What happened
The provided documentation outlines the operational procedures for various unmanned air targets used by the Royal Aircraft Establishment (RAE) Ranges Division, specifically regarding the use of Jindivik 103A and Meteor 16 aircraft. These targets were utilized for missile engagement trials at the Aberporth range. The records also detail the technical specifications for the Hunting P.56 Provost, a side-by-side trainer, noting its service history with the Eire Air Corps and other international air forces.
The investigation
The documentation establishes the safety protocols for managing target aircraft malfunctions. For the Jindivik 103A, specific procedures were in place for the use of infra-red flares (type SR 549) and miss-distance photography using AMPOR Mk. 3 camera packs. The records also detail the 'Command Destroy' protocol, which allows ground crews at Llanbedr to remotely terminate a target aircraft by activating elevator actuators and cutting fuel to ensure the aircraft descends within a controlled 45-degree cone.
Findings
- Target Safety Protocols: In the event of a malfunction, the 'Command Destroy' signal is designed to force a descent. For the Meteor 16, specific distance buffers from land are required: one nautical mile plus the aircraft's altitude for non-engagement trials, and larger buffers for missile engagement trials.
- Fail-safe Mechanisms: The Jindivik 103A features a 'Signal Fail' orbit mode. If the aircraft misses two successive Radio Hold pulses, it automatically enters a 30-degree orbit at an altitude between 4,000 and 6,000 feet.
- Aircraft Performance: The Hunting P.56 Provost (specifically the T. Mk. 51 used by the Eire Air Corps) is a two-seat trainer powered by a 550 h.p. Alvis Leonides engine, capable of a maximum speed of 195 m.p.h. at sea level.
- Solar Position Data: Astronomical calculations for March 24, 1968, at a specific coordinate near 52°N, 7°52'W, indicate solar altitudes of approximately 33° to 34° during the 10:40 to 10:45 UTC window.