PPRuNe Forums - View Single Post - A very, very bad day
View Single Post
Old 31st Jan 2003, 14:38
  #5 (permalink)  
forget
 
Join Date: Jul 1999
Location: 58-33N. 00-18W. Peterborough UK
Posts: 3,040
Likes: 0
Received 0 Likes on 0 Posts
The said Senator was certainly not responsible for the missile letting loose. This was probably the first recorded instance of HERF (High Energy Radio Frequency) interference.

Below from http://liun.hektik.org/hightech/herf/RF_Ignition.html

On July 29, 1967 the USS Forrestal (CVA 59) was cruising in the Gulf of Tonkin off the coast of North Vietnam when it experienced the worst carrier fire since World War II. The Forrestal had several A-4 Skyhawk jets on deck, fully fueled and armed with a variety of air-to-air and air-to-ground ordinance. A Zuni rocket was accidentally launched. The missile hit a parked A-4, igniting its drop tank. The resulting fire burned for 13 hours, claimed 134 servicemen, caused $72 million in damage and required 7 months to repair the ship.

Subsequent investigation showed that the missile launch was caused by perturbation of electronic systems being subjected to a powerful electromagnetic field. One of the missile cables apparently had an improperly mounted shielded connector. When a shipboard radar illuminated it, RF voltages were developed in the degraded connector, resulting in a Zuni rocket being fired across the deck.

Of course, increasing the range between the source of the energy and the potential victim can easily reduce the risk of similar electronic upsets. This is a primary reason for locating airport radar antennas in relatively remote areas of airfields. By calculating the maximum effective radiated power of an emitter, an appropriate minimum safe range can be defined. The critical piece of information in this derivation is maximum power from the antenna.

As high power microwave (HPM) technology advances, this RF susceptibility can be exploited by subjecting victim electronic systems to dangerous electromagnetic fields in areas assumed to be safe from such signals. An HPM weapon uses a beam of high power radio frequency (RF) pulses, similar to a radar, to irradiate a target, with the goal of coupling sufficient energy into the victim’s electronics, causing temporary upset or permanent damage.
forget is offline