What is the most produced oxygen mask in the world? While there is no definite answer, KM-32 might
be just that mask. While I cannot give an exact date when it was first produced, one can safely say
it was somewhere around 1960 and it stayed in production for more then next 30 years! In fact, I won't be
surprised to find out that it is still being produced today. Such high popularity could be explained
that it's the latest mask (at least latest mask that reached serial production in big numbers )
designed specifically to be coupled with leather helmets. Thus every fighter pilot who wore ZSh-3,
most likely also used KM-32. After fighter pilots started to receive newer ZSh-5s and ZSh-7s,
helicopter pilots continued to use the mask - in fact they might be still using it...
Over the years a number of different KM-32 versions were developed, but this page will cover
only the basic mask design (please check other pages on this site for more KM-32 versions).
KM-32 mask uses dual hose connection to the aircraft - the main oxygen hose enters on the left
side of the mask, while a smaller black hose connects in the center. The main oxygen hose delivers air
for the pilot, smaller hose provides air for KM-32's pressure demand system. Above certain altitude, human fluids start to boil due to a big pressure
difference outside and inside of the body - KM-32 pressure demand system is there to allow pilot
fly at higher altitudes. To allow that mask maintains a different pressure inside of the mask and
seals off inhale and exhale valves. As pilot starts to inhale, pressure inside the mask start to
lower and mask compensates for that by opening inhale valve and allowing air from oxygen supply come
inside of the mask. As pilot stops inhaling, pressure evens out and mask closes the inhale valve to
keep constant pressure. When pilot starts exhaling, pressure inside of the mask increases and mask
opens up exhale valve...
On the right side of the mask there is a round bump where internal microphone could be inserted,
but it's quiet rare to see KM-32 mask with one - for whatever
reason pilots still used throat microphones. Also found on the left side is the connector for
occipital bladder. The bladder itself is placed inside on the back of the leather helmet and
inflates during hard maneuvers, thus keeping pilot's face closer to the mask.
Mask connects to the leather helmet via 4 hooks - one on each side (featuring new style hooks for the
latest ShL type helmets), strap with a button on the bottom and a forehead connector.
KM-32 mask was produced with black or green (rare) bodies.
