As the flights could range across the southwest United States, sightings away from Groom Lake were also a problem. As the A-12 climbed and accelerated, its sonic boom was heard by "the inhabitants of a small village some 30 miles from the test site." A change in the flight path removed this problem.
Although the airspace above Groom Lake was closed, it was near busy Nellis Air Force Base. So, inevitably, there were sightings. In one case, an air force pilot was flying to a gunnery range in the northwest area of the base. He saw an A-12 climbing through his altitude off in the distance. He could see the shape and realized it was some type of experimental aircraft.
In another incident, several pilots in a formation saw an A-12. After they landed, a general told all of them that they were to say nothing. Some Nellis pilots saw the A-12 several times. It was common knowledge that something "weird" was going on out in the desert.[146]
To the southwest of Groom Lake was Edwards Air Force Base. NASA test pilots flew numerous X-15 training and support flights to tracking sites and dry lake beds across California and Nevada. The only areas they avoided were the nuclear test site and the Ranch.[147] At least one NASA test pilot saw an A-12. He radioed the Edwards tower and asked what it was. He was curtly told to halt transmissions. After landing, he was told what he had seen was vital to U.S. security. He also signed a secrecy agreement.[148]
Sightings were even made from the ground. At 5:30 A.M., an air force captain was checking the main runway at Edwards for any debris before flight operations began for the day. Suddenly, an A-12 made a low pass and then climbed away. Its shape was so unusual that he first thought it was two planes in close formation. The captain called the tower and asked, "What was that airplane?" The tower radioed back, "What airplane?"
The major source of A-12 sightings was airline pilots. It is believed that twenty to thirty airline sightings were made. One American Airlines pilot saw an A-12 twice. During one sighting, a pilot saw an A-12 and two chase planes; he radioed, "I see a goose and two goslings."[149] Word of these sightings spread among the aerospace community. Aviation Week and Space Technology picked up the rumors. The question became how long the secret could be kept.
The security problem became greater on May 24, 1963. Kenneth Collins was flying a subsonic training-test flight in Article 123. As he descended into clouds, the pilot-static tube became plugged with ice, which caused the instruments to display an incorrect airspeed. The A-12 stalled and pitched up. Collins was unable to control the plane, and he ejected. He landed safely, while Article 123 crashed fourteen miles south of Wendover, Utah.[150]
The Nellis Air Force Base base commander was called. "One of your F-105's has just crashed," he was told. He responded, "But that's impossible. They're all here, out on the field." He was curtly told, "Don't argue.
If anyone asks about a plane crash, you just report that one of your 105's crashed on a routine training flight north of Nellis."[151]
The F-105 cover story was issued to the press. It took two days to recover the debris. Persons at the scene were requested to sign security agreements. All A-12 aircraft were grounded for a week following the crash. The grounding order was raised once the cause was traced to icing.
The secrecy held despite the crash. The A-12 was ready to begin its quest for Mach 3.
The years 1963 and 1964 were spent bringing the A-12 to Mach 3-plus speeds and operational status. At times, Lockheed and the CIA despaired of ever succeeding. The problem was with the nacelle system and inlet spike.
As the A-12 flew faster, the spike moved back; this regulated the airflow into the engine.[152] The flight-test program had to develop the "inlet schedule," which would be programmed into the pneumatic system. This controlled the spike's position, according to the plane's speed.[153]
The A-12's test speed was increased at one-tenth Mach increments. The plane would take off from Groom Lake, then fly north to Wendover, Utah, and onward to the Canadian border. It would then make a 180-degree turn (with a diameter of 128 nautical miles) and head back to Nevada at 65,000 to 72,000 feet. The flight path was called "Copper Bravo." As the A-12 flew back, it would accelerate to the test speed, then decelerate and land. If trouble appeared, at least the plane would be flying toward home at thirty-five miles per minute, rather than away.[154]
The test flights soon showed that the pneumatic system could not compensate for atmospheric changes. The result was an "unstart." The out-of-position spike disrupted the airflow to the engine, which stopped producing thrust and began overheating. The loss of all thrust on one side caused the A-12 to violently yaw toward the dead engine. This literally bounced the pilot's helmet against the canopy. The pilot had to manually open the bypass doors to break the unstart. As with the U-2's early flameout problems, the unstart would have to be solved before the A-12 could fly in hostile airspace.
Lockheed engineers tried everything they could think of to cure the problem. The inlet geometry and schedules were changed. The manual trim of the fuel flow, spike position, and bypass door position were speeded up.
Yet, nothing helped. The two inlets on each A-12 never seemed to match.
This resulted in multiple unstarts on each flight. Even a special task force could not find a solution.
Finally, Johnson decided to scrap the existing pneumatic system and replace it with an electronic unit. Even this had problems. During a ground test, the pilot used the radio; this caused a false signal in the electronics and the spike retracted. Once the electronic interference problem was solved, the system proved far more effective, although at the price of much greater maintenance time. The electronic system was retrofitted to the existing aircraft and all new A-12s from Article 129 onward.
The unstart was only the most spectacular of the A-12's problems. The J58 engines' main shaft had to be redesigned to compensate for the high temperatures. The engine mounting points were also changed. The frictional heating raised the cockpit temperature to 130 degrees. On one flight, the control stick became so hot Park had to change hands to keep from burning himself. Changes in the air-conditioning system reduced the cockpit temperature to a "warm but livable" level.[155]
Another change caused by the heat was in the A-12's finish. The prototype had flown in a bare-metal finish without any markings. By late 1963, the edges of the chines, the spikes, and the cockpit area were painted in a heat-resistant black paint. This reduced the internal heating of the airframe.
The aircraft also received a full set of national markings. Finding paint that could withstand exposure to high temperatures and fuel was, like everything about the plane, difficult.
A continuing problem was foreign-object damage. Nuts, bolts, clamps, and other debris were sometimes left in the nacelles during construction.
When the engines were run up, the debris would be sucked in and damage the engines.[156] In one case, an inspector's flashlight caused $250,000 damage. The engines would also suck rocks, asphalt pieces, and other debris off taxiways and runways.
146
Private source. The author has extensive contacts within the Black airplane community, both personal and through publications. This provides an insight into both the latest information and the beliefs behind it.
147
Milton O. Thompson,
151
Jules Bergman, "Our Watchdog at the Edge of Space,"