I accept that I shouldn't have said "completely" safe. I meant to indicate that the Nimrod should not (now) be viewed, in safety terms, in a different light to any other aircraft.
The incident on 5 Nov is subject to an ongoing investigation and I will not comment.
The question to be asked, is why was the system reactivated after the XV227 incident?
The fault with the SCP duct on 227 was a duct failure. That particular fault was addressed and recommendations were made to examine other similar ducts, for the same symptoms. No-one considered that a perfect set of SCP pipes, and the pipes supplying the SCP, that carry air at 400C would get covered with fuel. That was a different scenario to the burst duct. So, the SCP was cleared for unrestricted use once it had been repaired.
Perhaps you can suggest how fuel from No.1 blow-off, could migrate upwards to No.7 tank dry bay.
Diagrams that you might have seen tend to indicate that the 7 Tank dry bay doesn't extend to the bottom of the wing root. The bay floor is actually the underwing panel that shrouds the SCP pipe. Therefore, the fuel didn't need to migrate upwards. It simply flowed rearwards and passed through the small gap between the front edge of the panel and the airframe.
Finally, do you have a date for the QQ hazard report, as it does not appear to be mentioned in the BOI report. I note that in the BAE hazard report, power supplies are mentioned as possible ignition sources.
I understand that QQ was commissioned by the IPT to carry out the study in Apr 07. It was not commissioned by the BOI. I believe the BOI had already seen the flawed Nimrod Safety Case and, as required by their Terms of Reference, reported their findings to the IPT. The IPT then commissioned QQ to conduct the hazard analysis. The report was eventually submitted to the IPT in Sep 07.
I note that in the BAE hazard report, power supplies are mentioned as possible ignition sources.
I haven't seen that report, so I can't really comment. However the QQ combustion analysis would address those "possible" sources. Taking your words verbatim, BAe might have suggested that power supplies could possibly cause electrical fires, or possibly cause fuel fires. Well, yes, it was possible until proven otherwise. I believe that subsequently the QQ combustion report proved otherwise in respect of the fuel fire scenario.
Someone jumped before the true state of SCP system was known. I am prepared to point my finger at who ever made that call.
I think thats a little bit unfair. Even if all of the similar pipes had been replaced with the SCP pipes, even as a precaution, the fact is that all of those pipes and the SCP would have been operating on 230 on that day. Indeed, it can be argued that changing the pipes would create possibilities of introducing leakage at the disturbed joints. So, IMHO the condition of the pipes was not contributory. However, it is disappointing that the recommendation to form a maintenance policy for the SCP and other similar ducts has taken so long to be decided on. Some of those similar ducts run very close to fuel tanks. Fortunately, none of those similar ducts are currently pressurised in flight.
Ed