PPRuNe Forums - View Single Post - TAM A320 crash at Congonhas, Brazil
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Old 31st Jul 2007, 16:07
  #767 (permalink)  
nada1234
 
Join Date: Jul 2007
Location: india
Posts: 16
Angel Forgot To Put Throttles To Idle?????

RatherBe Flying, Again going back to basic flying on any aircraft. What would your instructor have done if you "FORGOT" to put throttles to idle before landing? Guess you wouldnt be flying as he would have stopped your training then and there. Why would you not "FORGET TO LAND"? the actions are very clear and unambiguous in AB. Flare starts at 30 ft and you start hearing "Retard Retard". You bring and keep both TLs with your right hand to idle and with your left hand (for CM1 flying as PF) you land the aircraft. Then you move the TLs to retard position. The PNF then checks out spoilers, reversers and decel (if autobrake is armed). At 70 kts, you move TLs to reverse idle and before turning off the runway, you move them to idle. Thats it.
Problem occurs if you let pervious aircraft habits interfere here which is uncalled for. Or do something not called for like leaving ONE TL in clb detente. The system is confused as to what do you want to do now. you want to land or maintain speed.
Also, you do not want somethings to happen when you are doing a training touch and go. For that there are a different set of actions - like there is no arming of spoilers,no autobrakes and no selection of reversers after touch down. Then you stand them up by moving TLs forward and on GO from instructor, you move to TOGA to initiate go round.
In TAM accident, based on the current rumours, ONE TL apparently, is in clb detente. Now, they would have been neither here nor there. the system would want to know, are you wanting to land (as one half of TLs, is trying to do by being in reverse) OR you intend to go round (as one half of the TLs is trying to do being in clb detente). No amount of logic can prevent these Murphysque situations.
There is a talk of magic button. In this case, the magic button could be TOGA if action taken was sufficiently early since the spoilers would not have deployed and autobrakes not activated. However, going half way down the runway - wet and short, there is nothing much any braking or any magic button would have done. If the contention is that they hit the building at +94kts, they would have been doing much higher midway anyway. Now to stop that momentum, autobrakes could have been at max or any higher setting (imaginary), nothing could have stopped them. Anyway, i guess the brake pedals would have been to the floor in the panic (which corresponds to max autobrake application) anyway and if it still could get speed down to 94 kts only after overrunning runway, crossing the highway and then reaching the building, guess no magic button could have stopped them.
Guess what we all need to learn is to stick to the basics and know that it could happen to best and most experienced of us.
Happy and safe landings.
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