The Concorde saga, unsustainable flight:mindFly

COncorde accident

Summary

On 25th July 2000, during takeoff from runway 26 right at Roissy Charles de Gaulle Airport the Air France crashed and killed all on board. Shortly before rotation, the front right tire (tire No 2) of the left landing gear ran over a strip of metal, which had fallen from another aircraft, and was damaged. Debris was thrown against the wing structure leading to a rupture of tank 5. A major fire, fuelled by the leak, broke out almost immediately under the left wing. Problems appeared shortly afterward on engine 2 and for a brief period on engine 1. The aircraft took off. The crew shut down engine 2, then only operating at near idle power, following an engine fire alarm. They noticed that the landing gear would not retract. The aircraft flew for around a minute at a speed of 200 kt and at a radio altitude of 200 feet but was unable to gain height or speed.

Engine 1 then lost thrust, the aircraft’s angle of attack and bank increased sharply. The thrust on engines 3 and 4 fell suddenly. The aircraft crashed into a hotel. Final report: https://www.bea.aero/docspa/2000/f-sc000725a/htm/f-sc000725a.html

How the Concorde crashed

Performance

The total weights of the aircraft and of the fuel on board stated by the Flight Engineer (FE)at the time the aircraft started out were 186.9 t and 95 t respectively. The speeds selected by the crew were V1: 150 kt, VR: 198 kt, V2: 220 kt.

The actual takeoff weight was above the maximum permissible takeoff weight of the Concorde.

At the maximum structural weight at takeoff, the calculations provide the following values:

• V1: between 139 and 162 kt (the crew selected 150 kt)

• VR: 199 kt, rotation performed at 183kt.

• V2: 220 kt

Zero rate climb

The ATC gave takeoff clearance with winds at 090/08 knots. This meant that there was a 08 knots tailwind component.

Three components:

  1. Actual weight above the max permitted takeoff weight
  2. Calculated takeoff speeds, rotation speed 198kts would have been below the actual rotation speeds. This is considering the fact that the reported wind at takeoff had a tailwind component of 8kts.
  3. The rotation was performed 15kts before the calculated rotation speed. This would have been more than 15 knots since higher weight and tailwinds would have affected the performance detrimentally.

Conclusion


On the ill-fated day, all that could go wrong with the Concorde did go wrong. From the aircraft performance criteria, the aircraft was overloaded beyond the maximum permissible weight and there was a tailwind component. The calculated rotation speed was therefore much lower than what should have been based on actual conditions. This situation was exasperated by the early rotation by the Captain, 15 kts before the calculated rotation speed. The aircraft managed to reach a speed of 200kts but was lower than the minimum speed to maintain a level flight.


































































































About Capt. Amit Singh

I think therefore I am https://www.linkedin.com/in/traintofly/ Airlines Operations and Safety balance expert. A former head of operations/training and safety of successful LCC's in India. An experienced member of the startup teams of these airlines has hands-on experience in establishing airlines systems and processes.

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