OVERVIEW: The Boeing 707-337C (EW/ELINT) is a four-engine, long-range strategic aircraft modified for airborne electronic warfare and signals intelligence missions. Operated by the Indian Air Force, it was equipped to perform electronic surveillance, radar interception, and electronic countermeasure operations.

DETAILS: The Boeing 707-337C was originally built as a civilian cargo/passenger convertible model and later acquired by India for modification into a specialized EW/ELINT platform. Converted under a classified program reportedly with Israeli assistance in the 1980s, the aircraft was outfitted with sensors, antennas, and workstations for real-time intelligence collection and electronic support missions. Its primary mission was to intercept, locate, and analyze enemy radar and communications, enhancing India's electronic order of battle awareness. Powered by four Pratt & Whitney JT3D turbofan engines, it had a maximum speed of around Mach 0.81 and a ferry range exceeding 10,000 km.

The “C” in 707-337C stands for “Convertible” (cargo/passenger) in the original civilian airframe. The EW/ELINT variant used by India was designated as “Airborne Surveillance Platform (ASP)” and reportedly integrated ELINT and ESM suites. The aircraft featured dorsal and ventral antenna arrays, onboard operator stations, and extended mission endurance for broad-area surveillance. It served as a testbed for India's electronic warfare capability but was ultimately retired after a fatal crash in 1999 during further sensor system trials.

TYPE: Strategic Electronic Warfare / ELINT Aircraft

FUNCTION: Designed for long-range radar and communications intelligence gathering, electronic order of battle mapping, and electronic countermeasure roles. Its onboard systems enabled wide-area surveillance and threat detection in support of air force situational awareness and command support.

NOTE:
IOC: 1959 (Boeing 707 base model), 1987 (Indian EW/ELINT variant)
Manufacturer: Boeing (USA)
Operators: India
Conflict used in: Not deployed operationally; used for surveillance development and trials (1987–1999)

SOURCE:
Indian Ministry of Defence Annual Reports ; Jane’s All the World’s Aircraft: https://www.janes.com/defence-news ; Federation of American Scientists (FAS): https://www.fas.org/man/dod-101/sys/ac/row/boeing707.htm ; Boeing Historical Archives ; Flight International Archives ; AirForces Monthly, Key Publishing