THE GYROJET FLARE LAUNCHER

By Chuck Madurski

Emergency distress signaling gear has been a standard item of issue since prior to World War II. The large, heavy projectors and shells of that era gave way to the smaller, lighter and more efficient pen-gun types by the time of the Vietnam War. These were characterized by a knurled aluminum pen-shaped launcher with a thumb knob that retracted a spring loaded firing pin. One end of the launcher was threaded to accept the flare cartridge, which was percussion fired upon impact by the firing pin.

The flares would reach an altitude of 200 to 250 feet using this system. Used by the Air Force, Navy and even Army Aviation, the performance of these flares was considered adequate for the expected situations in which they might be used. For some, that all changed with their experiences in bailing out over the jungles of Vietnam. Having to bail out generally meant landing in jungle with a high, dense canopy – often higher than the flares maximum altitude.

At this same time a totally unrelated project was under development: the Gyrojet family of rocket pistols. Though eventually it was deemed inappropriate for its intended use, someone in the right place at the right time, someone who knew of the Gyrojet and understood the problems of jungle search and rescue put the two together, and the Gyrojet Flare Launcher was born. Unfortunately, research was unable to uncover whether it was a military individual or someone from MB Associates who suggested the idea of using a rocket propelled projectile to get the distress signal through and above the canopy of tree tops. Regardless of this, by adapting the miniature rocket technology of the Gyrojet projectile to a flare, this level of performance was accomplished without a needless increase in size and weight of the whole system.

As near as can be determined, the Personnel Distress Kit, Red, A/P25S-5A (also called the M-201 in early editions) was first issued to Air Force and Army aircrew personnel around 1970. Some documents also refer to it as “Foliage Penetrating Signal Kit,” an interesting admission of its purpose. As issued, it was part of the Air Force SRU-21/P Survival Vest, which was also used by Army helicopter crews. It was also part of the unique Army OV-1 Aircraft Survival Vest used by of the OV-1 Mohawk, one of the few fixed wing aircraft in the Army inventory. For some reason, the Navy did not issue the rocket flares, choosing instead to continue using the traditional screw-in percussion fired pen type flares and launchers, though some rocket types have appeared in Navy survival kits. Since Naval aircraft flew missions from carriers, maybe it was determined that it was less likely for pilots to “punch out” over land, thus lessening the need for the performance provided by the rocket flares.

An August, 2004 “Sources Sought/Market Survey” Solicitation from the U.S. Army Field Support Command of Rock Island, IL provides an excellent description of the A/P25S-5A:

“The Personnel Distress Kit, Red, A/ P25S-5A is used by downed airmen or others exposed to emergency escape and evasion situations. The kit includes a hand fired launcher and a bandoleer assembly. The bandoleer assembly contains a plastic molded bandoleer holding seven red signals. The signals consist of small solid propellant rocket motors actuated by a percussion primer, a delay element, and a pyrotechnic candle in a metal case. The surface of the metal case is dyed red to match the color of the candle. The launcher is black anodized aluminum; it has a retaining device and a firing mechanism. The retaining device precludes the signal from falling out of the launcher when the loaded launcher is aimed vertically at the ground. The firing mechanismconsists of a free traveling firing pin with an actuation knob and spring. The launcher is connected to the bandoleer by a lanyard. Physical dimensions for the launcher are Length 5.5 in.; Diameter 0.8 in. Signals are loaded individually into the launcher with nozzle down into the launcher until the signal bottoms out. The firing pin inside the launcher upon firing, strikes the primer in the signal which ignites the propellant. Exhaust gases are expelled through nozzle holes in the signal and propel the flare out of the launcher in a spin stabilized flight. The signal should be able to completely penetrate moderately dense jungle or forest foliage. After traveling approximately 600 feet, the payload ignites causing separation from the rocket motor. Burning time is approximately 9 seconds and provides an average candle power value of 2,500 lumens for the first 7 seconds. Physical dimensions for the signal are Length 2 in.; Diameter 0.5 in.”

References list the maximum height attained by the signal itself as being either 1,100 or 1,500 feet which makes sense with presumed rocket motor burnout (at separation from the payload) occurring at 600 feet. Total burn time of the signal is said to be 9 seconds. The visibility distance is listed as up to 3 miles in the daytime and 10 miles in the dark of night. The retaining device in the launcher mentioned above for keeping the flare in place until the moment of launch is a simple, springy fourfingered collet in which the flare sits fairly deeply. When fired, the only sound is the minor crack of the primer that ignites the solid rocket fuel which overwhelms the subdued “whoosh” of the rocket venturis as the flare speeds on its way while the user also feels a brief wash of warm air from the rocket exhaust.

MB Associates was the supplier to the military for about ten years following the adoption of the Gyrojet Flare Kit. Drawing No. 11-1-1783 from the U.S. Army Natick Laboratories titled Survival Kit Individual; Vest Assembly (the SRU-21/ P), dated 3 May 1972 shows an Item List just above the title block. In that list is Item 4, Signal Kit, Foliage Penetrating. The material (source) column says: MB Associates Model MBA-2016 FSN 1370- 490-7362. “MBA” is engraved on the gripof the launchers made by them along with other information. Flares will have ink stamps on them indicating lot number beginning with “MBA” as well, sometimes with a manufacture date, matching the cardboard instruction sheet packaged with the kits. Lot numbers from subsequent manufacturers use a different code. The latest MBA marked kit observed is dated 11-81. According to samples inspected for this article, another company had taken over by December 1990. The actual date suppliers changed could not be found but it was obviously sometime in the 1980s.

Originally conceived as a more efficient means to kill enemy combatants, the Gyrojet technology found its real home as an aid to saving lives and finding downed airmen. Additionally, the Gyrojet Rocket Flare Kits were not just issued in survival equipment, but used as consumables in SERE schools for familiarity training. It is easy to see that many hundreds, if not thousands, have been manufactured over the years. And the date on the quoted “Sources Sought/Market Survey” makes it clear that the Gyrojet rocket flare system is still an issue item to this day. Not bad for a 40 year old failure.