Oldies but Goodies
Written by Peter Buxbaum
SOTECH 2011 Volume: 9 Issue: 2 (April)
Some of the more commonplace weapons systems mounted on the smaller aircraft flown by special operations forces are also some of the oldest. Their longevity is a testament to their effectiveness, flexibility and versatility, say experts, as well as their amenability to be improved over time.
In fact, the Hydra 2.75-inch rocket, which was introduced in the 1940s, and the M60 7.62 mm machine gun, which goes back to 1960, have been enhanced with a variety of improvements over time. But the M3 .50 caliber machine gun, whose history extends 100 years, is in need of a major redesign, said one expert, an event which is now on the horizon.
The 2.75-inch rocket was first deployed in the late 1940s and was used extensively by U.S. forces in the Korean and Vietnam conflicts. General Dynamics Armament and Technical Products (GDATP) has been manufacturing the Hydra version of that weapon since 1996, and has since produced over 3 million of the weapons in support of the Army’s Joint Attack Munition Systems Project Office.
“The Hydra’s longevity is attributable to its versatility,” said Joe Yodzis, senior director for business development for the Hydra rocket at GDATP. “It is a method to deliver a payload.” Recent enhancements allow the Hydra to deliver bigger and more diverse rounds.
One of the attractions of the M60D, an enhanced version of the original weapon, is its compatibility with a variety of platforms, noted Steve Helzer, general manager at U.S. Ordnance, manufacturer of the weapon. “One of its nice features is that it fits into most NATO mounts,” he explained. “The M60D can be mounted on a variety of air frames.”
The M3 .50 caliber weapon, on the other hand, “has not been redesigned since the first part of the last century,” said Tim Bero, president of TNW Inc., which is currently researching redesign possibilities. “In a lot of ways, the weapon is outdated both in terms of production and technology.”
GDATP is the system integrator of the 2.75-inch Hydra-70 family of rockets. The rocket system contains three components: the MK66 MOD 4 rocket motor; one of 11 warheads; and their associated pointdetonating, omni-directional and remote-set fuzes.
“Hydra-70 fires from the existing seven and 19-tube launchers and can be mounted on most rotary and fixed-wing aircraft, including the Apache, the Cobra and the F-16,” said Yodzis. In total, the Hydra is compatible with nine rotary wing platforms and 10 fixed wing aircraft.
These rockets include unitary and cargo warheads for use against point and area targets, with the warheads used for a variety of antimateriel, anti-personnel and suppression missions. The warheads include several high explosive varieties, illuminating and infrared flares, a pointed steel projectile known as a flechette, white and red phosphorous smoke, and several practice versions.
“These warheads provide low-cost munitions capable of area suppression and defeating threats at extended ranges, as well as providing battlefield obscuration, illumination and marking,” Yodzis said. “When these components are selected and combined, they provide a tailor-made solution to the warfighter’s situational requirements.”
The MK66 MOD 4 rocket motor is the latest innovation to the rocket system and provides substantially higher thrust and a longer range than the older MK40 motors. “Innovations are driven primarily by the user community and the customer,” said Yodzis. “We do … some engineering support as directed by the customer.”
Yodzis suggested that future innovations could include expanding the portfolio of warheads compatible with the system. “We are also always refining the warheads’ performance in terms of lethality, safety, range and precision,” he added. Other potential future improvements include fuze, propulsion and launcher innovations.
“The Hydra has been a resilient weapon against a variety of targets,” said Yodzis. “It has been an effective and efficient way to deliver ordnance from a variety of aviation platforms.”
The M60 made a name for itself during the Vietnam War when it was often mounted on Bell UH-1 Iroquois “Huey” helicopters. “The big selling point today,” said Helzer, “is that NATO has standardized on the M60. That gives them a common platform, spare parts across all services and branches, and no certification needed for a country to buy them. The M60 has been in use since Vietnam, so obviously it is deemed airworthy. It is simply a drop-in solution.”
In addition, Helzer added, the “slower rate of fire on the M60 allows you to carry the same amount of ammunition and stay in the fight longer.”
U.S. Ordnance manufactures a configuration of the M60 known as the M60D Enhanced. It features a redesigned machined aluminum feed cover with an integrated M1913 Picatinny rail for mounting optics and a forward M1913 Picatinny rail for other sensors giving the weapon 24 hour capability. The M60D Enhanced is fitted with spade grips for flexible use and an aircraft ring sight for rapid target acquisition.
“The rail system and sensors support quick target acquisition and aiming,” said Helzer. “These innovations made the weapon capable for a greater variety of missions.”
The M60D Enhanced is a gas operated, disintegrating link, belt fed, air-cooled machine gun. It fires from an open bolt and features a quick-change Stellite-lined barrel. “The gas system and the barrel components have been the big improvements to the M60D Enhanced,” said Helzer. “The earlier weapon had a lot of redundant parts that tended to vibrate loose, and these have been eliminated.”
The M60D Enhanced is used on the UH-1B Huey (using the M23, XM29, M59, and the Sagami mounts); the CH-47 Chinook (using the M24 and M41 mounts) in both door and ramp locations; the ACH-47A “Guns-A-Go-Go” variant of the Chinook (using the XM32 and XM33 mounts); and on the UH-60 Black Hawk (using the M144 mount).
The fail-safe reversible gas piston allows the weapon to be loaded with the bolt forward. “With earlier versions of the M60, if a soldier loaded the weapon backwards it would fire once and then not cycle,” said Helzer. “The reversible system is a big safety improvement.”
The newer M60 is also equipped with a new bipod system so that the weapon can easily be removed from the airframe in case it is downed. “The crewmen can take the weapon off and use it as a ground mounted weapon until they are evacuated,” said Helzer. “It is now a mission requirement to equip the weapon with a ground mount kit.”
An improved feedcam assembly on the M60D Enhanced eliminates charging jams and improves operator safety by allowing a belt loaded but not charged feature. “Debris sometimes gets caught in a link when landing in rough terrain,” said Helzer. “This problem can now be overcome. The 30 percent improved belt pull provides increased reliability.” Improvements to the barrel eliminate the need for a heat mitten for barrel changes and improve its longevity with the use of chromium cobalt.
Potential future improvements to the M60 are focused on the structure of the weapon and include, according to Helzer, substituting stronger material in the design and reshaping the weapon to make it more ergonomic.
The M3—a real workhorse of a .50 caliber machine gun that has been around for almost 100 years—is in severe need of a redesign, according to Bero. The M2 .50 caliber machine gun, the forerunner of the M3, was mounted on Mustang and Corsair aircraft during World War II. The M3 was introduced in the 1950s for a newer generation of faster aircraft. These days, the heavier M2 is consigned to ground vehicles, while the M3 is still mounted on Army helicopters.
“What needs to happen in the future is to make it lighter and more readily manufacture-able,” he said. “The weapon is now a century old and there are a lot of things that can be updated.”
Bero’s company, TNW Inc., which manufactures M2 and M3 machine guns for collectors and museums, has a contract to supply some of these weapons to a defense contractor for research and development. “This will eventually lead to a new gun,” he said. TNW’s models will serve as a test bed for the required innovations. Bero declined to name the contractor TNW is working with but said he believes both the Army and the Navy are interested in these developments.
Among the improvements Bero foresees is to replace what he calls the old “boiler technology.” That means “the gun is currently riveted together like an old steam boiler,” he explained. “There are a lot … better ways to build that gun today. It needs to be disassembled component by component.”
Bero also predicted a new version of the M3, which will probably take another two years to develop, will use a sheet metal receiver and be equipped with a muzzle brake that will ease the stress on the mounting system. Making the weapon lighter will make it more controllable, said Bero, without slowing its firing speed of 1,000 rounds per minute. ♦