The X-15 Rocket Plane: Flying the First Wings into Space

1. The Whole Nine Yards

1. The Whole Nine Yards There is no such thing as an accident. It was either designed wrong, built wrong, or used wrong. Generally, it’s used wrong. A. Scott Crossfield Scott Crossfield started the x-15’s rocket engine and moved the throttle forward to 50 percent thrust. The bright exhaust lit up the surrounding area as a long string of Mach diamonds formed and stabilized. Scott then throttled forward to 100 percent. Firmly secured to the test stand, the aircraft strained to pull away with more than 50,000 pounds of force. At a level of 140 decibels at the cockpit, the noise generated by the lr-99 rocket was crippling if unprotected. Inside the nearby control room there was a loud muffled roar, something felt through to the bones. The purpose of the test was to check the ability of the rocket to restart. Crossfield shut down, then primed the engine for a second ignition. As he brought it back up to 50 percent, the safety system automatically stopped the sequence. Scott called over the radio, “Malfunction. Throttle off.” His hand moved toward the instrument panel to make another attempt to relight the engine. He called, “Reset.” The moment Scott hit the switch, the x-15 exploded. Eleven weeks previous to the accident, on 28 March 1960, the first xlr99rm -1 powerplant for the x-15 was delivered to Edwards Air Force Base (afb) in the California desert. It was shipped in from the Reaction Motors plant in Denville, New Jersey. By late May the engine was mounted into aircraft no. 3, and the entire assembly was trucked down to the Propulsion System Test Stand (psts). It was backed into the fixture, with the exhaust nozzle of the lr-99 butted up against the rectangular yellow and silver structure 2 | the whole nine yards at the rear of the stand. A four-foot-diameter hole in the fixture allowed the exhaust gasses to pass through during the test. The aircraft was firmly secured in position for the first engine firing, which was successfully accomplished on 2 June at the psts. On Wednesday, 8 June, another run was scheduled to test the restart capabilities of the engine. People from North American Aviation (naa), nasa, and the military started arriving at the facility. Vehicles seemed to be parked haphazardly. Hoses, toolboxes, barrels, and ladders cluttered the area. Power carts and a fuel truck added to what looked like a chaotic scene. For those people whose job it was to make the x-15 ready, everything appeared in perfect order . Crossfield approached the aircraft wearing business attire rather than the expected silver spacesuit. In this instance, he was not planning to fly but to remain firmly attached to the ground, so there was no need to put on the cumbersome and hot multilayered garment. He climbed up an aluminum ladder into the cockpit, while engineers and technicians continued their work. Preparations proceeded well into the waning light of the early evening hours. Surrounding the aircraft, two banks of three light boxes atop tall poles provided bright, even illumination. Crossfield put on an oxygen mask, since he did not have his spacesuit supply to breathe. Finally, the canopy was closed and secured over Scott. Even bolted to the test stand pad, with access panels removed for instrumentation wiring and miscellaneous plumbing, the x-15 looked ready to leap into space. It was easy to imagine the speeds this rocket plane would achieve in just a few short years. One by one, and in groups, everyone cleared the area, entering the protection of the blockhouse about fifty feet away. The rectangular command structure had steeply angled exterior walls, giving the casual impression of a truncated pyramid. Inside were racks of electronic instruments and television monitors, and even a periscope for more direct observation. Most important , the blockhouse provided protection for everyone in the event of a malfunction of the highly volatile rocket motor. It was fueled by 18,000 pounds of liquid oxygen and anhydrous ammonia. The concrete structure was a recent addition to the rocket test facility, having been installed barely a month previously. Strapped into the vehicle, Scott had no such protection. Crossfield lit the rocket, and the first run was completed successfully. the whole nine yards | 3 He reset for the second, which triggered the powerful explosion. As the aft...