Korea's demilitarized zone is the world's most elaborate tripwire, a ravaged strip of mine fields, barbed wire, and tank traps designed to slow an invasion. From fortified positions south of the zone, U.S. and Republic of Korea soldiers peer northward as if watching a long-dormant volcano for signs of eruption. They know that North Korea could react at any moment to its current dire economic condition by launching a military foray into the South.
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But for years U.S. commanders have relied on a set of eyes that look deep into the north from a vantage point high overhead and miles south of the DMZ. These eyes can instantly spot any vehicle movements and record them on film that is processed in seconds to be scanned and relayed to the ground. If even one truck were to move anywhere within a vast area to the north, U.S. commanders on the ground would know it within minutes. This powerful vision belongs to a combat-proven airborne radar system, and the system is mounted aboard one of the oddest looking tactical aircraft that has ever served the United States in combat: the Grumman OV-1 Mohawk. The Mohawk is also the only fixed-wing aircraft ever built specifically for the U.S. Army since the Air Force became a separate service in 1947. In September 1996, it flew its last mission over Korea and was retired after nearly 40 years of operations in two wars over some of the most hotly contested geography on the planet. Despite its distinguished service record, the Mohawk remains largely unknown outside the small communities of men and women who flew, maintained, and loved the small, ungainly-looking aircraft.
"It's an unsung hero," says Russ Wygal, a pilot with the Army's 224th Military Intelligence Battalion at Hunter Army Airfield in Savannah, Georgia, the last stateside unit to fly the Mohawk. Wygal says that when he tells people he flew an OV-1, they often confuse it with the North American OV-10 Bronco, a twin turboprop developed specifically for counter-insurgency campaigns like the Vietnam war. "Then I have to describe what it looks like," he says. "It's not like an F-14 Tomcat, where everybody goes, 'Ooo, aah, Top Gun.'"
The OV-1 finally retired because it had been superseded by newer systems, newer aircraft, and the evolution of the satellite, which had been little more than a symbol of cold war one-upmanship when the Mohawk made its first flight on April 14, 1959. The OV-1 was designed to meet a joint Marine Corps-Army requirement for a short-takeoff-and-landing battlefield surveillance aircraft. It was intended to operate close to the front lines in support of unit commanders, and after the Marines dropped out of the project, development was continued for the Army. The first version, designated OV-1A, was configured to provide a platform for photographic and visual reconnaissance. Because form followed function, the result was an airplane with a large, bulbous cockpit, slender fuselage, and odd triple-tail arrangement; it looked like a cross between a helicopter, an airplane, and an insect.
The initial design called for a T-tail, with the horizontal stabilizer set atop the vertical fin, but because the aircraft had handling problems at low speed, Grumman adopted the Lockheed Connie-style three-tail arrangement. Two Lycoming turboprop engines sit atop the Mohawk's wings. Like many multi-engine airplanes, its engines are canted outward to improve handling when the aircraft is flown on only one engine. But Wygal, who was required to practice single-engine flight during training, likened the rudder pedal force required opposite the dead engine to being "in a gym doing leg presses with only one leg. It's very demanding."
The OV-1's roomy cockpit features large, bulging side windows that give the airplane a bug-eyed appearance and allow an unobstructed view of the ground immediately below. The pilot sits on the left, and a technician or observer sits on the right. Unlike other tactical aircraft in which the crew sat side by side, like the Air Force's F-111 or the Navy and Marine Corps' A-6, right-seaters on the Mohawk were almost always members of the enlisted ranks rather than officers. They were primarily responsible for monitoring the panoramic camera and surveillance systems while providing another set of eyes to scan the terrain below. Once it was in the air, there were no blind spots below: "You can lift the Mohawk 35 feet in the air and the pilot's vision and observer's vision will converge at a point directly underneath the aircraft," says Joel L. DiMaggio, who, as a Grumman production line worker, began an association with the Mohawk that would last the lifespan of the airplane.
The next version, the OV-1B, incorporated side-looking airborne radar (SLAR), which would ultimately shape one of the airplane's primary missions throughout its service life. The radar's antenna was contained within a long boom--like a big railroad tie--that was mounted below and to the right of the fuselage centerline, giving the Mohawk an even gawkier appearance. As the airplane flies along its assigned track, the radar creates a strip map of the terrain below and on either or both sides of the track. With this system, the Mohawk also gained the ability to detect moving targets, which would prove immeasurably valuable in Vietnam, along the borders of the former East Germany, along the DMZ in Korea, and ultimately, during the Gulf War. Over the relatively open terrain of Korea and Europe, Mohawks gathered SLAR intelligence by repeatedly flying over the same tactical areas and comparing the images.
"The reason you do it every day is that [the SLAR] is a surveillance and intelligence system, rather than just a target locating system," DiMaggio says. "You start out with a clean slate, look out there, and make a count on a road in East Germany, for instance, that normally has a certain number of vehicles going from one point to another. When things get hot, you begin to see more vehicles in different places--that's how you gather intelligence: by noting changes." DiMaggio, who after working on the Mohawk assembly line served four years in Germany and a year in Vietnam as a Grumman field representative, says that Mohawks could detect trucks and vehicles with SLAR and, using their infrared detectors, the hot engines of vehicles under cover at night. Once they were located by Mohawks, the targets could be attacked by fighter aircraft.
Successful SLAR missions required the Mohawk to provide an extremely stable platform while the radar scanned the land below, so most were flown on autopilot. However, straight-and-level is not the preferred flight orientation for a combat pilot. "It made you a sitting duck," said Gerry Durnell, who flew the OV-1 in Vietnam.
The OV-1C was the first Mohawk to be equipped with infrared systems, and they proved valuable for detecting Viet Cong guerrilla units, which were normally small, mobile, and hard to find. "The infrared Mohawks were able to pick up the heat from VC cooking fires," says Paul Reed, a former imagery analyst with both the Army and the Central Intelligence Agency. "There were a lot of VC that got very upset when artillery rounds came in on them while they were fixing breakfast."