The U.S. Army Built Night-Fighting Gunships to Hunt the Viet Cong

But the helicopters were past their prime

The U.S. Army Built Night-Fighting Gunships to Hunt the Viet Cong The U.S. Army Built Night-Fighting Gunships to Hunt the Viet Cong
Heavily-armed helicopter gunships became a fixture of America’s war in Vietnam. But the U.S. Army’s low-flying attack choppers were pretty terrible at spotting the... The U.S. Army Built Night-Fighting Gunships to Hunt the Viet Cong

Heavily-armed helicopter gunships became a fixture of America’s war in Vietnam. But the U.S. Army’s low-flying attack choppers were pretty terrible at spotting the Viet Cong at night.

In 1967, the ground combat branch hired the Hughes Aircraft Corporation to design a night-fighting kit for the UH-1 Iroquois helicopter, more commonly known as the Huey.

The entire system—the chopper, guns and night vision gear—became known as the Iroquois Night Fighter and Night Tracker, or INFANT.

But by the time Hughes had delivered its first INFANT systems, the Huey gunships were becoming obsolete. They simply couldn’t compete with the newer AH-1 Cobra — the world’s first truly purpose-built attack helicopter.

The Army was frantically developing night vision systems before the INFANT. The ground combat branch even created the South East Asia Night Operations office—a.k.a., SEA NITEOPS—at Fort Belvoir in Virginia to keep tabs on the various projects.

“The Viet Cong, although harassed by daytime air strikes, have enjoyed a large degree of freedom during night operations in the past,” a report on an earlier Army program stated. An “illumination system may have the effect of removing the cloak of darkness which now protects the Viet Cong.”

At that time, aviators in Vietnam were testing out a crude, high-powered spotlight. The system, nicknamed Firefly, consisted of a seven landing lights taken from C-123 transport planes mounted in a cluster on a metal frame.

Crews could strap the Firefly — which cost less than $1,000 to make — onto their Huey transports and gunships. The device used on-board power supply systems, and someone in the main cabin had to manually swing the beam of light around once they were airborne.

Left—a Huey gunship with a Firefly light. Right—troops show off the later Nighthawk setup. At top—one of the INFANT-equipped UH-1Ms. Army photos via Ray Wilhite

But the cluster of lamps shone bright … maybe too bright.

“Feedback illumination … prevented observers in the searchlight aircraft from identifying anything on the ground except large, contrasting objects,” Army technicians in Vietnam reported back.

In practice, the Firefly chopper did its best when other scouts or gunships followed behind. These trailing helicopters would use the light to find their targets and blow them up.

More worrisome, pilots discovered that these spotlights made them perfect targets for guerrillas on the ground. The Army needed a system that could illuminate targets on the ground without putting American crews in danger.

Enter the INFANT system.

The core of the system was a complex turret with an image intensifier — which boosted ambient light — and an early infrared video camera. Both devices fed imagery into displays inside the cockpit and cabin area.

Hughes’ engineers bolted the whole arrangement onto the Huey’s nose. The pilot and copilot could swivel either sensor independently of the other.

The Huey helicopters had an M-21 armament subsystem, with two Miniguns and two rocket pods. The fast firing guns had infrared spotlights to light up targets on the night vision screens.

Tests in the United States by SEA NITOPS showed the system worked well enough, but had some significant problems. INFANT simply weighed too much for the already underpowered UH-1C gunship.

Worse, the muzzle blast from the Miniguns blinded the cameras and caused permanent damage to their inner workings.

A UH-1M with Hughes’ INFANT kit. Army photo via Ray Wilhite

To get a more suitable chopper, the Army installed the UH-1H Huey’s more powerful engine into the smaller C models. The first of these new upgraded UH-1Ms went straight to the INFANT program.

Army weaponeers solved the problem with the Miniguns by fitting flash hiders to all six of the weapon’s barrels. The Army’s Weapons Command cooked up a special “dim tracer” bullet that wouldn’t burn too bright for the scopes.

With these issues fixed, three UH-1Ms with INFANT gear set out for Vietnam. In November 1969, the choppers touched down at Lai Khe in South Vietnam for their trial by fire.

For the next three months, the special gunships fought with troops from the 1st Cavalry Division and 25th Infantry Division. “The evaluation concluded that INFANT provided an increased nighttime operational capability,” Army officials explained to their superiors in a final report.

Unfortunately, the night vision gear broke repeatedly during the field tests. Despite a crash course from Hughes’ representatives and Army technicians, the helicopter crews had trouble using the cameras and fixing them when they stopped working.

Even with the extra power, the UH-1Ms still had trouble with the turret. With so much weight up front, pilots worried about losing control of their helicopters.

“The aircraft should be restricted to 100 knots during straight and level flight and 120 knots in a dive,” the Army’s final evaluation stated. “The turret causes the aircraft to assume an unusually nose-low attitude when approaching these air speeds.”

But INFANT’s biggest problems had little to do with the system itself. As the hardware arrived in Vietnam, troops with the 25th Infantry had come up with an improved version of the earlier Firefly setup.

This new Nighthawk system used spotlights initially taken from knocked out M-551 tanks, which could pump out visible or infrared light. Crews bolted the lamp and a night vision scope together and strapped the whole getup inside the main cabin of their UH-1H troop carriers.

Next to the light, another crew member manned a Minigun or a .50-caliber machine gun.

“It has been concluded that INFANT is an effective, covert, night weapons system,” Lt. Gen. Frank Mildren, who had been second in command of all Army troops in Vietnam, wrote in an official debriefing statement. But “I question its cost effectiveness when compared to the Nighthawk.”

On top of that, the Army had begun adopting the faster, sleeker and just generally all around more capable AH-1 Cobra. During the trials, the modified UH-1Ms would often spot targets for the Cobras rather than shoot at anything themselves.

In the end, Army evaluators concluded that INFANT was just too complicated. The final report recommended that the Army take what it could from Hughes’ gear and develop improved equipment instead.

The service bailed on a plans to install a newer type of infrared camera on the Hueys. Today, the Army’s Apache gunships and Marine Corps Cobra helicopters include night vision systems.

Washington later sold some of its UH-1Ms to El Salvador, where they fought against communist rebels. Back home, the gunships continued to serve in the Army National Guard into the 1990s.

After that, the Army used them as unmanned target drones for war games … and blew them up.