On reflection, bearing in mind the routing of the crossfeed duct, which is necessarliy open to supply air (at up to 500C, 250psi) to the SCP, I now believe that the aircraft is at considerable risk whenever the SCP is operated with the engines at or above cruise power. This effectively makes the system either useless or dangerous, by design, IMHO.
Furthermore, and far more importantly, whenever the crossfeed duct is open at or above engine cruise power, the aircraft and those on board, are at risk due to possible leakage from nearby fuel or hydraulic pipes. This is why we now have procedures prohibiting us from opening the duct above 80% (air and ground use).
This is basic stuff and should have been identified when the MR1 and R1 aircraft were built, tested (Jimmy Jones) and released into service.
Bottom line: while the SCP system might be safe, as a standalone system, it cannot be used due to the unsafe nature of the crossfeed pipe, when open, in most circumstances.
Ed
PS. While the maritime Nimrod force has been castigated by other operators for many years for flying around with serviceable engines shut down to save fuel, it is now apparent that we were at a greater risk of a fuel/hydraulic fire than we ever were of a loss of thrust. It was only because the engines were shut down that the crossfeed duct was open in flight. Truly ironic.
Interesting. I take back my initial assumption that the SCP design when embodied was safe. It appears that while not perhaps overtly unsafe, some features of its implementation/operation did include some significant potential safety shortcomings/risks from day 1 that should at least have been recognised.
While I can sympathise with the design team missing the "AAR venting fuel & it re-entering the fuselage" risk, the crossfeed pipe (at 400C) being near a potential (if probably remote) source of a fuel leak is a fairly fundamental risk that probably deserved some tangible mitigation in the first place, irrespective of AAR.