Five people to face Concorde crash trial

[M2dude]

This thread had now become full of comments, some of them a little colourful regarding the disaster, and a few more taking pops at me personally again; it’s ok, I’m a big boy and can take it. I’ll try and put my ‘pennies worth’ in here and answer, from MY perspective, as many of the points that I can. To save writing a veritable odyssey in one go, I’ll deal with a couple of points at a time, working backwards;

1. WINGSFOLDED Not much to say about your legal points, don't profess to be a legal person, but my point never was one of French Bashing. It is possible to obsess on both sides of this particualar issue, my point always was the way that Concorde was operated there, and the outright refutal by the BEA of some fairly critical points. I hope most people would want not to indulge in such things.
2. Chucks; the indicated CG was derived from the ‘fuel CG’, derived from the FQI fuel weight from each tank, modifying this for the individual tank CG moment arm and also total fuel weight. The Formula used by the CG computer was( (ZFW*ZFCG) + all 13 FQI fuel mass moment sums))/(ZFW + total fuel weight). This data was then modified by manually inputting zero fuel weight (obviously the weight of the A/C itself plus payload), and zero fuel CG (the individual A/C CG (known from periodic A/C weighing) and actual payload distribution). The manually inputted data, obtained from ‘dispatch load control’ depended on its accuracy on accurate payload data (as well of course as accurately stored individual A/C weight data) ACCURACY HERE WAS ABSOLUTELY CRITICAL!! . A/C CG was then computed and displayed as a percentage of the aerodynamic chord line, Co. The FQIS data was obviously dependant on the FQIS being able to ‘see’ all of the fuel also. Of particular interest here is ZFCG; As you say, the ‘frozen’ CG here is 54.2 %, this in itself although 3.7% total in error, is within the operational tolerance.. (There is a historic issue regarding the 54% limit; when the A/C initially entered service in 1979 T/O CG was limited to 53.5 %, but to enable higher T/O weights a modification was embodied to extend the limit, when required only, the limit was extended to 54%. The limit had to be manually selected by the FE, via a solenoid latched switch. The latch was broken once either Tank 9 Trim Pump operated. Now the limits on CG were presented on the CG indicator as two orange limit bugs. These bugs would move rearwards as a function of Mach Number and total A/C weight, and at Mach 2 the aft limit would be 59.2%. If the CG deviated from the limits, a ‘Mach CG’ limit warning would be generated. To enable the 54% limit. Because of the criticality of the system, the three trim transfer tanks had dual gauging channels, for added accuracy. Now, we have an indicated CG of 54.2, but , leaving aside any other issues of conjecture, there are 19 suitcases in the rear hold NOT ON THE LOADSHEET. Now these poor souls are German tourists going on a world cruise, one can only speculate the average weight of the cases; if you assume a minimum of, say, 20kg, you have an unaccounted weight of 380 KG. If you assume 25KG, then you have 475 KG, getting on for half a tonne overweight. But this additional weight was in the aft hold, situated just forward of the aft trim tank; we are significantly aft of the 54% limit, without considering any other factors
3. BRIT312; Very good points made here. Your point regarding the load sheet is particularly valid here; you relied totally on the accuracy of the data you were given. As you say, although no runway check was normally carried out, there was a rigid FOD check done, both on the stands at LHR and JFK. The JFK check even extended into the confines of the initial taxiway, the rest of course being down to PONYA. Your point about the tank override switches are taken, ununreservedly withdraw my previous comments about this, I cannot use this as part of the arguement. I apologise to anyone who disagreed with me in any way on this particular issue. The Concorde Tyre Deflation Warning System, installed in the early 80’s (as part of the ongoing issue of preventing tyre failures). It was far cruder than the modern TPIS sensors used in present day Boeing and Airbus A/C. It worked on a differential strain gauge system, where the front and rear bogie loads were compared on each side. As crude as it was, it was good enough to detect a 10% deflation, and helped prevent many taxiing tyre failures. As you point out, above 130 KTS, the system was inhibited for the reasons stated.

More later.