ALASKA AIR EMERGENCY LANDING HAWAII

[tdracer]

The newer installations don't use pressure switches - they use differential pressure transducers (typically strain gauge type). Switches fail (especially in the adverse environment of an engine) - transducers are far easier to fault detect, and monitored by the FADEC they are typically dual channel redundant. Typical installation will set a fault when the delta P gets above a certainly level (if anyone's looking it says it time to replace the filter), then set a flight deck message when the delta P approaches bypass.
All that being said, I don't know what the CFM56-7 uses...

[WingNut60]

Originally Posted by tdracer

The newer installations don't use pressure switches - they use differential pressure transducers (typically strain gauge type). Switches fail (especially in the adverse environment of an engine) - transducers are far easier to fault detect, and monitored by the FADEC they are typically dual channel redundant. Typical installation will set a fault when the delta P gets above a certainly level (if anyone's looking it says it time to replace the filter), then set a flight deck message when the delta P approaches bypass.
All that being said, I don't know what the CFM56-7 uses...

Yep. Transducers are more reliable, especially at higher pressures. But they do fail too.
Hence the redundancy.
Do you want to see what a shoe box full of 'em looks like?

[Deadstick126]

I don't know if turbulance is a consideration in an engine out situation, but Maui approach is considerably bumpier then HNL.

[aterpster]

Originally Posted by Deadstick126

I don't know if turbulence is a consideration in an engine out situation, but Maui approach is considerably bumpier then HNL.

Nope, only if there are TRWs that block the approach path. Otherwise, runway winds only.