pdf download.

[411A]

Kingpilot--
Yes, quite familar with the FSF...who am I to say they are wrong, just that in the past crews were trained dive&drive and I just cannot help thinking that they were/are better trained IMHO.

BEagle--
Yes would agree that if an MDA is treated as a DA, an allowance is needed.
I was involved in training years ago at an asian carrier, and the new F/O's were trained in the aircraft (B707, not an easy acft for the inexperienced) and they had no difficulty with flying level at MDA with an engine inop...but then, fuel was cheaper. They normally received at least 40 landings before being released to the line. With this practice, their handling skills were very good.

[fms146]

Very interesting reading this debate and it highlights an area of dificulty I had when comming into the Airline environment from GA where NPA's are the rule rather than the exeption...On a dark night in winter flying freight on my own into some god foresaken place in the middle of nowhere I got into the habit of planning a constant rate decent to the MDA..it made life a lot easier I assure you and I felt no need to prove I could fly to within 50 ft of any intermeadiate level.

I know from previous posts that 411A and 2daddies are very experienced training pilots on heavy aircraft..with two very different opinions about how the NPA should be carried out..but just imagine how hard it is on a new FO when he flies captains of differing opinions and you get the "What are you doing" when all you are doing is what the other guy wanted.

Now who am I flying with today...

[411A]

Well fms146, that can be a real problem.
I have noticed DE Captains joining an airline and then adopting their own procedures (from another carrier)and this drives the F/O's to distraction.
A new Captain should let the F/O follow the airline standard operating procedures when he/she is PF and NOT try to change the plot.

[Dan Winterland]

The MDA is just that - a minimum. If you fly the constant descent profile in a very heavy aircraft, say a 747, you will bust the minima if you TOGA at MDA. For that reason, my the Jepp plates my company uses all have an extra 50' added to the NPA MDAs.

I used to fly with BEagle (in fact checking my logbook, he did 5 of my 6 IRs on that aircraft!) The company policy then was to descend slightly below the notional 3 degree GP and level off to make the MAP at the MDA (legal on all NPAs except SRAs which have lower minima based on the notional 3 degree GP). This is fine if the aircraft can do it, and you stay in currency on that type of approach - we used to have hours allocated for currency training on the aircraft (not the Sim) and had to do one of these approaches every two months. But now I'm flying a much heavier aircraft and rarely flying NPAs - the constant descent and a 50 ft buffer make good sense.

[Kingpilot]

411a, I still cannot agree with you. IMHO the better trained pilot is the one who has been taught the safest way of doing the approach. Perhaps your method REQUIRES more skill but who is to say that pilots trained in the constant ROD would not be able to fly level at MDA if they were required to do so? It has been said before but I will say it again, a good pilot uses his superior judgement in order to avoid having to demonstrate his superior skill.

[411A]

Well Kingpilot, you are certainly entitled to your opinion, just as I am to mine.
Those airlines who use MDA=DA+50' and a constant descent certainly have their reasons, although I would not necessarily agree...but hey, that's what makes a debate.
All good fun.
What ever you do, be safe....as those non-precision approaches are not always easy.
Many times there are traps for the unwary.

[RedUnderTheBed]

Interesting?
First off - using 'dive & drive', steps & level MDAs to MAP etc can be very hairy in a wide-body, the pitch changes are horrendous, even if you're name is Chuck with a 'Y'. Not nice in the sim and even less nice with 200, 300, 400+ trusting souls on board. Piece of cake in a small aircraft with in-line thrust engines though.
2: Treating MDA as a DA or DH is definitely fail material in NZ. The lag of the go around, especially with high by-pass fans, means you sink below MDA! Get out of that one Bloggs!
And, finally, a true story:
Some years ago I was going into Hong Kong when Kai Tak (ah!! the nostalgia) was the joint. The IGS (off-set ILS) was U/S and the favoured approach was a TNDB across HK Harbour AT NIGHT - stirring stuff! Not long after we checked in with HK ATC a United jet called up and when advised of the approach to be flown there was a 'stand-by' followed shortly by a request for vectors to CKS in Taiwan as he "...didn't have that approach in the can."
There was some harrumpphing on my flight deck until it was pointed out that he was probably the most professional pilot in the area that night.
We got in on our TNDB at night OK, but I still wonder... :confused:

[2daddies]

I get the impression that there may be a touch of confusion arising from the dual discussions of "dive & drive" Vs. "continuous descent" and MDA Vs. DA.

Legally (no matter how you get down to the minima) an MDA is an absolute floor - it MUST NOT be descended below until all criteria for a visual approach/ circling and landing are met, while a DA is just that - an altitude at which a decision MUST be made. Allowances are made for descending below that altitude if the approach is discontinued.

These rules are incontrovertable.

411A, after reading some of your ensuing posts I'm beginning to see your point a little more clearly and I do agree with it to a certain extent - the longest amount of time spent at the minima does give you the best chance of becoming visual and executing a successful landing. But bearing in mind that legally you must remain at the MDA (or above) until both visual AND established inside the circling area, I still fail to see the point of diving to that minima miles from the airport. Why not just create a constant descent to place you at the correct altitude coincident with the circling area (to be maintained until the MAPT)?

fms146, 411A and I clearly do come from different schools on the issue, but I'd like to think that if we worked for the same airline we'd adopt and practice the same procedure - the one which the airline determines for us. Individuality is an asset at certain times, but not when trying to conduct a single-engine non-precision circling approach to an airfield in marginal conditions!

P.S - fms, you flatter me! I'm actually nothing more than an humble FO with strong opinions on the topic, so I can sympathise with you about flying with Captains who like to run to their own rules. Thankfully, there aren't many where I work now! :D

[Chimbu chuckles]

Seems to me you're all missing a few important points.

1/. Dive and Drive has lost favour for one very important reason. It's a lot less safe than a constant profile. In any aircraft let alone Transport Cat Jets.

2/. If the NPA you are flying is a runway approach you'll fly to the MDA and if not visual go around immediately. WHY? Because 99% of the time the MAP is at the aid and the aid is to close to the runway to make the straight in approach from the MAP. You cannot circle from that minima so there is no reason to hang around. The absolute safest way to fly these types of approach in heavy aircraft is to fly a constant profile to the MDA.

3/. If you're flying an NPA that is not a runway approach you descend to the higher circling minima and at the MAP decide whether you have the criteria to circle. In my opinion there is no good reason to get down early for a better look because what the ceiling/vis etc is 3nm from the MAP is not as relevant as that from the MAP onwards in the piece of sky you will be circling in! Thus a constant profile descent to a point say 2nm before the MAP should be sufficient to level the aircraft, have a look, decide and then GA if not visual. The other risk that this avoids is when you get 'visual' at the edge of the circling area and descend further to stay visual before actually sighting the runway, and then subsequently lose visual reference, requiring a GA from below MDA and possibly offset somewhat towards the edge of 'protected airspace'.

I spent years flying NPAs for real in everything from Islanders to F28s and Bae146s and the dive and drive is only practiced by old and bolds who refuse to change, for no other reason than they perceive their way as the way "real pilots do it", or "that's the way we did it in the good old days". They usually fail to remember that they were in a DC3 or some such.

The NPA I fly most often these days is the Kathmandu VOR/DME and you can bet your ar$e that I have the relevant profile written on the plate, there is simply no safer, more predictable, and for 411a, more professional way of flying that, or any other NPA.

411a the reasons CRM and descent profiles have evolved (among other things) is because the way you 'old guys' did it in the 'good old days' was not the best way it could be done! Certainly not in the equipment that has prevailed in airlines of the last 30+ years! I suspect that you are retired now anyway, there is no way that any airline C&T department would tolerate you diving and driving on your sim checks these days!

Chuck.(C&T Dassault Falcon 200)

[Scando]

Some time ago I read an article on CFIT. A nice setup for a CFIT is a non prec app in IMC and/or night conditions, into an airport surrounded by high terrain. This setup presents itself on a fairly regular basis in my part of the world.
Dive and drive = multiple level offs = multiple possibilities for level busts = multiple possibilities of CFIT. Stating the obvious: MDA is not the only place you need to level off, failure to do so at any minimum (hard) altitudes during the app can kill you.
When, a few years back, we were retrained for the constant angle/rate approach, instructors had very few problems doing so. They found out that was precisely what most linepilots had been doing all along. It was considered poor airmanship to level off more than absolutely neccessary, so we tried to fly NPA's just touching the minimum altitudes. Which is basically what a constant angle approach is all about.
Treating MDA as your DA in this scenario makes sense. You will touch MDA very close to your DP, and if not contact, go around. 35´ added (in our the procedure) for sink through. By treating the NPA as an ILS, we have made the procedure easier.
Dive and drive works. Constant angle approaches, to me, just seem like a step in the right direction. Safer.
I would really hate to have an engine seizure when level at 200 ft agl, IMC, in a high thrust, landing config.

[411A]

Would agree that the constant descent, go-around immediately at MDA+50'.... is generally fine for everyday ops.
However, there are times when you have to be down and dirty at MDA to see the runway.
Go to the alternate...well yes but suppose you ARE at your alternate or your alternate has gone below minimums, and you MUST make the most of your situation. If the "fly level at MDA" until the field is sighted is not practiced in the sim (yes, even with an engine out) and the particular situation demands that this be done before dry tanks...well you would be up the creek without a paddle, or SOL.
Or, take another situation...on approach to the the old HKG airport, IGS trips off (very heavy rain) and the only other approach is the CC NDB. This particular approach requires crossing CC NDB at 1500', descending to (as I recall) 745'msl and then tracking for 10 miles toward Stonecutters NDB where a right 130 degree turn is required toward RW NDB and the runway. If you tried the "constant descent, miss at MDA+50' scenario, you would never see the runway. Extreme case you say, well yes but there are many non-precision approaches where if you do not fly level at MDA....the runway would never be sighted.
This is why the FAA requires level flight at MDA to be demonstrated, and yes, with an engine out. No one said it was always going to be easy at the pointed end.

[maxalt]

Go to the alternate...well yes but suppose you ARE at your alternate or your alternate has gone below minimums, and you MUST make the most of your situation.

411A, The superior pilot uses his superior judgement in order to never have to demonstrate his superior skills. :D

[411A]

maxalt---
Your superior judgement....controls the weather, blocked runways, navaid failure, or one of the very many other variables?
Hope you remain so blessed....many others do not have your good fortune.
Better let your Captain do the thinking :D

[RedUnderTheBed]

411A
Yup - flown that approach at night in a B747; what's the OCL between CC & Stonecutters with all those ships' masts, derricks etc? Doesn't bear thinking about really!
I think the essence of ANY approach, particularly in large aircraft, is that it is stable. A problem with levelling off at MDA and flying to/through the descent point for the runway is losing the stable approach at low level and THEN trying to re-establish it before touch-down, that can be feat,especially when acquiring the runway late, and has lead to heavy landings or worse.
I take the point on contingencies but I think the comment of maxalt calls to mind another tried and true maxim: "The only time you've got too much gas is when you're on fire!"
If everywhere is on minima then have enough gas to land somewhere easy.
:D

[moggie]

Dan Winterland

We who advocate the stabilised approach are NOT syaing that you should hit TOGA at MDA - quite the reverse. If you read my first post you will see that on of the airlines for which I train pilots calculates it own DA from the MDA plus a factor to allow for the dip below when the TOGA button is hit (or even manual go-around is commenced!!!!!!!!!!). This is typically 50-60' for a B737. Therefore, a state published 610' MDA becomes a company 660' DA (for example). Then if the go-around is coimmenced, you will not go below MDA. This keeps you safe and legal. This airline, by the way, has an enviable safety record and has not had an accident on NPAs in over 40 years.

If you level at MDA (maybe 400' above the threshold) and track to the MAPt, what do you do when you see the runway when you are crossing the threshold 400 up? What you probably do is go around because if the vis/cloudbase were too poor to see before MDA then they are too poor for a circling approach. Nothing has been gained but safety and fuel reserves have been compromised by an unnecessary level off.

411A you say you trained pilots in Asia to "dive and drive". However, we only have to look at the safety record of Korean Airlines and China Airlines to see that this kind of high workload approach is not a great idea.

[maxalt]

411A, I believe it was Ernie Gann who wrote:

Always keep an out in your back pocket.

Couldn't have put it better myself. ;D

[ 03 December 2001: Message edited by: maxalt ]

[TechFly]

With respect for the MDA flyers I think that 3° descent is the only way to "standardize" the general XX company for a safe and stabilized approach.

This conclusion comes from many years of CRM & studies of pilot technique on NPA.

It is not wrong to use MDA level for a look but it is "recommended" the std 3° calculation (if the Jepp. chart doesn't depict DME/alts).

We can continue speaking a lot about IF .. Then... but the calculation of fuel should include allowances so it not correct, for my part, to generalize the NPA procedure for the last shot.

Cheers.

Fly safe & enjoy life

[2daddies]

All the talk about Force Majeures getting in the way of successfully completing a landing at an alternate, with min fuel and no other escape etc. etc. seems to be without regard for the fact that, if the crew declare an emergency or for any justifiable reason (only to be justified AFTER the fact) deem it necessary to bust the minima, then they cannot be stopped from doing so.

Rules are rules but not even regulators want to see you turned into a smouldering pile of wreckage just because you couldn't get visual at the minima IN AN EMERGENCY!!!! They'd have to fill out too much paperwork!

[Kingpilot]

Absolutely 2daddies! But I would further ad to what u say, if you are desperate and MUST get in on NPA the safest way to do so is off a stabilised 3 degree descent. Heres a thought, when this method becomes the norm around the world there may well be a case for actually reducing MDA on some approaches if you are flying the constant ROD. After all, you are not descending so low, so far away from the runway. I may have opened myself up with that one but is just a thought. Any how, if I were in the desperate position that 411a describes the only thing I would do different is continue the descent all the way to MDA, or even below. What do you have to lose if you are about to crash due to fuel starvation anyway?

I really would also like to hear from 411a on the question of a stabilized approach. My company, like many others, requires the approach be on glideslope, on centreline and on speed by 500 feet. How do you do this if you are flying level at an MDA of say 350 feet AGL?

[greybeard]

NPA's have evolved from the only way to find a place in the dark, usually from an NDB sometimes without a DME, which made for the concept of "get to the MDA as soon as possible so you can see the place"
Now they are mostly a secondary approach, usually aligned with the landing surface and with VOR/LLZ/GPS lateral guidance.

Sophistication of GPA's, GSpeed indications, Nav Displays etc have made it a lot easier to be situationally aware, BUT the object of getting SAFELY to the gate with your SLF is just as difficult.

DC-3's etc did all this at 100kts or less, we do all thos at 180 or so with the really heavy metal, so the increase in nav aids is only just keeping us ahead.

For Chimbu, I also go down the VOR at KTM, usually at max ldg wt, TAS 185, 2000+ fpm sink rate with a 300hr F/O calling the steps if he can still speak above the ATC yelling to all and sundry.
GOOD CHARACTER BUILDING STUFF, thanks to the good grounding of my mentors in a real Airline before Ansett made it a joke. You dont forget 400 ft circuits in a jet at YLA because the cloud base was 2000 ft said the man. The trouble was YLA was 1650 ft and you didn't need an alternate in that operation so the NPA was the end of the road and NOT aligned with the runway.

Good stuff from all on this so keep blue side up.

:D

[411A]

Kingpilot, the short answer is you cannot, just as you cannot have that stabilized approach from a circling approach at 600'agl.
However, the FAA still requires these maneuvers for the type rating and, IMHO, for very good reason. It shows the skills the Commander needs for the position, nothing more or less.
Of course, individual airlines certainly have the option of limiting the scope of normal line operations if they so desire, and many do.

[Chimbu chuckles]

Greybeard, indeed good character building stuff :D

We go to KTM probably 4 or 5 times a year, we also fly occasionally the NPAs at Padang, Bandung and a few other places scattered around South East Asia.

From memory(I deliberately make no attempt to commit these things to memory) we fly the KTM VOR/DME on a 400'/nm profile, configured in the Falcon up to, but not including landing flap. This gives about 1200'/min at 170KTAS and cuts no steps. The inbound leg at KTM is the easy part, it's the missed approach that scares the crap out of me :D

Chuckles

[sabenapilot]

After reading all your posts, I think I can make this final(?) conclusion:

Both the dive-and-drive and the constant descent rate NPA have their loyal fans, although we can all see the later one is quickly becoming the standard with most airlines all over the world.

The reason for this IMHO is that it is slightly safer(?), more comfortable (pax) and very similar (crew) to the regular ILS approach. However, I think the breakthrough of the stabilised NPA came with the introduction of FMS, INS, EFIS and all other modern stuff in the flightdeck, which allows us to calculate and follow up our descent path easily and accurately...

Those guys still using the good old dive-and-drive technique against all odds are of course intitled to doing so, but they should understand that their technique is considered non-standard, even somewhat old-fashioned and that many big companies around the globe will not really like them to use it. In fact it even goes so far that at least one airplane manufacturer (Airbus) more or less forbids their technique althogether!

However, as long as these guys (and girls of course...) keep on flying those good old B727, 737-200 or DC-9 for companies who have no state of the art planes in their fleet, changes are that the dive and drive techinique will be around for at least a few more years...

[TechFly]

"VDP: a defined point on the final approach course of a NonPrecisionApproach (straight-in) procedure from which NORMAL descent from the MDA to the RWY touchdown point may be commenced, provided the approach threshold of that rwy, or appr. lights, or other markings identifiable with the approach end of that rwy are clearly visible to the pilot."

How do you interpret "normal" if you don't follow a descent closed to a std 3°?

Cheers.

Fly safe & enjoy life.

[scanscanscan]

DGF ...From the MDA altitude ..you quote, some could say that means you would be maintaining MDA and be expected to be useing duck and drive methods.
However you could get to the mda at the vdp point, if you are lucky, and use the stabilised approach slope of 3degrees to get there.
I think the main problem is the stabilised, 3 degree boys are useing Jepperson plates which show stepdowns as a profile to be flown and no defined VDP fix,they show level offs and a level drive into the map.
In a court of law, if you lived to tell the tale, you were not flying or even attempting to fly the published profile, and you would be guilty, with your employer, of doing your own thing and not in accordance with the plate, even if you used the defence that it is a minimas plate and our method was based on not busting them.
Also the judge would see that the pf could not fly or monitor (if in map mode) properly from his approach plate, and had to hope the pnf could interpret the whole lot useing raw data off his dive drive plate,and communicate that to pf, whilst on a stabilised 3 degreeish path, with the little hills all around.
If the commander was the pf (flying blind) it is necessary for the 300hr fo to order the 411a in the left seat to turn, descend, goaround etc,etc, to a judge it would appear that NPAs today are generally real snafus and the BBC panorama and Daily Mail readers would agree.
On a npa both pilots are in a heavy high speed jet,and often useing plates still predicated on an Apache twin.
From MDA to 1500ft agl on a missed approach in a A330 comes up pretty dam quick at diversion weights on two engines at goaround thrust, flying that manually and not nailing the 1500ft in the sim helped lose a pilot I know his 330 command and later his job.
I feel heavy metal aircraft need redrawn stabilised,3degree NPA plates, that reflect this modern profile and allow for the vastly increased aircraft performance.
If the USA and Faa wish to maintain duck and drive then they can, however the rest of the world should have proper 3 degreeish stabilised plates and fly to them legally.
Many more folk will die due to confused pilots unable to cope in the time allowed or available in the situation that exists today.
How many loft exercises include a cancelled ILS on downwind vectors to real time vectors for a non familiar NPA to a different runway, and keep your speed up, and say your soles on board,change frequency etc...it does not not have to be made so difficult that only senior dedicated sky pilots can do them solo after 6 sim sessions of study.

[Chimbu chuckles]

Went to KTM again yesterday!

500'/nm not 400 as my feeble memory had suggested. 85kt crosswinds, ruducing to 55kts later in the approach, reducing to 8kts tailwind for landing. Held at 15000' for too long by busy ATC requiring very high rod to recapture profile! Approach completed safely because we knew exactly what altitude we had to be every 1nm down the approach, and because my 3000hr mate in the RHS kept feeding me good info all the way down.

It would be impossible to fly the KTM VOR/DME as a dive and drive because of too many steps too close together. It can't be flown as a 3x profile either because the steps are too steep. 1/2 the DME + Elevation works, but my preference is 500'/nm back from the MAP/MDA to the 11800' MSA.

As Greybeard said, charachter building stuff!

Chuck.

[411A]

....and that is what the aircraft Commander is paid the big bucks for...he has to have the skill AND the management ability for the exercise...and if he does not,...SOL.
The FAA has their collective ducks in a row when they insist that the Captain must be able to demonstrate proficiency. The crew MUST act as a team. Junior guys, with the proper training will certainly be OK.

[sabenapilot]

Not only the captain needs to have all the skills; in Europe (JAR-OPS) the co-pilot too needs to have a full type rating just like the captain! I have been told that in the USA this is not (always?) the case...

Besides, many companies require a NPA in IMC to be flown by the co-pilot (monitored by the captain), so I wouldn't count too much on the captain for this then.

[TechFly]

scanscanscan,
it was Jeppesen definition for VDP.

Cheers.

Fly safe & enjoy life.

[scanscanscan]

DGF.. Yes I know it is Jep, and that is exactly the point I was trying to make (badly).
The FAA and Jepperson know exactly how they want a NPA flown, and require it, Flown as Drawn.
The rest of the world has to hack this plate around to fit a FMC 3 degree profile into their computers, physical or mental.

I do not expect todays KTM plate has height v.v. every mile on it,and shows step downs, easy to draw,ok to fly in an Aztec/Apache, impossible to fly in fast modern equipment.

The responsible pilot above, has spent hours of study to figure how to do it in his small high performance machine and with his regular and experienced copilot they have well rehersed it. It is a great credit to him that he tells the truth that this approach and goaround very much concerns him.
Possibly like him, I also spent some time in the loo with the KTM plates and sids, as the accident record there was so chilling,and the profiles made my bottom go "Two and six and nine pence".
In their wisdom my company was to operate 767 and 340 into and out of KTM, and as a bonus, only at night.
I was never required to go there, however the service does operate and I am content to have missed the KTM call out when on a day off or standby.

[ 06 December 2001: Message edited by: scanscanscan ]

[Fokker-Jock]

Hi Guys,, interesting debate.

Here is how a NPA is flown in our company:

We use a concept of CANPA = Constant Angle Non Presicion Approach.

The way the approach is constructed is basically taken from the CAA own plates and prosedures as they comply with Pans-Ops.

The way it is done, is that from the Mapt a constant angle line is drawn from it and outwards towards your DP = Descend Point (Now going backwards. This line is designed to touch the point that has the highest ALT/DIST ratio therfore it will never go below any mandatory altitudes. This means that your descend point on a CANPA approach can be moved forward (Closer to the THR). The way it is flown is that on our approach plate there is calculated an altitude for every mile after the descend point. Our Company regulations states that if you are below 150 ft. on a non-mandatory altitude a missed appr. must be made. A tolerance of +150 / -0 is tolerated on an mandatory altitude. When you reach your MDA this altitude is to be regarded as a DP so if no contact is made then missed approach. (There is nothing other than company regulations in our company that prohibits you from flying level at MDA to your Mapt). On our plate there is also a speed vs ROD table given, so you just set that VS for the autopilot and tracks the radial or NDB whatever by using either HDG or NAV (Radial tracking APP). Crew Coordination is so that PNF=Pilot not flying calls applicable CANPA profile altitudes and the deviation for every mile. A hundered feet before MDA/DP PNF looks out and calls runway insight or if no call is made before MDA/DP the Missed.

It works fine as long as you can consentrate on your flying during this approach. Therefore it is a good rule of thumb to be fully configured and completed all checklists before DP. I mean an approach at 160 kts or more requires a ROD of app. 950 (933) ft/min on a 3,5 degree slope things happends fast if one pilot is flying and the other one reading ;)

2Daddies and others:

Seems to be a little confusion about the terms MDA DA DP Mapt DH.
According to design criteria for approaches used in Europe (Pans-Ops 4) also refered to as old Pans-Ops, not correct in my opinion as 1,2,3 are also old and even older :) )

MDA = Minimum Descend Altitude is the term for the Minimum altitude you are allowed to descend to on a Non-presicion Approach.

Mapt = Missed Approach Point is the point (Either a distance from a source or the time flown from passing a source NDB/VOR during the initial approach. This is usually also your FAP=Final Approach Fix) At which the Missed Approach segment of your approach starts and is therefore the point at which you would have to start your missed approach.
Mapt and MDA together constitutes a DP = Desicion Point. As the point at latest a desicion to either continue or abbandon the approach has to be made. These are the terms used for NPA's

DH = Desicion Heigh is the height above the ground from where you must have made a desicion to continue or go-around. This is also a DP as DH is used on a Presicion Approach thereby giving a three dimentional fix from where the missed approach segment starts. As DH is the minimum height at which an approach can continue down to it is also the point at which your DA is calculated (Field elevation + DH = DA) This height is minimum 200 ft on a CAT 1 approach and minimum 100 Cat 2 and so on down to CAT 3c minima of 0 ft.

DA = explained

Hope this clears up the confusion on the terms.

Happy landings!!

[quid]

Just to set the record straight-

I'm an Examiner for a major airline in the US. The Regulations here DO NOT require an engine-out non precision approach. I've never done an ATP or a type ride where I've asked for one, and doubt that I ever will.

[RatherBeFlying]

Question on the constant 3 degree descent slope to MAP in uneven terrain:

How do you set it up when the PAPI slope is significantly steeper as at ZRH?

Either
1: you get a steep descent from the FAF crossing altitude after flying level to the top of descent or
2: you increase your rod upon acquiring the PAPI and destabilize.

Missed approach in case 1: would require a DA significantly higher than the MDA because of the steeper descent path; also, a verification that climb would begin by the MAP where terrain clearance is tight.

No big problem either way in an Aztec with both engines; how about a 777? Perhaps certain NPAs should be restricted to suitable a/c types.

[Kingpilot]

Kujock- Are you using the actual CAA plates or are they Aerad? Does anyone know if Aerad are making any changes?

Scanscan- you may find that Jepp are starting to change their tune on this one. I have seen several Jepp plates now that, while they have the same profile view, also have a little table showing ideal altitudes/DMEs. This,if it is there, is along the bottom of the plan view. I think only approaches that do not have multiple level offs and DME fixes depicted on the profile have this. I think this shows that Jepp do not expect all the level offs to be flown as drawn. Any how, it is time Jepp Aerad etc got their acts together and cleared this one up.

Quid- Glad to hear that, I thought that was the case. Flying level at MDA in a big jet with an engine out is hard work. Doing the same thing in a light twin is impossibe! Most, if not all, will not maintain altitude on one engine with the gear down. In fact it was in light twins that I first came across this method, it was a company requirement to practice NPAs single engine with a constant ROD and GA immediately upon reaching MDA. It was impressed upon us that level flight at this point was not just difficult, it was suicidal!

[scanscanscan]

Quid.. Thank you for posting the FAA checkride requirements for our mate 411a,however 411a is right, as he (nearly) always is, that it does seem to leave his "younger!" pilots exposed and poorly placed, if it happens one day.
Then the pilot is unexamined on his ability and probably not trained either on the more demanding NPA with an engine out.
It could be that the FAA basically never want you to do a NPA with an engine out, emergency declared or not, as they still think in Aztec terms.
Maybe as they do not cover it, they would throw their book at you if you did one in your jet and lived.
Personally I think the reality is more old experienced heavy metal captains have actually crashed on NPA anyway and the FAA and the people who draw these killer approaches are light years behind the modern aircraft and constant descent methods.
Although legal,is this FAA stance and requirements wise in todays conditions.?
This engine out, NPA thing, I feel is where the simulator sessions would be of real value, if only to make one aware of their inabilities, on a duck and dive, before they attempt to kill themselves by overconfidence,...an aversion crm therapy session, for the old and younger guys!
Meanwhile in this untrained, unchecked situation,I feel it would be wise if all airports that accepted fare paying passengers were required to have a fully operational and checked, active in limits ILS runway and be "Required" to offer the same to the pilot, irregardless of residential noise considerations.
Incidentaly I also believe in Father Christmas, and that he lives in the underfloor galley of a L1011!
Cheers.

[Chimbu chuckles]

In both the previous airlines for whom I worked we did assy NPAs with a GA from the MDA in the sim.
I distinctly remember arriving at the MDA after a loft excercise where I had essentially lost almost everything. The Checky had decided to go beresk with the buttons :D
We had lost an engine, therefor half the hydraulics(F28)and had to do an alt extension + wind up the gear doors, then the flaps failed requiring alt extension also, then they jammed at 6 or 7 degrees requiring Vref recalc(+1kt for every degree of unavail flap).
It was my sector on the LOFT(F/O in those days) and the Capt was working like a dog, out of his seat to wind up the gear doors etc :D
We got to the MDA and were visual but no airport :( Night graphics by the way. Well I firewalled the trusty remaining Spey and we sorta looked left and right but we were on track so it should've been right in front! We were fast approaching the Mapt but what are you gonna do with the gear stuck down and the flaps jammed?
About this time we heard the checky muttering to himself about why couldn't he get the graphics to work, and that if we were not visual we should go around anyway.
My fearless leader turned in his seat and said "and where the F**K would you like us to go in the peice of crap you've left us to fly?" :D
The Checky (Fleet Captain in fact) hit the freeze button!
The Skipper whinged long and hard after about the stupidity of simulating multiple failures as a teaching tool.
My attitude was, and is, if you're in a sim why not? If the graphics had worked we'd have landed no probs! As long as it's used as a learning experience and not a fail item I see no problem with 'testing to distruction'.

Chuck.

PS While not ideal, as we have no sim, I do give my pilots assy NPAs on their 6 monthly prof checks in our Falcon. But it's MDA + a bit, quick glance and GO AROUND!!

[ 07 December 2001: Message edited by: Chimbu chuckles ]

[411A]

quid--
Pity the "younger guys" are not required to do these things (in the sim)...all of my type ratings (7) have required a NPA with an engine out, and two were circling...in the aeroplane.
The old way...much better IMHO. :D

[Chimbu chuckles]

I presume you're joking that the 'old way' in the actual aeroplane was better!

In the old days how did you practice an electrical failure/fire?

In the sim training I've done we had actual smoke in the cockpit, which required going to emergency power then working through the restoration procedures in real time. That was followed by a diversion back to Singapore and a 02L ILS down to 200 DA on linited panel! With the RHS pilot holding a torch on my instruments so I could see what I was doing as his HSI etc were still failed and I had no lighting! Some of it, his HSI malfunction, was a sim glitch, but we got it on the ground in one piece and recieved a round of applause from the Fleet Captain. As I brought the aircraft to a halt on the runway I realised my heart was racing and my knees were shaking. I had been so engrossed I'd actually forgotten it was 'just' a simulation!

And 411a, given your obvious disdain for us young blokes we were both F/Os doing initial F28 type ratings, both initial jet as well.

There is simply NO BETTER way of training than in a full motion simulator!

And you get to roll it afterwards :D

Chuck.

[ 07 December 2001: Message edited by: Chimbu chuckles ]

[quid]

411a-

Were any of those type ratings done in the USA?

I can't imagine any Examiner or Inspector trying to justify how he could bust you on a type ride if an engine-out NPA was the only manuever you screwed up. And....if it's not a bust maneuver, why subject you to it?

I try to make a pilot's type ride the easiest I can. No rushing (to meet MY wants), and no compounding to ridiculous extremes (which I've seen).

(I speak only to the US rules.)

[TechFly]

411a I understand you prefer the "old way" (either for training and pilot technique on NPA).

I respect your opinions and p. techniques but there are others way of training and managing NPA on big jets (in terms of profile, requirements for checkride, etc..).

A lot of people here is giving a lot of helpful information and I think this international debate is constructive for everybody!

Cheers.

Fly safe & enjoy life.

[411A]

Yes quid, nearly all were...
For example, my first heavy jet type ride (B707, circa 1974) ended with an NDB approach (engine out, idle thrust) which required a circle to land with the second engine failed (same side) on final...the FAA only wanted to know the new Vref and maintaining 25 flap for the landing, all went well...PanAmerican training was, IMHO, the BEST. If you did not cut the mustard, you were OUT.
I still think that the aircraft commander MUST have the skills for the procedures required....I wonder sometimes about the "new" guys.....
There is always the unexpected to bite you in the....ah, behind.
THAT is what the SIM is for....'tis called "train hard, fight easy".
:D

[vheijens]

Who doesn't know the easy rule of thumb?
(GS X 5) + 5 = ROD for 3° GP

It is that easy.
Ok, if your app. isn't a 3° GP, use your common sense. But please no diving!!!!!!

Try the stepdown procedure with a 747, you will have to give almost full t/l to level-off. And, oh yeh, think about the passengers to please.

[Helpful One]

I find it interesting that no-one appears to have mentioned noise-abatement.

Surely we have a moral responsibility NOT to "dive-... " and anything unless we want to attract even more noise complaints from local residents. Descending to MDH unnecessarily early on any approach could be fun, I suppose, but is it always sensible - regardless of the handling ability of the crew. A good handling test but not a sensible SOP.

How about flying level to MDH/MDA when you need to, but maintaining a nominal constant glidepath as a norm?

Before anyone asks - no Im not a tree-hugger.

[vheijens]

Noise abatement is a good one, HO.

If you descent at a constant ROD, there will be a minimum of noise. This is for the pax also.

Keep in mind the following advise (in this order) when flying non-precision app.s:
1. Safety
2. Pax comfort
3. Airline costs

If you comply with these rules you will fly the best non-precision app. ever.
:)

[greybeard]

Here I am again on this.

The "YOUNG GUYS" as described do not have and hopefully will never need the "skills" that were needed to do a DME arival/NDB track to the night minima at Paraburdoo in the dark followed by a 270 degree circling approach in a "black hole" to actually survive as no alternate was planned or needed under the "rules" as they were on the day.

We did it in DC3, F27 and F28 on a regular basis and even when the WX was CAVOK if we were not "current" we were encouraged to practice the proceedure so it was hopefully as close to second nature as we could make it.
The Crossair may be a CFIT or an iceing or a rollback or a stuffup or God knows what BUT it was a NPA when others were available and it may have caught out our fellow aviators.

Most airlines these days go from ILS to ILS and a NPA is usually a runway orientated approach which is ABSOLUTELY best flown on a constant slope. Training and PRACTICE are the only way to achieve the SAFE and CONSISTENT standards required for this "non standard proceedure".
Most Airlines make the high use of the flight directors in normal operations and these need more "programing" and UNDERSTANDING in NPA mode as the steps are usually required to be set by SOP's, V/S mode can intrude at "capture" of a step etc etc. This increased workload must be trained for and UNDERSTOOD by the crew, the trainers, the checkers and the Airlines SOP's.
The DIVE method does have its followers and may be appropriate in some places with low sector altitudes, MDA/MAP on your side of the airfield from arrival direction followed by a circling approach and needs to be TRAINED, PRACTICED and UNDERSTOOD.
Regretably most training these days is to the minimal cost for the required result and does not in my book provide what is needed in Airmanship, awareness or sadly common sense.
I have for my sins been and am again in the training seat and the lack of awareness of some is a concern in many areas, not only in the recruits, but much further up the food chain.
The system will reap what it sows.
Debates such as this will help to keep the "blue side up" so keep it coming.
:D

[Chimbu chuckles]

Hmmm I don't know if I qualify as 'a young guy' anymore 'cause I turn 40 tonight at midnight.....and not a second before. :(

But I still think like an 18 year old, some would say a 12 year old, especially my 12 year old daughter, kids these days have no respect :D

I suspect you're correct grey beard about the circling approach skills of the 20 somethings, particularly those who have rushed into, or started in the airlines. But I'm sure the kids who are out in the bush in Australia, Alaska, PNG or Africa in C402s, Twin Otters etc are getting their fair share, unfortunate isn't it that airlines don't seem to appreciate that sort of experience much these days.

I would think we're only a few years away from being asked by a young F/O, "Hey you would have been around in the days of NDBs?" and "How did they work, what was it like doing one of those in pi$$ing rain and low cloud?"

I'll go one better! In PNG we used to regularly do REAL DME homing and DME letdowns. Even in the F28s!! Done one of those down to 400' over the jungle 411a? We used to depart Port Moresby in a Bandit(single pilot) for Kiunga or Tububil and track the aids outbound till we were out of range, turn 'over' Kikori(whose NDB didn't work in the Gulf wet season)by using an NDB/DME 109nm away as a 'fix'(when it was working, otherwise just turn on time) then fly another 200 odd nm before picking up the Kiunga DME. We would bracket it, get overhead within 2nm(usually a lot less) and then carry out the letdown till we popped out the bottom over the Kiunga river in, more often than not, very poor vis and low cloud circle at 200' and land on the crushed gravel strip! Did we have fuel to divert to Daru, the nearest suitable alternate, not after leaving cruise we didn't! Now THAT'S Charachter building stuff.

At PX DME Homing and Let Downs were also common at Hoskins in it's wet season, followed by manouvres at 400 or 500 feet to position for a straight in over the water for landing, real 'white out stuff'.

When we did NDB approaches they were always flown at Flight Idle using a drift down method. We'd start overhead at 10000' and not spool up till the gear went down at 1500 AGL. When you know how much fuel a Spey uses down low you know why! If we had to circle, as we often did, it would be at 400 or 500' in tropical rain to a limiting runway.

I did a drift down NDB approach at Siem Rieb in Cambodia some months back, just for fun and to keep my currency. I briefed what I was going to do to the F/O who sat there watching in wonderment cause he'd never seen one before, the tower never had either judging by the number of queries we had about what altitude and where are you now :D

All great fun though :D A thing of beauty when done right!

But the 20 somethings will just say "Yeah yeah so what, we don't need to be able to do any of that" and they are fast approaching being right, but not yet!

Chuck.

[ 11 December 2001: Message edited by: Chimbu chuckles ]

[411A]

No Chuck, I have never circled at 400' over the jungle but have circled at 400' in the Libyan desert (oil company flights in F.27 acft, NDB approach) with the vis at 'round 1200 metres...great fun! And in heavy 4 engine jets at 600'/3200 metres.
The junior guys most likely will never know the feeling.
Just as well, as suspect that most do not have/are not trained with the skills, and therefore cannot keep current.

[vheijens]

Ok, I haven't flown a jet on an NDB app.(just some simwork, but this doesn't count) But I've flow a Beech Baron (seem speeds as a King Air) more than once to the bare mins., which resulted more than once in a goaroud (if I wasn't unable to pick up an ILS-signal).

If you practice NDB app.s in Europe, you will fly them regularly at the mins. And if you do so, you won't be surprised if you HAVE to do an NDB because the rest has failed.

And yes I'm in my 20's, and yes I know what an NDB app is. ;)

http://users.pandora.be/linda.basstanie/TopFly.gif

[greybeard]

Perhaps I should qualify my remarks as to the Young Ones.

Those who are out there in GA as I will call it have the skills as they use them all the time, as in PNG, Libia, Bamaga, Newman etc etc.

The more direct entry, Cadet course entry system is the one I now have to work with and the skills have not been attained by the majority of these people. No fault of theirs, just the system and the time and space to acquire these is difficult to attain as the system is geared to produce numbers in a given time.
When you end up in a very large Airliner with only 300/350 log book hours and then get 2 or maybe 3 PF sectors a month to an ILS and are more than encouraged to use the automatics, the ability to gather skills is limited. The ever increasing number of the Captains in many Airlines who have and in the future will come along this path is one for the bean counters to work with as the future is in their hands.
I will shortly be "Extinct" in the Industry I have enjoyed for more than 40 years, I wish it well, but I worry a little as to the custodians as times.
I think the roast is done, Fosters was nice and a merry Xmas to all.
:p

[doublechecker]

...about the missed approach: you can start your go-around procedure any time you like, however do not fly the missed approach procedure as far as TRACK goes until you have reached your missed approach point.
Greetings.

[Ignition Override]

Very interesting debates up there!

fms146 and 411A had unique comments about FOs flying approaches with procedures which Captains might not expect. Did the FOs brief such different methods beforehand?

What is the cost to install a VASI or PAPI approach light system by a US runway (whether served by airlines or not) which has no ILS available? Is our Congress planning to use the multi-billion dollar Airport Trust Fund for other priorities?

[ 15 December 2001: Message edited by: Ignition Override ]

[ 15 December 2001: Message edited by: Ignition Override ]

[ 15 December 2001: Message edited by: Ignition Override ]

[caulfield]

IMHO,any NPA with DME should be flown using constant rate.Without it,the dive-and drive is better.Aircraft type also enters into the debate.Latest generation Boeings give you the black-hole approach option which always works out nicely,given the luxury of GPS position updates.If you consider that pilots are notoriously susceptible to get-homeitis,the dive and drive is always worth considering even if a little messier.I dont know how many pilots I've seen scrub a npa because they didnt get down in time.Including myself...

[GlueBall]

A "dive" at Quito (El 9228) ILS Rwy 35 is necessary when visibility is at minimums (4 km) because the G/S would take you 2,723 feet beyond threshold on its short 10,236' pavement! D/H is 652 AGL. :rolleyes:

[2daddies]

What also must be borne in mind is the fact that there are both normal and maximum descent gradients predicated not only for precision approaches (eg - ILS @ 3 degrees) but also for NPAs.

In Australia these are as follows:
INITIAL Normal - 4%
SEGMENT Maximum - 8%

INTERMEDIATE Normal - Level
SEGMENT Maximum - 5%

FINAL Normal - 5.2%
SEGMENT Maximum - 6.5%

If you can contain any diving required within these criteria then you will remain within legal tolerances. If not then the approach MUST be aborted.

Case in point being the GPS NPA for RWY 23 at Dubbo, in New South Wales. At the FAF you may descend from 2500 feet to the minima of 1400 feet (1300 feet on Actual QNH). Problem is that at around a mile after the FAF there is a 1460 foot obstacle. In other words if you are so keen to drive it down and forget the maximum descent gradient then, even though you have passed a step which allows you to fly to the minima, you may very well kill yourself.

Constant descent is my preference but dive and drive does have a place WHEN USED CAREFULLY.

[scrubba]

2dads,

aren't you quoting the design criteria for the approach? on what basis do you reckon that translates in operational legality? what rule has been broken?

[partagas]

Am fairly open-minded on this topic, but would like to make a few observations.
Fistly, the perennial tendency to attempt to reinvent the wheel is apparent.Cf. the recent discussion on crab versus wingdown crosswind technique on this forum.I sense a number of the contributions are from relatively newly qualified pilots merely evangelising the doctrines freshly instilled by their training captains.I question the validity of many of the objections raised against the traditional technique.
(1) Many contributors state,(in a mildly dismissive vein) that the non-precision approach plates were promulgated to be flown by light twins such as Aztecs and Apaches.However this is surely not so.Many are drawn specifying different tracks for CAT A,B,C,D aircraft. These approaches were flown by Super Constellations, 707s and DC8s, significantly more demanding to handle than the 767 and A320 that I fly.

(2)Regarding unsafe rates of descent.The expression "dive and drive" is pilot vernacular.Excessive rates of descent are not advised,just as in X wind landings it is not suggested that one literally " KICKS off drift" .

(3)Regarding FPA approaches using the map display.These work very well nearly all the time because radio updating maintains a high degree of map accuracy.However this accuracy is diminished when updating is not available reducing the efficacy of this method to a corresponding degree.In everyday circumstances this may not prove disadvantageous,BUT, in the extreme situations referred to in the preceding posts,eg. engine failure with low fuel following diversion ,your absolute priority will be to attain sufficient visual reference to land off the approach.Another missed approach is not desirable in this scenario - and by the way take note of the accident statistics for go-arounds, even with all engines operating!

(4) Regarding the dangers of non-precision approaches "per se". Certainly they are more hazardous than precision approaches, but please show me convincing evidence that accidents resulted from the use of "dive and drive" instead of FPA. I am familiar with the circumstances of a number of NPA disasters, and the common factor was failing to adhere to the profile of the procedure as drawn on the approach plate not the technique used to manage the descent.Poor depiction on the plate , esp. on Jeppersens, has often been cited as having invited such errors.

[ 18 December 2001: Message edited by: partagas ]

[2daddies]

Scrubber,
Yes these are the design criteria for NPAs - just like the requirement to abort an approach if you fail to remain established inbound (+/- 5 degrees). They are not only a number surveyors and approach designers use to "build" an approach, they are also a legal limit.

Exceed the limit for any given descent and you are outside tolerances. Which equals missed approach.

It's not a difficult concept to grasp. :rolleyes:

[scrubba]

2dads,

i agree that it is not a difficult concept to grasp. defining the concept might be the problem.

despite your confidence, the design protected airspace for lateral tracking is not based on +/- 5 degrees at all, so they are not the same thing. but i know that aip says i can't descend below a step or whatever unless i am within that tolerance. so i know what that rule is.

my question was where is the aip reference that makes your quoted figures a rule? and don't procedure designers use a 1:7 rule to clear obstacles after stepdown fixes?

[Chimbu chuckles]

The PIA crash on the KTM VOR/DME was apparently caused by confusion on the part of the pilots about the steps.

Two Questions,

1/. What was a Captain doing on the flight if he had so little knowledge of the approach/ability to read an approach plate?

2/. Wouldn't a company published FPA or approved profile, i.e. 500'/nm from 11800', have avoided that confusion?

CFIT is like a taxiing accident, there is just NO excuse!

Chuck