What would happen to a 777 if the pilot flew it up and up and up?

[Avalux]

I'm wondering....

I've now heard that the transponders were turned off manually, 15 minutes apart. I've also heard that the plane continue to fly for 4 hours, based on pings to satellites. The most interesting to me is that the plane supposedly increased in altitude to 45000 feet.

So I'm making an outlandish speculation...what if the pilot flew the plane up? What would eventually happen to it?

[Logical]

1. Its max ceiling is 43000 feet. n-t

[Avalux]

6. Max ceiling....

when the engine would stall?

[Logical]

12. And wings would not provide enough lift to go higher based on the size of the plane. nt

[Avalux]

13. Ok, that makes sense....

so I read 45000 feet and thought it very strange. Why do you think a pilot would do that?

[Logical]

14. Drunk. n-t

[Avalux]

16. Certainly plausible...and really, really horrible to think about. n/t

[The Velveteen Ocelot]

19. The stall would occur on the wings.

As the air becomes thinner At higher altitudes the airplane needs to fly at a higher angle of attack in order to generate enough lift to keep flying. Lift occurs because the shape of the wing (more curved on the top than on the bottom) causes air to move more quickly over the top of the wing than the bottom, which causes a pressure differential that effectively "pulls" up. What happens when a wing stalls is that when the angle of attack (pitch-up) becomes too excessive the airflow over the wing is disrupted and no lift can be generated.

The effect on the engines is different. An engine needs air to combine with fuel in order to burn the fuel, and if there isn't enough air (air pressure, more accurately), the engine won't produce enough power. But that's not a stall. There is such a thing as compressor stall, which occurs in the compressor (intake) stage of a jet engine but that is usually the result of a sudden abnormal change in engine parameters. Engines don't actually "stall" otherwise.

[Avalux]

28. I didn't know that. I kept thinking engine stall.

Are you a pilot?

[The Velveteen Ocelot]

31. Yes.

Retired instructor for an airline.

[Avalux]

32. I thought so.

Do you still fly?

[The Velveteen Ocelot]

33. Too expensive

if you have to pay for it yourself!

[Avalux]

34. Yes that's true!

I always wanted to take lessons but never did, still thinking about it!

[Renew Deal]

2. It would stall and fall out of the sky

And hopefully they'd be able to recover before it hit the ground.

[Avalux]

4. Ok....so if it couldn't recover, would plummet and hit the ground.

So there would be debris, correct?

[Renew Deal]

10. In my uneducated opinion, yes.

[Agschmid]

18. My uneducated opinion tells me it depends on what angle they would have hit the water...

Think bellyflop vs. pencil dive vs. cannonball.

[Avalux]

21. So if the pilot went up, then did a nosedive down into the water....

there may be very little debris as opposed to a belly flop. Just like a diver.

[Agschmid]

26. You would think...

I assume it also depends on the depth and chop conditions of the water to some degree...

See the ending of Air Force One, the Harrison Ford movie ( though very Hollywood).

[Gravitycollapse]

30. The plane would disintegrate on impact. Similar to the aircraft in the 9/11 attacks.

[Reter]

41. There is always debris

Nothing currently can just vaporise something as large as 777 into nothing, not even the most powerful military laser in the world.

[Avalux]

42. Let me clarify. I know what goes up must come down...

but if the pieces are small and scattered over a very large area of the ocean, it may be extremely difficult to find them. Is that possible?

[uppityperson]

46. The debris could be under water, the thing could have sunk. Or under vegetation in the

jungle, not viewable from the air.

[Gravitycollapse]

3. The density of the air would decrease until the wings lose too much lift or the engine stalls.

Or both.

[Avalux]

5. But how high up could it go?

Do you know the altitude for when the engine would stall?

[Gravitycollapse]

17. It would be substantially higher than the service ceiling. By how much I'm not sure.

[Agschmid]

20. It's wiki but it seems scientifically accurate...

The absolute ceiling, also known as coffin corner, is the highest altitude at which an aircraft can sustain level flight, which means the altitude at which the thrust of the engines at full power is equal to the total drag at minimum drag speed. In other words, it is the altitude where maximum thrust available equals minimum thrust required, so the altitude where the maximum sustained (with no decreasing airspeed) rate of climb is zero. Most commercial jetliners have a service (or certificated) ceiling of about 42,000 feet (12,802 m)[citation needed] and some business jets about 51,000 feet (15,545 m).[2] While these aircraft's absolute ceiling is much higher than standard operational purposes, it is impossible to reach (because of the vertical speed asymptotically approaching zero) without afterburners or other devices temporarily increasing thrust. Flight at the absolute ceiling is also not economically advantageous due to the low indicated airspeed which can be sustained: although the true airspeed (TAS) at an altitude is typically greater than indicated airspeed (IAS), the difference is not enough to compensate for the fact that IAS at which minimum drag is achieved is usually very low, so a flight at an absolute ceiling altitude results in a low TAS as well, and hence in a high fuel burn rate per distance traveled. The absolute ceiling varies with the air temperature and, overall, the aircraft weight (usually calculated at MTOW).[1]

[Avalux]

27. Thank you.

Do you have an opinion of why the plane was at 45,000 feet? As mentioned above, it is beginning to seem as if the pilot did it.

[Agschmid]

29. I don't...

I really have given up on opinions on this one.

We might know more, someday.

[Loudly]

25. Full throttle, probably about 70,000 feet.

And it's not the engine stalling, it's atmospheric physics which become the limitation.

The air pressure above the wing can no longer be kept lower than the air pressure under it.

Simply because there's not enough air density to create the necessary effect.

At 70,000 feet, the airfoil becomes too degraded to sustain lift.

[Avalux]

38. And then if the plane fell....

would you say it's possible that it would have broken apart and there may not be distinguishable debris?

[Loudly]

43. They found plenty of recognizable debris from Columbia.

And that fell from much higher up and suffered partial incineration upon reentry.

It was quite geographically dispersed though.

http://history.nasa.gov/columbia/debris_pics.html

[Loudly]

7. The air becomes so thin that no lift can be created.

The plane stalls and drops.

If the pilot can regain control and position the plane to create a new airfoil, the plane can continue to fly.

Otherwise, the plane continues in an uncontrolled descent until it crashes onto the sea or land.

[Tommy_Carcetti]

9. E.g. the last scene of the movie "The Right Stuff"

Wherein Chuck Yeager attempts to set a new altitude record before his plane stalls out and crashes to the ground.

[The Velveteen Ocelot]

8. It would stall and descend quickly.

It would have to lose quite a bit of altitude in order to recover from the stall, but it probably would be a recoverable stall (assuming the engines also didn't core-lock as a result of an abnormally high angle of attack and insufficient airflow through the engine cores).

[Avalux]

11. Thank you.

I guess what I'm trying to figure out at what altitude this would occur? I thought it so strange they said it ascended to 45000 feet. Why? Perhaps to appear to travel farther than it really did? (If hijacked).

[The Velveteen Ocelot]

24. It depends on the aircraft type, weight, and the engines.

Usually the airplane is certified for a maximum altitude, and that limitation could be based not only on how much power the engines can produce at altitude but whether the airplane can maintain adequate pressurization. The maximum service ceiling (certification limit) for a 777 is 43,100 feet, though it probably could go somewhat higher for a period of time.

[penultimate]

15. Malaysia joins the space race.

[A HERETIC I AM]

22. It would bump into the space station.

You got the answer from the others

The service ceiling is 43,100 feet or FL 431.

It could fly higher than that, but it is not certified to do so and the aircraft would probably not be able to keep itself from stalling if it went too much higher. The higher it goes, the faster it would have to fly to keep the same amount of lift. It is just not designed for that.

The reason the SR-71 and the U-2 spy planes can fly at 70,000 + feet is because the 71 uses higher speeds (Mach 3 and above) and the U-2 uses larger wings. By larger I mean, it has wings like a glider - quite a bit longer in relation to the fuselage than a typical airliner.

[Avalux]

23. And you gave me a laugh!

Thank you for the info...I knew where to come for the answers.

[2naSalit]

35. Here's some info

from some informed dudes...

http://www.msnbc.com/all-in/watch/deliberate-change-of-course-for-flight-mh370-195571779822

The info on that idea is not corroborated and should not be taken as a probability. That said, it's hard to say what actually happened without physical evidence.

The question that I keep revisiting is: WHO was one that aircraft? That might be a big lead at this point, especially if the plane was flown to some as yet to be discovered location, and even if it was crashed. There was a passenger list and it should be looked at a little more closely. All we know about, really, are the two stolen passport bearers and the folks who missed the flight. So who was on the flight that might be of note in some way?

[applegrove]

36. Heard expert say that the air is so thin there that the plane cannot get lift

off the molecules as they are too far apart. So the plane would flop around, fall till it finds the right air pressure. Also plane could break apart at that height. And people would fall unconscious.

[Avalux]

39. So there may not be debris. n/t

[applegrove]

40. No if the debris is from high up there would be a wide debris field I think.

Only if the plane landed a la Sully Sullenberger and then sank would there not be any debris.

[The Velveteen Ocelot]

44. Water droplets???

Water droplets have nothing to do with generating lift. And at that altitude there wouldn't be water droplets anyhow.

[applegrove]

45. molecules....sorry. I'm not good at verbatim recall.

[Calista241]

37. Outer space!

Maybe Aliens got the plane.

[2pooped2pop]

47. stall out? n/t

[ladjf]

48. Some type of stall, depending on the exact speed and power at the time

of the stall. Pilot may be able to recover during the descent unless the plane went into an inverted spin.