747-400 HST Refuelling

[QAVION]

I've noticed that many airlines have rid themselves of the Horizontal Stab position warning light on the wing fuelling panel and that a stab position outside of 5~7 units no longer prevents fuelling of the HST. Was their some kind of _mechanical_ modification made to the HST or its associated plumbing which now allows refuelling in any position?

NB: I believe Boeing(?) Service Bulletin #28-2155 refers to the modifications carried out, but I don't have ready access to them.

Thanks.
Rdgs.
Q.

[gas path]

Q
The stabilizer fuelling lockout system was installed to maintain the accuracy of the FQIS system, but additional testing found that that the stab. FQIS was accurate regardless of stab position.
Depending on which group a particular aircraft fell into dictated the work required, basically removal of the stab. position switch, capping and stowing (or removing the wiring looms)plus some changes to the p54 and p42 panels. Some airlines also had a flight deck refuel (M5???) panel that required modification.
I don't think there were any plumbing changes!

[QAVION]

Thanks, GP... I'm inclined to believe you. I can't recall any mechanical mods being made myself, but an (often correct) engineer friend said that he "thought" there had been.

Cheers.
Q.

[redtails]

qa from what i know we havnt recieved any mod for that yet

[QAVION]

"qa from what i know we havnt recieved any mod for that yet"

I have info to the contrary, redtails(pls check your e-mail).

Rgds.
Q.

P.S. I also checked OJJ yesterday(System deactivated).