SR71 Blackbird YF-12A number 06935 blasted off the runway at Edwards on December 11,1969

sr71 blackbird two seat version

SR71 Blackbird YF-12A number 06935 blasted off the runway at Edwards on December 11,1969

, on the
first phase of it's born-again test proqrarn. The initial phase of this program was under the
aegis of the Air Force, and included test objectives aimed at answering some questions
about implementation of the 8-1, which was as sure a thing as the SST, they thought. On
this first flight, the YF-12 climbed to 75,000 feet, accelerated out to Mach 3, then suc-
cessfully intercepted a 8-57 which was flying at 30,000 feet and Mach 0.5, effectively veri-
fying the status of the radar. Air Force objectives for it's portion of the tests included ex-
ploration of it's use in a tactical environment, how AWACS would control supersonic air-
craft, and how YF-12 programs could be adapted to the 8-1 development program.
The NASA tests would answer questions such as how engine inlet performance af-
fected airframe and propulsion interaction, boundary layer noise, heat transfer under high
mach conditions, and altitude hold at supersonic speeds would also be investigated. The
NASA budget for the 21/2 year program was $14 million, of which $4 million came from ex-
cess funds from the X-15 and X8-70 programs. The Air Force portion of the program was
budgeted at $4 million.
The U.S. Advanced Supersonic Technology Program, conducted by NASA's Flight
Research Center at Edwards AF8 also used the SR-71 prototype, 06937, in tests that
lasted far longer than the originally intended 21/2 year program. The two Blackbirds
averaged 6 months per year of ground time, during which instrumentation packages were
developed or removed and analyzed. While on flight status, the two aircraft averaged one
fligh.t per week, usually generating enough new data to require several days of analyzation
and Instrument recalibration. One of the first discoveries made was that, unlike the triple-
sonic airflow generated in wind tunnels, the Mach 3 airflow over the airframe surfaces in
flight was smooth. Data gathered in early test flights enabled aerodynamicists to design
high mach number wind tunnels that were free of the normal disturbances.
The altitude-hold problem concerned not only the YF-12/SR-71 aircraft. It had also been
encountered by the Anglo-French Concorde SST, and would be a major problem for the
U:S. SST. Altitude excursions of up to ± 3,000 feet were encountered at high altitude and
high mach numbers. Temperature variations, which were totally unpredictable, were
thought to be the cause of these oscillations, and a computer that would connect
autopilot to engine and inlet controls was the proposed solution.
Whil.e the USAF and NASA test programs proceeded, and were high-profile Blackbird
operations, the 9th SRW was flying operational SR-71 recon missions world-wide. All of
the world's hot spots came under Blackbird surveillance. Vietnam, the Middle East, Cuba
all. were photogr~phed on a regul~r basis b.y SR-71 s flying from bases in England,
Okl.n~,:",a, and Thailand. Most of the time, the Air Force managed to keep a tight lid on the
a~tlvltle~ of the SR-71 force. Occasionally, the lid was lifted just high enough to afford a
glimpse Into the nether world of Electronic Intelligence (ELI NT) missions.
As President Nixon was preparing to shock the world with his opening to China in 1971,
the 9th SRW was completing a detailed mapping of the Chinese mainland. This had involv-
ed literally hundreds of overflights (500 official protests had been made by the Peking
Government), and years of effort. As a quid pro quo for his trip to China, President Nixon
reportedly promised to stop the SR-71 overflights. Aviation Week reported in November,
1971 that unmanned reconnaissance flights were continuing over the Chinese mainland.
A 1972 R.amparts Magazine article quoted a former Air Force sergeant, who had worked
for the National Security Agency, as saying that there was virtually no way that the SR-71
c.ould.be br.ought d0:-vn. He mentioned specific instances of attempted Chinese intercep-
tions In which the Mlg-21s that had scrambled to intercept the Blackbird were left looking
at each other, and wondering what had happened to their quarry. He also asserted that
SR-71's had overflown Russian airspace, while NSA listening posts on the borders of the
USSR monitored Soviet air defense reaction. According to the 26-year old former USAF
sergeant, the ELiNT capabilities of the United States allowed them to keep track of virtual-
ly all Soviet military aircraft, and even to determine who was flying them at any given time.
The SR-71 was an important part of this overall capability.
In an October 15,1973 article, U. S. News and World Report stated that· "Fewer than 10
of the 24.6 million dollar airplanes are still on duty. The rest of the origi~al two wings -
several dozen planes - have been put Into mothballs." The main thrust of this article was to write the epitaph of the manned reconnaissance airplane, and specifically, the SR-71.
Where they got their figure of 24.6 million dollars is not known. Other sources have indi-
cated that the initial cost of the airframe alone was probably close to $50 million 1963
dollars, and that did not include avionics or engines. There were, of course, never two
wings of SR-71 s, and there were less than three dozen built. Their figure of less than 10
operational aircraft may have been close to accurate, but their assertion that the SR-71
was about to be retired was as inaccurate as the rest of their article. Indications are that
the SR-71 will still be flying operational missions well into the 1980's. Remotely Piloted
Vehicles, (RPVs) which were supposed to have replaced the SR-71 and U-2 recon pro-
grams, have been shrouded in even more secrecy than the Blackbirds.

There was a two seat version of the A-12, used for pilot tralnlnq, This one is in storage at
Palmdale. (John Andrews)

Protests of overflights were not limited to the Chinese. In October of 1973, at the height
of the Yom Kippur War, the Egyptian government registered a detailed protest of a viola-
tion of Egyptian airspace which could only have been accomplished by aircraft of a type
possessed by the United States exclusively. The Egyptian communique said, "The two re-
connaissance planes violated Egyptian airspace at 1105 GMT 13 October 1973 over Port
Said, went deep into Egypt at Nagaa Hammady, 590 kilom~ters south ~f Cai'ro, turned
back ov~r the capital and flew eastward in the direction of Jordan and Syria, then back to
the Mediterranean Sea. This is the first time Egypt's airspace has been violated by this
type of plane." Whether or not it was the first time that SR-71 s had overflown Egypt is
open to debate. It was obviously the first time that they had been detected by the Egyp-
tians.
Public consciousness of the Blackbirds was raised considerably by several record-
breaking and setting flights during the 1970s.
In April, 1971 USAF Lt. Cols Thomas B. Estes and Dewain C. Vick flew back and forth
across the United States twice, and made a complete circle of the Western states in under
101/2 hours. The flight covered a distance of 15,000 miles and earned them the Harmon
and Mackay Trophies for their efforts.
One of the most highly publicised flights ever made by the Blackbird came in
September, 1974. The then-existing record time for a flight from New York to London was
4 hours and 40 minutes, set by a Royal Navy F-4K Phantom in 1969. The USAF decided to
break the record. Considering the new record time, "break" hardly seems an adequate
description of what they did to the old record.