Three views of an A-8B oxygen mask. © Bluelight

Message 197:
Hello Ron, The A-8B was a constant flow 02 mask, patterned after the original design by Boothby, Lovelace, and Bulbillion (the mask was originally known as the BLB mask), and one of a continuing series of refinements of this old oronasal type mask. The 'bag' you refer to is a rebreathing reservoir to concentrate the 02 for 02 enrichment. The A-8 type mask was originally used in all aircraft of the 30s era, latter replaced by A-9, A-10, and A-14 Diluter-Demand type oxygen masks. However, the mask found a certain application in circumstances wherein a simple, constant flow 02 supply was all that was needed (hypobaric chambers, etc.). As Bill Cook pointed out, this caused the A-8B type mask to remain in use for those odd applications well into the 60s, even through the design harkens back originally to the early 30s. Use of the the rebreathing bag type mask was superseded by development of the Diluter-Demand regulator, which entrained ambient air and mixed it with oxygen to provide the concentration appropriate to the need of the user. As you probably know, for flight above 25 or 30 feet use of the Pressure-Demand system became mandated (hence development of the A-13 series in late 1944, that later became MS22001 designated and remained in use well into the 80s, in various forms). The books Bill Cook refers to are excellent sources of definitive technical information about and history on all of the American 30s & 40s 02 aviation 02 masks, from the original "Pipe-stem" constant flow system through the A-13 Pressure-Demand type. Hope this is of some help. Cheers, Chris Carey.

Message 196:
The A-8 was introduced as a replacement to the A-7 Ora-nasal mask. It covered the mouth and nose and was a constant flow mask. There was a rebreather bag attached. The mask was quickly modified to A8-A and then A8-B and it was replaced in service fairly quickly as well. The mask is still being produced today by Scott Aviation as an emergency mask. The WWII masks had a bakelite nose bridge piece and leather straps. Later masks had a green plastic nose bridge piece and elastic straps. I have attached a couple pictures. One is a fairly current mask, the other is 1947 dated and in the process of restoration. Note it has elastic straps, while earlier versions had leather straps. Hope this helps, Steve

Message 194:
The A-8B was actually used up into the 1960's, mainly for training in those high altitude tanks. I have seen photos that date to that period. I even beleive that there is a photo of the Mercury astronauts using them in the altitude chamber. This is why you see some A-8 's with sage green nylon straps. they were made into the 60's. Bill Cook
-------------------original message---------------
> Does anybody know when the A-8B was used and are there any
> pictures of this mask around? That way I can see what I am
> missing. I have the face piece, two black plastic cups, two valves,
> one hose, two elastic black straps and some clamps. No mic or
> comm cord. Thanks, Ron