initial rudder inputs.
L.B, Hi.
Your observation is consistent with the delay in the #4 engine achieving afterburner light off and rated thrust. This does appear to be a fairly small lateral acceleration. The first 2 LH rudder inputs appear to have quite a lag before generating a LH acceleration, but may be characteristic of the aircrafts lateral control response.
The Investigation
It is unfortunate that the excellent work conducted by the BEA on their analysis of TO performance, 5 May 2008, using Erik Hollnagel's Failure Resonance Analysis Method, FRAM was not used on the investigation of F-BTSC, as it may have lead to a more holistic understanding of the event, and perhaps would have quenched some of the enthusiasm of the Judiciary to test a few individuals accountability vs the general and (arguably) understandable failure of the system to adequately protect the operation from a relatively complex failure mode.
After the fact it is easy to draw straight lines from the effect backwards to the perceived causes, it is far tougher to develop the risks from the start of operation, and predict the consequences of multi factorial resonant behavior.
At some point do the authorities place the politicians on trial as well? as they are a factor in the provision of resources, and regulatory structure under which it is assumed that the DGCA and COA personnel worked under.
It is easy for the inquisitor to hold the individual accountable for not acting on knowledge that didn't exist at the time of the occurrence, where this knowledge becomes identified post event; what is forseeable pre- and post- event are quite different, although there was a fair amount of evidence accumulated before 25th Jul 2000 to indicate that the SST was susceptible to compound failures arising from a forseeable failure of a tyre; that this opportunity was missed is clearer post event than it would have been pre event, but as is occasionally the case, each component of the failure had been assessed separately and were evaluated to be adequately protected or remote enough not to be a factor. On the day, all that could go wrong, did.
The failures of tyres/wheels/hydraulics/gear retraction/engine damage were documented well prior to the accident, stemming from either tyre failure or FOD damage leading to tyre failure.
Last edited by fdr; 8th Feb 2010 at 13:30.