twa 800 Why & could it happen again?

[purple haze]

i was watching a documentary on the twa 800 tragedy in 1996 on sat on ch.4. .. .the reasons given for the accident was the fact that the centre tank was quite low on fuel , which heated up and evapourated due to long wait on stand. this was due to a/cond. units keeping the a/c cool.. .. .this caused the fuel to evapourate. this normally would not be a problem as jetA is quite difficult to burn.. .. .but on takeoff as air density decreases the air was sucked from the tanks causing concentration to increase further.. .. .on the cvr the capt. pointed out crazy fuel flow to engines. apparently the ignition or spark started from the wiring responsible for that indicator.. .. .the program maker interviewed one of the boeing directors and he said that this is a rare event and they have taken further precautions to prevent this from happening again.. .. .my question is, fare enough wires can be checked and insulated further to prevent a spark, but how about the air conditioning units heating up and the heat being disappated in the half full centre fuel tank and scenario starting again. . .. .does that mean that the centre fuel tank should always be filled first and what happens if an a/c is on standby for long periods in hot weather?. .. .how can this situation be prevented and why is it not more common?( if the above reason are true).. .. .PH. .. .PS sorry if i have any misunderstood any facts. . . . <small>[ 03 March 2002, 23:53: Message edited by: purple haze ]</small>

[Thunderbug]

Purple. .. .&lt;&lt;does that mean that the centre fuel tank should always be filled first&gt;&gt;. .. .Nice idea - but.... On the big transports the wings are filled first and then the centre tanks(hence why TWA800 had such a small amount of fuel in the centre tank). The fuel is then used in the reverse order of centre, then wing tank. If you have multiple wing tanks you try to burn from centre out to the wing tip. The reason behind this is reduce the bending stresses at the wing root. Fuel in the wing essentially balances out some of the weight in the body. If all the fuel is in the centre and none in the wing, the stresses are at their max and probably result in a payload or other weight restriction. The 767 that I fly can have 10,000Kg in the centre, but you have to have 4,700Kg in each wing tank and you take a hit on the available payload. . . . .&lt;&lt;what happens if an a/c is on standby for long periods in hot weather&gt;&gt;. .. .The solution here is to try and use ground electrics and pre-conditioned air piped from the terminal or jetty. This means you can in theory dispense with the APU and the air conditioning packs. The performance of some pre-conditioned air systems does though leave much to be desired and are availble (usually for airport noise reasons) at only a few places.. .. .Also TWA800 was ready to go and was awaiting some bags, this probably means that had they been using such a system, they would already have removed it.. .. .Nobody said it was going to be easy.....