81 votes

How miraculous was the miracle on the Hudson?

This would be an extremely difficult question to answer without being opinionated, but I'll give a try. As part of the investigation, the NTSB, along with other agencies carried out a number of tests ...
aeroalias's user avatar
  • 100k
63 votes
Accepted

Why not just drop an engine on fire?

The current position of regulators like the FAA is that dropping things off of airplanes in flight is a bad thing. Dropping extremely large and heavy things like engines would be extremely bad. This ...
fooot's user avatar
  • 73.2k
63 votes

What is a "runaway supercharger"?

The B-17 had General Electric exhaust-gas-driven turbochargers (or more correctly, turbo-superchargers) that had pilot selectable boost levels. A selector dial in the cockpit controlled the operation ...
John K's user avatar
  • 131k
59 votes

Scared of flying in an Airbus A220

Multiple airlines grounded their entire A220 fleet amid engine concerns Paradoxically, this should make you feel safer, not less safe. The A220 has had zero accidents. Grounding it is not a sign that ...
Chris's user avatar
  • 15.5k
51 votes
Accepted

Have there been any incidents caused by an inability to shut down an engine?

Qantas Flight 32 Enroute to Sydney, Engine Number 2 of the A380 disintegrated explosively. The shrapnel of the explosion destroyed many systems, including a hydraulic system, the anti-lock braking ...
Noah Krasser's user avatar
  • 8,992
40 votes
Accepted

What is a "runaway supercharger"?

The B-17 uses the term "Turbo Supercharger" which refers to just a Turbocharger (As John K points out in the comments, the former is actually the technically correct term). The B-17 had an ...
Dave's user avatar
  • 101k
39 votes
Accepted

Why do uncontained engine failures still occur?

One of the absolute requirements of an aircraft turbine engine (usually some sort of turbofan or turboprop) installation is that, in the event of a destructive failure of the engine, the engine ...
Jan Hudec's user avatar
  • 56.3k
38 votes

Do commercial flights continue with an engine out?

The image looks like four engines running at the same cruise thrust. The wake vortex is blowing the exhaust of the inboard engines down and the exhaust of the outboard engines out and in the ...
Jan Hudec's user avatar
  • 56.3k
35 votes

How miraculous was the miracle on the Hudson?

It's important to note that there were many elements of both skill and luck involved in the US Airways 1549 "miracle" landing - the NTSB report and NTSB deliberations make for an interesting day of ...
voretaq7's user avatar
  • 68.4k
32 votes

Why are all engines identical in typical commercial airplanes?

Engines don't fail, on average. And if they do, it's a very low probability that two engines will fail at the same time. Modern jet engines are extremely reliable, with failure rates on the order of ...
vidarlo's user avatar
  • 1,526
32 votes

Does a windmilling propeller create more drag than a stopped propeller in an engine out scenario?

I would not follow the advice in the forum. While the reasoning that a windmilling prop does create more drag is sound, I have seen no empirical evidence that says how much it actually translates to ...
GdD's user avatar
  • 53.9k
28 votes

Have there been any incidents caused by an inability to shut down an engine?

Cathay Pacific flight 780 on 13 Apr 2010 Fuel contaminated by super absorbent polymer jammed fuel valves caused engine control problems. The aircraft eventually landed with one engine at about 70% N1 ...
Jan Hudec's user avatar
  • 56.3k
27 votes
Accepted

Is turning off engines before landing "Normal"?

There's virtually no chance of the pilot deliberately switching off all 4 engines, and even less chance of all 4 engines failing at the same time. It's not entirely impossible for it to happen, but it ...
Jon Story's user avatar
  • 10.4k
27 votes
Accepted

Is there any legitimate reason for adding momentary power when descending at idle with full carburettor heat on?

straight out of the Airplane Flying Handbook, pp 9-4 Operating the engine at idle speed for any prolonged period during the glide may result in excessive engine cooling, spark plug fouling, ...
Romeo_4808N's user avatar
  • 73.7k
27 votes

Could an airliner with only one functioning engine recover from a stall?

Yes, but the challenge is managing the asymmetric thrust effects when applying power during the stall recovery. Pilots are trained in the sim for two stall (actually, just stick shaker onset) ...
John K's user avatar
  • 131k
26 votes
Accepted

What is the minimum altitude needed to return to the takeoff airport in a 737 after dual engine failure?

Most modern airliners have L/Ds of 18 to 22:1 (sorry I couldn't find a direct reference). So from one nautical mile, 6076 ft, in the air you can glide around 18 to 22 nm in still air. Departure climb ...
John K's user avatar
  • 131k
25 votes
Accepted

Are jet engines designed in a way to make an explosion result in the least damage possible?

The most (kinetic) energy is in the fan and turbine blades and disc. The engine is enclosed in a containment chamber whose purpose it is to protect the rest of the airplane from shrapnel in case of a ...
Jörg W Mittag's user avatar
24 votes
Accepted

Why are all engines identical in typical commercial airplanes?

In IT more hardware is redundancy, but in aviation a liability Short answer In IT, having redundancy and diversity is low cost and no liability, but high gains in service reliability. In aviation, ...
MichaelK's user avatar
  • 2,377
23 votes

Could an airliner with only one functioning engine recover from a stall?

A stall recovery doesn't require engines (although they help, especially if altitude is an issue). To recover from a stall, you need to lower the angle of attack. You can do this by lowering the nose ...
Ron Beyer's user avatar
  • 36.2k
22 votes
Accepted

How fast does cabin air pressure leak after a total engine failure?

The valves will not be able to maintain cabin pressure until the plane descends to 10,000 feet at best glide speed. The oxygen masks will deploy before then. At least that was the case for Air ...
Christian Lee's user avatar
22 votes

Why are all engines identical in typical commercial airplanes?

Maintenance costs are a big deal. Maintenance costs across multiple engine types for a fleet of the same airplane would be a big deal - training, parts, etc. Worldwide weather tracking & ...
CrossRoads's user avatar
  • 8,795
22 votes
Accepted

In an engine failure, should I expect less range than with the engine in idle?

Yes to some degree. It depends on the idle rpm, prop pitch, engine compression and your gliding speed, but if the engine is off but windmilling, there is substantial drag from the energy needed to ...
John K's user avatar
  • 131k
21 votes
Accepted

What could cause both engines on a 737-200 to fail at nearly the same time?

Generally, without knowing the details of this accident, dual engine failures are typically caused by one of the following: fuel events exhaustion starvation (e.g. due to iced fuel filters) ...
DeltaLima's user avatar
  • 83.4k
21 votes

What is the minimum altitude needed to return to the takeoff airport in a 737 after dual engine failure?

First, the actual "impossible turn possible" altitude number is going to vary dramatically by factors such as hot, high, heavy, wind, how wind interacts with your departure path, and ...
Harper - Reinstate Monica's user avatar
21 votes

Scared of flying in an Airbus A220

How will you be getting to the airport? Flying in an airliner with a relatively poor safety record is still orders of magnitude safer than traveling by car, for example. – Frog Driving in a car – ...
FreeMan's user avatar
  • 16.2k
20 votes

Why not just drop an engine on fire?

The fact that the modern aircraft could fly with one engine out does not mean that the offending engine should be dropped. It is better to have it in the aircraft rather than risk the engine taking ...
aeroalias's user avatar
  • 100k
20 votes

Could an airliner with only one functioning engine recover from a stall?

With enough height, any aircraft can recover from a stall without any engine power required. In fact, for under-wing engined aircraft like the 787, it is sometimes necessary to reduce the thrust, ...
Ben's user avatar
  • 14.3k
19 votes

In which direction should a turn-back be made after an engine failure on a multi engined airplane after take off?

That depends on a lot of factors. Are you declaring an emergency? What altitude are you at what speed are you at when this happens etc? What kind of aircraft are you flying? Does it have enough ...
Romeo_4808N's user avatar
  • 73.7k
19 votes

Have there been any incidents caused by an inability to shut down an engine?

Etihad Airbus A340-600 This famous crash happened on the acceptance engine run-up test. The causes were unrelated to engine problems, but after the crash, due to damages, two engines couldn't be shut ...
Zeus's user avatar
  • 9,063

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