Message 2896, Jun 13, 2001
Bluelight: I believe the valve at the end of the parallel hose is your over-pressure valve. The corrugated hose is the primary oxygen feed. I'm sorry on my explanation. The KM-34 and KM-34D are exactly the same - mask wise. I didn't know that one had an overpressure valve and the older version did not. The KM-34D series 1 upgrades by putting the microphone inside the mask, but that's it for upgrades. Thanks for the information. I'll use it and my answers to update the KM-34 KM-35 page on my web site.
All my best, Craig

Message 2881, Jun 12, 2001
Hi Craig, Thanks for your answers but I am afraid that I am the irritating kind of person where answers do not necessarily create satisfaction but more questions. I have had the opportunity to look closely at a KM-34 and a KM-34D next to each other. No microphone in this KM-34D. The only difference I could find (except for a slight difference in the colour of the fibreglass shell) was a small valve-like protrusion on the KM-34D on the lower end of the thin hose that is running parallel to the corrugated oxygen hose. The valve is situated just above the connector and protruding at a right angle. Any idea what that might be?
Cheers, Bluelight

Message 2875, Jun 12, 2001
Hi Bluelight! The KM-34D is simply an older model of the KM-34D series I. Before the Soviets knew they were going to make more of the same in the series, they went with the simple title. The KM-34D may or may not have an internal microphone (nestles into one of the exhaust ports). It depends if it was upgraded or not. You won't see many of the KM-34D around that are the plain jane versions. These things were of poor quality and died quickly. The KM-34D series I is manufactured the same way, but is newer. Consequently, less wear and a pilot would always prefer the Series II, which doesn't look like a KM-34D series I at all. However, the series I and series II have all the exact same connectors - oxygen, overpressure, occipital bladder, and microphone. The KM-35 has a different oxygen connector (larger, without an overpressure hose). Bottom line - a KM-34D and KM-34D series I are the same, just the series I is newer and will have a built-in microphone. There's the difference.
"RAZM" is short for Razmer, which is Russian for "size". The sizes of these masks come in 1 through 4 (I believe) for the KM-34D series I and 1 through 5 for the KM-34D series II. 1's and 4's are in short supply. 3's are the most common. 2's are just a little small and are more for a little fella. I've seen a couple of the size 5's and couldn't believe the pilot whose face that thing would fit could actually worm his way into a MiG-29 seat. Andre the Giant size comes to mind. A 4 is very comfortable, but not a tight enough fit on your average-sized face. A 3 is probably best all the way around if you fit the average pilot profile - 5'11" 175 lbs (plus or minus a couple inches and about 10 pounds). Of course that size comparison does not apply to retired fast mover jockeys, who may have blossomed in their retirement. Let's call it the "fighting weight" comparison.
I hope this helps, Craig

Message 2874, Jun 12, 2001
Hi all, Anyone who can explain the difference between a KM-34 and a KM-34D Series 1 oxygen mask? Craig? And what does RAZM-II mean? Is it an indication of size? (it is written on the fibreglass shell opposite of the type designation on my KM-34D)
Cheers, Bluelight

Message 2207, May 9, 2001
I think the preferred method is that the Crew Chief (in the Soviet days, this could have been a bird Colonel) places his boot heel on the pilots forehead and using both hands, rips the mask off the pilot's face. Yes, they were getting paid the same, but the extra bennies for being a pilot were a cause for jealousy and envy.
On a serious note - if the bayonets don't stick (after you've cleared the retractable pins, then you should worry that the bayonets or the bayonet receivers are loose and worn out. This is true on both the ZSh-5 and the ZSh-7 series (whether you use the KM-34D series I, II, or KM-35 masks). They should stick - all the good ones do. The spring on the bayonet pin should be stiff - give it a hard pull straight out of the mechanism and it will remain in good condition. I would be hesitant to twist these as the bayonet itself is of two piece construction and extra twisting may cause the bayonet itself to separate.
I hope this helps, Gauntlet

Message 2205, May 8, 2001
OK, that confirms my experiences with the bayonets. I have found that, if I give them a twist right at the end, they come out fairly well.
Gato