snanceki
What prevents the CWT pumps from restarting due to aircraft attitude change once they have initially shut down due to the 9000kg limit being reached. Presumably the answer is nothing.
When the 900kg message is shown to the pilots, they turn off the CWT pumps by operating the switches on the overhead. They will not restart with these switched off.
I wonder how long an engine takes (at idle) to use the fuel present in the lines from tank to engine? 5 secs, 10 secs, 30 secs, min before starting to spool down?
A lot longer. When you shut an engine down using the spar valves it runs for 30-50secs on the fuel in the pylon, so from the boost pimps it will probably run for about 2 minutes.