B747-400 Stabilizer Tank

[moosp]

I understand that there is a Boeing generated restriction on the use of the Stab tank on the -400 issued on or about 22nd November. Anyone have any further info?

Thanks

[gas path]

Yes!..... An AD was issued on Sunday 24th. ALL stab fuel tanks to be locked out by Wednesday 27th.
The reason? Some pumps have been found with 'blueing' of the rotating parts. There is also a restriction on the use of the CWT.

[moosp]

Thanks g p. I just got access to the FAA stuff on it. Its inconvenient for the carriers who need that fuel for the range.

It also thickens the plot on the whole fuel pump issue. Gulp.

[jetboy]

Bulletin: FAA has come up with new procedure that allows for HST fuel provided pumps are shut off sequentially as fuel quantity decreases, ensuring pumps remained submerged at all times. Requires a lot of vigilence on the crew's part, but allows for non-stop long haul operations.