OXYGEN MASK RETENTION RECEIVERS AND CLIPS
Hard shell helmets implementation, following the increase in aircraft and potential ejection speeds, required suitable and easy to use system for fitting and adjusting oxygen masks. Over time, compared to old soft helmets' “snap-on buttons and hook" fittings, new designs and improvements were implemented.
NOTE: This page is limited to different types of oxygen mask clips and receivers fitted to past and present Swiss Air Force "jet era" helmets.
CAST BAYONET RECEIVERS AND “T” BAYONET CLIPS
Cast bayonet receivers were used with the so-called "T" bayonet clip. Introduced in the late ’50, they consist of a lightweight receiver enclosed in a cast aluminium housing. The housing was (is) intended to avoid parachute risers to become entangled during opening. The receiver can be rotated in both directions up to 15 degrees in order to properly adjust the mask on the wearer's face. Housings are commonly painted to match the helmet colour.
The small metal plate used to secure and adjust the receiver usually carries the receiver or helmet manufacturer's logo. Cast metal receivers and “T” bayonets clip set were typically installed on “early” hard shell helmets as the H-5 , coupled to the era MS22001 and successive MBU-5/P oxygen masks.
“ULMER” RECEIVER AND STRAIGHT BAYONET CLIPS
The left hand bayonet is kept locked in the receiver by a small threaded stud installed on the clip tongue tip which locks in a spring loaded bracket installed on the helmet's receiver.
In order to unlock the clip, the bracket needs to be pulled inwards by the small protruding lever visible in the right picture .
LIGHTWEIGHT RECEIVERS AND OFFSET “J” BAYONET CLIPS
Lightweight oxygen mask receivers are basically the same as the ones installed inside the cast bayonet receivers.
They are directly fitted to the helmet by means of a plastic spacer in order to compensate the helmet shell radius and reduce weight.
Those receivers are adjusted for oxygen mask proper positioning when fitted to the helmet, consequently not adjustable anymore.
Lightweight receivers are used with "offset" bayonet clip, also known as "J” clip. First introduced in the late 1970s (around 1978 or 79) with the MBU-12/P oxygen mask, this style of clip is the standard for most oxygen masks in use today. Analog to the "T" bayonet clip, the offset unit has dual adjusting straps on each side. The clip itself has been angled about 45 degrees upwards and the strap bar has been designed to be flush with the helmet (edge roll) contour. This allows for better fit of the oxygen mask. They are normally in use today installed to the HGU-55/P or JHMCS helmets, fitted to HA-LP/PPB oxygen masks harness.
The HA-LP/PPB offset “J” bayonet clip are similar to the standard offset clip, featuring an optimized strap bar matched with the mask configuration.
"J" bayonet can be found also coupled with cast receivers. In this case to a Protection Inc. DH-151.