BA 744 - any ideas?
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Join Date: Apr 2000
Location: United Kingdom
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BA 744 - any ideas?
Driving past LHR on the M25 this afternoon, I watched a BA 747-400 climb out after take-off on 27R. I was puzzled because he was climbing away with his gear down. I continued to watch him and there was no sign of the gear being retracted at all.
Does anyone have a rational explanation for this unusual occurance? Would it have to be a malfunction or was it some sort of (very) non-standard procedure?
Thanks in advance for your thoughts...
UK
Does anyone have a rational explanation for this unusual occurance? Would it have to be a malfunction or was it some sort of (very) non-standard procedure?
Thanks in advance for your thoughts...
UK
Couldonlyaffordafiver
Join Date: Dec 2000
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Not a definitive answer by any means, but if the aircraft was positioning to the maintenance unit at Cardiff, it would have been at an extremely light weight and would have climbed like a homesick angel, even at minimal power, with the attendant risk of an excessive climb speed unless the nose was hauled up to an excessive angle. The drag from the gear remaining down would keep this under control.
However, someone will probably prove me wrong as usual ...
However, someone will probably prove me wrong as usual ...
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Havent got a clue about that B744....... but the B747 aircraft has a provision in the MEL that allows dispatch with one or two brakes deactivated by capping the lines or removal. Due to a lack of pressure to stop the wheels spinning after lift-off, there is a requirement to leave the landing gear down for two minutes. Takeoff weights and speeds have to be adjusted accordingly.
Mutt.
Mutt.
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If the a/c was heavy and had endured a long taxi with frequent stops the brakes may have been hot, (yes, even in an English winter!), in which case it is permissible to leave the gear down to increase brake cooling. There is a chart in the performance section of the Ops manual that will show the rate of cooling airborne with gear down and the rate of cooling just remaining stationery on the ground.
Human Factors answer and Mutts answer are both realistic possibilities too.
Human Factors answer and Mutts answer are both realistic possibilities too.
