An Informal History of Chinese Flight Helmet and Oxygen Mask Developments
By Kalikiano kalei
[Note: This survey of Chinese aircrew flight helmets and oxygen breathing masks does not presume to be authoritative or even wholly accurate, in view of the extreme difficulty encountered in securing cooperative confirmation of facts and details concerning this equipment from official Chinese government sources. Some of this assay is therefore based upon logical and informed analysis of the relatively sparse data available (i.e. educated assumptions), while other parts of it are based on actual specimens of the flight helmet and oxygen breathing masks referenced. It is important that this summary of information be best approached mindful of this status quo. As more information and confirmed data are acquired, this paper shall be updated as appropriate to reflect a higher confidence in its overall accuracy.]
Some important background context
In recent years, more has been written about military aviation aircrew life support gear (generally termed ALSE, for Aircrew Life Support Equipment) than in prior decades, but the subject is still only lightly touched upon in commonly available media. Western developments (specifically those taking place in the United States and the United Kingdom) are typically covered to a far greater extent than are those of the former (and present) Communist nations (Russia and China) and in fact, due to a long tradition of Sino-Soviet political/defense secretiveness, it has only been in the last 15 or so years that any verifiable information on or examples of Russian and Chinese personal flying equipment have become available.
With the overthrow of Soviet Communism and the recent moderate loosening of Chinese Communism’s tight lock on many aspects of its internal affairs (most importantly those having to do with military or defense subjects), concurrent with introduction to those regimes of elements of western style free market capitalism, topics such as Russian and Chinese aviation technology have been more somewhat more openly discussed in the West and access, hitherto largely denied altogether, has been gained to actual examples of and information bearing on Russian and Chinese ALSE technology. Actual examination and study of those artifacts that have become available have proven to be both illuminating and instructive to historians engaged in charting the path of developmental progress made in aircrew personal equipment by the People’s Republic of China over the past half century.
Since up until about the time of the final collapse of Soviet Communism (1989-1991), China was still closely associated with the Soviet Union (militarily and economically), any study of Chinese ALSE must necessarily first briefly survey the development of Russia’s own aviation personal equipment technology. In terms of specific informational articles themselves, Russia’s flying helmets and oxygen masks are best described at the internet website ‘Red Pilot’. This excellent documentary and image resource is the work of an individual (Alexei Gershin) who for many years specialized in Russian ALSE history, long before others took an equal interest in such subjects. His images and descriptions of Russian flight helmets and oxygen breathing masks constitute a standard reference for anyone interested in identifying and/or understanding the various differences and characteristics of Russian personal flight gear. Sadly, although the website is still active, Alexei Gershin has seemingly dropped from the radar (or he at least has been recently preoccupied by other concerns), since there is no evidence of ongoing or updated activity at the URL in reference. However, aside from Alexei’s pioneering tyro study of Russian aircrew personal equipment, and excluding one other website maintained by Gauntlet International ‘s Craig Martel (also now largely inactive, due to Martel’s other concerns), little further authoritative reference material presently appears on the internet about Russian ALSE. [In this connection, it should be mentioned that a very interesting website dedicated preponderantly to Chinese ALSE may be found at ‘Chinese Flying Gear’, maintained by Michael Little. There are many useful references to flying equipment used by Chinese military aviation forces there.]
As has been pointed out in other articles related to the subject in discussion here, the principal difference in modern era (e.g. the age of post WWII jet turbine powered aircraft from about 1947 onwards) Russian ALSE and western (US & UK) gear lies in the fact that in Russia, all aspects of aircrew ALSE systems technology (regarded as comprising aircrew personal life support equipment, survival gear and egress systems) are integrated under the aegis of a single overall entity (the NPP ZVEZDA group, a Russian joint stock company) which has for nearly half a century or more been responsible for all research, design, and development of Russia’s aviation and space ALSE. Since ZVEZDA produces the Russian helmets, oxygen breathing and egress (AKA: ejection seats, et al) systems ‘in-house’, as it were, every component of each aircrew system is developed to work perfectly with every other one. Thus oxygen breathing masks, protective flight helmets and emergency escape systems are exhaustively tested together (as a total concept) to assure completely satisfactory operational integrity. NPP ZVEZDA was responsible, not just for aviation ALSE systems, but in fact for all Soviet ALSE developments related to space flight technology and human factors science throughout the so-called ‘Cold War’ years. One can therefore only guess at the significance of the immense aggregate of expertise clustered together and uniformly shared within all these related areas of technological development. More recently, despite the appearance of a few excellent reference books on ZVEZDA developed space flight ALSE (see bibliographic remarks at end of this paper), the area of Russian aviation flight gear has received hardly any formal attention by academic/scientific authors or historians.
By contrast, the norm for western ALSE RD&OTE (research, development, and operational testing/evaluation) is for each area of individual ALSE development to be contracted out to a private commercial company. In recent years, corporate mergers and amalgamations among western defense contracting corporations have made this somewhat less problematic (for example, the large western GENTEX Corporation now includes facilities for design and development of helmet and masks systems under its overall aegis, due to mergers through the years with other smaller ALSE companies such as Protection Incorporated, etc.) within an ‘integrated systems’ context, but the western model for research, development and production of ALSE still doesn’t function as smoothly as the long-standing Russian counterpart model has for many decades.
Understanding the origins of Russian ALSE as a ‘Chinese ALSE Rosetta Stone’
Given the foregoing background, one must begin by going somewhat farther back into the past (the pre WWII Soviet Union years) and long before NPP ZVEZDA came into being, it is not just helpful but vital to understand the strong influence that German aviation science and ALSE technology of the 1930s and early 40s had on the development of Soviet ALSE equipment.
In the mid-1930s period Russian aircraft were for the most part still very simple and all but a few were of the biplane design with open cockpits. Radio communications (only recently introduced to western aircraft) came rather late to Russian military aircraft and it was only due to the pressing urgency of countering the military threat posed by the German Third Reich’s air forces that substantial improvements in Russian flight gear rapidly became necessary.
By the mid-1940s and concurrent with the introduction of a whole array of technically advanced aircraft designs, Germany’s Luftwaffe had also developed a significant variety of summer and winter leather flying helmets for aircrew use, most featuring ‘Siemens gerat’ (or Siemens radio communications system avionics). Helmets in use by the Luftwaffe, two common representative types of which were the LKpN-101 and LKpW-101 (summer and winter) leather flying helmets, were of a very distinctive cut, well made, close fitting, comfortable, and equipped with integrated Siemens radio communication receivers equipped with cable leads that ended in German DIN standard connectors (for attachment to the aircraft’s radio/avionics equipment).
Late 1930s Luftwaffe aviator oxygen breathing systems featured demand-type regulators and masks developed by the Drager and Auer companies that were well advanced from earlier, reservoir type constant flow rebreathing masks, enabling operational ceilings up to about 30,000 feet. So well suited to military aircraft applications were these helmets and masks that the Soviets took captured specimens and examined them in exhaustive detail, eventually electing to adopt the same German DIN standard 4-pin connection in use by the German Luftwaffe. Although by the end of the war, Russia had produced virtually identical clones of the German LKpN-101 and LKpW-101 helmet designs, many Russian pilots are known to have occasionally used captured German helmets interchangeably with the first wholly Russian copies of the German models, such was their identical nature.
One conspicuous development originating on the Luftwaffe leather winter and summer helmets was a third oxygen mask attachment point situated on the upper forehead section of Luftwaffe flight headgear. An adjustable vertical strap was secured there that ended in a looped wire attachment, to which the upper suspension strap of a three-point oxygen mask (such as the Drager Model 10-69 fighter pilot mask) could be secured, for extra stable mask retention during maneuvering. Conceptually proven to be effective and its efficacy fully established throughout the war by Luftwaffe fighter aircrews, this feature, along with other Luftwaffe helmet devices (such as studded side mask securing points and a twin laryngofone or throat microphone set-up), was quickly incorporated into Russian leather flying helmets. The effective practical result was that shortly after war’s end, the Soviet Air Force was flying with leather helmets that were closely modeled upon and clearly influenced by their WWII German Luftwaffe inspirations.
Similarly, taking the Luftwaffe’s Drager basic demand-type aviator oxygen mask design, the Soviets introduced (post-war) several new oxygen breathing masks. The first of these new masks was a constant flow rebreathing mask designated the KM-15 that featured a simple rubber oronasal facepiece attached to a rebreather bladder that provided simple twin open orifices for the wearer to exhale through. In principle it was somewhat similar to familiar US Army Air Force constant flow rebreather masks such as the A-7 & A-8, but did not have exhalation check valves. A further development known as the KM-15i mask, this development more closely modeled after the German Drager aircrew demand mask featured a rubber oronasal facepiece equipped with simple inlet and outlet valves, to which a corrugated, flexible rubber oxygen delivery hose was attached. The KM-15i mask far more closely approximated the Drager concept, although it wasn’t until an even newer Soviet design known as the KM-16 came out that the excellent features of the Drager Type 10-69 design archetype were more fully emulated. The early Russian Type KM-16 mask used a bilateral, single fabric strap for suspension that secured to a single metal stud on either side of the leather helmet and was distributed with two easily installed studs to thus equip any helmet not already configured for use with the new mask. There was no third attachment point (forehead) on the early KM-16 mask (pictures taken during the of Korean War show this mask in common use by DPRK MiG pilots).
Although a fairly straightforward and functionally simple demand oxygen mask, the early Soviet KM-16 was clearly an optimized Drager Model 10-69 mask in both appearance and function, and it was this mask (good for use up to about 30,000 feet, the practical maximum altitude limit for any non-pressure demand oxygen mask design) that was in common use when the first Soviet MiG-15 jet turbine powered aircraft began to be introduced to Russia’s air forces and those of its close allies.
Quickly following the Soviet ‘clone’ of the German LKpN-101 helmet in Soviet Air Force use was a new Russian design that would become known as the Russian ShL-50 aircrew helmet. Featuring so-called ‘pig-tail’ radio communications cords exiting at the aft base of the helmet (following the previous German archetypal design), receivers were fitted to each side and housed within external molded oval rubber components. On the forehead section of the new Type ShL-50 the German inspired third mask attachment point remained in the form of a looped wire (again, quite similar to the German original). On each side metal studs could be installed on the helmet, still faithfully following the WWII German model for bilateral mask attachment, and a throat microphone system (LA-3 and later LA-5) quite similar to the German LKpN-101 counterpart was used, although on the new Soviet helmet the microphone assembly was not joined to the aft nape of the leather helmet but was instead a separate component. German DIN standard 4-pin connectors remained in use on this helmet (and all succeeding Soviet/Russian leather ‘ShL’ type helmets even well past the introduction of newer ‘hard shell’ helmets in the 1960s) to connect to the aircraft radio/communications avionics.
Thus, as the Korean War loomed in the late 1940s and as the radical new, swept-wing Mikoyan-Gurevitch MiG-15 aircraft came into Soviet Air Force service, this last described ShL-50 type helmet and the corresponding KM-16 two-point demand oxygen breathing mask comprised the standard set of ALSE items issued to Soviet Air Force (and all Soviet allied) pilots flying the new MiGs.
As soon as it became apparent that North Korea would initiate hostilities with the United Nations forces positioned in South Korea, plans were immediately made by the Soviets to supply quantities of the new MiG-15 swept-wing and turbojet powered fighter to both North Korea, since the Soviet Union understandably viewed this as an excellent opportunity to subject the new MiG to actual, rigorous operational testing. China had by then already started to receive the new jet and along with the aircraft themselves, suitable quantities of the standard Soviet ShL-50 leather flying helmet and early KM-16 type mask were also provided Chinese Peoples Liberation Army Air Force (PLAAF) pilots. [Note: The masks issued to the Chinese were the original KM-16 two-point securing type, as briefly mentioned above, lacking a forehead securing point and attached to the face (helmet) only with single bilateral fabric straps. Soviet MiG pilots were just beginning to be issued the newer, improved three-point suspension modified KM-16N mask.]
Since the new MiGs posed significant challenges to poorly trained and prepared Chinese ( later to Korean) pilots, it was deemed desirable that the Soviet Union covertly provide certain numbers of highly capable, WWII veteran pilots to not just instruct Chinese pilots in use of the MiG-15, but also to surreptitiously fly actual combat missions against the United Nations air forces when the Korean conflict finally began. These pilots also flew wearing Soviet ShL-50 type helmets and KM-16 masks.
China begins to produce indigenous copies of Soviet (Russian) flight gear for use in its MiGs
Meanwhile, as China began to take increasing numbers of the new MiGs, it began to undertake production of its own copies of the Soviet flight gear. Progress on this idea developed rather quickly and very soon China had produced what is referred to as the Chinese Type-50 leather aircrew helmet. Appearing from a distance to be virtually identical to the Soviet counterpart that inspired it, the Chinese helmets were visually distinguishable by their use of brown leather (instead of black, as used in all Soviet helmets). Goggle restraining straps on the Chinese Type-50 helmets also featured a distinctive star on the metal snap fittings (vice unadorned, plain metal snaps on Soviet helmets). There was no padded ‘bumper’ pad on the top-most crest of the Chinese leather helmets (a style identical to the Soviet helmets) until a much later period, when the Type-50 was supplanted by the newer Type-59 helmet, with its distinctive cushioned pad on the crown. The Chinese Type-50 helmet and simple bilateral strap secured KM-16 mask continued to be used throughout the duration of the Korean War by both Chinese and North Korean pilots, simultaneous with the Soviet ShL-50 helmet and KM-16 mask being used by the combat-trained ‘instructors’ provided by the Soviet Union.
Although there is no definitive evidence available at this time to verify the supposition, logical analysis suggests that there was considerable Chinese innovation undertaken in helmet and mask design in the late stages of the Korean War era and in the period immediately afterwards. China was also intent on producing its own oxygen breathing masks and although it still produced cloned copies of established Soviet masks like the KM-16 and the later KM-30/32 masks, the PLAAF introduced its first all-Chinese mask in the Type YM-6501. An improved version of this wholly Chinese updating of the KM-16 was soon thereafter introduced and designated the YM-6502 mask. Both designs were strictly demand-type oxygen masks, conforming to the same principles and altitude limitations underlying the Soviet KM-16 series masks and all non pressure demand oxygen breathing masks. The YM-6502 mask featured a two-point bilateral stud-fastening suspension with no forehead-sited third attachment point.
In the late 1950s an improved Chinese version of their Type-50 leather flying helmet came into standard use, designated the Type-59 leather flying helmet, and with it a Chinese copy of the new standard Soviet pressure-demand oxygen breathing mask (the Soviet KM-32) designated the Chinese YM-6504 mask. Produced in green rubber, as opposed to the standard Soviet black rubber counterparts, the YM-6504 mask was otherwise virtually identical to the Soviet KM-32. Today, as aging effects darken the green rubber of these older Chinese masks, they are often mistaken for black rubber Soviet KM-32 masks until a casual search for size markings on the masks accidentally reveals their true identity.
Concurrent with production of the Chinese Type-50 helmet and YM-6504 mask, several variant designs were also experimented with and produced on a somewhat limited basis. Since factual documentation is so sadly lacking on specifics with regard to these developments, at present only educated guesses may be made as to the full range of types, dates of production and/or designations. That having been said, several specimens in private flightgear collections clearly display evidence that the Chinese used (however briefly) the early Soviet KM-30 mask, the very first Soviet pressure-demand precursor that inspired the subsequent and definitive KM-32 mask, for one helmet known to exist is fitted with the distinctive upper and lower clasp (4-point) attachments that uniquely characterised the KM-30 mask suspension system. This helmet in reference also features the enhanced ventilation features of the Soviet counterpart versions of the WWII German ‘netzkopfhaube’ (literally ‘netted head helmet’) but has a small cushioned pad on the front of the helmet, effectively precluding the use of either the standard Soviet PO-1M ‘bug-eye’ goggle or its Chinese clone (because of the frontally placed pad, this helmet appears suitable only for use with the much earlier WW II type aviator goggle known as the P0-1 design). Whilst on the subject of goggles, it should be remarked that at no time do the Chinese or North Korean pilots seem to have routinely used goggles in their MiGs, a practice quite divergent from Soviet aircrew practice, since Russian aviators would uniformly use them with their ShL type leather helmet and mask sets. [Note: Separate, hard external protective shells (such as the Soviet ZSh-3 type ‘exoshell’) were never worn by Chinese or Korean pilots until much later, after the Korean War conflict had ended, and only then on very rare occasions…or so extant photographic evidence tends to suggest.]
As research into and development of hard protective shelled helmets gained momentum in the west, beginning in the mid-to-late 40s as the fast new jets came into use, resulting in the first US hard protective helmet designs (such as the USAF P-1 and the US Navy H-1), and as the Soviet Union developed its own hard shell protective helmets [Note: despite certain researches involving study of early 50s US hard helmets and even after the limited production of a Soviet clone of the US Air Force’s P-3 helmet, designated the Soviet ZSh-2 helmet, the Soviets elected instead to keep their ShL leather helmets and simply incorporate a hard external shell over them, resulting in the ZSh-3 two-part helmet design.], China continued to fly its Soviet developed jet aircraft without introducing a new and wholly Chinese hard protective helmet.
China develops modern new hard protective aircrew helmets
In the late 60s, however, this status quo came to an end with the introduction in the early 70s of a new Chinese hard shell helmet designated the TK-2 [Note: the Chinese TK-1 helmet was a pressure helmet based quite closely on the US K-1 and appearing very much congruent with the Soviet GSh-2 pressure helmet, itself inspired by and based upon the USAF K-1 design.]. Jet aircraft performance had improved remarkably in China since the end of the Korean conflict and the higher speed capabilities of new aircraft types mandated improved and vastly more adequate protective pilot headgear for aircrew flying them; although not entirely over and done with, the age of simple leather protective flight helmets was rapidly coming to an end, in China as well as in the west.
In China, acknowledgement of this came into being as the new one-piece hard shell protective helmet known as the TK-2. The origins of the TK-2 are worthy of no small amount of focus here, since it was heavily inspired by American hard shelled protective jet helmets. Originally, when Russia adopted the new ZSh-3 hard outer shell worn over its ShL type leather assemblies for its MiG pilots in the late 50s, quantities of this new Russian design were also introduced to China. [It should be remembered that Russia drew directly upon American protective helmet research for its own jet protective helmets, since before making the decision to keep the existing leather flight helmet and simply use a hard shell over it (e.g. the ZSh-3 design), Russia obtained examples of the American P-3 helmet that were captured by the North Koreans from crashed Sabre pilots and produced an entirely Russian copy of the US helmet and mask (P-3 and A-13A mask) designated the ZSh-2 and KM-24. The ZSh-2 and KM-24 were flown extensively to determine their effectiveness and quantify their technology, but eventually the American one-piece helmet design lost out to the Russian ZSh-3 two-part helmet. When the new hard shell ZSh-3 helmet was offered to China for evaluation and suitability (in the late 50s/early 60s), Chinese PLAAF pilots uniformly rejected the aluminum shelled ZSh-3 as cumbersome, awkward and generally not to their liking. Due to this and adverse economic circumstances then extant in China, a decision was made to continue using the Types 50 and 59 leather flight helmets alone in the early PLAAF MiGs until a more suitable solution was found.]
Meanwhile, several events occurred that had an effect on China’s search for appropriate protective headgear for its MiG-17 (Shenyang J-5 two seat version) and MiG-19 (Jianjiji F-6) pilots. In 1963, a Taiwanese Nationalist pilot flying the NAA F-86F Sabre defected to China. His American issued P-4A flight helmet was soon passed along to Chinese flight test personnel for detailed evaluation and analysis. The results of this close scrutiny of American hard protective helmet technology played a significant part in Chinese plans to develop their own protective hard helmet.
Subsequently, in 1965 a US Air Force F-105 Thunderchief fighter-bomber from the Vietnam theatre was shot down by elements of the Chinese Air Force and the personal flightgear of its pilot were passed along for evaluation similar to that performed earlier on the US P-4A design; the American HGU-2/P type helmet was given to the Chinese engineer who would soon produce the new all-Chinese design known as the TK-2 helmet.
The entirely new Chinese TK-2 ‘hard’ protective helmet that resulted featured the same basic head protection concept as the latest (late 50s) US Air Force and US Navy generation helmets (the USAF HGU-2/P and the USN APH-5), all having a hard fiberglass outer shell lined with a crushable, impact-absorbing foam polymer material (similar to Styrofoam). The TK-2 also featured a left-side manually activated, single shaded sun-visor that was protected from scratching (following the US helmet feature) by a fiberglass housing. Simple clasp-type hooks (not dissimilar to those used on earlier Russian and Chinese leather helmets) were used to secure the chin strap and mask suspension attachments were also of the simple clasp-type design (a rather old technology feature that would remain in use well into the 1980s on Chinese hard-shell aviation protective helmets) . A comparison of the dark sky blue painted TK-2 hard-shell helmet with contemporaneous USAF and USN helmets clearly reveals the American (and Soviet) design influence on the Chinese TK-2, since the TK-2 also featured wind-blast pressure relief orifices in its shell, intended to enhance helmet retention during high-speed ejection (functionally identical to those featured on Russian ZSh-3 outer shells and US HGU-2/P and APH-5 helmets). Foam earphone cushions inside the helmet contained Chinese earphone receiver elements that were linked by a communication cable fitted with the same Soviet DIN 4-pin connector (originally developed and used by the Luftwaffe) for interfacing with the aircraft radio/communications avionics. Visually most distinctive was the prominent Communist red star that was painted on the forward visor cover of the TK-2. [Note: Although a common feature of all Chinese hard protective flight helmets up to the present, none of the Soviet flight helmets have to our best knowledge ever featured a red star emblazoned in this manner, despite apparent popular belief].
The TK-2 helmet remained in use by PLAAF pilots flying newer, faster jet aircraft over an approximate 10 year period while China’s new developing air forces expanded and gained further expanded air combat capabilities. In the mid-1980s an improved version designated the TK-2A flight helmet came into use, intended as a significant upgrade of the earlier TK-2, and although painted white instead of azure blue, at first glance it shared many similarities with its blue antecedent. Slight changes in the later shell areas over the earphone were apparent upon close inspection but the communications cords and connectors remained virtually identical to those used on all earlier Soviet and Chinese helmets. Rather than adopting the well-proven and standardized Soviet KM-32 pressure-demand oxygen breathing mask (or China’s own YM-6504 clone of that mask), China elected to develop and produce its own unique pressure-demand design that was designated the YM-6505 mask. Using a hard green polymeric outer shell, much like the American MBU-5/P mask, the new YM-6505 mask’s rigid external shell contained a green rubber facepiece that featured a face-seal portion lined (as found on the Soviet KM-32 mask) with chamois material. A small diameter hose exited the left side of the assembly to link with an inflatable pressure bladder fitted to the inner occipital portion of the shell to enhance mask retention, using the same principle featured on all Soviet pressure-demand masks. Whereas the older blue TK-2 helmet was originally used with the Chinese YM-6502 demand mask , the newer white TK-2A helmet was issued with the new YM-6505 pressure-demand mask, both items being (apparently) a standardized set-up for Chinese PLAAF fighter pilots. Internally, the white TK-2A helmet was essentially similar to the older blue TK-2, with no substantial protective or safety enhancements apparent upon direct examination. Of note is the fact that despite the relatively late date of the TK-2 and TK-2A helmets, the YM-6505 pressure-demand mask lacked an internally fitted microphone, thus requiring use of the same throat mic (LA-3,4,5 laryngofone) set-up that all Soviet and Chinese helmets had required from the late 40s through the early 80s.
In the early 1990s, two newer and further improved flight helmets came into use, designated the TK-10 and TK-11 helmets, both painted white with the ubiquitous red star on the visor cover. These designs bear very close superficial resemblance to the earlier TK-2A design, being white and featuring similar wind-blast orifices in their shells, and using similar impact absorbing inner cushioning (Styrofoam) features, but gained more sophisticated leather earphone cushioning and interior lining. The most notable improvement in the new TK-10 and TK-11 appeared to be the incorporation of substantially improved oxygen mask retention receivers and bayonets, being virtually identical to those in use on all modern Soviet flight helmets. Situated just inside the helmet shell (following the Russian ZSh-7 example) rather than externally (as on modern US helmets), the new receivers provide a much more secure and modern system for mask retention. Somewhat surprisingly, the communications cords used on the TK-10 and TK-11 helmets remain exactly congruent with and identical to the same classical 4-pin DIN connector standard originally pioneered on German Luftwaffe helmets in WWII!
Along with the new TK-10 and TK-11 (each variant otherwise differing only modestly in terms of communications receivers and their fittings), China introduced several new pressure-demand oxygen masks that bespeak a considerable effort on the part of Chinese R&D to produce an improved and modernized oxygen breathing mask design. Notable among these new masks are the Type YM-9915 and YM-9915G developments. Each is remarkably different in appearance (despite sharing a numerical designation), with the YM-9915 mask featuring a rather awkward and complex arrangement of its main and pressure compensation oxygen hoses that appears intended to offset inertial forces acting on the wearer during high-G maneuvers (this has been done by moving the mask’s center of gravity mass closer to the face and reducing the suspended weight of the hoses in the front of the facepiece: see images for a better idea of this). However, since the masks still used the rather old-fashioned and inelegant pressure compensation valve system inherited from Soviet masks, such an attempt is rendered far more difficult than it would otherwise be, were a more sophisticated combined inhalation-exhalation valve (such as used on the American MBU-5/P, MBU-12/P, and MBU-20/P masks) utilized. One noteworthy aspect of the YM-9915 mask is the fact that for the first time in Chinese mask design, the face seal portion of the facepiece is natural silicone rubber and is not lined with chamois material, as found on all previous Chinese and Russian masks. The main oxygen delivery hose on the YM-9915 mask’s facepiece is also of a green rubber corrugated construction (lacking an integral bonded fabric outer surface, as had been the accepted practice on all prior Russian and Chinese masks).
Analysis suggests that although apparently actually produced and issued to Chinese aircrews (distribution numbers unknown), the limitations of this awkward appearing design may have been quickly recognised and a further development designated the YM-9915G mask was initiated. The latter ‘G’ upgrade design, although still featuring the old Soviet pressure compensating valve component, presents a somewhat radically different appearance from that of the preceding YM-9915 mask. Interestingly, the face seal of the YM-9915G again returns to use of chamois material, but the main oxygen delivery hose and pressure compensating valve both exit from the front of the facepiece in a more conventional manner, presenting a somewhat superficial resemblance to the late 50s introduced American MBU-5/P mask. Both the YM-9915 and YM-9915G masks feature a green rigid polymeric outer support shell fitted over a softer rubber facepiece (as on the MBU-5/P), but both the YM-9915 and YM-9915G masks depart from earlier practice in that the occipital bladder tube exits on the right side of the facepiece, rather than on the left. Further, both masks utilize a new type of ‘T-bayonet’ on each side supposedly intended to optimize mask retention and enhance fitment (it is in fact clearly modeled after the American ‘T-bayonet’ components used on twin-strap MBU-5/P masks). Although a significant step forward (the ‘T-bayonets’), both masks feature rather flimsy and unsubstantial nylon suspension straps that do not interface effectively with the rather too-wide slots provided on the bayonets. Thus, it is again a somewhat awkward attempt to arrive at what the west has long-since perfected with its own offset bayonet/receiver systems (as found on the American MBU-12/P and MBU-20/P masks). Both the YM-9915 and YM-15G masks are fitted with internally mounted microphone assemblies (a first for Chinese masks), eliminating once and for all the need for PLAAF airmen to use the (Soviet type) LA-5 type throat laryngofone. Interestingly, as mentioned earlier, the YM-9915 mask features a new type of non-fabric covered corrugated rubber main oxygen delivery hose, while the newer YM-9915G mask features a fabric-encased nylon hose sleeve that appears much like that used on the Russian KM-35 mask.
One further mask worth mentioning here is the Chinese YM-6512 demand oxygen mask, a mask that replaces the earlier YM-6502 type demand mask and which is most commonly seen in use by PLAAF pilot trainees (this mask is employed at lower altitudes not requiring pressure-demand capability). Using the characteristically green colored polymeric rigid outer shell over a softer green rubber facepiece concept, the YM-6512 mask contains an inner microphone assembly and features a non-fabric coated main oxygen delivery hose (a departure from most other Chinese and Russian masks that have used an external, bonded fabric layer over their corrugated hoses since the earliest days of the KM-16 mask). The YM-6512 (green) mask comes with loop-latch type attachment fasteners (used with older TK-2A and soft leather helmets), while the YM-6512A model comes with bayonets (for use with TK-10/11 type helmets). A newer version of the YM-6512 mask designated the YM-6512G appears to be identical to the earlier green versions and comes with bayonets, but is gray overall in both hard and soft facepiece components.
Another Chinese hard protective helmet design is the Type TK-2C helmet, used exclusively by the People’s Liberation Army Naval Air Forces (PLANAF). Featuring a hard fiberglass external shell painted in gray, the shaded sun-visor uses the earlier TK-2A type left side actuation mechanism, but lacks the former’s external visor cover (thus bearing a superficial initial resemblance to the old USAF P-4B helmet). Internally, the TK-2C helmet retains the simple side-mounted oxygen mask fastening clasps (and chin strap clasp), but has upgraded leather fitting pads and earphone cushions. The communications cords are identical to those used on all earlier Chinese flight helmets. The mask apparently most often used with this helmet is the YM-6512 demand mask, although it can certainly be used with a pressure demand type such as the YM-6504. There is, of course, no occipital bladder fitted, although this too may be mounted in it for appropriate use.
Still another Chinese development for use strictly in the latest Russian Su-27M type air superiority fighter (and in the Chinese produced clone, designated the J-11) are copies of the Russian ZSh-7 helmet and the Russian KM-35 oxygen breathing mask. Designated the Chinese TK-12A (ZSh-7) and the YM-9925A (Km-35), this set of items is replicated to congruently conform to the Russian counterparts. Differing only by virtue of a slightly grayer shade of off-white than that found on the Russian ZSh-7’s outer shell, the Chinese TK-12A helmet is otherwise indistinguishable from its Russian inspiration..at least externally. Internal fittings and appointment also match those found on the ZSh-7 helmet, but a Chinese identification/specification sticker may be found on the lower inside shell, by slightly lifting the lateral fitting cushions. Also, a metal ID plate stating ‘TK-12A’ may be found attached to both right and left oxygen mask receivers on the helmet. Aside from these small identifying characteristics, the Russian and Chinese versions are difficult to tell apart. For its part, the Chinese YM-9925A pressure demand oxygen breathing mask, although functionally identical to the Russian KM-35M mask, is produced in that characteristic dark jade green color (both rubber and hard-shell components) so that the Russian and Chinese masks are immediately identifiable. The YM-9925A mask may also be produced in the same shade of air-superiority gray now favored by the very latest Chinese flight helmets, but further information (other than photographic evidence) on that is lacking at this time. Due to the highly specialized nature of Su-27/J-11 aircraft operations by the PLAAF forces, the TK-12A and YM9915A set of items is almost impossible to acquire outside China (by collectors, for example). When they are, a set of the two items can command a present ‘best price’ cost of approximately US$ 1200!
The very latest Chinese oxygen breathing masks now in use by the PLAAF are the YM-6, the YM-9, and the YM-12 types. Both the YM-6 and YM-9 masks are of the pressure-demand type and are an entirely new development that places them on a technical plane somewhat approximating the American MBU-20/P series (and the Russian KM-36M, one of the latest of their designs). Benefitting from combined study of both Russian and American mask design elements, these new side-hose masks are used with bayonets to attach to receivers similar to those found on the TK-11 helmet. The YM-6 mask seems to be molded from the characteristic dark jade green rubber used on most all previous Chinese oxygen masks, but the YM-9 mask appears to be molded in a newer air-superiority gray colored rubber. The YM-12 mask (dark jade green) is of the non pressure demand type, obviously intended for use at lower altitudes and lacking a pressure-compensating valve component. All three of the new style masks utilize an internally fitted microphone, following the standard western custom and all three masks use a rubber faceseal concept, rather than the prior chamois material approach. The first two masks (YM-6 and YM-9) feature occipital bladder connectors exiting from the left side of the facepiece)
Two further Chinese helmets not previously mentioned are the TK-11B and TK-11C. Although not confirmed, the TK-11B helmet, which features gray shell paint and an uncovered smoke sun-visor (in the manner of the TK-2C PLANAF helmet described earlier), appears to be an upgrade design for use by Chinese People’s Liberation Army Naval Air Forces aircrew. It features interior appointments that match those found in the TK-11 and TK-10 helmets and may or may not have recessed (secured within the shell) oxygen mask receivers (a specimen has not yet surfaced to enable a detailed, close-up examination). The Chinese TK-11C helmet appears to have a light gray outer shell color (with the standard red star) and is purported to be intended for use by rotary-wing aircrew (with boom-mics, etc.). Still a more recent update of the TK-11C design has been designated the TK-11CII helmet. It looks to be quite similar to the TK-11 in almost all of its viewable features and appears also to use common 4-pin DIN type com connectors like all previous Chinese flight helmets. Internal sizing pads, earphone cushions, mask bayonet receivers, and other ‘comfort’ details are also apparently not much changed (if at all). The visor is covered and articulated by the same type of left handed latch system first used on the TK-2A helmet. Not much other information is presently available about the TK-11CII design, unfortunately, although word has it that the TK-11CII helmet is another extremely difficult helmet to obtain from outside China due to its relative newness and present scarcity in production inventories.
Latest generational helmet developments: the ‘smart helmet’ era
Most recently, Chinese prototype designs for what are termed ‘smart’ flight helmets (that is, compound or two-part helmet assemblies fitted with integrated, computer-interfaced weapons targeting and sighting visual displays) have emerged and are now being developed. Information on these latest designs are, understandably, sketchy and still somewhat shrouded in the usual blanket of security obfuscations and in the not-too distant future they may well replace all older, ‘dumb’ protective safety helmets presently in use by PLAAF and PLANAF aircrew, but one of the latest of the older ‘1st gen’ hard helmets is the Chinese type TK-21. One such helmet is the TK-14 model that incorporates an early, first generation optical weapons targeting system similar to that used in Russia. Available images reveal it to be largely a conventional (TK-11 type) design with visor mounting of target optics.
Evidence indicates that a new helmet designated the TK-21 and provided with gray shell paint (including a new three-dimensional red star device in place of the previously painted red star emblem) is now also in use among PLAAF pilots, although there are very few available details on it at this time. Said to be typically used with the gray rubber YM-9 pressure demand oxygen breathing mask, very little factual data and few images of it have emerged in the west to help differentiate it from earlier types (like the TK-11 or TK-11CII). The few images shown of it suggest that there is little radical difference between it and more recent helmets like the TK-11 series. One trend that is becoming apparent is that future Chinese PLAAF helmets (and oxygen breathing masks) shall in all likelihood be produced in a sort of air-superiority gray coloration, closely approximating the same lusterless gray color featured on American HGU-55/P CE helmets. Exactly why this is the case in unclear, but it is a known fact that in the USA, a few decades ago, helmet color was changed from white (originally thought to help facilitate wearer cooling under sun-heated transparent glazed canopies) to dull gray due to concerns about the visual contrast aspects of white helmets possibly aiding visualization of the cockpit by opposing hostile aircraft. Perhaps similar reasons exist for China’s switch to dull gray, but on the other hand, perhaps it is all simply a reflection of present ‘international military fashion’?
Addendum: 18 Jul 2010
Please note: Chinese PLAAF pressure helmets of the TK-1 and TK-4/A/B types have not been covered here, since they are specific to high altitude flight. It is possible that this article may be slightly expanded to cover them as well, in future, although the need for high altitude capability throughout the air forces of the world appears to be diminishing, due to the present technical sophistication of ground-to-air intercept weapons (missiles, et al) systems. The present day formidable anti-aircraft threat these weapons pose to combat aircraft has resulted in a general reduction of high-altitude combat strategy and a reintroduction of high-speed, low-altitude stealth missions (and lower altitude air-superiority combat, for which ordinary pressure-demand oxygen systems and pressurized cockpits appear perfectly adequate).
Addendum: 8 Nov 2010
It has recently been noted that there are also versions of PLAAF flight helmets known as 'parade helmets'. These are a type of non-flying helmet used by massed marching formations of PLAAF aviators during state celebrations. The helmets appear to be closely based on the same simplified style as the recreational-use 'flight style' motorcycle helmet and apparently lack communications components (earphones/wiring harness/com cords). Externally and from a distance, they appear to be standard aviation-rated flight helmets, but are produced only for massed formations of marching PLAAF aviators. ['Parade helmets' are not found in the West, since Western air forces do not march en masse in flight suits and flight helmets. This practice seems to be unique to the Chinese PLAAF.]