Tuesday, December 11, 2012
The Fine Art Of Crashing
The how and why of crashing a 727 for science
Unlike the 1984 crash, where the main point was to see if the experimental fuel would ignite, it was imperative that this airplane NOT burn as a result of the crash, lest all the scientific data be lost. That's a neat trick with a 120-ton airliner if you can pull it off.
They did. Slocum and his flight crew headed for a 3,000-foot-long patch of desert laid out in the shape of a makeshift runway. They configured the airplane for landing with gear and flaps down, and established a consistent descent at 135 knots. At 3,500 feet AGL, the captain turned control over to the Skymaster crew flying in loose formation. Then he exited through the rear door, and the 727, nicknamed Big Flo by Captain Slocum, was on her own.
(The aircraft was also rigged with a fail-safe device dubbed "Deep Six," designed to control pitch only. If the standard radio-control system failed, Deep Six would dive the 727 steeply into the desert floor.)
The result was fascinating television, especially for airplane buffs and those interested in the science of crash investigation. It also didn't hurt that something would be totally destroyed in front of anyone with a picture box.
The aircraft crashed slightly nose down, and the nose gear immediately dug in and caused the entire cockpit to break away and fold under the fuselage. Both main gear snapped off exactly as they were designed to do, absorbing some of the impact. Later, it was determined that anyone remaining in the crew compartment wouldn't have survived, and that most passengers forward of row seven also would have suffered fatal injuries.
Big Flo skidded pretty much straight ahead, but finally came to a stop in three pieces. The radio-control system in the Skymaster had brought all three engines to idle before touchdown, but the force of impact sent the center engine back to full power, raising a huge cloud of dust. Firefighters poured a stream of water into the intake and eventually drowned the turbine to a stop.
When the dust had settled and the fire risk was deemed unlikely, the scientists went aboard and began to investigate the results. Against all odds, all 32 channels of streaming data had worked perfectly, providing much of what the scientists were seeking.
One of the first discoveries was that, while most of the fuselage was intact, the impact had deconstructed the roof panels and caused wiring and cables to fall down into the cabin. That would have represented a significant hazard in trying to exit the aircraft.
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