PPRuNe Forums - View Single Post - Airbus prepares safety warnings following A321 incident
Old 8th Dec 2010, 20:58
  #126 (permalink)  
320 driver
 
Join Date: Aug 2006
Location: London
Posts: 51
Likes: 0
Received 0 Likes on 0 Posts
Captain Crunch

Could you miss the mountains in a pull up with this type of g-limiting and bank-limiting A320 FBW sidestick?
No, I don't think you can. FBW will save the airframe from overload first, but ultimately hit the rocks as I understand it. It will reject the pilot's command to pull say seven g's. FADEC will slow spool the engines to save TBO but hit the trees as it did in Toulouse. Flying around on Alpha mode on the back side of the power curve is insane below ten thousand feet but simulator gods, test pilots and check airman seemed unconcerned about fostering such a dangerous habit when we first got the airplane.
I am honestly dumb-struck at your ignorance of your own subject.

Higher g will only offer advantage in the first few metres of a pull-up, the ability to pull max alpha will give more advantage in almost any conceivable GPWS scenario, something which is much, much easier in an alpha protected FBW type. Numerous studies have shown that such aircraft will massively outperform conventional types in GPWS pull ups.

If you pull seven g then you don't need to hit the mountain, you will have destroyed your aircraft all by yourself.

No-one to my knowledge has ever 'fostered the habit' of flying on the back of the curve at low level (and I have been flying this machine for 16 years). It is a facility that can be useful in certain unusual situations. Flying the aircraft at SOP speeds (O, F, S) keeps you right in the flat part of the curve. If you are operating on the back of the curve then it is your poor practice, not a defect of the aircraft, its makers or its operating philosophy.

FADEC does not slow spool the engines to save TBO. It does so to avoid surge/stall. All large fan engines are slow from idle with or without FADEC. FADEC just makes the acceleration safer and more reliable.
320 driver is offline