Thank you! I’ve been looking for videos explaining these systems more in depth. I’ve learned how to start these planes, now I want to know what I’m actually starting! Invaluable content.
This is an excellent video. You were able to provide a good description and simplified enough for the average simmer. I have worked maintenance for Southwest Airlines for 25 years and intimately familiar with these systems. Thank you for your videos.
Glad you enjoyed it! I was afraid already that an engineer is going to take my video apart because it's intentionally simplified to match flight simulation and the average simmer ;-)
Your videos are the reason why I bought both 737-600 and 737-700 from pmdg! You are motivating me to learn more and more with every video! Thank you very much for your content!
You deserve more subscribers. Your channel is a must have for every flight sim enthusiast (at least for flying airliners). Is there any update about the release of the PMDG 737-800 by the way?
Thanks, Emi! I have recently purchased the PMDG 738 and have often wondered what all these lights are for. There is a lot of "monkey-see-monkey-do" on RUclips, but few RUclips University videos which i consider your contributions to be. I seem to learn more when i know the "why" rather than the "do-what-I-say". I have made a flight with the engine bleeds off on the sim and we encountered hypoxia. Thanks!
Great Video for Sim Pilots. Good Video for line Pilot level understanding. For Aircraft Techs and engineers it was entertaining. Still enjoyed your videos and Subscribed.
So when you have APU bleed and Engine bleed both ON at high engine power setting, it can potentially overwhelm the non return valve on APU side with back pressure. Correct me if I'm wrong.
Why are you not turning off the engine bleeds until you started them and turned off the APU? Seems like that would make sense and you could even stay in auto mode
I'm basically using the isolated pack operation on every single start. It gets so hot so quickly in the cabin, I tend to say, when it's warm outside (or rather: When it's not cold outside) I do it.
@@A330Driver Really? So..ENG #2 isolate, R Pack auto. with apu bleed ON for engine #1 start? or is this with isolate off+dual bleed from eng#2/APU run. i didn't think that would be enough for pack op+starter..maybe for one pack?
Enjoyed your explanation of the bleed air system. Hope PMDG fixes that error you saw when switching off the packs for engine start the needles should have increased to around 30 psi instead of dropped.
That’s actually how it is supposed to work. When the packs were turned off there was no demand so the APU Bleed valve schedules about 10psi. Had he selected an engine start switch it would have then delivered approximately 30psi. I provide a simplified description under Typhoon’s comment.
Nice video. Just wondering - is the bleed air clean air? If it comes from the engine compressor, wouldn't it contain engine exhaust and be unsuitable to, say, pressurize the cabin?
Compressor is before combustion section of the engine (same as apu, that’s just a smaller jet engine itself). So it’s highly compressed, very hot fresh air. Basically any bacteria or crap from the outside air is completely vaporized by the heat generated just from compressing the air. That compressed air then is bled off to run the bleed system. What isn’t bled off, runs into the combustion section of the engine where the fuel is introduced. From my understanding, pretty much all jet engines with a bleed system is this way. I can say for certainly the CL-65 (CRJ series) and 737 is this way. I’m type rated on the CRJ and going for the type on the 737 next month.
I thought I'd seen in another tutorial that you're supposed to start the #2 engine first - how does this work when starting off the APU if it only provides bleed air to the #1? The isolation valve allows for the APU bleed to cross to the other side?
Awesome video, real insight, thank-you. By the way would you yourself be allowed to host a download link for the FCOMs etc... for the old PMDG manuals? I have the old 737ngx ones but none of the 777 or 747... Didn't know if this is something you'd be allowed to do or not.
I did research regarding reference document used in this tutorial. It’s not longer supplied with PMDG’s aircrafts, due to intellectual property of Boeing.
It's not included with the MSFS version I'm afraid. I still have mine from the FSX days... Boeing asked them to remove those docs from the product, even though they had initially granted a license for them ten years ago.
I just wish I still had access to all of the manuals that I paid for with my PMDG 737 NG for FSX that I paid $90 for years ago, that they won't restore the purchase of.
As far as I know PMDG is currently on resolving this, they are waiting for the licensing rights of Boeing. Found something about it in the PMDG Forums. Someone asked the support, where the manuals are and posted the answer of the support. So maybe the manuals will get send after some time to the customers via an Update?
Thanks for this amazing upload! I dont understand at 14:45 were you turn off the bleed packs. I would assume turning off the packs would result in a higher pressure but the gauge shows a reduction in pressure. Is it correct that packs auto also create pressure?
Since you are in the PMDG development team maybe you can help me. I have a problem with my rudder pedals. It works fine with every other aircraft , but with the 737 it doesn't work properly. I can not use both pedals for the rudder to steer left and right. Its like the whole axis is just on one pedal. So when i don't press for example the left pedal, the rudder is on the far left. When i fuly press it, i'ts on the far right. Same with the right pedal, but opposite direction. I just have no idea what the cause is.
hello manuel, I have a question, if I have the engines off and APU operational, and I'm going to close both packs, the pressure should not rise, instead of going down?
Good question Typhoon. You are not confused at all. The pressure in the ducts is sensed prior to the pack valves so they will always read pressure. However, the APU Controller receives signals from the systems on the aircraft which require bleed air and adjusts the APU bleed output according to demand. With the packs off, no engine start, etc, not much air is required, so the APU Controller modulates the "inlet guide vanes" on the APU towards closed to reduce bleed output. Not all aircraft types have this "demand" system.
The APU Bleed Air Shutoff Valve (APU BSOV) is an “On-Demand” valve. With no engine bleed air (engines off or engine bleed air valves off) and the APU BSOV open the APU will pressure the duct to approximately 10psi. If a pack is selected on or the engine starter is engaged the APU BSOV will open as needed to provide approximately 30psi.
That's more of a question for an engineer than a pilot. I don't know. I see the light, I react to it LOL The exact conditions, like which temperature and which pressure, are not in the FCOM.
Thank you! I’ve been looking for videos explaining these systems more in depth. I’ve learned how to start these planes, now I want to know what I’m actually starting! Invaluable content.
Thank you for your videos. I’m currently on 737 type rating for the same airline as yours 😊. To be honest, your videos are very useful. Thanks a lot !
Awesome, thank you!
This is an excellent video. You were able to provide a good description and simplified enough for the average simmer. I have worked maintenance for Southwest Airlines for 25 years and intimately familiar with these systems. Thank you for your videos.
Glad you enjoyed it! I was afraid already that an engineer is going to take my video apart because it's intentionally simplified to match flight simulation and the average simmer ;-)
Your videos are the reason why I bought both 737-600 and 737-700 from pmdg! You are motivating me to learn more and more with every video! Thank you very much for your content!
Great to hear! Thank you very much for the nice words!
You are a gem. Thanks for sharing your knowledge!
Great Stuff.. Always loving the more in depth looks about particular systems.. Please keep 'em coming :)
Thanks!
Thank you so much for the support!
@@A330Driver you’re welcome! I’ve been diving into the 737-600 and your videos are so wonderfully informative and thorough. They are the best around!!
Thank you my friend! Been flying PMDG since 2008 and I was doing it wrong the whole time. Lol good video.
You deserve more subscribers. Your channel is a must have for every flight sim enthusiast (at least for flying airliners). Is there any update about the release of the PMDG 737-800 by the way?
Thanks for the kind words! I have no comment that I could share on the -800 at the moment.
Thanks, Emi! I have recently purchased the PMDG 738 and have often wondered what all these lights are for. There is a lot of "monkey-see-monkey-do" on RUclips, but few RUclips University videos which i consider your contributions to be. I seem to learn more when i know the "why" rather than the "do-what-I-say". I have made a flight with the engine bleeds off on the sim and we encountered hypoxia. Thanks!
You're welcome! Thanks for the nice words!
Great Video for Sim Pilots. Good Video for line Pilot level understanding. For Aircraft Techs and engineers it was entertaining. Still enjoyed your videos and Subscribed.
Many thanks!
Very much appreciate you sharing your knowledge. Thanks.
Great video again. I think the duct pressure pointers would need some better animations to be smoother when moving.
Great video! Could you please share the pmdg manual / fcom ?
Thanks, very good explanation
You are welcome!
Very helpful, thanks.
Tnx Capt❤
I might have missed it in the video, but where could we get that Operations Manual?
So when you have APU bleed and Engine bleed both ON at high engine power setting, it can potentially overwhelm the non return valve on APU side with back pressure. Correct me if I'm wrong.
Why are you not turning off the engine bleeds until you started them and turned off the APU? Seems like that would make sense and you could even stay in auto mode
Great video again, I like the "explaining the ac systems" videos very much.
I'm basically using the isolated pack operation on every single start.
It gets so hot so quickly in the cabin, I tend to say, when it's warm outside (or rather: When it's not cold outside) I do it.
@@A330Driver Thank you for this 'insight', Emanuel!
@@A330Driver Really? So..ENG #2 isolate, R Pack auto. with apu bleed ON for engine #1 start? or is this with isolate off+dual bleed from eng#2/APU run. i didn't think that would be enough for pack op+starter..maybe for one pack?
Packs to Off and presure decreasing with APU runing & APU Bled On ummmmm nice switch to crossbleed start subjet ;-)))
I guess is PMDG glitch.....
Thanks
Enjoyed your explanation of the bleed air system. Hope PMDG fixes that error you saw when switching off the packs for engine start the needles should have increased to around 30 psi instead of dropped.
That’s actually how it is supposed to work. When the packs were turned off there was no demand so the APU Bleed valve schedules about 10psi. Had he selected an engine start switch it would have then delivered approximately 30psi. I provide a simplified description under Typhoon’s comment.
@@SwaFixer Ok I see. So the system only shows what the current demand is rather than what’s available.
Nice video. Just wondering - is the bleed air clean air? If it comes from the engine compressor, wouldn't it contain engine exhaust and be unsuitable to, say, pressurize the cabin?
Compressor is before combustion section of the engine (same as apu, that’s just a smaller jet engine itself). So it’s highly compressed, very hot fresh air. Basically any bacteria or crap from the outside air is completely vaporized by the heat generated just from compressing the air. That compressed air then is bled off to run the bleed system. What isn’t bled off, runs into the combustion section of the engine where the fuel is introduced. From my understanding, pretty much all jet engines with a bleed system is this way. I can say for certainly the CL-65 (CRJ series) and 737 is this way. I’m type rated on the CRJ and going for the type on the 737 next month.
@@JJay512 Thanks for that info, and good luck on your 737 type rating!
@@tzampini Thanks!
I thought I'd seen in another tutorial that you're supposed to start the #2 engine first - how does this work when starting off the APU if it only provides bleed air to the #1? The isolation valve allows for the APU bleed to cross to the other side?
Correct, the Isolation Valve lets air pass from one side to the other.
Awesome video, real insight, thank-you. By the way would you yourself be allowed to host a download link for the FCOMs etc... for the old PMDG manuals? I have the old 737ngx ones but none of the 777 or 747... Didn't know if this is something you'd be allowed to do or not.
Thank you fro your kind words!
Unfortunately I am not allowed to publish those documents, they are still copyright protected.
@737NG Driver @coder 101 You have to download the old versions to get the FCOM´s have you?
I did research regarding reference document used in this tutorial. It’s not longer supplied with PMDG’s aircrafts, due to intellectual property of Boeing.
Yup, that's it. I own the FSX 737 NGX so I still have them. But they are not allowed to deliver them anymore with new versions.
@@A330Driver Luckily Internet is a big place, so I found 737 FCOM version for me as well :)
Danke !
The PMDG document on the left hand side, that’s the one included with the aircraft, right ?
It's not included with the MSFS version I'm afraid. I still have mine from the FSX days... Boeing asked them to remove those docs from the product, even though they had initially granted a license for them ten years ago.
I just wish I still had access to all of the manuals that I paid for with my PMDG 737 NG for FSX that I paid $90 for years ago, that they won't restore the purchase of.
As far as I know PMDG is currently on resolving this, they are waiting for the licensing rights of Boeing. Found something about it in the PMDG Forums. Someone asked the support, where the manuals are and posted the answer of the support. So maybe the manuals will get send after some time to the customers via an Update?
Great video :)
Glad you enjoyed it
After starting APU why do you wait 2 mins before turning the APU Bleed Air on? I observed you saying that in one of your flights
Thanks for this amazing upload! I dont understand at 14:45 were you turn off the bleed packs. I would assume turning off the packs would result in a higher pressure but the gauge shows a reduction in pressure. Is it correct that packs auto also create pressure?
Where you get the manual of the b737 pmdg
It was included with the 737NGX for FSX ten years ago. Boeings licensing agreement no longer allows to include it with the new products.
Since you are in the PMDG development team maybe you can help me. I have a problem with my rudder pedals. It works fine with every other aircraft , but with the 737 it doesn't work properly. I can not use both pedals for the rudder to steer left and right. Its like the whole axis is just on one pedal. So when i don't press for example the left pedal, the rudder is on the far left. When i fuly press it, i'ts on the far right. Same with the right pedal, but opposite direction. I just have no idea what the cause is.
For support contact support.pmdg.com, there you'll get help.
hello manuel, I have a question, if I have the engines off and APU operational, and I'm going to close both packs, the pressure should not rise, instead of going down?
Good question Typhoon. You are not confused at all. The pressure in the ducts is sensed prior to the pack valves so they will always read pressure. However, the APU Controller receives signals from the systems on the aircraft which require bleed air and adjusts the APU bleed output according to demand. With the packs off, no engine start, etc, not much air is required, so the APU Controller modulates the "inlet guide vanes" on the APU towards closed to reduce bleed output. Not all aircraft types have this "demand" system.
The APU Bleed Air Shutoff Valve (APU BSOV) is an “On-Demand” valve. With no engine bleed air (engines off or engine bleed air valves off) and the APU BSOV open the APU will pressure the duct to approximately 10psi. If a pack is selected on or the engine starter is engaged the APU BSOV will open as needed to provide approximately 30psi.
@@737simviator I don't think you understood what Typhoon was asking.
@@ImperrfectStranger thank you for the answer, I had always wondered about this thing and thanks to you now I understand, good day
Do you know the temperature at which the bleed trip off light illuminates?
That's more of a question for an engineer than a pilot.
I don't know. I see the light, I react to it LOL
The exact conditions, like which temperature and which pressure, are not in the FCOM.
@@A330Driver Gotcha :)
252c to 260c
The over temperature switch operates at 490F
How do I access this document?
Ok 🔥🔥🔥
I think it’s time to invest in a new mic…
I'm Emanuel , I'm a fake 737 pilot & a fake member of PMDG tech team 😄😆
Dude did you make this video for yourself? Jesus