Aircrew Flight Equipment:
British Oxygen Mask Hooks in detail
This is a simple guide is written to clear up confusion over which mask hooks belong with which UK flying helmet types.
Applicable to the H2-Type, P, Q, V and X Type families, and ADOM oxygen masks.
G-Type (and Mk1) flying helmets
Mounted on a triangular plate with three pop studs to attach to either side of the cloth G-type helmet, can be worn under a Mk1 protective helmet. Two height options are available by selecting the upper or lower set of helmet pop studs.
Black knurled length adjuster allows for correct mask fitting / tightness to face.
They are secured to the helmet by the addition of a small countersunk screw and nut on the rear pop stud. the screw is fitted from the inside of the helmet, and the nut sits on the outside of the mask hook. The protruding nut can cause scuffing to the inside of Mk1 protective helmets.
It is not possible to fit these hooks to the F-Type helmet as the rear pop studs are not installed.
Mk 2 series flying helmets
"Triangular-ish" sliding height adjustment plate, allows height adjustment via a screw on the outside of the helmet shell. This plate runs up and down against a strip of aluminum which is part of the helmet's internal webbing attachment.
These hooks needed to be quite long due to how far back inside the helmet shell the plate is mounted.
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Black knurled length adjuster allows for correct mask fitting / tightness to face.
Mk 3 series flying helmets
Identical to hooks for the Mk2's, with identical "triangular-ish" sliding height adjustment plate, as the Mk2 and Mk3 helmet shells were very similar in construction.
Later versions of these hooks had an orange knurled length adjuster, which are to be seen on most Mk3 series helmets.
NOTE: The Left Hand hook of this pair has had a repair carried out, as the pivot rivet has been replaced with a screw, nut and washer. It has ended up on the opposite side of the bracket to original riveted config.
Mk 4 series flying helmets
These hooks were screwed to plastic mounting blocks at the helmet shell front opening, meaning they were made shorter as the pivot point was further forward than the MK2 / 3 helmets. This results in a stumpier appearance, and there is no need for a sliding height adjustment plate.
The triangular-ish mounting plate was not needed for the Mk4 helmets.
The helmet plastic mounting blocks allow for 3 height positions, by using one of the three brass threaded holes set into the plastic block to mount the hooks. The mounting screws allow the hook to pivot up and down as they are machined with a bigger diameter shouldered shank.
Mostly seen with orange knurled length adjuster, but some early hooks had the black knurled length adjuster, as shown here.
These hooks can also be installed onto a MK10 / Alpha helmet.
Mk4, Mk10 / Alpha series flying helmets
While many Mk10 helmets are fitted with the normal mask hooks from Mk4 helmets, in the 1990's a totally new form of mask fitting came about; the MQR - Mask Quick Release. Mk4 series helmets have also been used in service with MQRs.
A bullet shaped fitting on the mask harness is inserted into a latch mechanism on the helmet. These fittings were originally only released on the Mk10 series helmets but can be installed onto a Mk4.
The length adjustment was moved form the helmet to the mask harness, two lengths of harness are available, giving two adjustable ranges, adjustable by rotating the bullet on the end of the wire.
Height adjustment remains by the three screw holes of the mask hook mounting plastic blocks attached to the helmet shell, as per the Mk4 helmets.
The screws of the MQR's have no shank, but instead use a black plastic bush passed through the MQR mount plate.
