Evaluation of airborne systems has taken generations of Aviation Week pilots, engineers and editors aloft. On the surface, “system evaluations” would suggest they are more benign than flights devoted to wringing out a new aircraft for a full-blown pilot report. Not always. Several have involved a few moments of stark terror that surface during hangar-flying sessions—tales that begin, “There I was. . . .”
On takeoff for a night flight dedicated to seeing the developmental Lantirn (Low-altitude navigation and targeting infrared for night) system at work, a brilliant white light suddenly lit up the sky behind our F-16B. Col. Gary Matthes, an experienced F-16 test pilot, yanked the throttles out of afterburner, but continued to climb.
“Zoom six-six, you have a very bright flame behind you, about 20 ft. long!” the tower controller radioed.
Oh s***. I glanced at the EJECT light. It was still dark.
“Is it still there?” Matthes asked, after acknowledging the tower’s call.
“Not as bright, but still flickering,” I replied, eyeballing a reflection on the inboard surface of our left wingtip missile rail. Then I shut up, knowing the pilot was mentally processing info at Warp 6.
We’re on fire. Wing and centerline tanks are full. Punch ’em off? No; not with that road below. Eject? Not yet. Still flying. . . .
“Engine looks good,” Matthes clipped.
“Light’s out,” I replied. “Don’t see that flickering.”
We were still climbing and turning left to a high downwind for Edwards AFB’s long main runway. Matthes asked the California base’s tower whether any fighter-type aircraft were up. Fortunately, a NASA-Dryden test pilot in an F/A-18 was nearby. He joined up, took a close look and reported, “You look good. Nothing burning.”
Something obviously wasn’t right, so Matthes declared an emergency and we landed without incident, cleared the runway and braked to a stop. An array of hulking green fire trucks faced us, flanked by several firefighters in silver “scape suits.”
SEE ALSO
I unstrapped as Matthes ran through our ground egress plan: open canopy, climb over the left side, drop to the ground and run upwind. No fire to worry about . . . maybe, but the F-16 carried a load of hydrazine to operate its emergency power unit. If that system had been breached, or the EPU had fired briefly, a whiff of deadly hydrazine could ruin our whole day.
Ultimately, all ended well. That super-white flame was caused by one exhaust nozzle “tail feather” failing to open, when afterburner was selected on takeoff roll. That thin slab of exotic alloy, sticking into the ’burner flame, finally failed and ignited.
Nevertheless, our Lantirn evaluation flight was scrubbed. When Matthes and I walked into the maintenance-debrief office, a call from the flight-test center commander, a general, was waiting. Matthes took the phone and assured his boss that we were safe and the F-16 wasn’t damaged. Matthes looked at me, eyebrows raised. I shook my head, drawing fingertips across my throat. Matthes said, “And he won’t write about it.”
The Lantirn evaluation flight was rescheduled, but Matthes would not fly me. By then, he was off to a new assignment.
Lantirn Provides Breakthrough in Night-Fighting Capabilities (April  25, 1988, p. 34)
I was fortunate to eventually fly back-seat in an F-16B dedicated to flight-testing the USAF’s new Lantirn system at Edwards. Although still in development, the night attack system was scheduled for operational duty within the year.
Credit: Aviation Week Archive

The 1.3-hr. flight with Maj. Chris Glaeser consisted of flying a simulated low-level attack route through rough desert terrain and the Sierra Nevada—what another test pilot described as “the roughest terrain in the world, ranging from the lowest spot in the continental United States [Death Valley, below sea level] to the highest spot [Mt. Whitney], at over 14,000 ft.”
Lantirn’s forward-looking infrared (Flir) system clearly represented a technological breakthrough, literally giving fighter pilots a window into the night. At one point, the Flir image of an abandoned water tank was sharp enough to show bullet holes in the metal.
In automatic terrain-following mode, Glaeser set the clearance plane altitude to 200 ft., and we made simulated bombing runs on a radar site, an industrial complex, a cement plant, and several trucks and cars on a highway.
At one point, Glaeser demonstrated how the Lantirn system enabled approaching laterally—wings level—to within 150-200 ft. of the terrain. There was just enough moonlight to see soaring cliffs racing past our wingtip.
“I commented on how close our wingtip was to the trees and Glaeser responded, ‘It’s worse in the daytime. You can see every chipmunk in the trees.’”
Later, after writing a lengthy flight report, my boss, Ropelewski, called and opined that “the chipmunk” comment was not really professional enough for Aviation Week and suggested I take it out. I did and the article was ready to be fired off to the printer, when Donald E. Fink, the then-editor-in-chief, called. He complimented the Lantirn story, mentioning, in passing, that he particularly liked that bit about the chipmunks in the trees.
Oops! I told him Rope and I had just removed “the chipmunks” and why. Fink ordered the rodents back into the story and we complied pronto. To this day, I run into readers who recall that Lantirn story. They invariably add, “And I really liked that comment about the chipmunks in the trees!”
100 YEARS OF AVIATION WEEK
Perfecting Protection (Aug. 2, 2010, p. 55)
Occasionally, Aviation Week has an opportunity to evaluate a system in its early development stages, then reassess a matured version when being deployed operationally.
Air Force Research Laboratory/NASA

In 1999, I flew in the rear cockpit of an F-16 for one of the most dramatic missions of my 40-year flying career, witnessing a nascent Automatic Ground Collision Avoidance System (GCAS) in action (Feb. 1, 1999, p. 76). The flight from Edwards involved intentionally diving at the ground to simulate loss of situational awareness at night, or becoming disoriented during air-to-air engagements and bombing runs. I flew with Maj. Kevin E. Prosser, the Auto-GCAS project pilot.
In the flight report, I commented on a low-altitude test run that involved flying directly at “GCAS Mountain” the test team’s nickname for Fremont Peak. “Our first run was a wings-level, 465-kt. approach to GCAS Mountain. . . . The [head-up display] HUD’s flight path marker was aimed about two-thirds up the peak, and the desert rocks, dirt and scrub brush raced rapidly at our windscreen. About the time I would have liked to have suggested ‘Pull NOW!’, the system took over and the 5g-plus pull-up drove me down in the seat. The g-onset was so rapid that the oxygen mask threatened to slide over my nose, and the g-suit tried to compress my lower body to half its normal size, it seemed.
“ ‘That one was pretty close to my comfort level,’ Prosser quipped. ‘I wouldn’t have gone, maybe two more seconds,’ which was about two beyond the Aviation Week guy’s comfort level.”
The development program was a resounding success, but budget constraints and leadership decisions prevented Auto-GCAS from being fielded.
By 2010, the Air Force had finally committed to putting operational Auto-GCAS units on later-model F-16s, Lockheed Martin F-22s and F-35s. Aviation Week’s Guy Norris was invited back to Edwards,  to assess the now-matured system.
His report explained the USAF’s belated epiphany: “[T]he Pentagon predicts that around 250 lives and 280 fighter aircraft worth $12.7 billion could be saved during the next 25 years.”
Norris also flew back-seat in an F-16 test aircraft to see how the operational Auto-GCAS performed. Ironically, he flew with the same test pilot, Prosser, who repeated the hair-raising assault on that same mountain.
“The following test consisted of low- and high-speed runs against the 1,200-ft.-high Fremont Peak near Edwards,” Norris reported. “Having experienced test flights of commercial terrain-awareness and warning systems, the sensation of deliberately aiming at a mountain was not new to me. What was new, however, was the 540-kt. speed at which we closed on the high terrain.”
Thankfully, the Auto-GCAS again performed flawlessly.
Norris concluded his report by noting: “The demonstration thoroughly convinced me that Auto-GCAS will save lives and aircraft without getting in anyone’s way.” 
William B. Scott retired in 2007 as Aviation Week & Space Technology’s Rocky Mountain Bureau Chief, having logged 2,000 hr. in 80 different aircraft types. He is the author or coauthor of three novels and two nonfiction books. His latest is The Permit, a techno-thriller based on actual events.