Originally Posted by Magplug
PJ2.... Your narrative is incorrect.
Well, so is yours. Actually having read the report and its appendices helps.
The FE shut down an engine on the runway prior to V1 without any reference to anybody else on the flight deck (read the CVR transcript). There is no 2/3 crew SOP in the world that has one guy shutting down engines below a safe height let alone unmonitored. As the other engine subsequently failed before the gear could be raised their fate was sealed....Unable to accelerate to V2 and all the drag of the gear hanging in the breeze.
The engine shutdown was past v1.
Please read the CVR transcript:
Originally Posted by CVR Transcript, English translation
14:43:03.7 - F/O: "V1"
14:43:10.1 - Noise
[...]
14:43:13.0 - F/O: "Watch Out!"
14:43:13.4 - VHF: "Concorde, [...] you have flames behind you"
[...]
14:43:20.4 - F/E: "Failure engine 2"
[...]
14:43:22.8 - Engine Fire Alarm
[...]
14:43:24.8 - F/E: "Shutdown Engine 2"
14:43:25.8 - CPT: Engine Fire Procedure"
Please read my analysis, made after consultation with Concorde's Chief aerodynamicist, Clive Leyman. It shows that, regardless of the appropriateness of the F/E's shutting down engine no. 2, it would not have worked anyway as long as the fire was burning, because it was ingesting kerosene and/or flames. Even engine no. 1, farther away from the flames, did not reach its full power.
Even so, only one second after the Flight Engineer announced that he was going to shut down engine no. 2, the Captain ordered the engine fire procedure, which includes shutting down the engine. Presumably, the F/E took more than one second to announce his intentions, so it coincided with the Captain's orders.
Had the FE not embarked on that Maverick course of action there should have been enough Hyd pressure from the two lame engines to raise the gear and fly away.
1/ Engines 1 and 2 provide Green hydraulic pressure, which is the only hydraylic system available for gear retraction.
2/ Engine 1 was anything but lame. It was running, after a brief loss of power, at normal takeoff power, although, unlike engines 3 and 4, it did not quite reach the demanded contingency power.
2/ The gear could not be raised because tyre pieces had damaged a door, preventing door movement and thus a necessary signal for unlocking and movement of the landing gear proper.
When the fuel cells were empty the spectacular fuel fire would have ceased, with some good flying they may just have saved the day. Being two tonnes over max tyre speed did not help, neither did ignoring eight knots of tailwind.
1/ Those canisters in the aircraft that hold fuel are called "fuel tanks". a "Fuel Cell" is a hydrogen/oxygen-fueled cell that provides electric power. Concorde has no fuel cells.
2/ Assuming a constant fuel flow rate, the fire would have continued burning for at least another 2 minutes. As the fire prevented the left hand side engines from working normally, nothing could have been gained. In practice, fuel flow from the leak would reduce when the tank was becoming near empty. It is even conceivable that a nearly-empty tank might contain an explosive fuel-air-mixture and explode. Waiting for the tank to empty was not an option.
3/ The wing was starting to deform from the intense heat of the fire, accelerating loss of control.
4/ There are indications that the flight crew was well aware of a slight overweight/tail wind condition, leading to tyre stress very close to, or possibly slightly exceeding the rolling limit. Apparently they attempted, regardless of the approaching runway edge, a somewhat early, but slow, rotation.
The reason for the extraordinary tyre stress on Concorde aircraft is the combination of a very high Vr/V2 speeds, and practically zero lift prior to rotation. Rotation-initiation produces a small amount of negative lift for a brief time, so an early and slow rotation can alleviate tyre stress on Concorde takeoffs. Conventional aircraft already produce significant lift during takeoff roll before rotation.
AF ploughed in an A320 F-GGED [...]
What has this got to do with Concorde? Oh, you're trying to "prove" that all Air France cockpit crews are incompetent. Nice try.
Bernd