Thanks Chris. Appreciate the instructions on operation and stowage of the eros masks. Its not documented as well as it should be considering it's a critical bit of gear.
Absolutely amazing information, Captain Brady. I'm looking forward to your updated guide, I'll definitely be grabbing it as soon as I can. While, unfortunately, I am not a real pilot, your videos really enhance my simulation experiences and make them feel more authentic. In my opinion, you have the best 737 channel
@@ChrisBrady737I'm having trouble getting hold of the original book. The books all seem to come from the USA even though you presumably are from the UK. It would be good if Waterstones have it.
Stainless steel lines aren't just used for quality btw, it's also for fire resistance. If there's a fire in the e&e bay, the last thing you want is for the lines to burn through depriving the crew of oxygen AND allowing high pressure o2 to blow directly onto the fire. Stainless is the best choice in terms of compatibility with o2 (the chromium forms a passive layer on contact with o2) and melting point. Much better overall choice than aluminum or titanium.
Hi Chris - Location of O2 bottles on BCFs - I see from the video at 1:09:38, that the bottles are stated to be "just aft of door 1L on the 9G bulkhead", which would make them inside the cargo compartment...? If I cross-reference this with the Freighters video at 1:00:00, the decompression door is just aft of the 1L door on the BCF... I think the O2 bottles on the BCF must then be on the supernumary vestibule side of the 9G bulkhead, which would make the bottles just aft of the *1R* door on the forward side on the 9G buklhead, not the 1L? Or perhaps just *forward* of the 1L door? I also think placing the bottles in the cargo compartment would make them susceptible to damage in the case that the cargo moved and impacted the 9G barrier, rendering them unusable or may breach them in an accident, which might ruin ones' day...
Some more note on pax gas system and pressure requirement: From Boeing's presentation, 300lt protective oxygen for crew (15min as the claim) is the limit factor for normal 12/22min pax oxygen equipped aircraft, as the decent profile would not exceed that, so the normal chart for crew oxygen requirement is basically 660/990/1320 liter oxygen for crew at given temp. For pax gas system, the table is much more complex, 1 table for protective oxygen, 1 for 14000 level off time, and 1 for above variate level-off time above 14000. they gives you liter, then table 4 and 5 convert them into pressure under different temp. Well, good news for the crew is, our dispatch just give a minimum pressure requirement for such complex route based on hottest possible day, also another number for pax system as well. BTW it's required for flight crew to use supplementary oxygen whenever cabin altitude is above 10000', that includes when taking off/landing at such airport, we used to uses the normal crew oxygen system, but that would deplete it rather quickly and may to a point not able to dispatch for next leg, so now we use portable oxygen bottle in cockpit as well for high land operation.
@@umi3017 admittedly I made the comment before watching the whole video. I’ve been working on B737’s for over 28 years and never seen a gaseous passenger oxygen system on that type. It was never covered in any of the training material nor talked about. I’m guessing it’s a BOEING customer option?
I highly recommend all the work in the web site, book and videos resources is done with great passion ....and cab help any one wandering an airline interview or rating test understanding...believe me fcoms from those cie is much than 1k pages of pleasure....and very practically what I like with Mr Chris is the common good logic and daily crew life experience and that critical thinking and resolution or finding solutions that some time we don't teach in grounds schools 😉 so thanks sir we are all grateful for your work and help 👍
Thank you so much for all these insights Chris! Classroom training on masks isn't really helpful. For instance, nobody is thinking about wearing a pair of big sunglasses - works fine. Finding the controls of the mask it helps a lot to grab the hose and move your hand up to the mask. Your thumb will end up right at them.
Very interesting. Can I ask if there’s smoke why move to oxygen only on the FD? 100% oxygen creates more explosive environment. Is it purely because no supply of clean air other than the oxygen bottle. (Careful to differentiate between air and oxygen!)- is use of oxygen just to make best use of cylinder capacity ?
The dispatch table talks about cylinder temperature, is it still ok to consider OAT for those calculations?? I can't find how to check the cylinder temperature specifically
What’s the purpose of the supplemental system again ? I think you said it eliminates the generators at the seats. Why opt out of having the individual generators ? Custom interiors ?
@13:30 - I’m actually surprised there’s no temporary film like a 3M type that would protect the lenses from scratching and dust and dirt; Like with a tab where you could pull off the film and have a clean unscratched transparency
@@ChrisBrady737 Thanks Chris. btw, I noticed that this incident isn't showing up in your News page - last news item 20th Nov 2023 www.b737.org.uk/accident_news.htm
If I did, it would be along the lines of the FMC video. You cant really learn how to use the automation from a video, you have to use it in the sim or on the line.
@@ChrisBrady737 you're 100% right, i'll go watch your fmc video, all of your videos have been absolutely amazing to watch while reading the FCOM, hopefully Ryanair will be pleased with what i've learnt
Are either of the pressure relief systems burst discs, such that they will empty the whole bottle? If so, what’s going to happen if there’s an over pressure during a cabin decompression emergency? Make an emergency call to the purser to bring two of the portable bottles to the cockpit?
I'm not convinced by the hot day vs cold day for a bottle that isn't being serviced at the time. Consider a cylinder doing nothing. PV=nRT. n, R and V are fixed, so P goes up proportionally with T. Going from 1850 psi to 2600 psi is increasing P by about 1.4x. Starting with T at 294 K (21 degC), and scaling that up the same way gives you 411K (138 degC). Even the hottest day isn't going to trigger the pressure relief system. However, if someone fitted the wrong type of bottle (eg. a 300 bar cylinder), the relief system could prevent a lot of damage. The next relief valve protects the downstream pipework from a regulator failure. If you're unlucky enough to have that happen, it won't be 100 psi (which might do some damage), that's just the lower bound. You don't want to be near this thing if you can help it. To answer Pete's question - the pressure drop from a sudden decompression can't be much more than the cabin pressure safety relief valve rating, which is ~9 psi. Even if that failed, it isn't physically possible to drop more than 1 atm (14 psi) no matter how high you fly. That's a lot for people, but it's small change for a system operating at 1850 psi.
@@ChrisBrady737 I’m interested in the unlikely corner cases, though. Do I see insulation around the bottle? What if that caught fire? Could that be enough to cause the overpressure valve to burst?
Sadly it has been known for passengers to steal life jackets. This is part of the reason why the cabin crew need to check everything in between flights.
@@NicholasRiviera-Dr Yes in all of the airlines I have flown with they reach under the seat and touch them to ensure that they are still there. This forms part of the security check when looking for items that may have been left on board from the previous flight, and of course for general tidying up.
Thanks Chris. Appreciate the instructions on operation and stowage of the eros masks. Its not documented as well as it should be considering it's a critical bit of gear.
Yes, the FCOMs are a bit light on it. Glad the video helped.
@ChrisBrady737 tanks a lot for your effort and very comprehensive knowledge that you summarize into one fantastic and very useful video.
@hexatus thank you very much for your donation. Great to hear that you find the content useful.
Absolutely amazing information, Captain Brady. I'm looking forward to your updated guide, I'll definitely be grabbing it as soon as I can. While, unfortunately, I am not a real pilot, your videos really enhance my simulation experiences and make them feel more authentic. In my opinion, you have the best 737 channel
Thank you for your kind comments. It will take me a couple of months to produce the new book.
@@ChrisBrady737I'm having trouble getting hold of the original book. The books all seem to come from the USA even though you presumably are from the UK. It would be good if Waterstones have it.
Printed copies are still available. Use this link to order one from Blurb: www.b737.org.uk/book.htm
@@ChrisBrady737 Many thanks Chris. Just thought if there is a new edition coming out I might hold off. ✈️
Stainless steel lines aren't just used for quality btw, it's also for fire resistance. If there's a fire in the e&e bay, the last thing you want is for the lines to burn through depriving the crew of oxygen AND allowing high pressure o2 to blow directly onto the fire. Stainless is the best choice in terms of compatibility with o2 (the chromium forms a passive layer on contact with o2) and melting point. Much better overall choice than aluminum or titanium.
Great additional info as always. Thank you!
"Not for mile high couples" you are great Chris, thanks for a very illustrative presentation
You are welcome, thank you for watching
Captain Chris my man 👏🏽👏🏽 dope content. If you were my instructor for 737 type rating I would have be the best engineer in my country 🤣
Thank you very much for your kind comments
Thank you for making these videos, you are my go to when I need to brush up on my systems knowledge.
My pleasure, glad you are finding them useful.
My god these are so much better than those robot Boeing CBTs. Amazing work.
That is what I am aiming for, thank you!
thank you very much for sharing, extensively covered the topic.
My pleasure, thanks for watching
Hi Chris - Location of O2 bottles on BCFs - I see from the video at 1:09:38, that the bottles are stated to be "just aft of door 1L on the 9G bulkhead", which would make them inside the cargo compartment...? If I cross-reference this with the Freighters video at 1:00:00, the decompression door is just aft of the 1L door on the BCF... I think the O2 bottles on the BCF must then be on the supernumary vestibule side of the 9G bulkhead, which would make the bottles just aft of the *1R* door on the forward side on the 9G buklhead, not the 1L? Or perhaps just *forward* of the 1L door? I also think placing the bottles in the cargo compartment would make them susceptible to damage in the case that the cargo moved and impacted the 9G barrier, rendering them unusable or may breach them in an accident, which might ruin ones' day...
Thank you very much. Great technical details.
You are welcome, glad it was helpful
Some more note on pax gas system and pressure requirement:
From Boeing's presentation, 300lt protective oxygen for crew (15min as the claim) is the limit factor for normal 12/22min pax oxygen equipped aircraft, as the decent profile would not exceed that, so the normal chart for crew oxygen requirement is basically 660/990/1320 liter oxygen for crew at given temp.
For pax gas system, the table is much more complex, 1 table for protective oxygen, 1 for 14000 level off time, and 1 for above variate level-off time above 14000. they gives you liter, then table 4 and 5 convert them into pressure under different temp.
Well, good news for the crew is, our dispatch just give a minimum pressure requirement for such complex route based on hottest possible day, also another number for pax system as well.
BTW it's required for flight crew to use supplementary oxygen whenever cabin altitude is above 10000', that includes when taking off/landing at such airport, we used to uses the normal crew oxygen system, but that would deplete it rather quickly and may to a point not able to dispatch for next leg, so now we use portable oxygen bottle in cockpit as well for high land operation.
This is the B737 channel? Passenger oxygen is via chemical generators
@@NicholasRiviera-Dr 1:04:21
@umi3017 Thanks Umi, I always appreciate your input.
@@umi3017 admittedly I made the comment before watching the whole video. I’ve been working on B737’s for over 28 years and never seen a gaseous passenger oxygen system on that type. It was never covered in any of the training material nor talked about. I’m guessing it’s a BOEING customer option?
I highly recommend all the work in the web site, book and videos resources is done with great passion ....and cab help any one wandering an airline interview or rating test understanding...believe me fcoms from those cie is much than 1k pages of pleasure....and very practically what I like with Mr Chris is the common good logic and daily crew life experience and that critical thinking and resolution or finding solutions that some time we don't teach in grounds schools 😉 so thanks sir we are all grateful for your work and help 👍
Thank you very much for your kind comments. I am very pleased to hear that my work has been useful for your understanding of the aircraft.
I laughed a lot at the Darth Vader impersonation 😂
😂
Thank you captain well done
You are welcome, thank you for watching
Thank you so much for all these insights Chris!
Classroom training on masks isn't really helpful. For instance, nobody is thinking about wearing a pair of big sunglasses - works fine. Finding the controls of the mask it helps a lot to grab the hose and move your hand up to the mask. Your thumb will end up right at them.
There are somethings that you can’t learn from a manual. Hopefully this video will have helped some people
Very interesting. Can I ask if there’s smoke why move to oxygen only on the FD? 100% oxygen creates more explosive environment. Is it purely because no supply of clean air other than the oxygen bottle. (Careful to differentiate between air and oxygen!)- is use of oxygen just to make best use of cylinder capacity ?
Thanks Chris!
My pleasure
The dispatch table talks about cylinder temperature, is it still ok to consider OAT for those calculations?? I can't find how to check the cylinder temperature specifically
It is the best we can do. Arguably the cylinder is closer to the flightdeck temperature as it is in the E&E bay
What’s the purpose of the supplemental system again ? I think you said it eliminates the generators at the seats. Why opt out of having the individual generators ? Custom interiors ?
It is for when operating in very high mountainous terrain where you need more than the standard 12 or 22 minute pax oxygen.
I find it interesting that Temperature is given in both English and Metric units, whereas most other quantities are English units only.
The manuals usually have both units
@13:30 - I’m actually surprised there’s no temporary film like a 3M type that would protect the lenses from scratching and dust and dirt; Like with a tab where you could pull off the film and have a clean unscratched transparency
Like Formula 1 helmet visor tear-off strips!
Chris, are you planning a video on the rudder issue that N47280 suffered ?
Possibly. At the moment there isn't enough info to go on. I have compiled some info here: www.b737.org.uk/incident_n47280.htm
@@ChrisBrady737 Thanks Chris. btw, I noticed that this incident isn't showing up in your News page - last news item 20th Nov 2023 www.b737.org.uk/accident_news.htm
Is anyone else extremely upset that the decal showing the oxygen cylinder size says "02" and not "O2" ?
Thanks Captain
You are welcome
Love it!
Thank you!
Who the hell measures gas cylinders in cubic foot ffs
'MURICA🦅🦅🦅🦅🦅🦅🦅🦅🦅🏈🏈🏈🏈🏈🏈🏈🏈💥💥💥💥💥💥💥💥💥
is a chapter on automation ever gonna come out? need it for the type rating
If I did, it would be along the lines of the FMC video. You cant really learn how to use the automation from a video, you have to use it in the sim or on the line.
@@ChrisBrady737 you're 100% right, i'll go watch your fmc video, all of your videos have been absolutely amazing to watch while reading the FCOM, hopefully Ryanair will be pleased with what i've learnt
Are either of the pressure relief systems burst discs, such that they will empty the whole bottle? If so, what’s going to happen if there’s an over pressure during a cabin decompression emergency?
Make an emergency call to the purser to bring two of the portable bottles to the cockpit?
Only the overboard discharge line could empty the bottle. An overpressure in-flight is unlikely as the temperatures are colder.
I'm not convinced by the hot day vs cold day for a bottle that isn't being serviced at the time.
Consider a cylinder doing nothing. PV=nRT. n, R and V are fixed, so P goes up proportionally with T.
Going from 1850 psi to 2600 psi is increasing P by about 1.4x.
Starting with T at 294 K (21 degC), and scaling that up the same way gives you 411K (138 degC).
Even the hottest day isn't going to trigger the pressure relief system. However, if someone fitted the wrong type of bottle (eg. a 300 bar cylinder), the relief system could prevent a lot of damage.
The next relief valve protects the downstream pipework from a regulator failure. If you're unlucky enough to have that happen, it won't be 100 psi (which might do some damage), that's just the lower bound. You don't want to be near this thing if you can help it.
To answer Pete's question - the pressure drop from a sudden decompression can't be much more than the cabin pressure safety relief valve rating, which is ~9 psi. Even if that failed, it isn't physically possible to drop more than 1 atm (14 psi) no matter how high you fly. That's a lot for people, but it's small change for a system operating at 1850 psi.
All very good points.
@@ChrisBrady737 I’m interested in the unlikely corner cases, though. Do I see insulation around the bottle? What if that caught fire? Could that be enough to cause the overpressure valve to burst?
@@PetesGuideno insulation around the bottle
What is the reason an airline would select a PSU with life vests over under seat placement?
More space under the seat for cabin baggage and less likely to have the life vests damaged or stolen.
@@ChrisBrady737 Stolen? Or misplaced?
Sadly it has been known for passengers to steal life jackets. This is part of the reason why the cabin crew need to check everything in between flights.
@@ChrisBrady737are you suggesting that cabin crew check life vests under every seat before each flight?
@@NicholasRiviera-Dr Yes in all of the airlines I have flown with they reach under the seat and touch them to ensure that they are still there. This forms part of the security check when looking for items that may have been left on board from the previous flight, and of course for general tidying up.
The best place to learn about 737 system 👍🏼🛬
Thank you and thanks for watching
@@ChrisBrady737 All the best!
Always watching!
Thank you captain well done
You are welcome, thank you for watching