Dancing in the Dark
Night vision goggles can save a pilot's life or, if he hasn't had adequate training, take it.
- By John Croft
- Air & Space magazine, November 2004
USAF/Tech. SGT. Scott Reed
(Page 3 of 5)
But the pilots felt that they had to make it work: "The only way we'd survive [in hostile airspace] would be down in the trees, and we needed goggles to do that," Fridd says. A major threat for helicopters then, as now, was shoulder-launched missiles. Anderson says the PVS-5, though not designed for aviation, gave the Army a real edge. "It didn't take long for the strategists to figure out that we'd have a huge advantage working at night," he says.
Both Fridd and ITT's Anderson say pilots eventually discovered that cutting away some of the casing below the PVS-5 eyepiece would give them a much more comfortable view both outside and inside the cockpit, a finding that was later built into Gen 3 units, which sit an inch or so away from the eye. Also problematic at the time were instrument panel lights that swamped the NVGs with photons, making it hard to see the outside scene. Pilots dealt with the problem by turning off the instrument lights and illuminating the panel with chemical light sticks—"chemsticks," which emitted light in a narrow part of the spectrum. Today's NVG-compatible aircraft emit light in the blue end of the visible spectrum or have glass filters to cancel out the white lighting of older cockpits.
In 1980, Operation Eagle Claw, the attempt to rescue 53 U.S. hostages in Iran, proved disastrous when an RH-53 helicopter collided with an EC-130 refueling aircraft, killing eight soldiers. The mission had been planned as a night operation, but pilots had received only 15 hours of NVG training, and instrument panels had to be taped over to prevent interference with the PVS-5s. As is often the case, disaster spawned research.
Gen 3 NVGs, which introduced image-enhancing gallium arsenide photocathodes, longer life (10,000 hours, up from 2,000), and other enhancements, came into service in the early 1980s and, when combined with experience gained in training and in designing compatible lighting, proved themselves in night operations in the 1991 and current Iraq conflicts. Almost every U.S. military aircraft is now equipped with compatible lighting, and crews are training to use NVGs for every night flight. Goggles continue to improve, though the technology is still called Gen 3.
Widespread use in the military has slowly begun driving NVG devices into civilian aviation; when military pilots retire or finish their tours, they bring their Gen 3 experience to the private sector. Lately, petroleum companies, medical transports, pipeline patrol outfits, and even mosquito-spraying companies are clamoring to certify their aircraft and crews to fly with NVGs.
The FAA, not wanting to duplicate the entire history of NVGs in the military, 10 years ago began developing guidelines for civilian use. Unlike police units, civilian operators must get FAA approval for their goggles, interior lighting systems, and training programs. On tap for next year are minimum standards for goggle performance, in part to prevent pilots from using substandard night vision equipment now available from "Eastern bloc countries," says FAA rotorcraft specialist William H. Wallace. Bell uses NVGs made by Northrop Grumman; that company and ITT Industries are the principal U.S. manufacturers of the devices.
Until the civilian rules are in place, FAA approvals are granted on an individual basis and can be somewhat ad hoc. In 1999 Rocky Mountain Helicopters became the first air taxi company to earn FAA approval to use NVGs for its EMS helicopters. The company later was bought by Denver-based Air Methods, where Fridd is an NVG instructor.
Chuck Antonio, a former Navy fighter pilot and flight surgeon who later helped develop the NVG training programs for various aircraft in the Navy, Marines, and Air Force, leads a government and aviation industry committee that is advising the FAA on formulating the rules. Based on the military's experience then and now, Antonio believes most NVG accidents are caused by inadequate training, poor crew coordination, and flying too fast for the limited contrast and visual cues that NVGs provide. Antonio studied Air Force, Navy, and Marine accidents in fast-moving jets like the F/A-18, AV-8B, F-16, and A-10 and found that pilots would neglect their flight instruments in favor of the emerald world outside and become disoriented.