KM-34 and KM-35 Oxygen Masks

This needs the most clarification from the Jet Age Flight Helmets book.  The KM-34 was the first oxygen mask for the ZSh-5 helmet.  It had the clips on the side that fixed into brackets on the side of the helmet.  Earlier masks hooked on outside clips, but the new masks hooked via an inside mechanism.  

As for the KM-34D Series II and the KM-35, there is much discussion on this topic.  The two masks are unique, but the KM-35 is not the one shown in the JAFH.  That KM-35 was a prototype version and the final one uses the same shell as the KM-34D series II.  See below for more.

 Here is an example of a brand new KM-34 with its passport.  The fiberglass shell is a gray, with a black or green canvas strip that attaches to the mask clips. Both the KM-34 and KM-35 have the same type of microphone connector and pressure connector which attaches to a bladder at the back of the ZSh-5 or ZSh-7.  The bladder fills when demand for oxygen increases, pressing the pilot's nose and mouth more tightly into the oxygen mask.  The KM-34 requires a throat microphone for communications. 

This example is used.  The color in the fiberglass fades readily when it is exposed to sunlight.  This is an older example that is in good shape.  The rivets holding the clip straps are not rust resistant.  The edges of the fiberglass chip readily.  It is difficult to find truly superb samples of this mask (like the one above).

Here's a complete setup of a ZSh-7A with a standard KM-34.

This mask is a KM-34D Series II.  The passport on the right is the correct passport for this mask and it specifically states on the front that it is the KM-34D Series II.  However, inside the mask, the nomenclature on the rubber nose cup states KM-35.  This passport is from 1993 and was pre-printed.  The serial number on the mask was handwritten onto the paperwork.  Consequently, this provides undeniable proof that the two nomenclatures are for the one mask.  In the JAFH, the KM-35 is shown as one that looks like the mask to the left, but the hose comes out of the bottom center.  The KM-35 that was noted in the JAFH was only the demonstrator and did not make it to final production.  The hard plastic outside shell and internal parts remained. The intake hose was moved to the side and it became the new KM-35.  

The KM-34D Series II and KM-35 have a number of interchangeable parts.  If there is a tag on the inside of the hard plastic shell that designate the mask as a KM-34D Series II, then that's what it is, despite the fact that the rubber nose cup will be embossed with "KM-35".  The rubber nose cup is an integral piece to both masks.  Consequently, if there is no tag inside the hard plastic shell, then the mask can probably be called the KM-35.

Note that this newer version KM-35 (still labeled as the KM-35) has a larger exhaust cup on the nose.  You'll see that the attachment for the intake hose is the same color gray as the older KM-35 - showing interchangeable parts between the two. Also note that the hose attachments are slightly different between these two.  The upper KM-35 has a second hose for overpressure.  The bottom mask only has a single intake hose connection.  The KM-35 has a microphone on the inside of the nose cup, consequently, the KM-35 does not use the throat microphone.  I have to guess that this KM-35 is for a very unique aircraft - possibly the Su-27/Su-35.  The single hose from the mask, wrapped, makes it a very unique item..

These masks are from the collection of Mark Sindiong.  The next few entries represent his photo-view of the differences between the masks.

This is a close-up of the KM-34D Series II.


This is one of the earlier nose-cups.  It does not say "KM-35".  This is a very nice example.


This is the tag inside the above mask - clearly labeling it as a KM-34D Series 2, Size 2, Serial 5693.
Here is the KM-35.

This is another very nice sample, showing a non-standard plastic shell.  The shells that are most common do not have the embossed "KM-35" size "3" on them.
This is the most common rubber nose-cup.  It can be found on both the KM-34D series II and the KM-35.

This is a superb sample of a very rare label.  The KM-35MS, size 3, number 1305.  I believe that the "M" on this designation is for "Morskoi" which means "Naval".  Also, it appears that Pilots of the Su-27 from the Kuznetsov were carrying this type of mask (see the picture on the main page of this site).

Thanks for the great photo-spread, Mark!

These are all KM-34D Series I masks.  Note the variations in color.  These are all in pristine condition, so the variation in mask body color is not due to sun fading or aging.  The hoses are various colors from khaki to bright green.
The mask on the far left is a KM-35M.  All others are KM-34D Series II.  Note the variation in color on hoses and mask bodies.  Yes, the second from the left is the lightest gray and the hose is black.  

Here's the latest and greatest ZSh-7AP with KM-34D Series II.  

Purchaser tips:

On the KM-34, it is all pretty obvious.  Look for rust on all the connectors and for rust on the pins that connect into the helmet brackets.  The hose will show rubbing after a short amount of use.  And finally, the shell will fade readily with exposure to the sun and the shell also the edges will chip readily because they becomes brittle with age.

 As for cost - buy the masks with a matching helmet.  But if you want to price them separately, a KM-34 in good condition will draw $50 and a KM-35 in almost any condition is worth about $100 - pristine is worth more (up to $150).