HAWK21M From India, joined Jan 2001, 31457 posts, RR: 57 Posted (6 years 6 months 2 weeks 1 day 4 hours ago) and read 1586 times:
On some B752s the Fwd boost pump is mounted on the Front spar.However on later models it was moved along with the Aft boost pumps on the Rear spar.
Anyone aware of the reason for this shift in location.Was it to get all components accessable from the rear spar.
Buzz From United States of America, joined Nov 1999, 697 posts, RR: 23 Reply 1, posted (6 years 6 months 1 week 5 days 12 hours ago) and read 1496 times:
Hi MEL, Buzz here. All our 757's have the forward spar mounted boost pump. It's barely accessible through the small panel you can open if you need to change it.
Things on the aft spar are much easier to get, assuming you have a tall enough ladder. The wheel wells and area where the shock strut retracts into give lots of elbow room - and even some light to see what you're doing.
The boost pumps have pickup tubes inside, so the fuel is drawn from what ever part of the tank the engineering guys plumb it to. Notice on the 737-300 series, all the boost pumps are in a row: center, forward, aft and they're on the lowest part of the wing skin. Pickup tubes allow the pump to draw fuel from the forward, or aft section of the wing.
HAWK21M From India, joined Jan 2001, 31457 posts, RR: 57 Reply 2, posted (6 years 6 months 1 week 5 days 7 hours ago) and read 1475 times:
Thanks Buzz for the Info.
Was accessability the only reason for the Fwd Boost pump location being shifted.These are questions Mx has,which only the Manufacturer knows.I wonder why under the wing was not considered aka B737.
RoseFlyer From United States of America, joined Feb 2004, 9191 posts, RR: 52 Reply 3, posted (6 years 6 months 1 week 4 days 12 hours ago) and read 1445 times:
Quoting HAWK21M (Reply 2): Was accessability the only reason for the Fwd Boost pump location being shifted.These are questions Mx has,which only the Manufacturer knows.I wonder why under the wing was not considered aka B737.
Unfortunately I can't tell you the answer. If your maintenance people really want to know, then they'll have to contact Boeing. For the purpose of trade secrets, reasons like that are typically not said on places like the internet. But there are often lots of reasons for moving the location. Accessibility is one factor, but the 737 is progressing towards lean manufacturing and there are many things that get redesigned or moved to lower costs.
If you have never designed an airplane part before, let the real designers do the work!