KM-32 (ShL-61, ShL-78, ShL82, ZSh-3, etc.) The most common Soviet/Russian pressure-demand type oxygen mask. It was used both with ZSh-3 assembly and leather helmets alone. Available in black (late model) and green (early models) colors. This mask contains a connector for the occipital bladder located within the back of (under) the leather helmet. The bladder was filled with air as pilot started doing high-G straining maneuvers, an act which pushed pilot’s head firmly against the mask and allowed a better face sweat-seal. Most of KM-32 masks do not have built-in (MG-1 type) microphones installed, although the mask had provision for one (pilots preferred to rely on the neck mounted La-3 and La-5 microphones). Virtually the same Chinese version of this mask is the YM-6504 mask (green or black rubber). One rare variant of the KM-32 mask featured a hole situated directly over the front of the facepiece, allowing a rubber plug to be removed from it for purposes of drinking water through a tube.
KM-32AG (ShL-50, ShL-61, ZSh-3, etc) Facepiece same as KM-32 in almost all respects, but has early-style loop-hooks that allow it to be used with older ShL/Z-50. Mask is also missing occipital bladder connector and the smaller diameter oxygen hose that connects to the front of the mask, since it is strictly a demand mask and NOT a pressure demand mask; uses a simple frontal exhalation valve with one-way check diaphragm where the standard KM32 mask’s pressure-demand exhalation value would be located. The KM-32AG mask lacks the third-point forehead securing hook found on all other KM-32 masks.
KM-32NBC (NA) This mask covers the whole face of the pilot and is held in place with upper and lower rubber straps running around back of head (as on gasmasks). Outside shell is made out of rubber for a better seal and there is no chamois skin layer on the face-contact sweat-seal portion. Top part of the mask is made out of clear plastic, while bottom part contains the oronasal oxygen mask itself, as well as a built-in microphone. Similar to whole face Russian GP-7 type gasmasks in concept and does indeed look like a ‘gasmask’.
KM-32 DD-M This mask is an automatic inhalation sensor (backpressure valve) DD-M (Respiratory Sensor – Modernized).
It is part of the oxygen equipment system (usually as part of the KM-32 oxygen mask).
Main functions and device
Automatic inhalation valve under pressure: The device ensures normal breathing of the pilot at altitude. At high altitudes, oxygen is supplied to the mask under excessive pressure (so that the pilot can breathe in rarefied air conditions). The DD-M sensor does not allow oxygen to freely leak out and opens only when the pilot’s inhalation pressure exceeds the set excess pressure in the mask.
Flow direction: The white arrow on the body shows the direction of the inhaled air flow (inward).
Switching connector: A round threaded connector is visible at the bottom – it is used to connect an electrical circuit (in particular, a headset cable or a normal breathing/pressing sensor). This is special equipment, not a “basic” valve
A regular KM-32 mask in the standard version is equipped with a mechanical inhalation valve (without electrical connectors and complex sensors). The DD-M sensor is a specialized device that was not installed on all masks in a row, but only on those sets that were connected to emergency or specialized signaling/recording systems (for example, to transmit a signal about the frequency and fact of the pilot’s breathing to on-board systems or a black box).
