Joe said:
Richard S said:
For those who don't understand how a pilot can be so fooled, even if rated for such conditions and very experienced, please remember that what an occupant of an aircraft feels is simply the force of the wings interacting with the flow of air the plane is passing through. It does not matter at all what the attitude of the plane is in relation to the ground below. Even if totally upside down in relation to the Earth, the passengers will still feel as if the plane is straight and level in relation to the Earth, even though it is not. So, there is absolutely no way to tell by what one feels about a plane's attitude and the pilot must totally rely on the instruments to determine the attitude.
Not sure I understand you here. I've been in planes where the "attitude" changed abruptly and I was very aware of what the plane was doing.
Yes Joe, you are perfectly correct when you say that abrupt changes are easily felt.
However, when a plane is in serious turbulence and there are gusts which arrive and suddenly disappear, where there are sudden updrafts and downdrafts, it is rather difficult to separate all these effects and determine what is actually happening. In addition, the airspeed indicator and vertical speed indicator and possibly the altimiter will be bouncing around all over the place and what you see at one second may be quite a bit different a few seconds later. The pilots are also being bounced around quite a bit making it often difficult to read the instruments in very turbulent conditions.
Asino has explained that what you may feel does not necessarily correspond to the actual attitude of an aircraft. This is why so many of the early Air Mail pilots crashed and were killed in cases where they could not see the ground because of clouds and fog. Before the invention of gyroscopic attitude instruments there was absolutely no way to tell what the attitude of an airplane actually was. Even now, when these instruments are in almost every plane, someone not well trained may be led to trust his 'feel' rather than the instruments and end up spiraling in to a crash.
I once had a few passengers who thought they could determine the plane's attitude by 'feel'. I found a lone cloud and flew into it. I asked them to tell me what the plane's attitude would be when we left the cloud and could again see the ground. I did it several times and they were wrong each time. So much for 'feel'!
The most dangerous time for aircraft is usually landing approach because the plane is relatively slow and not very high. The reason for this is that there is not enough speed and altitude to recover from an unusual situation. It is also in a relatively high-drag condition with landing gear and flaps extended and low power from the engines as it descends.
A microburst in a downward direction would suddenly and rapidly force the plane to lose altitude at a great rate. What would be needed would be to raise the nose and apply full power to halt the sudden rapid descent. Large jet engines do not accelerate their rotational speed very quickly and can take up to 10 seconds to raise from near idle speed to full power. Meanwhile, as you have raised the nose, perhaps quite a bit in the attempt to halt the rapid downforce, in a high-drag configuration, airspeed drops rapidly. Below a certain speed the drag on a plane increases rapidly as the speed decreases, and it is a fact that below a certain speed even full power is not enough to maintain flight unless the nose is dropped quite a bit and the pull of gravity is additionally used to increase the airspeed. At a low altitude, there may not be enough time and space to recover.
The same is true for a wind shear condition which has downed many a plane. This happens when an air mass which is moving toward the plane is suddenly replaced with one which is not moving, or is moving in the direction with the plane instead of against it. The
air speed can suddenly drop to nearly the stall speed of the plane or even below that. The same scenario as above happens and can be fatal.
Because it was shown that the plane hit tail first, it seems to me that something like that was likely the cause of the accident because the pilots would have been doing their best to make the plane reverse the downward path and make the plane climb. Once something like the above occurs, even if the reaction is immediate, sometimes there is just no way to recover from it.
Hope this helps.
