Boeing Lounge Boeing 737 LRD

[ZapBrannigan]

So bleed off on the (affected engine)
Isolate
Bleed that isn't on the (affected engine) side stays on?

Not exactly. The only one that matters is #1 engine. The idea keeping fumes and smoke restricting visibility out of the cockpit so left bleed.

It's to buy you time until you can pull the fire handle.

Supposedly Boeing is working on a fix that would immediately close the PRSOV as soon as LRD activates. But knowing them, lord knows what other unintended consequences THAT will cause.

 

[BEEF SUPREME]

Not exactly. The only one that matters is #1 engine. The idea keeping fumes and smoke restricting visibility out of the cockpit so left bleed.

It's to buy you time until you can pull the fire handle.

Supposedly Boeing is working on a fix that would immediately close the PRSOV as soon as LRD activates. But knowing them, lord knows what other unintended consequences THAT will cause.

SEVERE FIRE DAMAGE OR SEPARATION (#1 ENGINE) - L Bleed closed?

But not #2?

Hopefully the fix won't mess up my career outlook...

 

[ZapBrannigan]

SEVERE FIRE DAMAGE OR SEPARATION (#1 ENGINE) - L Bleed closed?

But not #2?

Hopefully the fix won't mess up my career outlook...

I'm not saying either of us should do what Bill Bulfer is suggesting.

I'm just saying I get where he's coming from. If LRD reduces cockpit visibility to 6" in 15 seconds (not ideal with an engine eating itself at low altitude) and turning off the bleed could buy you time to get through the QRC and pull the fire handle... it's hard to argue against it.

(The number two provides air to the cabin. We aren't immediately concerned about visibility back there. The number one provides air to the cockpit. We definitely ARE concerned about visibility up there.)

 

[Beaker]

TBM 700, PC-12, KA200, CJ1, 2 and 3, CitationX, Falcon 900, EMB175, 737. They all kind of fly the same with the exception of the landing flare for the straight wings. Since the X every aircraft has had the mains behind the CG. All really similar IMO.

The mains are behind the CG of every tricycle geared airplane, no? Otherwise they would all tip back on their tails on the ground.

 

[ASpilot2be]

The mains are behind the CG of every tricycle geared airplane, no? Otherwise they would all tip back on their tails on the ground.

The 737 and A321 will do that if not careful.

 

[inigo88]

Supposedly Boeing is working on a fix that would immediately close the PRSOV as soon as LRD activates. But knowing them, lord knows what other unintended consequences THAT will cause.

I’m 50/50 torn whether they will bungle the fix, or whether your employer will lobby them out of fixing it in the first place to prevent needing a new type.

 

[ZapBrannigan]

I’m 50/50 torn whether they will bungle the fix, or whether your employer will lobby them out of fixing it in the first place to prevent needing a new type.

That's fair.

I'm going to go with create a fix that unintentionally creates a second set of unintended consequences.

 

[derg]

That's fair.

I'm going to go with create a fix that unintentionally creates a second set of unintended consequences.

Boeing’s never done… uh.. that… Awww crap, never mind.

 

[Sculprit]

Came across this really good video this morning. Illustrates in detail the LRD, and lack of corrective action.

View: https://youtu.be/swlVkYVSlIE?si=uqQ77lV2BhXP_Wfb

 

[Sculprit]

My shop now has a reference to the LRD in the latest revision to the flight manual. So I suppose some progression is happening….

 

[ZapBrannigan]

Ours too but they're just sticking to if it happens follow the engine fire, severe damage, separation QRC. The problem is how long it takes to get to that checklist and pull the fire handle.

 

[ozziecat35]

Bill Bulfer (the guy who wrote the Cockpit Companion book and app) added his own personal memory items to the Max throttle system notes in the app.

Essentially, left bleed off as the first step in the fire, severe damage, seaparation checklist.

Something to keep in the back pocket in the event the fecal matter hits the fan.

I'm not saying either of us should do what Bill Bulfer is suggesting.

I'm just saying I get where he's coming from. If LRD reduces cockpit visibility to 6" in 15 seconds (not ideal with an engine eating itself at low altitude) and turning off the bleed could buy you time to get through the QRC and pull the fire handle... it's hard to argue against it.

(The number two provides air to the cabin. We aren't immediately concerned about visibility back there. The number one provides air to the cockpit. We definitely ARE concerned about visibility up there.)

I know what my memory items / QRH at my shop say. Since I upgraded, I also know I have a bit of leeway in discretion during an emergency. Am I telling people to make stuff up? Not at all. Am I working on muscle memory and feel w/ regards to the number 1 bleed switch location? Well…never bad to know where things are by feel.

 

[inigo88]

Am I working on muscle memory and feel w/ regards to the number 1 bleed switch location? Well…never bad to know where things are by feel.

Good on you. Definitely seems like “engine bleed off!” may be the next Sully turning on the APU.

 

[Soku39]

Dear god why am I learning this from a youtuber.

 

[BEEF SUPREME]

Dear god why am I learning this from a youtuber.

View: https://youtu.be/9OpIbiFmY60?si=zIZ0hVLaEK-Z9Xsx

 

[ctab5060X]

I know what my memory items / QRH at my shop say. Since I upgraded, I also know I have a bit of leeway in discretion during an emergency. Am I telling people to make stuff up? Not at all. Am I working on muscle memory and feel w/ regards to the number 1 bleed switch location? Well…never bad to know where things are by feel.

If you want to close the left bleed valve, why not pull the #1 Engine Fire Switch?

It will close the same valve and there are only 3 of those large rectangular handles within easy reach. IMO, that is easier muscle memory than trying to correctly identify one switch among many. Especially when you are possibly experiencing an adrenal dump and losing your fine motor skills.

 

[Soku39]

If you want to close the left bleed valve, why not pull the #1 Engine Fire Switch?

It will close the same valve and there are only 3 of those large rectangular handles within easy reach. IMO, that is easier muscle memory than trying to correctly identify one switch among many. Especially when you are possibly experiencing an adrenal dump and losing your fine motor skills.

Because that handle does many more things than just close the bleed valves.

That said, I'm not a fan of making up procedures or "non boldface boldface".

The company manuals should be changed to reflect the changes needed to ensure safe flight. If left eng bleed valve "off" should be step one on an eng fire, eng severe damage, suspected birdstrike (I apologize if my wording is wrong I'm not a tech pubs pilot), then that should be a memory item.

 

[ctab5060X]

Because that handle does many more things than just close the bleed valves.

And for us it is item #4 on the quick checklist for severe damage. As opposed to the bleed only being turned off to drive the other pack into high flow.

Officially, just follow the procedure as published by your shop/manufacturer.

 

[Soku39]

And for us it is item #4 on the quick checklist for severe damage. As opposed to the bleed only being turned off to drive the other pack into high flow. Officially, just follow the procedure as published by your shop/manufacturer.

Again, not memory items, if the cockpit fills up with an atomized oil smoke it might not be so simple. I also like to take my time, make sure you get the right one.

 

[Autothrust Blue]

Dear god why am I learning this from a youtuber.

I mean, it wasn't that long ago that pilots did have to know things about the airplane, other than "the HI STAGE light means a bleed air is malefunkshun."

I understand a desire to not tell us things, as it can lead to troubleshooting/going down the wrong path/etc., but it would seem to me that both with MCAS and this, the pendulum was waaaaaay too far on the side of purposeful ignorance, to the point of hazard.