MS22001, A-13 series and MBU-3/P oxygen masks
Article on Flightgear On-Line
Latest update 14 April 2006

Message 76:
In looking through my files, I found an extremely interesting reference to an oxygen mask. I am trying to determine if the mask was actually produced. The mystery mask is USAF, late 1950s or early 1960s dated. It will look like an MS-22001 oxygen mask using a Hardman kit and o-mask bayonets (Can't tell which style bayonets). The mask I am searching for should be marked with the military specification MIL-M-26653 and have a standard 3 pin bayonet connector on the end of the hose.Looks like the hardshell is blue (probably a dark green headed towards blue). I realize it will be a pain to look at the MS-22001s in your respective collections but I am hoping one of you might have one of these. Good Luck and Happy hunting, Steve Norris

Message 178:
Did the USAF use rubber and silicone MS22001 masks?
Only rubber. Rich Mays

Message 453:
A-13A 02 masks progressed through several mic upgrades, in both USAF and USN applications, as newer com systems came into use. Original (1945) USAF and USN A-13A mics were identical to those used in the A-14A series masks and were basic carbon element mics, designated ANB-M-C1; they usually were paired with cords that ended in PL-291 (short wire, USN) or PJ-292 (long wire, either service) connectors for use on USAF helmets that had pigtail com cords. Later, improved headphone/communications systems resulted in mandatory use of newer dynamic mics. Most typical and common among the newer mics used with a few late model USAF A-13A and MS22001 masks was the M-32B/AIC, which could be paired with several com cords, depending upon which type of helmet earphone/communications set and aircraft radio system it was being configured for. The M-32B/AIC mic was in tern replaced by the M101/AIC in USAF applications, which was common to MBU-5/P (and newer), masks but the M101/AIC could as well be retrofitted to MS22001 masks. Attached is a photo image of the ANB-M-C1 mic and the M-32B/AIC mic. The M101/AIC we are all familiar with (I am assuming). The US Navy kept the A-13A designation for its masks through the 50s and into the 60s, whereas the USAF adopted the MS22001 designation that was sometimes follows by a suffix "dash" number to indicate specific model during then Korean War period (i.e. MS22001-7). Therefore many early Korean War era USAF helmets are correctly paired with A-13A masks and the ANB-M-C1 mic; later war issue helmets and most USAF helmets of the 50s were used with MS22001 type masks (or with A-14B, MBU-4/P, and MBU-3/P masks) fitted with the M-32B/AIC. The "typical" late 50s/early 60s USAF masks are invariably fitted with the M-32B/AIC type mic. Of note is the fact that here were, technically speaking, several minor differences in the A-13A and MS22001 masks. These involved mask suspension straps and harness, fittings, connectors, etc., and at this point "standard config" understandings became substantially more complex, accordingly. This is a grossly simplified explanation, but I hope it helps. Cheers, Chris

ANB-M-1 (left) and H-32/AIC microphones used in early USAF A-13A and MS22001 oxygen masks. Picture DocBoink. Click on thumbnail for larger picture.

Message 541:
The A-13 mask was the first American pressure demand aviation mask produced in America, being developed in about late 1944. The A-13 mask was slightly modified and standardised as the familiar A-13A which the Navy and Air Force used in the late 40s and early 50s until the A-13A (with a few minor changes again) became standardised as the MS22001 oxygen mask. The US Navy continued to use the original A-13A through the late 50s, later going to the MS22001 also. In view of this history, this example is an extremely rare and very, very difficult to find precursor to the well known MS22001 mask. The original A-13 mask was usable as either a standard demand mask or as a pressure-demand mask. The difference between both lay only in the exhalation valve. This specimen has the standard black hard rubber exhalation valve (similar or virtually identical to that found in the A-14A & B masks), which tells me that it was intended to be used as a demand mask only. The pressure-demand conversion would have been simply effected by the substitution of a special metal pressure-demand exhalation valve (identical to that found in all conventional MS22001 masks) for the black hard-rubber demand valve. Note that this specimen has its microphone cable plug in place, signaling that it is an unissued example. If it had had the early pressure-demand valve in it (instead of the simply demand valve), I would have been sorely tempted to bid it way up into the stratosphere; since it doesn't, I decided to be prudent and consider the sad state of my somewhat overstretched budget first and foremost (and not bid on it). Still, even without the pressure-demand valve in this particular mask, it is an extremely rare, valuable, and (as the usual 'schticky' eBay description puts it) "impossible to find" (truly, for once) ancestor of the MS22001 mask we in the flightgear group are all familiar with. If these facts are already known or are common knowledge to you, forgive my redundant reiteration of the obvious; for those who aren't aware of the importance of this specimen in the history of US aviation oxygen mask development, this information may be of some interest! For further useful background information on the history of the A-13 pressure-demand oxygen mask, consult your copy of Glenn Sweeting's excellent book: COMBAT FLYING EQUIPMENT (pages 58-64). The two images accompanying this message are taken from the eBay site's item description. Best wishes to all! Cheers, Chris

A-13 oxygen mask. Copyright unknown. Click on thumbnails for larger pictures

Message 712:
Hi Steve,     Ever seen a late model (1965) manufactured MS22001 mask with this type of a com cord set up???? Mask is fitted with a late model M-32B/AIC microphone (not an M-100/AIC or M-101/AIC). This is a first for me--never encountered this combination of mask, cord, and mic before. The mask mic connects the HGU-2/P helmet headset (H-143/AIC) and mic (M-32B/AIC) with the aircraft via an early woven "Y" connector cord (in the conventional modern style, via the mask hose).     Cheers, Chris

MS22001 oxygen mask with unusual comm cord Pictures DocBoink

Message 901:
Thought you might find the enclosed photo interesting. It was taken recently and it shows a Royal Danish Air Force F-16 back-seater with an HGU-55/P and MS22001 oxygen mask. Old oxygen masks never die and they don't seem to fade away either... It should be mentioned though that our pilots use MBU-12/P. Cheers, Bluelight14

Message 902:
Oldie but goodie. Maybe some flyers prefer the more full face mask? The MBU-12/P is between the MBU-5P and MS2201 in face coverage. Gato

Message 903:
Hi Bluelight14, Thanks for the interesting shot of the Danish F16 jock wearing an MS22001 with Hardman kit suspension. Actually, the MS22001 mask is deemed relatively comfortable by many former users, although the cross piece that is situated at about upper lip level seemed to present some discomfort for those who had moustaches (RAF types, I guess). The MBU-12/P (and its USN variants) was developed specifically to provide greater wearer comfort, improved downward peripheral fields of vision, and substantially enhanced face-seal for high pressure/high-G situations. Imagine the chagrin of the USAF's Aircrew Systems Lab when it performed a study comparing face-sealing efficacy between the original MS22001, the MBU-5/P, and the MBU-12/P, some time ago and found that the vaunted "improved design" MBU-12/P was actually more prone to high-G face-seal leaks at high pressure rates that either the MS22001 or the older MBU-5/P. The old MS22001 is not entirely old fashioned and ready for the life support trash heap, as a consequence, and still finds many today who favor it. Again, however, facial conformation characteristics of each pilot dictate which is the best mask for the pilot in question and the mask that is the 'best' one is the one that most effectively fits the unique contours of your face. Cheers, DocBoink

Message 904:
This is the first time I have seen a MS 22001 with offset receivers anywhere OTHER than eBay! Rich

Message 951:
Hi all, As a complementary sojourn to Steve N's suggested Tour de P-Helmet I would like to see an account of the A-13A / MS22001 oxygen masks through their development stages including Ulmer and Swedish variants. Among others, I have noticed that DocBoink uses the designations MS22001-1, MS22001-2 and MS22001-3 on his website. It seems to have been a fairly popular basic design. Cheers, Bluelight 14

Message 952:
Bluelight14, The mask nomenclature and specs for A-13A/MS22001 masks are probably more confusing and complicated than the P-series particulars. The 'dash' numbers -1, -2, & -3, in reference to the MS22001 mask referred to small, medium, and large facepieces, but this comes from a reference dated 1965 from Sierra Engineering (per Steve Norris), and these numbers (the dash numbers) are not strictly correct for MC-3 or MC-3A connector equipped MS22001 masks (only for masks fitted with the MS27796 3-pin connectors). A reference dated 1970 is slightly different again. The A-13A mask and the MS22001 masks of the the early 50s were essentially the same in terms of function, and certainly similar in all functional details except for items such as the suspension straps and connectors. Originally, the A-13 mask had a standard WWII type friction fit (similar to the WWII Luftwaffe's 02 mask hose attachment system) connector on the end of the hose; it also had a standard constant flow system type connector fitted to a junction at the proximal end of the hose, between the facepiece and hose, to which emergency H-1 and H-2 type bailout bottle supplies could be attached. This was soon thereafter eliminated (late 40s) by a modification to combine both emergency bailout bottle hook-up and aircraft main 02 supply inlet in a single connector, fitted to the end of the hose. The Navy's ACEL pioneered this type of connector and it was adopted by both services (this was the USN BUAER spec 83-C-3 connector). The new system was found to be much better than anything previous used, but when it was found that connectors of this type were sometimes pulling loose from the female 02 hook-up receptacles unbeknownst to pilots (and thereby causing potentially fatal LOC due to hypoxia situations), the design was modified with a disconnect warning valve device built into the connector, which resulted in the type MC-3 connector designation. Alkl of these connectors featured a nylon snap-fitted strap that could be secured to prevent flail to some degree. A still further minor redesign of the emergency disconnect valve device resulted in the designation MC-3A (also known as the MS22016 connector), although at first glance all of these connectors appeared similar to each other (there were variations in the color of the anodised aluminium parts--early non-warning type connectors featured green anodisation, while later warning type connectors featured red anodisation). None of these early connectors incorporated suitable anti-flail features to keep hoses from inflicting windblast flail impacts on the pilots in emergency ejection situations (the nylon strap system was not always effective). This problem was rectified by development of system wherein an internal nylon cord connected the mask's distal facepiece connector to the distal hose connector; however this was a feature that only the MS22001 mask fitted with the new 3-pin connector had. The 3-pin connector attached to a chute harness connector which stayed with the pilot (this was the CRU-8/P, later replaced by the improved CRU-60/P, which incorporated both emergency disconnect valving and emergency bail-out 02 hook-ups). Very early 3 pin connectors were machined from a single piece of bright aluminium and had squared off pins (a close examination will reveal this); later versions featured round pins and refined machining techniques (as a result, these early bright aluminium 3-pin connectors are rarer and more valuable to a knowledgeable collector). The addition of the 3-pin connector to the hose of a mask, the use of a different length hose, or the use of a different helmet-to-mask suspension strap arrangement, all resulted in redesignation by different specific identification and spec numbers. Thus there were the different A-13A, the MS22001, the MBU-3/P, etc., masks, although in every case the actual mask itself and its function remained essentially the same (except for incidentals, such as have just been referred to). It was also pointed out in a previous commentary that the A-13A and early MS22001 masks could be used with a standard one-way rubber check exhalation valve (such as that used in the demand mask type A-14 and its variants); they are sometimes (although infrequently) still found with this type of exhalation valve fitted, instead of the positive pressure breathing exhalation valve that was used almost universally in masks of this type from the mid-50s onwards. Steve N. tells me that he suspects that the MS22001 mask was also used as an emergency demand type mask in certain aircraft, so this might also have resulted in the substitution of an ordinary one-way exhalation valve in an MS22001 or A-13A mask for the pressure-demand valve. This whole complicated area of concern is being addressed at this time, as a review of military 02 breathing masks systems that is currently underway in conjunction with Steve's Norris' book on flight helmets and 02 systems. Cheers, DocBoink

Message 954:
I have a document referring to a MS-22001-61... Steve N.

Message 955:
The matter of sorting out the A-13A / MS22001 particulars is getting interesting: the more I look into it, the more...as you put it....questions present themselves. Also, Bluelight14's suggestion of tracking the mask into its French and other licensed international reproductions is a good one, as well, but probably outside the immediate scope of the book. Cheers, Boink

Message 960:
Hi DocBoink, Well I can supply you with fact sheets of the Ulmer:A.13A, A.13.AB, A.13.AM, A.13.AMB, 16, 16.M, 16.MB, 19; All of which are the same basic type of mask with a different modification or use....... Interested? I enclosed a copy of one of the sheets. Bye HUD Ulmer A.13.AM datasheet

Message 1328:
Today's question for extra points is this: Has anyone ever seen a set-up like this on an otherwise conventional MS22001 USAF helmet/mask assembly? The helmet is an original spec HGU-2/P (Consolidated Controls mfrd) unit, dated 1961; The mask is a standard MS22001 mask, dated 1959, with an MC-3A connector. The com set-up involves a type M-100 mic, with short connector (as used on MBU-5/P mask), to which is attached a CX-4707/AIC com cord. This is unique to me. I have never encountered this configuration before, although there is no reason why it couldn't have been used. The helmet set reportedly came from an Air National Guard unit flying F-102A Deuces. Best answer gets 10 non-points and a free KC-135 AFD experience (without having to be in the airplane). Put on your thinking helmets, crew........     Cheers, DocBoink [Same pictures attached as for message 712]

Message 1431:
> Hello Bluelight 14:
> This appears to be a Canadian Forces helmet and mask. Notice the flash
> of white plastic viewable on the exhalation port of the mask? That was a
> special modification characteristic of CAF masks; they inserted a plastic
> former valve in the exhalation orifice to reduce back pressure and enhance
> cycling of breaths.
Hi DocBoink, Thanks for another interesting (as always) insight into the MS22001 family tree. Did the Canadians produce the MS22001 mask themselves or are they modified US production masks? The masks on Miroslav's P-3 helmets, are they produced in the US or in Yugoslavia? Cheers, Bluelight 14

Message 1441:
Bluelight 14: Haven't checked the rubber of my Canadian mask facepieces recently for mold marks, but I am 99% certain CDF bought them directly from US manufacturers. I'll check and verify this surmise. The Yugoslavian MS22001 that came with Miroslav's P-3 is of definite US manufacture (mold marks & dated confirmed). My understanding is that there were some MS22001 masks manufactured abroad under license, but I have little factual information as to where, when, and the identity of the non-US manufacturers. Anyone else out there have some actual statistics and citations on foreign (non-US) made MS22001 mask manufacture? Cheers, DocBoink

Message 1700:
Greetings all, This is a little bit off the current thread, but somewhat related. Has anyone ever seen a MATS modified MS22001 ? the article states that the proper mask that should be used in MATS aircraft is the A-14B, however the A-14B will not accommodate the AIC-10 microphone. The MS22001 mask was modified by removing the pressure valves, intake and respiratory. The A-14B respiratory valve is inserted. The modified masks were identified by a half inch wide yellow tape wrapped around the microphone cable guide. Finally it cautions not to use this mask on a pressure system (No Duh). This is from "The MATS Flyer" March 1959.
Cheers, Bones

Message 2181, May 8, 2001
Howdy Gents, Just wanted to bring something to your attention. A fellow in Switzerland named Rolf Steiner who is a collector, has brand new (never issued or used) and complete (with mic and all components) MS22001 size small oxygen masks for sale at about US$ 100 each. I have attached some detailed images of these masks. They were produced in 1965 for the Swiss Air Force (Suisse Patroule) and were kept in perfect storage conditions all this time. They are as packaged in protective plastic and are amazingly preserved. The rubber looks as if it were produced yesterday. I order four of them and I am literally stunned by how excellent these masks are. The hardshell mask suspension is not unique to Switzerland, as I have seen them in use elsewhere in the world, but it is interesting that the MS22001 mask was provided with such an excellent suspension system in foreign (non-USA) use, when the USN and USAF in this country was just getting the 'hardshell' idea firmed up.
I wouldn't hesitate to suggest that anyone interested get in touch with Rolf immediately and bag a couple of these beauties. They are fully compatible with a range of foreign helmets (and with US helmets as well, using snap fasteners and leather 02 tab systems).
Rolf's email address is: rolfsteiner13@bluewin.ch . Delivery is immediate and a range of payment options are available. Rolf speaks very adequate English but prefers German, if possible, so here is your chance to spread grief and despair throughout German-speaking Switzerland by trotting out that school-boy Deutschesprache, heh-heh. Anyone needing further information on the beauties, please feel free to contact me. I am as happy as a clam in a high tide in the Bay of Biscay with mine!
Cheers, DocBoink (rhymes with "OINK", but that's swine with me....)
02181Swiss MS22001_01.jpg (264657 bytes)02181Swiss MS22001_02.jpg (312513 bytes)