Aviation Historian 19
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B.Archer - Blackbird!
Looking like a malevolent insect, Lockheed SR-71A Blackbird 61-7962 makes its way from the parking area on to the taxiway at Mildenhall on December 6, 1984. Measuring some 107ft (33m) in length, the aircraft was powered by two huge 32,500lb-thrust Pratt & Whitney J58 turbojets
The first SR-71 to visit the UK was 61-7972, which set a new transatlantic time over distance record during its flight from Beale AFB in California to Farnborough on September 1, 1974. The aircraft is seen here six days later at the SBAC show at Farnborough. The previous record of 4hr 46min, set by an RAF Phantom between London and New York, was demolished by the Blackbird, which flew New York-London in 1 hr 55min.
Major Tim McCleary (pilot, left) and Lt-Col Stan Gudmundson (RSO) shake hands before the penultimate SR-71 return flight to the USA on January 18, 1990. Given the extreme altitudes at which the Blackbird operated, special pressure suits had to be worn by its crews. The David Clark S-1030 suit offered full protection in the event of a cabin depressurisation at altitude.
Just another routine landing at Mildenhall for 61-7962 - or is it? It is in fact the Palmdale-based test airframe, 61-7955, arriving in the UK under a false identity on July 9, 1983, a subterfuge that remained secret for more than a decade. The aircraft was in the UK to undergo trials with the new Goodyear ASARS-1 radar system.
Blackbird 61-7964 is prepared for its final journey home in one of Mildenhall’s purpose-built barns on January 18, 1990. The barns were erected to house Det 4’s two operational Blackbirds, and a large hangar provided accommodation for the reconnaissance interpretation equipment. Note the barn floor, awash with JP7 fuel - the SR-71 leaked like a sieve until the airframe heated up in flight and the joints tightened.
Blackbird 61-7974 is firmly anchored to the ground for static engine runs at Mildenhall in May 1982. The distinctive chined forward fuselage provided useful additional lift at supersonic speeds. The Blackbird’s innovative air inlet control system (AICS) featured movable spikes that travelled some 26in (66cm) fore and aft to regulate airflow to the engines.
Trailing its distinctive “tiger tails”, 61-7964 blasts off from Mildenhall for the last time, on January 18, 1990. On taking off from Mildenhall, SR-71 pilots would bank slightly to starboard, offering spectators a thrilling view of the diamond-pattern shockwaves.
Leaving a heat haze in its wake, 61-7958 taxies out from the barns to the end of the runway at Mildenhall on June 2, 1984. The total weight of the aircraft for a mission was usually more than 50 tons (50,800kg), of which almost 40 per cent was low-volatile JP7 fuel. Note the numerous support vehicles accompanying the Blackbird.
In August 1981 Blackbird 61-7964 became the first Det 4 SR-71 to divert to a foreign airfield when it suffered engine problems during a mission. Seen here at Mildenhall in November 1981, the aircraft has been “tagged” by Military Airlift Command groundcrew, who have chalked “MAC & Crew” and “For sale” on its port fin.
Blackbird 61-7958 is towed into position as the star exhibit in the static display at the Mildenhall Air Fete on May 29, 1977, the first time an SR-71 was put on display at the Suffolk airbase. This airframe made a total of four visits to Mildenhall, the last being from September 1983 to June 1984.
With engines running, 61-7972 prepares to depart Mildenhall on September 12, 1974, having completed a USAF evaluation of the type’s suitability for UK-based operations. Blackbird ’972 was joint most frequent visitor to the UK, along with 61-7964, both being deployed six times to Mildenhall during the type’s European operational career.
Blackbird 61-7975 on a mission over the USA in May 1982. This aircraft made only one sojourn to the UK to operate with Det 4, during July-October 1984. The SR-71A was painted overall in a black "iron ball" radar-attenuating finish which also helped to radiate heat away from the aircraft. The national insignia were applied in a specially-formulated heat-resistant paint.
With vortices streaming from the aircraft’s fuselage and engine nacelles, 61-7980’s starboard J58 coughs out a tail of flame during a particularly spirited display at the Mildenhall Air Fete in May 1986. The result of a temporary flame-out, unburned fuel ignited in the hot jet efflux, throwing out a fireball. The aircraft landed safely.