Tuesday, December 1, 2015

Air Asia flight QZ8501 crash report. Here we go again!

 Indonesia NTSC (air safely body) has determined that the cause of last Decembers crash was electrical issues which resulted in the crew having to switch off auto pilot. This in turn led to the crew having to fly the plane manually, something they were unable to do. In other words they came off auto pilot, got the plane into a stall and couldn't recover from t.
 Now we've been here before, sadly many times.  It seems that modern flight crews simply can't fly the planes properly on manual. Theres been quite a number of accidents caused by the flight crew even not knowing which way to pull or push the stick, indeed pulling back on the flight controls to "dive" the plane is surprisingly common (and totally wrong)   What happens is the plane looses speed so the crew member flying pulls back on the stick (or wheel) to put the nose up to gain speed and height.... except that has the opposite effect, slowing the plane down.  The point is reached where the plane stalls, at this point the crew are usually baffled by whats happening and try and pull the nose up more.
 When the plane finally stalls properly the crew should do what every student pilot is taught, level the wings to prevent a spin, push the nose down and add power, provided you have enough height this works well (as any student pilot will tell you) the plane will recover from the stall (note not a deep stall *) and provided speed is kept high enough the aircraft will continue to fly normally when you level out.
 The problem is modern flight crews simply don't fly the planes, it's almost all on auto pilot, with the exception of the first and last 2 minutes of the flight the computer does it all. These days they don't have any experience of actually flying, maybe they should all have to do 10 hours a week flying small aircraft to keep their hands in so to speak..
 Strange when you think that during the war, very young inexperienced pilots often with only a few dozen hours were flying to Germany and back often at night, and coming back many were shot up with engines out.  God help if most of out super-duper airline pilots tried it.

* Note some aircraft, mostly those with a high T tail can get into whats called a deep stall, the tail T part gets into the disturbed airflow from the stalling wings, this cause the elevators to loose effect, causing the flight crew to be unable to alter the pitch of the aircraft, this means they can't push the nose down to recover from the stall.

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