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Engine split duct pressure L=80 PSI R=40psi

PostPosted: 12 Oct 2020, 12:23
by ALFRED
-During engines start:
ENG#1(L) ENG#2(R)
N1 50%: 30 N1 50%: 30
60%: 30 60%:28
80%: 20 80%:25
-during climb:
Up to 25 000ft
L: *80* R: *40*
- during cruise:
L: 20 R: 25
- during descend:
L: 20 R:15
Left is high .
Replaced PRSOV,BAR no change
Who is experienced with this

Re: Engine split duct pressure L=80 PSI R=40psi

PostPosted: 12 Oct 2020, 13:02
by BoeingMn
According to the FCOM volume 2 page 2.20.2 it says

“Differences between L and R duct pressure on the bleed air duct pressure indicator are considered normal as long as there is sufficient air for cabin pressurisation.”

Re: Engine split duct pressure L=80 PSI R=40psi

PostPosted: 23 Oct 2020, 05:33
by Dunny
been seeing this a lot with stored airplanes coming back into service

we've been replacing the preecooler control valve sensor and the 450f thermostat. They are up in the pylon together, so it makes sense to replace them both whilst you are there.

Re: Engine split duct pressure L=80 PSI R=40psi

PostPosted: 24 Oct 2020, 15:46
by flyday
BoeingMn wrote:According to the FCOM volume 2 page 2.20.2 it says

“Differences between L and R duct pressure on the bleed air duct pressure indicator are considered normal as long as there is sufficient air for cabin pressurisation.”


ONLY IF duct pressure is below 50PSI ? ? ?