A-10A

 

Type A-10A summer helmet

 

Essentially a slightly modified and redesignated Type A-10 (which itself was a parallel development of the AN-H-15, but strictly Army venture) using the same Spec. No., the A-10A was introduced about 18 months after the Type A-11

It was almost identical to the AN-H-15, apart from the rear goggle retaining straps made of fabric and the chin strap of velvet covered webbing, the A-10A eventually replaced the former as standard AAF summer helmet in 1945.

 

Made of khaki cotton-twill cloth it accommodated factory installed earphone receptacles nicknamed "donuts"  for increased comfort and noise reduction. The 1943 rubber shortage forced the use of wool fiber and kapok to make these improved sound-insulated earphone mountings which can be found on numerous USAAF and USN helmet types.

Type A-13 pressure demand oxygen mask

Oxygen mask, Type A-13 with microphone

Manufacturer: MSA / Mine Safety Appliances Co.

Order No.: 44-12277

Specification No.:3165

Size: 1

 

When flying at altitudes above 33'000 feet (10'000 m) the normal diluter demand oxygen systems reach their limits, as even with breathing 100% oxygen, blood saturation begins to fall off and approaches a dangerously low level at arount 41‘000 feet. As military flying at high altitudes became more and more important, a solution had to be found.

 

One solution would have been pressurized aircraft cockpits, but with a few exceptions aircraft design of WWII was not ready for their mass production and operation, yet.

 

Favourable progress in comparatively short time was offered by the development of the pressure breathing system. Oxygen at a pressure higher than the surrounding air would now be forced into the lungs, thus enabling adequate blood saturation. This pressure had various side effects: no effort was made to inhale but a slight effort was required to exhale. Furthermore, voice communication became more difficult as the air had to be forced out of the mouth while exhaling, and transmissions were very difficult to understand. Pilots had to adopt and get used to completely new breathing techniques. But, to enable safe and sustained flight at altitudes above 41'000 feet represented a major technical breakthrough.

 

The new pressure breathing system required newly-designed oxygen regulators (Type A-14 pressure-demand regulator) and oxygen masks. First mask prototypes designated XA-13 were service tested by the USAAF as early as November 1943 and used in operations against the enemy in February 1944 by 14th Photographic Reconnaissance Squadron Spitfires. By November 1944 all new F-5 and F-13 aircraft (reconnaissance versions of the Lockheed P-38 Lightning and Boeing B-29 Superfortress) were equipped with the A-14 oxygen regulator.

 

The hard rubber of the pre-production models caused considerable discomfort, so the Mine Safety Appliance Company used now a softer, medium-green rubber for the improved Type A-13 mask. It consisted of a rubber face piece with inhalation valves and pressure compensated exhalation valve. Designed to be sealed against positive pressure, the mask was moulded with inside flaps which contacted the nose and mouth. The sealing caracteristics were of vital importance in pressure breathing at high altitudes. Large cheek flaps were included for protection against extreme cold and flash burn.

The mask was attached to the flying helmet by means of a webbed strap suspension harness which was fitted with a double snap fastener on the left and a metal hook on the right. This harness was helping to achieve a leak-proof seal and was supporting a plastic nose piece which held the shape of the mask.

A corrugated rubber hose delivered oxygen from the regulator and was held in place at the bottom of the mask by a clamp.

The mask included an integrally constructed microphone pocket and the oxygen-delivery hose features a bailout adapter for use with the H-2 emergency oxygen cylinder.

Polaroid 1065 all purpose goggles

The Model 1065 manufatured by Polaroid was identical to the Type B-8 goggles, except for the nomenclature moulded into the frame. Normally it came in a kit nominated 1068 in a felt lined brown leatherette box, including extra lenses.

This specimen has amber lenses fitted and features an adjustable strap with a friction buckle.