Sunday, February 26, 2012

If a plane loses power to 2 engines on a 4 engine aircraft, what needs to be done to keep flying?

Specifically, I'm asking what would happen if two engines on one wing died suddenly, but the other two engines on the other wing were okay. My cousin and I are betting $20 on whether or not the plane can be controlled and flown, or at least glided, to safety. And I'm just curious about what a pilot would do in that situation. The more details the better!If a plane loses power to 2 engines on a 4 engine aircraft, what needs to be done to keep flying?immediate descent to a lower altitude where the air is thicker (better lift), a ton of yaw with the rudder pedal, an easy way to descend in that situation would be to perform a "side slip"If a plane loses power to 2 engines on a 4 engine aircraft, what needs to be done to keep flying?
At cruising altitude, it would be a major event, but it should definitely result in a normal landing. This assumes, of course, that there is no other damage or other failures. For example, if one or more of the engines had an uncontained failure, parts of the engine could sever hydraulic and electrical lines making the picture much worse.



The pilots would point the plane at the nearest airport and execute a controlled and gradual descent. Once they are low enough to attempt a restart, they likely would attempt one unless it was clear that a restart was impossible. They would have to maintain a high enough speed to ensure enough rudder authority to keep the plane straight as the asymmetric thrust would try to turn the plane pretty severely. If necessary, the inboard engine could be kept at a higher power level than the outboard engine.



There is no reason a basically normal landing shouldn't be possible, though with a higher approach speed used. Use of thrust reversers on landing would probably not be advisable. A long, dry runway would be nice. Fortunately, assuming on other problems, they could fly as far as they needed to select a suitable airport.If a plane loses power to 2 engines on a 4 engine aircraft, what needs to be done to keep flying?A 4 engined jet, i.e A340 / 747 can still fly perfectly, even with 2 engines but it will yaw, which means it will turn to the side with less thrust (side with dead engine), but this can be compensated using the rudder, or vertical tail.

An airliner can glide to a suitable landing strip and make a safe landing. One engine always needs to be on to supply power to the instruments and controls, but in an emergency, the ram air turbine can kick in. The ram air turbine is a small propeller that generates limited electrical power for the instruments %26amp; flight controls that would make a emergency landing possible



A good example would be EL AL flight 1862, where 2 engines fell off the right wing, which damaged the leading edge. It would've landed safely if the engines didn't fall off. The main cause of the crash is the damage to the leading edge of the wing which disrupted the airflow and reduced lift.If a plane loses power to 2 engines on a 4 engine aircraft, what needs to be done to keep flying?
If it is in cruise flight at altitude, the airplane will descend to an altitude where the engines produce enough thrust to fly. It will remain controllable.



When I was flying the BAe-146, we'd do 2 engine approaches in the simulator for proficiency... no walk in the park, but it was manageable.If a plane loses power to 2 engines on a 4 engine aircraft, what needs to be done to keep flying?if they are within a safe distance then they could glide to a landing at an airport.

however if they are not then if they lower the thrust on the engines as well as turning both rudders in the opposite direction they could force a forward flight. turning in the direction of the two working engines would probably be really tricky ;P
The "plane geek" got it all wrong about Air Transat -

The causes, the technical explanations, the location etc.

A geek or a nerd - I do not know -If a plane loses power to 2 engines on a 4 engine aircraft, what needs to be done to keep flying?
Yes, it can. It would yaw like crazy to start with, but quick rudder application would cure that. The pilot would declare an emergency and land at the nearest suitable airport.
i would say the pilot would land it.If a plane loses power to 2 engines on a 4 engine aircraft, what needs to be done to keep flying?
A four-engine aircraft can typically fly on just two engines. It requires skill on the part of the pilot, who must know how to react quickly and correctly when the failures occur, but it's still possible to fly and land the airplane.



The loss of performance will typically require that the aircraft descend to a lower altitude (true of just about any engine failure). The pilot must correct for the very strong tendency of the aircraft to swing to one side (the side with the dead engines) when all the thrust is coming from one side of the airplane. But the airplane will continue to fly safely. Gliding isn't necessary unless all engines fail (and airplanes can glide to a landing safely, too).



In the case of jet engines, a double failure due to independent mechanical failures is essentially unknown, because of the very high reliability of jet engines. Multiple failures only occur if there's some sort of common cause, such as fuel exhaustion, multiple bird strikes, volcanic ash, etc. (and all of these have happened in real life on some occasions).



As far as more vs. fewer engines is concerned, the greater the number of engines, the higher the likelihood that at least one will fail. However, even though the chances of one failure go up, the chances of all power being lost decrease dramatically, and as long as the airplane can fly with one or more engines inoperative, multiple engines are safer.



Suppose you have an engine that has a chance of failure of one in 100,000. If you have a single-engine plane, your chance of having at least one engine failure is also 1 in 100,000, and so is your chance of having a total engine failure (since you have only the one engine). On the other hand, if you have a twin-engine airplane, the chance of at least one failure is slightly less than 1 in 50,000, but your chance of losing all engines drops to 1 in 10,000,000,000! So you are way better off with two engines, provided that the airplane can fly on just one engine (if it can't, then having two engines is actually worse).



As far as I know, there have never been any accidents in multiple-engine jet airliners that were due to independent mechanical failures of multiple engines. It just doesn't happen. In the olden days of multiple piston engines, though, it did indeed happen, since even the best piston engines are way less reliable than jet engines鈥攚hich is one reason why jets are so common today in commercial transport aircraft.
Well whoever bet that "nothing" would happen - would win the bet. Sure, there would be an adjustment made by the pilot so that the plane would fly striaght and steady. However, a passenger probably wouldn't notice other then one side of the airplane didn't have any engine noise. In today's commercial aircraft, the engines are so power (and reliable) that most planes, even the one's with 4 engines, could fly on one engine.



Another thing that would happen is that the aircraft speed would decrease - there woullod be a decline in total engine power. Your question of "can commercial aircraft glide" - the answer is that is YES. As a matter of fact there is a well documented flight in which a Canadian Airline - Air Transat flying from Toronto to Lisbon ran out of gas over the Atlantic. It was "pilot error", the pilot emptied the tanks when he was transferring fuel from one tank in the wing to another - the aircraft an Airbus 330 is a twin engine - shut down. Since today's airplanes are reliant on computers and electronics that many of the electronic systems are "linked" to the engines - so when the engines went out, many of the important systems went down. Airbus installs an emergency system in which a tiny propeller drops from the bottom of the airplane and the prop generates enough electricity to run some of the basic, but important, electronic systems. I just thought that was the neatest thing - talk about thinking ahead by the engineers. Luckily, the plane had enough altitude and was able to "glide" to the Canary Island and no one died. So there is some "fact" that you can tell your cousin or "hide from your cousin".



It's funny you asked this question. I'm a "plane geek" and a very good friend of mine had thought the same thing about if "one engine went out of a two engine plane, you couldn't fly." I kept telling him "Dude, you always want to have 2 engines instead of 1 - the more engines, the better." I don't know why he didn't believe me, especially since it was "plane oriented" but I kept telling him. Sure enough the guy dating his sister was a pilot and flew my friend and himself from DC to Atlantic City. He had asked the question to the pilot and the pilot said the same thing as I told him. You want as many engines as you can on a plane and you can fly on only 1.

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