PPRuNe Forums - View Single Post - Concorde crash: Continental Airlines cleared by France court
Old 3rd Dec 2012, 23:41
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AlphaZuluRomeo
 
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Originally Posted by Shaggy Sheep Driver
And again worth remembering the contribution made by Airbus after the accident to get the aircraft back in the air.
It should never have been grounded. At least the BA ones shouldn't have been. They were using an improved tyre and following correct operating techniques.
So, in your mind, a BA Concorde taking off - off course following correct operating techniques - and rolling on the (in)famous titanium strip would have been safe?
Why? In what way were BA tyres sufficiently improved (??) to be immune to that strip?
I'm aware the water deflector were better secured on BA fleet, but that's not the point. There was no NZG tyre on any Concorde in fleet at the time.
OTOH, BA & AF Concorde had numerous tyres bursts, not only in their first years of exploitation. In fact, from 1990 to the accident, 7 tyres events were recorded for each of the 2 companies.

Overall, AF certainly was more laxist than BA, given the recorded evidences (and others events), and for that the company (and the country) could be blamed.
But that's no sufficient reason to assess that BA Concorde were safer regarding to the danger of such a FOD on the runway.
Hence, while the problem was being worked on, I think grounding both fleets was a correct decision. Once again, I stand to be corrected if need be (keeping in mind that I suffer from a very Cartesian mind).



Originally Posted by CONF iture
From the AF lawyer with the smile : "That spacer was useless anyway"

Not exactly clear since when designers add useless parts and weight on aircrafts ... ?
Of course the spacer had a raison-d'ętre. Now, lawyers being lawyers, if the absence of said spacer had no influence on the events, then you can say (being a lawyer, remember) that it was useless.
And what said the technical report about that topic? Let's see:
1.18.2.5 Study of the Beginning of the Flight
In theory, the absence of the spacer could have instigated an asymmetrical trajectory, tyre overheating and slower acceleration than normal. Study of the marks on the runway as well as calculations of the trajectory and acceleration made on the basis of the data from the flight recorders show that this was not the case:
• During the takeoff run, the aircraft would have had a tendency to deviate to the left if the left main landing gear had created abnormally high drag. However, its track was straight before the loss of thrust on engines 1 and 2 and there are no observable right rudder inputs. On the contrary, some slight actions to the left are even noticeable before V1.
• Such abnormally high drag could also have led to an abnormal use of the brakes during taxiing to get to the runway. However, the crew performed the pre-takeoff checklist and, in accordance with this, announced the brake temperature, which was 150°C (the temperature must exceed 220°C for there to be an alarm).
Furthermore, it was the same for the left and right bogies. The temperature of the brakes was therefore not at all abnormal.
• The acceleration recorded by the flight data recorder is 0.268 G, which is the normal value for the Concorde when it is at its maximum weight. Furthermore, 34 seconds after the beginning of the takeoff run, the aircraft had rolled 1,200 metres and reached a speed of 151 kt. At MTOW, and with conditions as on that day, the Concorde must roll 1.150 metres and reach a speed of 150 kt in 33 seconds.
Aircraft performance was thus entirely in accordance with the design values up until the damage to tyre No 2 by the metallic strip. Furthermore, takeoff
performance on the flights that preceded the accident (but after the bogie replacement work) was in accordance with published norms. There is no significant difference compared to takeoff performance on other Concordes.
• Up until the time the aircraft ran over the metallic strip, no remarks or reactions by the crew indicate any abnormal aircraft behaviour.
The first tyre marks noted on the runway after the accident were those of tyre No 2 after it was damaged by the metallic strip. There were no identifiable Concorde tyre marks before this point.
In addition, a change in bogie perpendicularity might have occurred, preventing gear retraction. As shown in paragraph 1.16.10, this did not happen.


In conclusion, nothing in the research undertaken indicates that the absence of the spacer contributed in any way to the accident on 25 July 2000.
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