DV:
Clearly, from that statement and the points raised in your posting there is a strong indication that you are not as well informed as you make out to be.
Well, you would say that anyway, so I'll not dwell on it.
I did not identify the hazard, nor did I set the severity. They were done by BAE Systems Chadderton Airworthiness Dept and the Nimrod IPT. The hazard in Maitenence Zone 413/443 was identified during the Zonal Hazard Analysis and the development of the Hazard log leading to the issue of the aircraft level baseline safety case in 2004. As a result hazard NM/H66 in the Nimrod Phase 2 Hazard log was raised to detail the potential for hot air leaks from LP & HP ducting on rib 2 to impinge on surrounding structure and systems (electrical wiring, CSDU oil pipes, fuel pipes and hydraulic pipes). As a result of this, the hazard was set at INCREDIBLE/CATASTROPHIC.
I don't doubt your word. I strongly question the categorisation of CATESTROPHIC.
A HP air duct blow-out inside any one of the engine compartments will not bring the aircraft down. The very worst it will do is damage the engine, as you have just described, which is not catastrophic.
Well that has been set at "CATASTROPHIC" from day one, not by me, but BAE and the IPT.
Yes, I know. They are wrong. BAeS, IPTand QQ did not design the aircraft. BAeS and the IPT made some big mistakes in risk analysis before Sep 06, which is why the whole process has started over again.
By the way, with regards to mitigation, a temperature sensor (S7) is located at Rib 2 (17 " away from the duct failure), and was unable to detect the failure.
Which means that it was an insignificant failure. None of my colleagues are aware of this 2nd duct failure. Now I know why (based on what you have just said); it was so insignificant that it didn't activate the warning which means that an Incident Report was not raised (an IR is usually raised for a Rib 2 overheat; they are never catestrophic, but are worth publicity). The slight damage must have been discovered after flight.
But there again, nothing detected the failure on XV227.
. The XV227 (SCP) duct was not monitored for failure in the same way as the ducts in the engine compts. As you know, that duct has been out of service since 2 Sep.
Ed, if you still believe there isn't a problem, ask yourself why has MoD finally decided to change some 37 hot air ducts in the engine bay areas, many of which were declared as being "life expired and in need of replacement" back in early 2005. Stop burying your head in the sand and look at the facts.
If BAeS says that the ducts are lifex it does not mean, de facto, that they present a catastrophic risk. I agree that the ducts are more vulnerable to failure than in-life ducts, but it is simply not a problem if one fails. Please remember I am referring only to ducts in the engine compartments. I am not burying my head in the sand. I accept that you are passing on info from organisations that we should trust and you place great store in them, but they have been wrong before. I believe that in the fullness of time, the CATESTROPHIC evaluation will be downgraded.
Not bad for someone out of his depth.
True enough. I only wish I could show you the ducts and the amount of protection around them (and I don't mean the duct heat shields; I'm talking about titanium walls and and a very solid engine)
Regards
Ed Sett