If the BOI reconvenes I hope they've covered everything
1. What's the delivery pressure from AAR tanker?
2. Does this pressure ever surge (overpressure)?
2a. Was the tanker serviceable?
3. What checks are carried out prior to AAR sorties?
4. Are the fuel pipes (in the bomb bay) pressure tested to full system pressure, either routinely, or after component replacement?
5. Where is the ignition source?
6. Would Nimrod electrical wiring pass modern standards of 'Wiring Husbandry' checks (post TWA explosion)?
7. Can a bleed air leak ignite fuel?
8. Is the suspect cooling pack pipe, or any joints of that pipework, anywhere near electrical wiring?
There are plenty of clues out there.
SPHLC