Flying Wild Weasel missions involved a variety of airframes but just one philosophy: Do unto SAMS before they do unto you.
- By Robert Hanson
- Air & Space magazine, September 1998
(Page 2 of 5)
After first setting as a priority a reliable radar detection system, the team discovered that the technology already existed. Two radar homing and warning (RHAW) systems had been developed in response to an earlier Air Force requirement and were already in limited use in secret CIA air operations. Bendix had developed one system, and a small, relatively unknown company, Applied Technology, Inc., had produced a system packaged in five small gray boxes. The equipment, designed to help large aircraft avoid and jam radar, was called a Vector Sector, and it provided the basic electronics that could be used for offensive operations against SAM sites. Because the signals required to shield a large aircraft required so much power, the existing designs placed antennas strategically so that the jamming signals could be directed only where needed. "That [equipment] was in use at the time that all of the excitement began with the SAMs' arrival in North Vietnam," says Mel Klemmick, a former ATI field engineer. "There were certain people in the Air Force involved in those programs and they were aware of the capability, but no one could talk about the capability. We were the builders of both the jammers and direction-finding equipment, and we took a Vector Sector and repackaged it and gave it another number." But even before the equipment--which was designated the Vector IV system--had been designed, the elusive signals had to be analyzed and interpreted. "Unacknowledged, I think, is the work that went on in the background to break the codes for the guidance signals," Klemmick says. "There was a lot of coordination between the intelligence community and companies involved--more than just ATI--coming up with a way to figure out what those original guidance schemes were."
The two-seat North American F-100F was selected to undertake the new mission. The F-100 (or "Hun," short for "hundred") was the Air Force's first supersonic fighter and was loosely derived from the legendary F-86 of Korean War fame, but by the time it was flown in Vietnam, it was being outpaced by newer and faster fighters. John Paup of North American Aviation was named program manager. Given the urgency of the situation, a meeting was quickly organized with ATI representatives in August 1965 to hammer out an agreement, and in an unorthodox manner that was to live on in Wild Weasel lore, the details were written on a chalkboard in a briefing room, signed by the authorized representatives, and photographed as the binding contract.
Under the cloak of a top-secret classification, an F-100F was rolled into a hangar at Long Beach, California, and placed in the care of North American's Kay Bullock, who had to find a place to stash the five boxes that made up ATI's system. Klemmick remembers Bullock's encyclopedic knowledge of the F-100 as vitally important, especially when first installing, and later repositioning, antennas after the Weasels had been deployed to Korat, Thailand. "He knew those airplanes so well that he'd take a big two-and-half-inch-diameter hole cutter, walk up to an airplane, and start drilling into the side of it," Klemmick says. "And the line chiefs are going, "Oh my Godthe fuel lines are in there.' "No,' he'd say, "I know exactly where I'm cutting.' And sure enough we'd shove an antenna there. No problem behind it."
The Vector IV system consisted of an array of small antennas mounted on the airplane to receive signals from every quarter. A panel of warning lights was mounted in the cockpit to indicate the type of signal being received: SAM, AAA, or conventional surveillance radar. A three-inch, television-like cathode ray tube was installed in each cockpit to provide a graphic indication of direction to the signal source. A WR-300 launch receiver, which was tuned to detect the burst of energy specific to a SAM launch, was connected to a bright red light in the cockpit, guaranteed to get the pilot's attention. Wild Weasel crews later referred to it as the "Oh shit" light.
The installation was crude and fast, and made use of commercial-grade wiring and other off-the-shelf components, but it enabled the first F-100F to be ready to fly in just 10 days. The system worked as advertised with only minor tweaks, and three more F-100Fs were rolled in for the same modifications. They were redesignated EF-100Fs for "electronic fighter," and flown to Eglin Air Force Base in Florida, where five volunteer crews selected to evaluate the system joined them on September 4, 1965.
Crew training was conducted at Eglin, which featured a full-scale Fan Song radar simulator being used to train B-52 Stratofortress and B-58 Hustler crews in electronic countermeasures techniques. The pilots and EWOs were encouraged to get to know each other and select their own partners, and there were adjustments to make all around--single-seat fighter pilots were not used to having another crewman on board, and most of the EWOs (soon to become known as "bears") were completely new to fighter operations. Bears were experienced EWOs, drawn mostly from B-52s and EB-66 electronic warfare aircraft.
At Eglin, the new equipment installed in the F-100s was constantly modified and adjusted even as new systems, some of them to be fielded on future aircraft, were still under development. It was at Eglin that Bob Klimec, an Air Force pilot and electrical engineer, solved some of the basic problems associated with pinpointing SAM sites, and developed the basis of a defensive system that would eventually be installed on different aircraft types, including the F-111 "Aardvark," which was soon to make its debut in Vietnam.
Klimec set out to improve on the existing RHAW system, which only told you that a SAM was looking, or launching, and gave only a general bearing to the radar source. At this early stage in anti-radar development, before specially designed missiles that home in on radar signals were available, the target still had to be visually acquired and attacked with conventional weapons like rockets, guns, or bombs.