If the boostpump discharge check valve or the inlet valve are suspect:
- That would suggest that all 4 boost pumps in the LH/RH main tanks failed to deliver due to above suspect reason (as explained by TopBunk) at almost the same time?
- What happened to suction feed in that case? That should have provided engine fuel feed in such a scenario. Certainly sufficiently enough with engines normally required to accelerate to somewhere above approach idle during adjustments on final approach in landing configuration.
By the way, the inlet valve (removal check valve) is a valve that closes when you remove the pump. This permits you to remove the pump when the tanks contain fuel. Therefore, i don't see how this particular valve could be a factor unless clogged with ice.
Green-dot