Lockheed A-12 / SR-71

Lockheed’s SR-71 Blackbird first flew in 1964 and was decommissioned in 1999. Not known until the mid nineties is that the SR-71 was developed from the top secret Lockheed A-12. The A-12, project Oxcart, was build for the CIA as high speed and high altitude reconnaissance aircraft as replacement for the U-2.

Project Oxcart

Design, development, testing and it’s complete operational life were done in high secrecy. Details about project Oxcart and the A-12 were only revealed to the general public in the mid nineties. More that 30 years after the project started!

The A-12 was way ahead of its time with many new technologies and shifted boundaries when it comes to altitude and speed. To cope with the required Mach 3 speed requirement the aircraft was made of Titanium, a first at that time. The shape of the design was also a radical new design as the aim was to make it as stealthy as possible by reducing its radar footprint.

Testing at Area 51

The radar footprint was tested by mounting an A-12 model on a pole at the secret test facility of Groom Lake, better known as Area-51. Although the A-12s were produced at Lockheed’s Burbank facility, they were shipped in secrecy to the even more secret test base where flight-testing commenced over years to come.

A new engine was developed by Pratt & Whitney, especially build to obtain speeds of Mach 3+. The J58 engine as they were called flew first in October 1962. The A-12 flew first on 26 April 1962, fitted with older J57 engines.

15 A-12’s were build of which one was a dual seat trainer. Also two A-12 were designated M-21 with the purpose of caring the D-21 drone. The training aircraft, named “Titanium Goose” had a raised second cockpit and unlike the other A-12’s it was fitted with the older J57 engines.

During testing five aircraft were lost (one M-21), which is a high number considering 15 were build. Off course this was a result of the innovative nature of the program. (see airframes section)

Operational history

During their complete operational career the A-12’s operated out of Groom Lake with deployments to Kadena Air Base on Okinawa. During operation Black Shield (1967), the A-12 was used to overfly North Vietnam and locate SAM missile sites. Again in 1968 the A-12 was used to fly over North Korea to locate the captured USS Pueblo, later called the Pueblo Crisis.

Strange thing is that these missions were flown after retirement of the A-12 was announced and should be completed in favor of the SR-71. Just two week before final retirement an aircraft was lost over the Pacific Ocean. This was the last A-12 crash, with the remaining aircraft stored at Palmdale from 21 June 1968.

The aircraft remained in storage for nearly 20 years! Before there were send out to various museums around the country.

M-21

The M-21 was an A-12 variant modified to carry and launch the Lockheed D-21 drone. There was a pylon mounted on the back of the M-21, and a second cockpit installed to house the Launch Control Operator (LCO). After the launch the D-21 would fly on it’s own, record mission data, eject the data package and self-destruct. The data package would be catched in mid-air (!) by a modified C-130.

After a drone collided with the M-21 after launch in 1966, the program was cancelled. The D-21 was modified in a B model, which was carried by a B-52. This drone flew actual missions over China before it was cancelled in 1971.

YF-12

First flight was on 7 August 1963. President Johnson publicly announced the YF-12, which was tested at Edwards AFB, so the A-12 could remain hidden.

The Air Force ordered 93 F-12Bs, the proposed production version of the YF-12. Although during the Vietnam War there was no funding, and with defence needs changing, the program (and order) was cancelled January 1968.

A fourth YF-12 (YF-12C) was actually a SR-71 (61-7951) with a fake designation, so the SR-71 could remain secret. The aircraft also had a fake registration 60-6937. The aircraft was used by NASA until 1978 when it was returned to the Air Force.

SR-71 Blackbird

The CIA had it’s A-12, but the Air Force wanted a reconnaissance aircraft of it’s own. So Lockheed developed the RS-71 from the A-12 design. Unlike the secret A-12, president Johnson publicly announced the RS-71’s existence. General LeMay preferred the designation SR-71 (Strategic Reconnaissance), so it was changed.

The SR-71 named Blackbird or Habu was build in Lockheed’s Palmdale facility, were it made it’s first flight on 23 December 1964.

Operational service

During operational service all SR-71s were assigned to the 9th SRW. The aircraft operated out of Beale AFB in the US and RAF Mildenhall in the UK. There was also a detachment in Kadena, Okinawa to cover Asia.

First missions were flown during the Vietnam War out of Kadena. The North Vietnamese fired 800 SAM missiles at the SR-71, none reached it’s target. Later-on typical missions were flown in the Baltic, near the Russian Border. Also China was overflown on several occasions.

The Pentagon decided the SR-71 was to be retired end of 1989. Aircraft were distributed to museums and some were placed in storage. 1993 congress investigated the reactivation of the Blackbird. 3 aircraft were returned to service with some modifications, including a near real-time data-link. The aircraft again flew with the 9th reconnaissance wing out of Beale AFB.

There was much resistance against the reinstated SR-71, and in 1998 the Air Force permanently retired the aircraft.

NASA

“SR-72”

Although not officially announced, media is speculating about a “SR-72” flying Mach 6. New Hangers were build at Area 51, but it will take some time before we know what is happing and if a follow-up aircraft is being developed. Officially the Air Force is now using the RQ-180 UAV for reconnaissance purpose.

Variants

Specifications

Airframes

A-12 / M-21

YF-12

SR-71

61-7982 till 84 were ordered but cancelled later.