737 MAX issue of interest!
02-09-2025 | 08:32 AM
#11
Gets Weekends Off
Joined: Dec 2011
Posts: 2,028
Likes: 246
From: A320 FO
This issue has been making the rounds for the past few months.
My big question is why does this only seem to effect the Max? Obviously the Neo's have the LEAP-1A' vs 1B's, but they also have the LRD so have the same issue of upon the LRD activating, it dumps the oil into the engine and thus the bleed system. Did Airbus engineers see the potential for this and programmed the system to quickly react to prevent this? Or just haven't had a case of an LRD activation on a Neo yet?
My big question is why does this only seem to effect the Max? Obviously the Neo's have the LEAP-1A' vs 1B's, but they also have the LRD so have the same issue of upon the LRD activating, it dumps the oil into the engine and thus the bleed system. Did Airbus engineers see the potential for this and programmed the system to quickly react to prevent this? Or just haven't had a case of an LRD activation on a Neo yet?
02-09-2025 | 01:47 PM
#12
Thread Starter
Gets Weekends Off
Joined: Feb 2008
Posts: 20,839
Likes: 160
02-09-2025 | 04:45 PM
#13
Gets Weekends Off
Joined: Feb 2008
Posts: 3,142
Likes: 4
From: FIRE ALPA
I figure I've lost at least 10 years of lifespan between the CRJ and 737 from fumes I've breathed from every engine start over the years. If I take a couple days before doing laundry after a trip it's a noticable odor on my uniforms. And sometimes its bad just taxiing in line in the 737, didn't notice that problem in the CRJ's.
02-09-2025 | 07:08 PM
#14
Line Holder
Joined: Mar 2015
Posts: 370
Likes: 13
ie., Left failure and LRD activation...a pilot only shuts off the left pack...where might the oil-contaminated left bleed air then go before the left PRSOV closes?...
(A hypothetical question, which any 737 typed pilot will understand. And admittedly not what rickair7777 suggested doing, just a fair warning not to mishandle the issue...)
02-09-2025 | 07:13 PM
#15
Prime Minister/Moderator
Joined: Jan 2006
Posts: 44,618
Likes: 558
From: Engines Turn or People Swim
To all those tempted to get bleed/pack switch happy with an LRD activation post engine failure, just don't forget what happens to the isolation valve as soon as any one of the four corners get shut off...
ie., Left failure and LRD activation...a pilot only shuts off the left pack...where might the oil-contaminated left bleed air then go before the left PRSOV closes?...
(A hypothetical question, which any 737 typed pilot will understand. And admittedly not what rickair7777 suggested doing, just a fair warning not to mishandle the issue...)
ie., Left failure and LRD activation...a pilot only shuts off the left pack...where might the oil-contaminated left bleed air then go before the left PRSOV closes?...
(A hypothetical question, which any 737 typed pilot will understand. And admittedly not what rickair7777 suggested doing, just a fair warning not to mishandle the issue...)
And I'd only turn one of them back on if above 15K and need to stay there due to fuel burn over water.
02-09-2025 | 07:18 PM
#16
Prime Minister/Moderator
Joined: Jan 2006
Posts: 44,618
Likes: 558
From: Engines Turn or People Swim
I figure I've lost at least 10 years of lifespan between the CRJ and 737 from fumes I've breathed from every engine start over the years. If I take a couple days before doing laundry after a trip it's a noticable odor on my uniforms. And sometimes its bad just taxiing in line in the 737, didn't notice that problem in the CRJ's.
But it's nothing compared to the known constituents of both engine oil and HYD fluid and the toxins they produce when cooked at high-stage bleed temps.
I'm not the tin-foil hat type but I'm reasonably confident that there are at least a handful of crews out on permament disability from HYD fluid getting into bleeds.
02-09-2025 | 09:32 PM
#17
Line Holder
Joined: Feb 2015
Posts: 1,596
Likes: 112
I was wondering that too. I assume the *potential* exists because the LRD thing has to be at the front of the engine, no way it's aft of the bleeds on certain models.
Seems like you could have the software quickly close the bleed valves with high VIBs or big mismatch between N1 & N2.
Seems like you could have the software quickly close the bleed valves with high VIBs or big mismatch between N1 & N2.
02-10-2025 | 03:57 AM
#18
Thread Starter
Gets Weekends Off
Joined: Feb 2008
Posts: 20,839
Likes: 160
the fix is already being done. The LRD exists in some form on all engines with the large fan disks. It is a certification requirement. The FAA has said it does not want manuals to be 6000 pages and include every little detail of every system in an airplane. It does not improve safety. The only reason this is news is because it is Boeing and that Limey F&$k wants clicks.
Thread
Thread Starter
Forum
Replies
Last Post
