Original Item: Only One Available. This is a solid example of a heavily worn Vietnam War APH-5 Flying Helmet, as used by all branches of service during the Vietnam War. This Helmet appears to have been very well used. Size is a “LARGE” and overall condition good with manufacture by Sierra Engineering Co.

The helmet came with a tag inside stating that it belonged to Sergeant First Class Mike Henry, a Crewman on an OV-1 Mohawk, though his name is nowhere to be found on the helmet. The helmet shell itself was painted black with green writing on it. The writing consists of PIPER on the reverse, CALIFORNIA on the left visor side and SHERRY on the right visor side. The interior of the helmet is in rather poor shape. The leather brow pads have come detached from the styrofoam padding and the ear cups are very brittle, which is unfortunately extremely common with these helmets, especially those that have saw extensive service.

A great example ready for further research and display.

Grumman OV-1 Mohawk
The Grumman OV-1 Mohawk is an armed military observation and attack aircraft that was designed for battlefield surveillance and light strike capabilities. It has a twin turboprop configuration, and carries two crew members in side-by-side seating. The Mohawk was intended to operate from short, unimproved runways in support of United States Army maneuver forces.

The APH-5
The APH-5 helmet was the result of more than two years studies conducted 1954-56 for a successor to the H-3 and H-4 series of helmets. VX-3 at NAS Atlantic City, the Aero Medical Branch of Service Test Division at NATC Patuxent River, Air Crew Equipment Laboratory, Naval Air Materiel Center, Philadelphia, and AirLant and AirPac Fleet units were among those who cooperated with the Airborne Equipment Division of BuAer in testing the gear. The studies and helmet development work concluded with the MSA-N2 design, an immediate predecessor of the APH-5, being manufactured in very
limited quantity. Another contract initiated work on an individually fitted (custom fit) helmets, designated the BBC and BBC-X2.

Production and entry into service
Initially, the APH-5 was designed without a visor, and the incorporation of a visor required a cover plate in order that the helmet shell itself would not be weakened by the visor guide slot. The final version was field tested for nearly a year by squadron pilots, during which time some 50 helmets had an average of 300 flight hours logged. From the comments and suggestions thus obtained, several modifications were made and the helmet was put into production. The distribution of the APH-5 helmets began in April 1956, the first
going to fleet squadrons as allocated by ComAirLant and ComAirPac. The first two contracts (2500 under first contract, 2500 under second contract for 7500) had been delivered by February 1957 allowing the helmet to become standard equipment in all fighter and attack squadrons as originally intended. As the years passed and more helmet became available they were issued to flying personnel from other squadrons as well.

Shortcomings
The APH-5 design was ground-breaking and set the standards for the vast majority of US flight helmets until the advent of the HGU-55 in the early 1980s. It did however suffer from a number of shortcomings, some more serious than others. From the beginning the APH-5 was suffering from heat built-up. The close fitting sponge rubber lining produced more heat than the old cross-strap webbing of the H-3 and H-4. An associated problem was that the sponge rubber collected perspiration in an unsatisfactory manner. Improved, leather-covered liner pads were therefore introduced. Another frequent complaint about the early helmets was that the visor lock button have been received -the binding problem was solved in later models by the use of a template for aligning the track before riveting, and by burnishing the visor track to reduce friction. The first 1500 helmets manufactured had a plastic female communications plug on the left side of the helmet. It turned out that it was poorly placed and subject to frequent breakage so later models had a lead-in extending from beneath the edge of the helmet.

Poor Helmet Retention
Poor helmet retention was the APH-5's most serious problem by far. In a time period of 12 months in 1958-59 there was a total of 52 cases of APH-5 loss during aircraft accidents in the US Navy. Of these 52 cases, 50 percent were fatal while an additional 23 percent had head injuries. Comparable figures for 1963 show 23 cases of APH-5 loss, with 48 percent fatal injuries and 26 percent non-fatal head injury. Retention in the APH-5 was accomplished by a nylon chin strap, nylon nape strap, three sizing pads of leather covered foam rubber situated in the front, top and rear, and by ear pads of foam rubber attached to polystyrene earcups.

The foam rubber composition of the sizing pads permitted very small loads to compress the pads completely. In case of compression of the front sizing pad, the nape strap lost contact with the head and became completely useless. In case of compression of the top pad the slack created in the chin strap made it ineffective.

Both the chin strap attached to the outside of the helmet and the napestrap had very limited skin contact and therefore very little retention capability, even before sizing pad compression, even if the straps were tightened to the point of intolerance for prolonged wear.

The earcups were attached with a screw through the helmet shell, but the screw was only fixed to the polystyrene earcup by a small fixture embedded in the foam. Even a small impact would fracture the polystyrene earpad; and when this occurred, most of the retention capability of the helmet was destroyed. Even if the polystyrene material remained intact, the soft foam rubber earpads were compressed very easily, impairing the retention capability.

ComfortThe APH-5 helmet was heavy and therefore uncomfortable to wear for longer periods. It weighed 4 pounds with Hardman receivers but without oxygen mask. In comparison an APH-6 helmet weihed only 3 punds 13 ounces. Some of the factors affecting the weight were the heavy rubber edge beading, large earphones, and fibreglass visor housing. Other factors adversely affecting comfort were problems with heat retention (even with the newer fitting pads), abrasive chin and nape straps, and difficult fitting due to only two helmet sizes available.

Oxygen Mask Attachment
The APH-5 went through several upgrades in order to improve oxygen mask retention. Originally the helmet was issued with leather oxygen mask tabs with two male studs on each, and the A-13A oxygen mask was attached using a Y-shaped metal yoke with webbing straps. It quickly proved to be inadequate so the Hardman retention system, or "Christmas tree" oxygen clip, were evaluated in 1957 and approved for use. The oxygen mask clip could be quickly inserted in a slot receptacle on either side of the helmet for a comfortable fit and a quick disconnection. Another step was taken when the Navy adopted the self-aligning Sierra type 345-30 oxygen mask receivers by 1961. The system retained the Hardman hardshell but introduced a new type of T-shaped bayonets, easier to insert and release.

Despite all the problems and shortcomings mentioned above, the APH-5 was used extensively throughout the 1960s even if its successor, the APH-6, was fielded around 1961. The APH-5 was modified with new fitting pads, new oxygen mask attachment systems, the chin strap was moved inside the helmet shell, and both chin and nape straps were fitted with cotton covered urethane pads for improved comfort. Some APH-5s were even modified with APH-6 type headsets with the well-known external disc.