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 3 of 5)
The Fan Song was one of the first electronic scanning radars--it directed its energy without having to move its antenna. "The way the Soviets built the Fan Song was to have [one] radar that tracks both the aircraft and the missile," Klimec says. "It would scan across 20 degrees and then go off the air, because you had to shut the radar down in order to preclude any kind of problems with the energy coming back inside and blowing out equipment--and then it would fly back, come back on again, and scan 20 degrees, and go off the air." The radar cycled several times per second and was directed so that a targeted aircraft was located at the center of the scan sector, which enabled the missile to be maneuvered freely inside, while the target was simultaneously tracked by the radar.
"So it dawned on me that if we could detect when the radar came on, and we could determine when the aircraft was illuminated on the radar in the main beam, and we could detect when the radar shut down to fly back, we could calculate the position of the plane relative to the scan sector," Klimec says. It was known that the Fan Song took about 100 milliseconds to complete a scan, so if an aircraft was "painted" by the radar 50 milliseconds after the radar turned on, the aircraft was in the mid-point of the scan sector. "And the aircraft ordinarily did not get to the center of the sector unless somebody put him there--and since the tracking scan system could only track one aircraft to make an intercept on one aircraft, if you found yourself in the center of the scan sector and you found you stayed there, then you knew somebody had selected you as a target," he says.
After design engineers devised equipment to verify Klimec's theory, he began monitoring the Eglin Fan Song simulator's emissions from the top of a hangar. "I talked on the phone to the radar site and got them to move it a little bit, and we verified that we could detect when the radar came on to start the scan, we could detect when it went off the air, and we could detect when we got the large spike of energy as the main beam came by," Klimec says. Klimec's innovation eventually allowed fighter crews to know whether or not they were targets and to take action only if they were.
By the middle of November 1965, the Wild Weasels were committed to cutting their teeth in combat. Four EF-100Fs, led by Major Garry Willard, arrived at Korat Royal Thai Air Base on Thanksgiving day after a turbulent flight from Hawaii. Only 84 days had passed since the first F-100 had rolled into a hangar for transformation. But the equipment and tactics had yet to be proven. "Everything that went with the first contingent and with the first Weasels was all unqualified equipment," says Bill Hickey, a former ATI technician. "The need was so great we didn't have time to go through all the qualification testing and all that. And it worked, so who cared? But the biggest problem that anybody had was tactics, because nobody knew what the hell to do."
The North Vietnamese Army had not been idle while the Weasels were forming--U.S. air losses had been heavy. With the help of Russia and China, the NVA had developed a system of coordinated and layered air defenses that could be supplied and expanded at will, since President Lyndon Johnson had ordered that North Vietnamese harbors and rail links into China be off-limits to U.S. forces. NVA air defense depended on SAMs to dominate the medium to high altitudes, which caused the fighters, in their dive to elude missiles, to fly into a waiting hail of AAA, much of it radar-guided and accurate. The AAA became thicker the lower the altitude, and below 4,500 feet it became more lethal than the SAMs themselves. The plan was simple: Drive the attackers down into the lethal envelope, where they would be destroyed.
By December, the small cadre of Wild Weasel crews began checking out their equipment and devising tactics for their first missions. The crews flew orientation flights along the North Vietnamese border and became familiar with the various electronic signatures of NVA radar. When the Huns did head north, they accompanied strike packages to targets selected by the air staff. Intelligence about the location of SAMs wasn't always accurate, since the sites were mobile and could be broken down and moved in four to six hours. Wild Weasel missions were code-named Iron Hand.
As the Weasels flew, field engineers from ATI and North American were back on the ramp at Korat, working alongside Air Force crew chiefs and technicians under primitive conditions and dealing with constant changes to equipment and installation of subsystems. "We got into the field where they're changing engines out all the time and the wiring was deteriorating really badly," says ATI's Mel Klemmick, who was sent to Thailand in 1965 for a tour that was to last 30 to 90 days but ended up stretching for two years. "Towards the end they were really falling apart. For example, you use commercial-grade coaxial cable for the rear antennas running right on the tops of those engines where the afterburners were. And particularly when they started flying the 100s out in front of the F-105s, those poor guys were in afterburner all the time."
Because they often worked in concert with faster F-105s and F-4 Phantoms, even by the time the Weasels arrived in Thailand it was clear a more capable airframe was needed. Both the Thunderchief and the Phantom were logical choices, but the Phantom was a much more complicated machine: With twin engines, multi-role mission capability, and an extensive array of weapons to carry, it was much more densely packed with wiring, cables, and systems. Just finding space for the Weasel equipment was a challenge. Once the systems were installed, technicians discovered incompatibilities with the Phantom's existing electronics. Because of its difficult development and a string of intervening cease fires in Vietnam, the first F-4C Wild Weasels wouldn't reach Korat until 1972.