747-400 Reserve Tank Transfer

[NSEU]

A friend has been programming a desktop flight simulator for the 747-400 and there have been more than just a few headscratching moments (not helped by the fact I don't always know what the pilots see).

According to the wiring schematics and the Maintenance Manual, the logic for reserve tank (2/3) fuel transfer is either (2/3) wing tank below 6000 gallons and aircraft in the air (PSEU system).

Does this mean the FUEL Synoptic reserve tank (white) arrows appear on liftoff on a short flight where the reserve tanks are not used (and remain in view for the rest of the flight)?

Similarly, on flights where the reserve tanks are used, do the reserve tank tranfer arrows appear when the tanks are below 6000 gallons in the air, and remain in view until touchdown? i.e. do they change from green to unfilled white and remain that way for the rest of the flight

Thanks gents. Hope you can help, as some of this desktop simulator work has led to the revision/correction of wiring diagrams and maintenance manuals (in the real world).

Cheers
NSEU

[NSEU]

Excellent... Thanks Mr. Cosmic :cool:

[parabellum]

My original comment has been removed. I got hold of the wrong end of the stick and made an inappropriate suggestion about a sim flight only forum. Sorry to all concerned.

[NSEU]

Thanks, Parabellum )

As coincidence would have it, I found an answer to my question yesterday. We had an Upper Deck Crew Rest heater problem. To test this, we had to put the aircraft into air mode (by "slugging" the nose gear air/ground proximity sensors). There were only about 3 or 4 tonnes of fuel in each wing tank, and none in the reserve tanks, but the reserve tank transfer arrows (white) appeared.

The CWT scavenge pump arrow also appeared. This is because the reserve tank transfer open signal can influence the scavenge pump logic.

Cheers
NSEU

[SMOC]

Yep they open once airborne if the fuel load is correct, and remain open with arrows in view until 5 min after landing.

We just checked selecting the fuel page after landing.

[NSEU]

Interesting, thanks!

I just can't find any reference to time delays after landing in our manuals.