HAI Convention News

NVG Night Flight An Eye-Opening Experience

 - March 4, 2013, 2:35 PM
Author Matt Thurber rode along in the Orange County Fire Authority's Bell 412EP on a night vision goggle training flight.

Lifting off from Fullerton Airport in the back of an Orange County Fire Authority (OCFA) Bell 412EP, the nighttime world of Southern California exploded into a vast ocean of suburban lights, interspersed with darker but clearly visible unlit areas, and all intersected by pulsing bright currents of car-clogged streets.

Karim Slate, a pilot for the OCFA and also an instructor at SRT Helicopters, invited me to ride along during a night training flight. Two Orange County firefighters needed to get recurrent on search-and-rescue procedures, and there was an empty seat in the 412. The flight vividly illustrated the benefits of night-vision goggles (NVG).

In the OCFA hangar, Slate set me up with a flight suit, jacket and helmet with NVG. He showed me how to adjust the diopter so I could see clearly through the goggles without wearing my glasses, then how to adjust the focus. NVG provide a maximum of about 20/25 visual acuity, which is plenty, especially at night, as I was about to learn.

The reason that light-emitting products inside the helicopter need to be NVG-compatible, Slate explained, is that near-infrared light put out by these lights will reflect off the inside of the windows, making it hard to see outside while wearing NVG. “All regular bulbs put out a tremendous amount of near-infrared light,” he said. NVG work well for detecting fires, he added, because fire emits a lot of near-infrared light.

The ITT Pinnacle NVG used by the OCFA pilots have a 40-degree field of view. “[NVG] tend to destroy depth perception,” he said, “until you learn to use other cues.” Pilots flying with NVG quickly learn to look both through the goggles and with peripheral vision outside the goggles, he added, to get the full picture.

During our training mission, Slate flew the 412 to a cliff near Lake Irvine, where Truck 61 firemen Dan Tessieri and Jeff Frazier needed to practice a hoist maneuver to stay current. Crew chief Jeter McApin rode in the 412’s left seat. Slate dropped me off at the base of the cliff so I could observe the action through the goggles. On the flight to Lake Irvine, I gained an instant appreciation of NVG; the lake sits in a dark area surrounded by hills and canyons. And while I could easily see the ridges and even into the canyons with the goggles, without them was like looking into a black hole. Looking up at the stars with the goggles revealed a new universe of heavenly bodies.

After the practice session at Lake Irvine, Slate received a call about a dog stuck on a steep beachside cliff near San Clemente. He offered to help rescue the dog, so we flew to San Clemente. After dropping me off at the staging area arranged by local sheriffs and firefighters, Slate, McApin and Tessieri took off. Tessieri rode the hoist down to a ledge above an 80-foot cliff where the dog was stuck. With my goggles, I could see the 412 clearly hovering and hoisting Tessieri and the scared dog, then dropping them back at the staging area. The dog was so flustered that it took off running, but at least it was was no longer on the cliff.

Slate is well aware that critics question the need to use an expensive helicopter and crew to rescue a dog, but he pointed out that the cost could be far higher if well-meaning bystanders try to climb down the cliff to get the dog and get stuck and require rescue themselves. One step toward the beach from the ledge where the dog was stuck means an 80-foot fall. “The helicopter is a force-multiplier,” he explained. The quicker that the rescue is done, the faster all the units involved can get back to work.

And after that flight with NVG, I don’t want to fly at night without them.