Is AAR Safe on Nimrod?
In order to answer this question we need to define "Safe". Safe, according to MoD is a condition where risk has been demonstrated to have been reduced to a level that is broadly acceptable. Let us now examine the following chain of events:
22-11-04 XV227 returns with fractured hot air pie in SPC and a "cooked" No.7 tank (port)
03-08-05 Report issued, but some recommendations not carried out. Preventative maintenance/lifing policy yet to be announced.
02-09-06 XV230 crashes after AAR and bimb bay fire. Explosion in wing root.
03-09-06 Fuel leak from cracked fuel pipe dicovered on XV255. Serious Fault Signal (SFS) raised for incident.
04-09-06 Forward deployed aircraft cleared to fly after "visual inspection"
??-10-06 XV250 fuel leak, post AAR. Aircraft returned to Kinloss.
13-10-06 XV231 fuel leak, post AAR.
20-09-06 XV231 fuel leak. Aicraft returned to Kinloss.
21-10-06 RTI/NIM/173 issued. Calls for SPC to be isolated and draining of No. 7 tank (Pt and Stb) before flight.
29-10-06 SFS raised for XV250 and XV231
02-11-06 Initail report for SFS issued. Claims that XV255 problem was "well known" to IPT.
08-11-06 Air Incident Report raised by aircrew of XV260 for fuel leaks after AAR.
08-12-06 Air Incident Report raised by aircrew of XV232 for fuel leaks after AAR.
N.B. Would by useful to know what the make up off the 52 fuel faults were prior to the accident.
Now that chain of events, by any stretch of the normal imagination, does not demonstrates a level of risk that is broadly acceptable. Therefore, I must agree with Tapper's Dad; the AAR system, No.7 tank and the SCP are "unsafe" until proven otherwise, and isolation is not the answer. Safety has to be proven by evidence, not by the lack of it.
Finally, on the question of whether or not ground crews will sign off defective systems, and aircrews accept them, of course they will not. That, as I read it, is not the issue. If IPT carry out "risk management", which is influenced by the opertional environment, and state that the aircraft are acceptable to fly with tanks and SPC isolated, then the aircraft goes. Regardless of what aircrews and ground crews believe.
DV