787 Fuel Tank Pressure & NGS System
Thread Starter
Joined: Feb 2004
Posts: 1,410
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From: Australia
Correct. The NGS pump is run by either of the 2 CMSCs on the R2 230 VAC bus. One of those usually runs the right outboard (R2) cabin air compressor and the other usually runs the left hydraulic system's electric motor pump. The outboard CACs aren't used on the ground. The R2 CAC also turns off during descent to allow the NGS to run.
Right. The NGS is controlled by the R4 General Processing Module of the Common Core System.
Right. The NGS is controlled by the R4 General Processing Module of the Common Core System.
On the subject of fuel, is there a minimum value for fuel in the CWT for takeoff on the 787-8?
I seem to recall "new" procedures on, for example, the 747-400, that insisted on a minimum fuel value. Whether this was still effective after the new EICAS message and pump logic came into effect, I can't remember.
I can't remember if extra fuel was uplifted to the CWT to meet that requirement or if fuel was transferred to the CWT by engineering using the wing fuelling panel. I think it was around the 109 tonne mark when fuel had to be put into the CWT.
On the 787-8, this seems to be around 34 tonne mark.
