David Learmount/LONDON
The scope of modifications which may enable the Aerospatiale/British Aerospace Concorde to win back its airworthiness certificates has been agreed by the UK and French aviation authorities, according to the UK Civil Aviation Authority.
Decisions on a test programme will be made at the next monthly review of investigation progress in London, set for 15 December. Measures include fuel tank protection in several alternative forms, one of which is a Kevlar fuel tank membrane.
French transport minister Jean-Claude Gayssot has gone out on a limb and predicted that Concorde will be flying again in April next year, but does not give any technical reasons for his optimism. The French Government research agency ONERA, however, is known to be conducting tests to devise potential Concorde fuel tank, hydraulic and electrical systems protection modifications.
Industry sources say that one of Air France's five remaining Concordes is being fitted out with a fuel tank protection system for airborne testing, but no-one will venture a timescale. A technical source says that static testing has not begun yet, so it will inevitably be "some time" before airborne tests take place. Air France refuses to confirm any of these reports.
British Airways confirms its commitment to resume Concorde services as soon as possible, but will not comment on industry reports that it is preparing to start a daily London-New York service in April, increasing to two flights a day by the end of next year if passenger reaction is favourable. Unconfirmed reports suggest that BA aims to go ahead with its planned Concorde cabin refit while the aircraft remains grounded, but it would not use the downtime to conduct the next life extension programme. Decisions on the latter would take into account market reaction after services restart.
Meanwhile, examinations of the crashed aircraft's Nos 1 and 2 engines have been completed by manufacturers Rolls-Royce and Snecma under the supervision of the Bureau Enquêtes-Accidents (BEA), so the BEA knows the full extent of the damage caused before the impact. Further study is needed, however, to establish the precise cause of the damage. In the 25 July take-off accident near Paris Charles de Gaulle airport the No 1 engine failed as a result of damage, at least some of which was "soft body" damage believed to have been caused by parts of an exploding main wheel tyre. Power on Nos 1 and 2 engines had dipped briefly before the crew shut No 2 down following an engine fire warning.
The scope of modifications agreed by the CAA and its French equivalent the DGAC includes changes to the engines, the fuel system, the hydraulics, and work to eliminate any potential ignition source for fuel should it escape. The CAA says that alternatives are being considered in each case, so that as further detail about the nature of damage to the wing, undercarriage and engines emerges from the BEA investigation, as many eventualities as possible will already have been considered.
Source: Flight International
