David Duckett wrote:There was another similar incident involving an F-102 or F-106 (?) which flew for awhile on its own.
The most noted such incident was the loss of an SM-62, Snark, intercontinental cruise missile during testing in 1956. It was launched from Cape Canaveral on a supposedly controlled round trip to Puerto Rico. Shortly after launch it went off course and the range safety officer could neither take control of it nor destroy it. The Snark had a bad reputation for an inaccurate and unreliable guidance system and a primitive threat assessment system that could not take evasive maneuvers to avoid interception. This test showed just what the treat assessment system could do when it worked although why it was on is a mystery in this case.
Since it's maximum cruising altitude was about 55,000 feet and it's maximum speed was about 650 mph, it was considered easy to intercept by fighters operational in the mid 1950s. Nothing could have been further from the truth. Every air defense system in the Caribbean was alerted and every type of fighter jet in the inventory of the Air Force in the area was scrambled, (The official report was that it was too late to scramble fighters when they realized it was off course.) along with the air forces of every country in the area. The missile could be easily tracked on radar, but the threat assessment system was operating and not a single interceptor could get close enough for a shot. It overflew several other heavily defended areas before running out of fuel (It's range was over 5,500 miles, although the official report said it only had 2400 miles of fuel on board.) and landing in dense jungle of Northeastern Brazil. The situation was so embarrassing that the fact that the missile was successfully avoiding interception on its own was left out of any public descriptions of the incident. It was finally found in 1983. The description I have of the incident was from someone who was involved with it.
Some of the reports are very instructive about the problems of interception with fighters of the 1950s. For example, at one point, an F-100 pilot got it in sight and made a head on pass. The Snark detected his gun sight radar and made and evasive maneuver, forcing the fighter pilot to miss his chance at a shot. It then returned to its original course after the fighter overshot. The F-100 was near it's service ceiling and the pilot was forced to make a very wide radius turn to avoid stalling at that altitude. By the time he had made the 180 degree turn and was in a position to chase the Snark he no longer had enough fuel to catch it at full afterburner and without the afterburner was not fast enough to catch it at that altitude. Basically, with the performance of the aircraft of the day, you got one shot at something with that kind of speed and altitude performance and if you missed you were done.