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Old 7th Feb 2010, 09:49
  #221 (permalink)  
Brit312
 
Join Date: May 2002
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I do not won't to get involved with you boy's arguements but thought I would add the following points :-

1]There were no routine runway inspections for the departure of British Airways Concorde. However from the early 1980's a rigorous inspection of the parking bay and push back area was imposed, as it was found out that this was where FOD could be most likely found. It was found to include catering objects such as spoons, and baggage pieces such as buckles along with nuts/bolts from engineering.

2] Concorde had high speed tyres fitted to it, which if I remember correctly had a top speed of 225kts so tyre speed in this incident was not the problem, but it was always in the back of your mind

3] Concorde did have a tyre deflation warning system, but only up to 132 kts after which it was inhibited. The reason for this was that most of the tyre problems experienced in the early days was from slow tyre deflation due to FOD on the ramp or in some case on the taxi way without the crew being aware of it. This led to the other tyre on that axle being overloaded and giving way / shredding during the take off run. From many test done it was found that a tyre could easily withstand an overload for a certain period and it was determined that if a tyre deflated after 132 kts it's partner could stand the overload for longer than it took the aircraft to get airbourne, so to prevent high speed rejects the tyre warning was inhibited above this speed. Therefore in this case as the tyre rupture happened above 151 kts there would have been no warning.

4] Taxing fast was accepted if not the norm on Concorde, but not for 100% of the time. The recommended proceedure so as to save brake wear and high temps was to allow the speed to build quite high and then brake almost to a stop, before allowing the speed to rise again. You might have seen the high speed bit!! In fact getting to the runway too quick was not always benificial as often it just meant sitting waiting for space in the tanks to transfer fuel for C of G reasons

5]From the wreckage a C of G gauge was found showing 54.2 % which is within the Take off allowable range. In this case they were taking off at 54% so the aft limit was 54.3% for take off. However this indication was a gauge to check the C of G was withing range after you had transferred the correct amount of fuel from tank 11. If the C of G was not then within the correct range it meant there was something wrong with the load sheet. Now all this is in the ideal world and of coarse there was a certain amount of flexibilty used, but not much.

6] What has been called here the fidlle of putting on extra fuel was no such thing, but rather an approved manufacture's proceedure, and in BA was used rarely, mainly when trying to get the official paperwork figure on for say LHR to BGI. However as you topped up the tanks slighty over normal max full level, but still leaving airspace in the tank, it did mean the the F/E had to wait during taxi out for some of this extra fuel to be burnt off for him to transfer fuel for C of G reasons as his transfer fuel valves would not open until the fuel level had dropped below the normal high level switches. So this was a good proceedure, but it did rely on the Dispatcher loading the aircraft in such a manner that very little fuel transfer [burn off] was needed to achieve the C of G for take off, otherwise you just held waiting for the burn off to take place to allow transfer

Opps sorry gone on for longer than I realised, hope it helps
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