lowfareair
Topic Author
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Oxygen masks accidentally deployed by pilot - folding question

Thu Jan 02, 2020 2:20 am

On tonight's LHR-PHL flight BA 69, the pilot was trying to activate one oxygen mask for a specific request (not sure what that was, maybe a medical thing?) and accidentally activated all of the oxygen masks. It caused a bit of a stir, but cabin crew quickly came through the cabin to announce it was a false alarm.

While a surprising thing to happen obviously, the question I have is around the folding of the oxygen mask. It's clearly done in a specific way so it doesn't get tangled up when it is deployed, and judging by the return BA 68 flight getting cancelled, I'm guessing it is not a quick task to accomplish. In addition to what people would expect (mask, bag, tube, strap), there is a string with a pin at the end. When you pull the mask down, the pin comes out and (according to the cabin crew), oxygen starts flowing.

In the World Traveller Plus (Premium Economy) cabin, many/most of the masks appeared to have the strap folded into the oxygen pouch, and in the middle of trying to get the mask on, I thought that that string with the pin was actually a broken strap. It wasn't until after the false alarm was announced and I started actually looking at the mask that I realized that the strap was folded in the center of the pouch, and mine was not alone. The person in front of me thought the exact same thing when putting on his mask, and it seems it was common throughout the cabin.

Club World (Biz) didn't appear to have this issue, the masks that weren't grabbed had the straps dangling down rather than folded into the mask.

Pictures of what I am talking about in the past several paragraphs here.

Is there a specific regulation regarding where the strap should get folded with the mask? It seems like it is a safety issue where either the folding process needs to be refined so the straps are easier to see, or if they shouldn't be folded like they were, someone at BA/sub-contractor screwed up when installing them.
 
CriticalPoint
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Re: Oxygen masks accidentally deployed by pilot - folding question

Thu Jan 02, 2020 2:45 am

So I can’t directly answer your question because I honestly don’t know.

However I would like to comment on what deployed the mask.......someone lied to you!

The pilot cannot deploy just 1 mask when they hit the button they all come out.

You can deploy a mask over a seat with a manual tool, but in no way will that tool deploy the entire aircraft.

Also you would never use the overhead O2 mask for a medical reason. All aircraft have portable oxygen containers that provide on demand or continuous O2 depending on the medical issue. The overhead masks don’t last very long.
 
71Zulu
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Re: Oxygen masks accidentally deployed by pilot - folding question

Thu Jan 02, 2020 3:11 am

Amazing the pilot thought this was a good idea.


Sent from my SM-N960U using Tapatalk
 
DashTrash
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Re: Oxygen masks accidentally deployed by pilot - folding question

Thu Jan 02, 2020 3:35 am

71Zulu wrote:
Amazing the pilot thought this was a good idea.


Sent from my SM-N960U using Tapatalk

I’m guessing he didn’t. Rubber jungle deployments in this manner are solely accidental and require maintenance to stow them again.


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WayexTDI
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Re: Oxygen masks accidentally deployed by pilot - folding question

Thu Jan 02, 2020 4:05 am

CriticalPoint wrote:
So I can’t directly answer your question because I honestly don’t know.

However I would like to comment on what deployed the mask.......someone lied to you!

The pilot cannot deploy just 1 mask when they hit the button they all come out.

You can deploy a mask over a seat with a manual tool, but in no way will that tool deploy the entire aircraft.

Also you would never use the overhead O2 mask for a medical reason. All aircraft have portable oxygen containers that provide on demand or continuous O2 depending on the medical issue. The overhead masks don’t last very long.

Some planes have Medical O2 outlets in the overhead PSUs; maybe that's what was insinuated.
 
strfyr51
Posts: 4177
Joined: Tue Apr 10, 2012 5:04 pm

Re: Oxygen masks accidentally deployed by pilot - folding question

Thu Jan 02, 2020 6:31 am

lowfareair wrote:
On tonight's LHR-PHL flight BA 69, the pilot was trying to activate one oxygen mask for a specific request (not sure what that was, maybe a medical thing?) and accidentally activated all of the oxygen masks. It caused a bit of a stir, but cabin crew quickly came through the cabin to announce it was a false alarm.

While a surprising thing to happen obviously, the question I have is around the folding of the oxygen mask. It's clearly done in a specific way so it doesn't get tangled up when it is deployed, and judging by the return BA 68 flight getting cancelled, I'm guessing it is not a quick task to accomplish. In addition to what people would expect (mask, bag, tube, strap), there is a string with a pin at the end. When you pull the mask down, the pin comes out and (according to the cabin crew), oxygen starts flowing.

In the World Traveller Plus (Premium Economy) cabin, many/most of the masks appeared to have the strap folded into the oxygen pouch, and in the middle of trying to get the mask on, I thought that that string with the pin was actually a broken strap. It wasn't until after the false alarm was announced and I started actually looking at the mask that I realized that the strap was folded in the center of the pouch, and mine was not alone. The person in front of me thought the exact same thing when putting on his mask, and it seems it was common throughout the cabin.
. the probem
Club World (Biz) didn't appear to have this issue, from Scott the masks that weren't grabbed had the straps dangling down rather than folded into the mask.

Pictures of what I am talking about in the past several paragraphs here.

Is there a specific regulation regarding where the strap should get folded with the mask? It seems like it is a safety issue where either the folding process needs to be refined so the straps are easier to see, or if they shouldn't be folded like they were, someone at BA/sub-contractor screwed up when installing them.

the problem isn't just the masks being deployed, the Problem could be in inspecting and replacing any Oxygen Generators that may have been activated. Once the masks are deployed they not only have to be repacked and any fired off O2 chemical generators replaced.., they then have to have the deploy system tested to Insure they will all drop in an emergency which depending on the Aircraft ? Could take 12-15 hours after all the parts are procured and in place. In the USA? the Chemical Generators cannot be shipped by air and must be ground shipped from Scott Co. in St, Louis MO.
 
bluecrew
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Re: Oxygen masks accidentally deployed by pilot - folding question

Thu Jan 02, 2020 7:16 am

WayexTDI wrote:
Some planes have Medical O2 outlets in the overhead PSUs; maybe that's what was insinuated.

Commercial? Or private/medical evac? Never seen that on any aircraft I've worked on. It also adds more complexity (and importantly, weight) to the PSU, increases fire risk if you're storing oxygen up there.
For medical reasons we have POBs onboard, often more than enough for all the cabin crew, jumpseaters, and 2-5 extra depending on the equipment. On the E190 there are more POBs than you could possibly know what to do with (at least at B6).
 
bluecrew
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Re: Oxygen masks accidentally deployed by pilot - folding question

Thu Jan 02, 2020 7:19 am

CriticalPoint wrote:
Also you would never use the overhead O2 mask for a medical reason. All aircraft have portable oxygen containers that provide on demand or continuous O2 depending on the medical issue. The overhead masks don’t last very long.

Correct. Also, the overhead mask is not an O2 supply, it is a chemical oxygen generator.
That's the last thing you'd use in a medical situation, even if desperate.

Plus you can MEL a portable oxygen bottle, in some cases if you don't use enough of it and the pressure is high enough you just get a new mask and you don't even need to defer it.

You can not MEL an overhead O2 mask. That plane will be going out of service.
 
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Starlionblue
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Re: Oxygen masks accidentally deployed by pilot - folding question

Thu Jan 02, 2020 7:47 am

bluecrew wrote:
CriticalPoint wrote:
Also you would never use the overhead O2 mask for a medical reason. All aircraft have portable oxygen containers that provide on demand or continuous O2 depending on the medical issue. The overhead masks don’t last very long.

Correct. Also, the overhead mask is not an O2 supply, it is a chemical oxygen generator.
That's the last thing you'd use in a medical situation, even if desperate.

Plus you can MEL a portable oxygen bottle, in some cases if you don't use enough of it and the pressure is high enough you just get a new mask and you don't even need to defer it.

You can not MEL an overhead O2 mask. That plane will be going out of service.


You can in fact MEL an overhead O2 mask module, provided the associated seats are "considered inoperative", i.e. may not be occupied in flight.

A chemical oxygen generator also supplies O2, so it is a supply of O2. ;) And many aircraft have gaseous oxygen instead of generators, typically in order to meet requirements for extended depressurised flight over high terrain. The 777 and A350 come to mind.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
unimproved
Posts: 138
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Re: Oxygen masks accidentally deployed by pilot - folding question

Thu Jan 02, 2020 10:22 am

strfyr51 wrote:
lowfareair wrote:
On tonight's LHR-PHL flight BA 69, the pilot was trying to activate one oxygen mask for a specific request (not sure what that was, maybe a medical thing?) and accidentally activated all of the oxygen masks. It caused a bit of a stir, but cabin crew quickly came through the cabin to announce it was a false alarm.

While a surprising thing to happen obviously, the question I have is around the folding of the oxygen mask. It's clearly done in a specific way so it doesn't get tangled up when it is deployed, and judging by the return BA 68 flight getting cancelled, I'm guessing it is not a quick task to accomplish. In addition to what people would expect (mask, bag, tube, strap), there is a string with a pin at the end. When you pull the mask down, the pin comes out and (according to the cabin crew), oxygen starts flowing.

In the World Traveller Plus (Premium Economy) cabin, many/most of the masks appeared to have the strap folded into the oxygen pouch, and in the middle of trying to get the mask on, I thought that that string with the pin was actually a broken strap. It wasn't until after the false alarm was announced and I started actually looking at the mask that I realized that the strap was folded in the center of the pouch, and mine was not alone. The person in front of me thought the exact same thing when putting on his mask, and it seems it was common throughout the cabin.
. the probem
Club World (Biz) didn't appear to have this issue, from Scott the masks that weren't grabbed had the straps dangling down rather than folded into the mask.

Pictures of what I am talking about in the past several paragraphs here.

Is there a specific regulation regarding where the strap should get folded with the mask? It seems like it is a safety issue where either the folding process needs to be refined so the straps are easier to see, or if they shouldn't be folded like they were, someone at BA/sub-contractor screwed up when installing them.

the problem isn't just the masks being deployed, the Problem could be in inspecting and replacing any Oxygen Generators that may have been activated. Once the masks are deployed they not only have to be repacked and any fired off O2 chemical generators replaced.., they then have to have the deploy system tested to Insure they will all drop in an emergency which depending on the Aircraft ? Could take 12-15 hours after all the parts are procured and in place. In the USA? the Chemical Generators cannot be shipped by air and must be ground shipped from Scott Co. in St, Louis MO.

The drop test isn't too bad, at least on the 777. You install a pin in each box that makes its open only a little bit so that the masks don't drop out.
 
chimborazo
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Re: Oxygen masks accidentally deployed by pilot - folding question

Thu Jan 02, 2020 10:27 am

bluecrew wrote:
WayexTDI wrote:
Some planes have Medical O2 outlets in the overhead PSUs; maybe that's what was insinuated.

Commercial? Or private/medical evac? Never seen that on any aircraft I've worked on. It also adds more complexity (and importantly, weight) to the PSU, increases fire risk if you're storing oxygen up there.
For medical reasons we have POBs onboard, often more than enough for all the cabin crew, jumpseaters, and 2-5 extra depending on the equipment. On the E190 there are more POBs than you could possibly know what to do with (at least at B6).


I can’t remember which planes or airlines but many times I’ve seen a bank of canisters which I assume are oxygen in the overhead bins (possible A32-) series aircraft. With “no stowage sign” on the bottom lip on that section of the open bin. Half the bin is canisters/piping and the other half for bags, again, as I recall, near the longitudinal middle of the plane. Possibly BA as I usually get exit row seats, but haven’t flown short haul BA for over a year.

The little black triangles on the PSUs/handrails indicate where there is a connection for emergency oxygen for crew to plug in to (possibly also for medical use).

I’d prefer there to be a fire in the PSU where it can be seen than in the hold where it can’t (despite having fire extinguishers down below). Now a cylinder exploding in the PSU or in the hold... tough choice! Either way, when was the last time we heard about an O2 cylinder going pop?
 
lowfareair
Topic Author
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Re: Oxygen masks accidentally deployed by pilot - folding question

Thu Jan 02, 2020 10:46 am

Thanks, some great information here. To clarify, I don't believe the pilot was trying to activate an in-seat oxygen mask, but rather some O2 device on the aircraft and hit the wrong switch.

One other thing that I thought was interesting and smart - when the oxygen masks are deployed, the IFE immediately turns off. Makes sense, so it removes that distraction.
 
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zeke
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Re: Oxygen masks accidentally deployed by pilot - folding question

Thu Jan 02, 2020 11:05 am

chimborazo wrote:
The little black triangles on the PSUs/handrails indicate where there is a connection for emergency oxygen for crew to plug in to (possibly also for medical use).


No the black triangle in Airbus aircraft is where a pilot can immediately identify the window where the flap extension can be verified. There is marks on the flap that can be observed from that window.
Human rights lawyers are "ambulance chasers of the very worst kind.'" - Sky News
 
ChrisKen
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Re: Oxygen masks accidentally deployed by pilot - folding question

Thu Jan 02, 2020 12:19 pm

zeke wrote:
chimborazo wrote:
The little black triangles on the PSUs/handrails indicate where there is a connection for emergency oxygen for crew to plug in to (possibly also for medical use).


No the black triangle in Airbus aircraft is where a pilot can immediately identify the window where the flap extension can be verified. There is marks on the flap that can be observed from that window.

That mark is usually on the sidewall directly above the window, not the bins/PSU rail but it's meaning (viewpoint) is correct.
Not sure if Boeing use the same marking/location or indeed bother with it. Been a while since I've had the misfortune to fly anything Boeing so memory recall isn't helping.


The Emergency Oxygen system IS NOT under any cirumcstances used to provide theraputic oxygen even in medical emergencies, as the system fails to supply enough O2 to overcome Dalton's law. (Legal, safety and maintenance factors also come into play below that).
 
lowfareair
Topic Author
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Re: Oxygen masks accidentally deployed by pilot - folding question

Thu Jan 02, 2020 12:36 pm

strfyr51 wrote:
lowfareair wrote:
On tonight's LHR-PHL flight BA 69, the pilot was trying to activate one oxygen mask for a specific request (not sure what that was, maybe a medical thing?) and accidentally activated all of the oxygen masks. It caused a bit of a stir, but cabin crew quickly came through the cabin to announce it was a false alarm.

While a surprising thing to happen obviously, the question I have is around the folding of the oxygen mask. It's clearly done in a specific way so it doesn't get tangled up when it is deployed, and judging by the return BA 68 flight getting cancelled, I'm guessing it is not a quick task to accomplish. In addition to what people would expect (mask, bag, tube, strap), there is a string with a pin at the end. When you pull the mask down, the pin comes out and (according to the cabin crew), oxygen starts flowing.

In the World Traveller Plus (Premium Economy) cabin, many/most of the masks appeared to have the strap folded into the oxygen pouch, and in the middle of trying to get the mask on, I thought that that string with the pin was actually a broken strap. It wasn't until after the false alarm was announced and I started actually looking at the mask that I realized that the strap was folded in the center of the pouch, and mine was not alone. The person in front of me thought the exact same thing when putting on his mask, and it seems it was common throughout the cabin.
. the probem
Club World (Biz) didn't appear to have this issue, from Scott the masks that weren't grabbed had the straps dangling down rather than folded into the mask.

Pictures of what I am talking about in the past several paragraphs here.

Is there a specific regulation regarding where the strap should get folded with the mask? It seems like it is a safety issue where either the folding process needs to be refined so the straps are easier to see, or if they shouldn't be folded like they were, someone at BA/sub-contractor screwed up when installing them.

the problem isn't just the masks being deployed, the Problem could be in inspecting and replacing any Oxygen Generators that may have been activated. Once the masks are deployed they not only have to be repacked and any fired off O2 chemical generators replaced.., they then have to have the deploy system tested to Insure they will all drop in an emergency which depending on the Aircraft ? Could take 12-15 hours after all the parts are procured and in place. In the USA? the Chemical Generators cannot be shipped by air and must be ground shipped from Scott Co. in St, Louis MO.


Looks like the plane (G-VIIB) was ferried back to LHR as BA9154 overnight. Makes sense as they can probably procure most of the materials and staff for this at LHR whereas there isn't even another airline flying the 777 into PHL at the moment.
 
WayexTDI
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Re: Oxygen masks accidentally deployed by pilot - folding question

Thu Jan 02, 2020 12:56 pm

bluecrew wrote:
WayexTDI wrote:
Some planes have Medical O2 outlets in the overhead PSUs; maybe that's what was insinuated.

Commercial? Or private/medical evac? Never seen that on any aircraft I've worked on. It also adds more complexity (and importantly, weight) to the PSU, increases fire risk if you're storing oxygen up there.
For medical reasons we have POBs onboard, often more than enough for all the cabin crew, jumpseaters, and 2-5 extra depending on the equipment. On the E190 there are more POBs than you could possibly know what to do with (at least at B6).

Seen it on commercial planes. I doubt O2 would be stored for this purpose in the PSU (as it'd be gaseous O2 and not a COG).
Remember, you already have O2 stored in the PSU for planes equipped with COGs.
 
WayexTDI
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Re: Oxygen masks accidentally deployed by pilot - folding question

Thu Jan 02, 2020 1:02 pm

chimborazo wrote:
bluecrew wrote:
WayexTDI wrote:
Some planes have Medical O2 outlets in the overhead PSUs; maybe that's what was insinuated.

Commercial? Or private/medical evac? Never seen that on any aircraft I've worked on. It also adds more complexity (and importantly, weight) to the PSU, increases fire risk if you're storing oxygen up there.
For medical reasons we have POBs onboard, often more than enough for all the cabin crew, jumpseaters, and 2-5 extra depending on the equipment. On the E190 there are more POBs than you could possibly know what to do with (at least at B6).


I can’t remember which planes or airlines but many times I’ve seen a bank of canisters which I assume are oxygen in the overhead bins (possible A32-) series aircraft. With “no stowage sign” on the bottom lip on that section of the open bin. Half the bin is canisters/piping and the other half for bags, again, as I recall, near the longitudinal middle of the plane. Possibly BA as I usually get exit row seats, but haven’t flown short haul BA for over a year.

The little black triangles on the PSUs/handrails indicate where there is a connection for emergency oxygen for crew to plug in to (possibly also for medical use).

I’d prefer there to be a fire in the PSU where it can be seen than in the hold where it can’t (despite having fire extinguishers down below). Now a cylinder exploding in the PSU or in the hold... tough choice! Either way, when was the last time we heard about an O2 cylinder going pop?

When the O2 cylinders are stored in the overhead bins, they are portable; never seen one hard-piped to a distribution network.

When was the last time we heard about an O2 cylinder go pop? Can only think of QF 30, July 25 2008. Quite a while ago.
 
Flow2706
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Re: Oxygen masks accidentally deployed by pilot - folding question

Thu Jan 02, 2020 4:13 pm

unimproved wrote:
The drop test isn't too bad, at least on the 777. You install a pin in each box that makes its open only a little bit so that the masks don't drop out.

Image
That's how a drop test looks on an A320 - the box opens just very slightly...
 
Tristarsteve
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Joined: Tue Nov 22, 2005 11:04 pm

Re: Oxygen masks accidentally deployed by pilot - folding question

Thu Jan 02, 2020 4:42 pm

lowfareair wrote:
Thanks, some great information here. To clarify, I don't believe the pilot was trying to activate an in-seat oxygen mask, but rather some O2 device on the aircraft and hit the wrong switch.

One other thing that I thought was interesting and smart - when the oxygen masks are deployed, the IFE immediately turns off. Makes sense, so it removes that distraction.


Correct.

The BA B777 (and B744) have a gaseous passenger oxygen system fed by rows of oxygen bottles in the freight hold sidewall. There are no generators.
There are two oxygen switches on the overhead P5 panel
One marked Pass Oxygen Reset/Arm/On and the other Therapeutic Oxygen Reset/Norm/On.
The same bottles and plumbing is used for both systems. A separate therapeutic outlet is fitted to some PSUs.
When a passenger needs oxygen, the cabin crew ask the pilot to switch on the therapeutic supply. This pressurises the ring main.
The crew then plug in a mask to the nearest outlet. On a long flight this saves the use of multiple portable bottles.

The pilot operated the wrong oxygen switch.
 
lowfareair
Topic Author
Posts: 275
Joined: Fri Jun 17, 2016 4:40 pm

Re: Oxygen masks accidentally deployed by pilot - folding question

Thu Jan 02, 2020 5:55 pm

Tristarsteve wrote:
lowfareair wrote:
Thanks, some great information here. To clarify, I don't believe the pilot was trying to activate an in-seat oxygen mask, but rather some O2 device on the aircraft and hit the wrong switch.

One other thing that I thought was interesting and smart - when the oxygen masks are deployed, the IFE immediately turns off. Makes sense, so it removes that distraction.


Correct.

The BA B777 (and B744) have a gaseous passenger oxygen system fed by rows of oxygen bottles in the freight hold sidewall. There are no generators.
There are two oxygen switches on the overhead P5 panel
One marked Pass Oxygen Reset/Arm/On and the other Therapeutic Oxygen Reset/Norm/On.
The same bottles and plumbing is used for both systems. A separate therapeutic outlet is fitted to some PSUs.
When a passenger needs oxygen, the cabin crew ask the pilot to switch on the therapeutic supply. This pressurises the ring main.
The crew then plug in a mask to the nearest outlet. On a long flight this saves the use of multiple portable bottles.

The pilot operated the wrong oxygen switch.


Thank you for that detailed response! Thoughts on the question I asked originally, as I haven't seen anyone comment on how the strap is folded in. Probably me thinking about it with a mask in front of me for 3 hours, but if I and at least one other person in the 40 person Prem Eco cabin (I overheard him, I didn't go around asking everybody if they noticed an issue) thought that the pin string was a broken strap, that folding of the actual strap into the bag could be an issue in an actual emergency.
 
Tristarsteve
Posts: 3631
Joined: Tue Nov 22, 2005 11:04 pm

Re: Oxygen masks accidentally deployed by pilot - folding question

Thu Jan 02, 2020 6:28 pm

Just had a read of the B777 AMM.
The main cabin centre oxygen mask is packed by
a. Put the headband lengthwise onto the open bag. Fold the bag into thirds over the headband.
followed by an A4 page of instructions.
It seems that yours are correct.
I have restowed dropped masks on the ramp before. Usually on our B767. It is very difficult to do as you have to roll up three masks and put them in the box and shut the door without dropping any. (It would be so easy to turn the aircraft upside down!!) It is very hard to get it right.
 
hotelmode
Posts: 194
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Re: Oxygen masks accidentally deployed by pilot - folding question

Thu Jan 02, 2020 10:01 pm

Tristarsteve wrote:
lowfareair wrote:
Thanks, some great information here. To clarify, I don't believe the pilot was trying to activate an in-seat oxygen mask, but rather some O2 device on the aircraft and hit the wrong switch.

One other thing that I thought was interesting and smart - when the oxygen masks are deployed, the IFE immediately turns off. Makes sense, so it removes that distraction.


Correct.

The BA B777 (and B744) have a gaseous passenger oxygen system fed by rows of oxygen bottles in the freight hold sidewall. There are no generators.
There are two oxygen switches on the overhead P5 panel
One marked Pass Oxygen Reset/Arm/On and the other Therapeutic Oxygen Reset/Norm/On.
The same bottles and plumbing is used for both systems. A separate therapeutic outlet is fitted to some PSUs.
When a passenger needs oxygen, the cabin crew ask the pilot to switch on the therapeutic supply. This pressurises the ring main.
The crew then plug in a mask to the nearest outlet. On a long flight this saves the use of multiple portable bottles.

The pilot operated the wrong oxygen switch.


Not necessarily. If the therapeutic oxygen is not correctly fitted and turned on by the cabin crew then the action of turning the therapeutic oxygen on in the flight deck will likely also cause the masks to drop too.
 
Lpbri
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Re: Oxygen masks accidentally deployed by pilot - folding question

Fri Jan 03, 2020 1:52 am

The therapeutic oxygen system must be a customer option. Never heard of it.
 
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Starlionblue
Posts: 19574
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Re: Oxygen masks accidentally deployed by pilot - folding question

Fri Jan 03, 2020 2:58 am

Lpbri wrote:
The therapeutic oxygen system must be a customer option. Never heard of it.


The MEL I'm looking at has a graph with diversion time and number of pax giving the number of required portable O2 bottles. The lines start at 60 minutes, which leads me to the conclusion that if you're not doing EDTO/ETOPS you might not need them. And regulatory environments vary.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
bluecrew
Posts: 30
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Re: Oxygen masks accidentally deployed by pilot - folding question

Fri Jan 03, 2020 8:34 am

Starlionblue wrote:
bluecrew wrote:
CriticalPoint wrote:
Also you would never use the overhead O2 mask for a medical reason. All aircraft have portable oxygen containers that provide on demand or continuous O2 depending on the medical issue. The overhead masks don’t last very long.

Correct. Also, the overhead mask is not an O2 supply, it is a chemical oxygen generator.
That's the last thing you'd use in a medical situation, even if desperate.

Plus you can MEL a portable oxygen bottle, in some cases if you don't use enough of it and the pressure is high enough you just get a new mask and you don't even need to defer it.

You can not MEL an overhead O2 mask. That plane will be going out of service.


You can in fact MEL an overhead O2 mask module, provided the associated seats are "considered inoperative", i.e. may not be occupied in flight.

A chemical oxygen generator also supplies O2, so it is a supply of O2. ;) And many aircraft have gaseous oxygen instead of generators, typically in order to meet requirements for extended depressurised flight over high terrain. The 777 and A350 come to mind.

Learn something new every day. Thank you.
My experience with the 777 and A350 have only been parked in a pax seat.
Is this a common option? I have never heard it mentioned or referenced among any US carriers, though, admittedly, my experience with that is limited.

Only experience with (a few) masks dropping was a flight down south and (contract, admittedly) MX took the plane out of service overnight. Turned into a nice overnight at a hotel we had no right to stay at though...

Lpbri wrote:
The therapeutic oxygen system must be a customer option. Never heard of it.

Likewise. Never encountered it or heard of it. That's definitely a new one for me.
 
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Starlionblue
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Re: Oxygen masks accidentally deployed by pilot - folding question

Fri Jan 03, 2020 8:57 am

bluecrew wrote:
Starlionblue wrote:
bluecrew wrote:
Correct. Also, the overhead mask is not an O2 supply, it is a chemical oxygen generator.
That's the last thing you'd use in a medical situation, even if desperate.

Plus you can MEL a portable oxygen bottle, in some cases if you don't use enough of it and the pressure is high enough you just get a new mask and you don't even need to defer it.

You can not MEL an overhead O2 mask. That plane will be going out of service.


You can in fact MEL an overhead O2 mask module, provided the associated seats are "considered inoperative", i.e. may not be occupied in flight.

A chemical oxygen generator also supplies O2, so it is a supply of O2. ;) And many aircraft have gaseous oxygen instead of generators, typically in order to meet requirements for extended depressurised flight over high terrain. The 777 and A350 come to mind.

Learn something new every day. Thank you.
My experience with the 777 and A350 have only been parked in a pax seat.
Is this a common option? I have never heard it mentioned or referenced among any US carriers, though, admittedly, my experience with that is limited.

Only experience with (a few) masks dropping was a flight down south and (contract, admittedly) MX took the plane out of service overnight. Turned into a nice overnight at a hotel we had no right to stay at though...

Lpbri wrote:
The therapeutic oxygen system must be a customer option. Never heard of it.

Likewise. Never encountered it or heard of it. That's definitely a new one for me.


Chemical oxygen generators only give you 15-20 minutes, which is fine if you can immediately descend to 10000 feet. On some of our routes, particularly over Central Asia, we might be over very high ground for hours, and we can't immediately descend to a safe altitude in case of depressurisation. So we need 40+ minutes of oxygen for pax. Hence the bottles.

AFAIK the 777 has large oxygen bottles in the cargo hold. The A350 has small bottles (IIRC) pressurised at 5000 PSI stored next to the masks. Same principle, different architecture.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
Tristarsteve
Posts: 3631
Joined: Tue Nov 22, 2005 11:04 pm

Re: Oxygen masks accidentally deployed by pilot - folding question

Fri Jan 03, 2020 11:35 am

hotelmode wrote:
Tristarsteve wrote:
lowfareair wrote:
Thanks, some great information here. To clarify, I don't believe the pilot was trying to activate an in-seat oxygen mask, but rather some O2 device on the aircraft and hit the wrong switch.

One other thing that I thought was interesting and smart - when the oxygen masks are deployed, the IFE immediately turns off. Makes sense, so it removes that distraction.


Correct.

The BA B777 (and B744) have a gaseous passenger oxygen system fed by rows of oxygen bottles in the freight hold sidewall. There are no generators.
There are two oxygen switches on the overhead P5 panel
One marked Pass Oxygen Reset/Arm/On and the other Therapeutic Oxygen Reset/Norm/On.
The same bottles and plumbing is used for both systems. A separate therapeutic outlet is fitted to some PSUs.
When a passenger needs oxygen, the cabin crew ask the pilot to switch on the therapeutic supply. This pressurises the ring main.
The crew then plug in a mask to the nearest outlet. On a long flight this saves the use of multiple portable bottles.

The pilot operated the wrong oxygen switch.


Not necessarily. If the therapeutic oxygen is not correctly fitted and turned on by the cabin crew then the action of turning the therapeutic oxygen on in the flight deck will likely also cause the masks to drop too.


On the BA B744 I can understand that, the door latches are opened by oxygen pressure.
But this was a BA B777-200. The PSU door latches are opened electrically. There is no electrical connection from the therapeutic outlet.
 
strfyr51
Posts: 4177
Joined: Tue Apr 10, 2012 5:04 pm

Re: Oxygen masks accidentally deployed by pilot - folding question

Sat Jan 04, 2020 3:44 am

unimproved wrote:
strfyr51 wrote:
lowfareair wrote:
On tonight's LHR-PHL flight BA 69, the pilot was trying to activate one oxygen mask for a specific request (not sure what that was, maybe a medical thing?) and accidentally activated all of the oxygen masks. It caused a bit of a stir, but cabin crew quickly came through the cabin to announce it was a false alarm.

While a surprising thing to happen obviously, the question I have is around the folding of the oxygen mask. It's clearly done in a specific way so it doesn't get tangled up when it is deployed, and judging by the return BA 68 flight getting cancelled, I'm guessing it is not a quick task to accomplish. In addition to what people would expect (mask, bag, tube, strap), there is a string with a pin at the end. When you pull the mask down, the pin comes out and (according to the cabin crew), oxygen starts flowing.

In the World Traveller Plus (Premium Economy) cabin, many/most of the masks appeared to have the strap folded into the oxygen pouch, and in the middle of trying to get the mask on, I thought that that string with the pin was actually a broken strap. It wasn't until after the false alarm was announced and I started actually looking at the mask that I realized that the strap was folded in the center of the pouch, and mine was not alone. The person in front of me thought the exact same thing when putting on his mask, and it seems it was common throughout the cabin.
. the probem
Club World (Biz) didn't appear to have this issue, from Scott the masks that weren't grabbed had the straps dangling down rather than folded into the mask.

Pictures of what I am talking about in the past several paragraphs here.

Is there a specific regulation regarding where the strap should get folded with the mask? It seems like it is a safety issue where either the folding process needs to be refined so the straps are easier to see, or if they shouldn't be folded like they were, someone at BA/sub-contractor screwed up when installing them.

the problem isn't just the masks being deployed, the Problem could be in inspecting and replacing any Oxygen Generators that may have been activated. Once the masks are deployed they not only have to be repacked and any fired off O2 chemical generators replaced.., they then have to have the deploy system tested to Insure they will all drop in an emergency which depending on the Aircraft ? Could take 12-15 hours after all the parts are procured and in place. In the USA? the Chemical Generators cannot be shipped by air and must be ground shipped from Scott Co. in St, Louis MO.

The drop test isn't too bad, at least on the 777. You install a pin in each box that makes its open only a little bit so that the masks don't drop out.

and when have you ever seen all the latches release on the first test? Folding and stowing the masks is easy. Insuring that all the doors release is the Pain.
 
889091
Posts: 31
Joined: Sat Apr 06, 2019 7:56 pm

Re: Oxygen masks accidentally deployed by pilot - folding question

Mon Jan 06, 2020 6:46 pm

After the masks were accidentally deployed, was the remainder of the flight restricted to FL100?
 
Tristarsteve
Posts: 3631
Joined: Tue Nov 22, 2005 11:04 pm

Re: Oxygen masks accidentally deployed by pilot - folding question

Mon Jan 06, 2020 7:58 pm

No need with a gaseous system. You only lose a tiny amount of O2, so can continue.
With generators, you have a problem.
 
strfyr51
Posts: 4177
Joined: Tue Apr 10, 2012 5:04 pm

Re: Oxygen masks accidentally deployed by pilot - folding question

Mon Jan 06, 2020 11:15 pm

chimborazo wrote:
bluecrew wrote:
WayexTDI wrote:
Some planes have Medical O2 outlets in the overhead PSUs; maybe that's what was insinuated.

Commercial? Or private/medical evac? Never seen that on any aircraft I've worked on. It also adds more complexity (and importantly, weight) to the PSU, increases fire risk if you're storing oxygen up there.
For medical reasons we have POBs onboard, often more than enough for all the cabin crew, jumpseaters, and 2-5 extra depending on the equipment. On the E190 there are more POBs than you could possibly know what to do with (at least at B6).


I can’t remember which planes or airlines but many times I’ve seen a bank of canisters which I assume are oxygen in the overhead bins (possible A32-) series aircraft. With “no stowage sign” on the bottom lip on that section of the open bin. Half the bin is canisters/piping and the other half for bags, again, as I recall, near the longitudinal middle of the plane. Possibly BA as I usually get exit row seats, but haven’t flown short haul BA for over a year.

The little black triangles on the PSUs/handrails indicate where there is a connection for emergency oxygen for crew to plug in to (possibly also for medical use).

I’d prefer there to be a fire in the PSU where it can be seen than in the hold where it can’t (despite having fire extinguishers down below). Now a cylinder exploding in the PSU or in the hold... tough choice! Either way, when was the last time we heard about an O2 cylinder going pop?

the cargo pits have fore suppression already the O2 bottles you mention are for Emergency and Cabin crew walkaround bottles just for emergencies. The 747 Bottles were ok but if there were a leak? The distribution system could be a Bear to Troubleshoot. We used to use a Helium test rig to find leaks with a Helium detector to sound the alarm of a Leak. It really worked pretty well.

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