View Full Version : Gliding Large Aircraft

26th Feb 2009, 08:51
In the past 14 months, there have been three well-documented crash landings by large aircraft flying on reduced or nil power. One was amazingly successful and it is probably no coincidence that "Sully" is also a sailplane pilot.

Briefly the background to my own career. 40 years as a professional. Began flying in RAF becoming QFI including "instructing instructors" at Central Flying School, and later a C130 Hercules conversion instructor. Then in civil life, IRE/TRE/Line Training Captain at various stages. Moreover, 50 years as a glider pilot with 3 diamonds.

Now glider pilots know that it is essential to "fly the energy" and that "stretching the glide" is not usually a recipe for success. If a landing away from an airfield - and field landings are part and parcel of the sailplane pilot's flying - it has to be planned carefully and it is vital to land the glider under control rather than "flop" on to the ground in a semi-stalled position.

In the old days of Spitfires, Hurricanes, Hunters, pilots regularly practiced "dead-stick" landings and when it was needed for real, the success rate was often high. When instructing on the Varsity (a largish twin piston) I used to entertain my squadron commander during routine continuation training. The boss would throttle back both engines at say 8,000 feet and enjoy seeing me glide the beast back to the airfield. So it can be done. (Pete Sawyer -are reading this?) But this was not a routine training exercise.

In the airline world, there was NEVER any dead-stick landing training. Aircraft WILL glide well. For example, during standard power-off descent from altitude 2 to 3 miles per thousand feet are achieved. But of course, we can't train for power-off descents right down to the ground except in the simulator.

Recent events have not always given pilots time to do things as "per sailplane" and the scenario has developed very quickly. However, I really think that there is a case for some investigation into simulator glide training. There are plenty of airline pilots who are also competent sailplane pilots. These would be the people to look into what is and what is not possible and perhaps devise some training regimes.

Jack Harrison

Old Smokey
26th Feb 2009, 09:19
In the airline world, there was NEVER any dead-stick landing training.

Come and sit in on one of my simulator conversion sessions.:ok:


Old Smokey

Black Stain
26th Feb 2009, 09:22
Hi Jack,

Dont know of an airline that formally includes glide approaches to touchdown in the training syllabus. But most pilots get to have a go during spare training time at recurrrent SIM sessions. I have done it three or four times now, and like you say it's an excellent training exercise. The A320 is a beautiful glider and the SIM sideslips very nicely.

I would like to see a SIM with visuals suitable for practice ditching at sea with significant swell and wind. This would be a very challenging exercise.

And wouldn't it be nice if Airbus would hot-wire the left landing light to the batteries so that if someone does ditch at sea at night with nothing but the RAT for emergency electrical power he might have a chance in hell of pulling it off. In this situation the radar altimeters are lost, at best we would have area QNH, and the only external light is the crew torch through the window. Airbus should revisit the design.


26th Feb 2009, 09:45
Could not agree more. In 25 years of flying twin engined jets for various UK companies, I can only remember one sim session that seriously covered this situation - coincidentally shortly after the Azores A340 incident.
Nothing was ever covered in the manuals but a few 'unofficial' bits of paper used to circulate with, sometimes conflicting, advice.
I believe the manufacturers have a part to play as well - rather than assuming that a double engine failure will always be resolved with a successful relight!
For most pilots, who are not glider pilots and whose light aircraft training might be in the distant past, finding oneself with no power will be a big psychological shock. I suspect this is where the glider pilot is at a big advantage since he is not in such unfamiliar territory. Simulator training (and not just once or twice) will help redress this balance as well as giving practical experience.
Some incidents, like the 777 at LHR and perhaps this latest one at AMS occur at low altitude, giving very little time. Others, such as the Hudson River, allow planning time and, depending on aircraft type, at least some reconfiguration. Type training should include in-depth discussion of this scenario and of the effects on speed and glide angle of gear and flaps (if available). CRM has a huge part to play in a successful outcome of course.
The engine out scenario needs revisiting regularly. It does happen and both airlines and and manufacturers need to come out of denial.

26th Feb 2009, 09:49
We actually covered that in our 3 year recurrent cycle and often did it in the spare time at the end of a session as well. It is fun and great training. And yes, my old glider flying instincts actually helped there.

Tee Emm
26th Feb 2009, 13:22
The boss would throttle back both engines at say 8,000 feet and enjoy seeing me glide the beast back to the airfield

In view of knowledge gained in later years on the subject of cylinder shock cooling, an extended throttled back glide with radial engines would not have been conducive to good airmanship in terms of engine handling.
Of course that is being wise after the event. At Butterworth in Malaya in the Fifties, the resident RAAF Dakota had an alarming number of engine failures over a three month period. The fault was traced to the squadron QFI who would rapidly close one throttle after take off to simulate an engine failure and leave the throttle at idle instead of zero thrust. He was tasked with conducting recurrent training on squadron crews and this included simulated engine failures by the dozen. It was this abuse of the engines that eventually led to real engine failures.

26th Feb 2009, 14:27
Over the years I have done it or watched it in BAC 1-11, DC-10, and A320 simulators - the last as part of the conversion syllabus in a forward-thinking airline. It is not part of the Airbus type rating course... perhaps it should be!

Floppy Link
26th Feb 2009, 14:53
Did it regularly in 7 years of sim sessions on 757/767, it helped to aim for staggered runways like MAN for some wriggle room:}

26th Feb 2009, 15:40
We did periodically warm the engines on the way down in the Varsity, but my original posting was long enough as it was without going in to such nitty-gritty details.


26th Feb 2009, 15:55
Over the years I have done it or watched it in BAC 1-11, DC-10, and A320 simulators - the last as part of the conversion syllabus in a forward-thinking airline. It is not part of the Airbus type rating course... perhaps it should be!

Sounds like BCAL

underread east
26th Feb 2009, 16:15
All Eng Inop included in type conversion and in recurrent training TWICE in last 6 years. And I think I am right in saying that our lot (B757/767) include this tri-annually.

26th Feb 2009, 16:44
Can't recall now (retired over ten years ago) but I think we might have done all-engines out (BAe146) as a sim drill but only for the purposes of practicing multiple relights. Certainly, I never remember doing all-engine out right down to the ground with one minor exception. The instructors used to like to play sometimes at the end of the session and leave you with just one outboard engine working. The 146 was virtually impossible to fly on one and I certainly would finish up doing the last 100 feet or so with the "good" engine throttled right back as it was much easier to keep lined up that way.

26th Feb 2009, 16:56
I did 'no power' flight in my last sim. (RJ100)

Made a mess of the first one but did a nice landing off the second.

Personally I thought it quite useful. I really had little idea of how far it would go from a given height and was quite surprised at how well it did.

I hope to never use the info for real, but it was only 10 mins in the sim and it probably trebled my chances of a good outcome should I ever run the sucker out of gas! ;).

(heaven forbid :ok:)

26th Feb 2009, 17:27
Did so many engine out landings that guys have stopped doing them out of boredom.

Having a lots of energy is easy. It's much tougher when you might have just enough energy. Then you have to know your glide speeds and basic gliding/airmanship skills(ground effect can be your friend).

Paradise Lost
26th Feb 2009, 19:08
Points well made....seems strange that chopper chaps practice autorotating frequently even when twin or triple engined. On most aircaft, I believe the optimum glide speed is the same as the holding speed at that weight.

26th Feb 2009, 19:20
"On most aircraft, I believe the optimum glide speed is the same as the holding speed at that weight."

Not totally wrong but we need to consider best glide angle and minimum rate of descent - not the same thing. Glider pilots know all about this. As a rule of thumb, holding speed +10% wouldn't be a bad speed for glide (clean - no flaps of course).


26th Feb 2009, 19:43
The problem I see with practicing engine-out glides is that I'm not sure the sim can simulate TOTAL loss of power. A glide in a jet-powered transport from altitude with the engines at Idle Thrust has to be different than an glide with ZERO trust.

Pugilistic Animus
26th Feb 2009, 20:06
DC-ATE only a marginal difference, but that slight glide path shift wont destroy the laerning value of the exercise--- the real importance are glide line position, ROD and AS control as well as execution of common sense--I not trying to be condescending,... I know you know this all, but you asked:)

Old Smokey
Come and sit in on one of my simulator conversion sessionsCould I take you up on that one day; I could use the practice? :}


26th Feb 2009, 20:13
Do you really mean minimum descent rate, or best L-D which gives the greatest glide distance? The two are different. Min Desc (aka min sink) gives the longest time in the air but unless the polar is a rather strange shape, not the longest glide path. The speed for the two is different - min sink is slower.

26th Feb 2009, 20:35
Well, I doubt my former employer would let me back in the door, but it would be interesting to try gliding to touchdown in "my" old DC-8. I think I'd like to be out in the prairie land though!

Loose rivets
27th Feb 2009, 05:27
We used to go to Stansted in an Eagle Viscount, and our fleet manager would get us to fly at 1500' until the runway was under the nose, then taps shut and land off it. The thing is that the although the Dart didn't like to have reverse torque, it wasn't known then, so what we got was something near to no power.

He was/is a good bloke. Gave us 900 hour rookies a feel for the machine that served well.

27th Feb 2009, 07:19
"......our fleet manager would get us to fly at 1500' until the runway was under the nose, then taps shut and land off it."

My bet is that he was an ex-Varsity instructor. That was a standard "fun" demonstration in the Air Force. But not quite what I meant at the start of this thread when what I was really talking about is sailplane-style management of energy.


28th Feb 2009, 21:48
.....not to mention stick/rudder co-ordination!

28th Feb 2009, 21:57
I did 'no power' flight in my last sim. (RJ100)

Isn't that SOP for an RJ?

Pugilistic Animus
3rd Mar 2009, 21:45
I did 'no power' flight in my last sim. (RJ100) don't fear!!! I believe the A340 derives forward motion and cruise speed using the component of the weight along the flight path with minor assistance from four Garrets:}:}:}


mr. small fry
4th Mar 2009, 00:13
As one now engaged in the corpoate world, we do from time to time get the chance to practice glide approaches when joining overhead for visual approaches by setting a target of 1000 ft at 3 miles. With practice it is surprising how accurate one can get at hitting the target before stabilizing for a normal approach.

It seems to me that excepting the standby gyro, the angle of attack indicator is the least used piece of kit in our tool box nowadays - despite being the main one that we need to rely on when (God forbid) it all goes quiet.

During more mundane flights and training sessions I've witnessed crews searching manuals for holding speeds, drift down speeds, best glide speeds, ref speeds, best rate speeds, best angle speeds, and even whether they can climb a further 2000 feet at any given weight. :ugh:

Do they no longer teach what the numbes on this dial actually mean, and how they may be used to provide instant and accurate answers to all of the above? I guess not..

4th Mar 2009, 00:43
Lore has it that Bob Pearson made a good guess at the best-glide-speed of a 767-200--the Gimli Glider--and came up with 220 knots IAS. I don't know if he looked it up or not, but the legend is that it was "because he was a glider pilot."

Why, forgodsakes, do they always call sailplane pilots "glider pilots"? Gliders go down. Sailplanes go up.

4th Mar 2009, 00:52
I have never understood why An AOA guage with indexes at useful points such as best glide / min drag is not required and installed as standard in all aircraft.

The only transport aircraft I have seen with this installed was on a Delta 767.

Perhaps it is no coincidence that Dal has a large number of ex Navy Pilots.

4th Mar 2009, 09:05
I had training in glide approaches in the A320 Sim, as well as the CRJ, using a simple "double altitude for distance" formula on both models. You can actually get the FD to capture the LOC, while handflying the descent. Works well.

In my 7 years on the A340 we never did this, but as it only flies by a little device called the "Improbability drive", one doesn't need it anyways.


PS: There is no actual guage, but a digital way to get the read-out of the AOA-probes on the CRJ. I have been watching the numbers, but as flightschool is so long gone and I never learned how to fly on the AOAs, I would be happy if any of you guys could give me some explanation or point me to some reading to enable me to put those digits to sensible use...

mr. small fry
6th Mar 2009, 18:35
Admiral, I spent 30 mins typing out a reply that may help you with AOA's for just about every eventuality in your FM, then lost the connection as I pressed to post.

PM me and I'll gladly do it again for you - but not tonight!

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