Single engine ferry on a large twin? Good luck getting that one approved! "Just feed the power in gently on the other one during the take-off roll" :-)

If you have an engine failure on a 777 post V1 the rudder can compensate for the asymmetric thrust.

I'm only SLF, but have been on one where it happened - and whilst it was obvious the engine was in trouble there was no perceptible yaw.

Below V1 it must be OK or an engine failure would result in you going off the runway.

Back in May 1996, a Virgin B747 LHR-LAX diverted to YFB for a medical. First 747 to land there. Whilst taxiing off the runway, one of the outboard engines clipped a structure. The plane needed to be repaired. They must have moved the building because A380 cold weather testing was done at YFB.

SLF3

I assume by "it" you mean being able to control the yaw/swing, control flight path etc with the good engine still producing lots of thrust whilst below V1??.

Apologies if I'm teaching you to suck eggs and apologies to the purists but simple answer follows .

It's assumed in Boeing, Airbus et.al. procedures that if you have an engine failure below V1 you'll immediately select idle on the (other) good engine PDQ, you don't leave it running at take-off power - because (and there are other reasons) you've got to get rid of the high level of asymmetric thrust - if that is sustained you may well indeed go off the runway....

The reason for this is that below a certain speed ( known as Vmcg, which varies but can be well over 100 knots on the likes of a 777) the rudder hasn't got enough airflow over it to be fully effective in countering the yaw produced by a single engine still running at take-off power.

Replace "can" by "at high speed, above Vmcg". Below Vmcg the rudder won't be able to compensate anything like enough, certainly in the event of an engine failure at low speed with high asymmetric thrust..( the low speed rudder effectiveness problem again). On a triple and probably all big twins if you set take off power on one engine at say, 30-40 knots, you are going to go off the side, even with full opposite rudder applied .....

This is why people here are commenting that in the event of you (madly) attempting a single engine ferry on a twin you'd need to feed in the (asymmetric) power slowly and wait until the speed has built up, quite possibly to well over 100 knots,, before applying takeoff power.

Very well explained wiggy , I would add it is same with old single propeller aircraft with very high power engines( say above 1000 HP) you have to apply power very slowly to get above a certain speed where you have enough aerodynamic rudder control to be able to apply take off power to counter the torque. Basic aerodynamics.

It might just be worth reminding ourselves that there has been absolutely no official announcement that even hints at a single-engined ferry scenario.

But don't let that stand in the way of a good story. :O

I can add to Uplinker's comments about taking off with 3 engines, having done so in the 146 for real, not just in the sim.

From memory, the engine opposite the dead engine is initially set to a low setting, having pre-determined and marked the appropriate higher setting on the thrust lever housing. At a given airspeed, the thrust is increased to this pre-determined setting, progressively. Even with inboard engines involved, and significantly de-rated thrust on the asymmetric engine, the swing is significant, and requires careful handling.

As for some believing that a single engine take-off is approved, sensible, or even survivable seems incredible.

Perhaps there is a special, previously unknown friction phenomena afforded by special snow on this runway that magically helps the nosewheel to maintain perfect tracking below Vmcg, against the enormous moment caused by the asymmetric thrust, where mere tarmac just can't cut it. Just sayin!

UplinkerIn the DC-10 & MD-11, i believe an engine-out ferry w/ #2 inop could present a related problem: Rapid power up on #1 & #3 might create enough nose-up moment to diminish or lose nosewheel steering effectiveness.

It's a case of the thrust line being well below the center of mass.

This is possibly the most ridiculous thread that I have ever read on pprune. The very idea of getting a crew together to attempt to fly a 1-engine ferry flight in a B777 is just so beyond the bounds of utter bol*lox that I cannot believe what I am reading.

I have carried out several 3-engine ferry take-offs on 4-engine aircraft and one 2-engine ferry take-off on a 3-engine aircraft.

No pilot on this planet would ever consider a 1-engine take-off on a 2-engine aircraft.

totally agree JW, pure and utter tosh being spouted about a s/e ferry. The aircraft gets repaired with two serviceable powerplants.....end of. I don't envy the engineering task ahead but nothing is impossible. Boeing/GE are just as keen as Swiss to see the aircraft airbourne asap.

TBF I don't think any pros have suggested a one engine ferry, most of the later posts have been aimed at telling the non-pros why it's not a good idea.

https://skyvector.com/airport/CYFB/Iqaluit-Airport
Seems like a nice place to visit if you have just lost an engine. New terminal and friendly folks.
I find the comments, or even the thought, of a single engine take off most amusing. Why would you want to even want to attempt it?

Wouldn't something like this work in lieu of a heated hanger?

http://www.aviation.com/wp-content/u...o_grey_sky.jpg

http://www.aviation.com/commercial/airbus-inflatable-tents-jet-engines/

SB, I'd expect they'll do something exactly like that. Given as often as a 777 lands there, I wouldn't expect them to build a hangar just for this one.

Based on the pix from the onsite report (:ok:), it'd be the largest building in town! :)

Not so I'm afraid. Granted, not a 777 but a twin jet nonetheless:

https://aviation-safety.net/database...?id=19980319-1

PROBABLE CAUSE: "The pilot-in-command's decision to attempt takeoff with the right engine inoperative, resulting in his failure to maintain directional control or attain adequate airspeed during the takeoff attempt. Factors included a fractured right engine starter-generator drive shaft, resulting in an inability to perform a normal engine start on the ground."

World Airways had just such an incident in Anchorage few years back doing a ferry with # 2 engine inop. Although they followed Boeing procedures, ( which called for setting takeoff thrust on 1/3 before brake release) the center gear had been retracted changing the cg, so the aircraft immediately did a wheelie and tail strike.

Copied from AVHerald:

"A passenger reported there had been no unusual sounds or vibrations before the captain announced that an engine had failed and they were diverting to Iqaluit. During talks with the cockpit while waiting for the relief flight the captain indicated the crew was puzzled too that the engine just ran down without any unusual indication, sounds or vibrations. On the ground in Iqaluit the aircraft initially could not turn around on the runway, a tow tug subsequently pushed the aircraft back onto the apron about 45 minutes after landing. The passengers were kept on board and were served dinner, customs in Iqaluit is geared to handle international flights with up to 15 passengers only and it didn't make a lot of sense of taking 217 people through immigration, which certainly would take several hours. In the meantime all school busses of Iqaluit were dispatched to the airport to transfer the passengers from the Boeing 777 to the relief A333. While mechanics arriving with the A333 started to check out the engine of the Boeing 777, the cargo was first moved from the B773 to the A333. As there was only one stair available, that could handle the Boeing 777 or A330, the passengers then needed to first disembark and enter the busses, the stairs were then repositioned to the A330, the passengers subsequently embarked the A333 including the entire Boeing 777 crew, who positioned to New York, too. After arrival in New York the passengers were rebooked onto direct flights to their ultimate destinations.

The engine needs to be replaced, the occurrence aircraft is estimated to remain on the ground in Iqaluit for at least 5 days. A replacement engine is being flown in. First information suggests a magnetic chip detector registered metallic particles in the engine oil."

Seem to be the locals put some skills to work and all well done...
There's always a first time.

Short bus : the problem with this particular model is this "
it is only able to withstand a wind speed of 30 knots (34 mph). This means that the tent would be inoperable in even a weak tropical storm, and would have to be reserved for the sorts of extreme weather that don’t involve high winds.

Metar this morning in Iqaluit is G25 Kts But I am sure they are stronger models existing.

GuadaMB: The locals are very hospitable, flexible and very inventive when you are in any kind trouble. You have to if you live there.
Yes there is a first time in everything , but this also proves that the system works quite well.

Somehow I just can not reconcile the paradoxical logic (presumably based on in-depth risk analysis) that says it is safe to operate a twin engine aircraft for up to 3 hours on one engine (ETOPS 180) but then says, in the case of an engine failure you had better land at the first suitable airport, at peril of losing your profession, if you elect to fly a little further to a "more suitable" location ..... ie support services, etc.
The inference, for me, is that the argument for ETOPS is not really as well founded as it should be.


And I guess we'll just have to sit and wait to find out what really caused the engine to shut down.
I guess also that incipient failure of a gearbox could start to shed metal and would be picked up by the chip detectors.
tdtracer - is there any level of engine protection on the engine itself? That is, at a level below the FADEC controller(s)?

Would any aircraft engineers like to comment about the challenges of a non hangar engine change in extreme conditions?

Aircraft engineers often have to work in miserable weather conditions out on the ramp: Is this sort of engine change seen as great fun and a challenge to be enjoyed, or an even more miserable than normal challenge?