Tuesday, December 20, 2011
Landing Without Flight Controls
Under some conditions, it’s possible to land an airplane without using normal aerodynamic controls
The Fedayeen were showing off for a French newsmagazine journalist and actually fired two missiles at the A300. The second missile missed, but the first didn't, and it was bad enough.
The missile took out all three hydraulic systems that control the operation of rudder, ailerons, flaps, slats and elevator, leaving the three-man crew with NO flight controls. The missile also punctured the left main fuel tank, which fed Jet A to a huge fire on the outer left wing.
The one-hour show concentrated on the crew's ultimately successful attempts to fly the airplane back to Baghdad Airport with nothing more than engine power, using asymmetric thrust for heading control and graduated power for altitude control.
The outer portion of the left wing was burning and at risk of failing completely throughout the airplane's short flight. The flight engineer had to cross-feed just enough fuel from the right-wing tank to keep the left engine running, hoping the left wing wouldn't explode, and that there would still be enough fuel remaining for the approach.
Somehow, the crew managed to return to Baghdad and land the airplane in the sand beside the runway, touching down at a speed 60 knots faster than normal. The copilot immediately put both engines into full reverse, and the airplane stopped in about 4,000 feet, relatively intact but with both engines totally FODed with dirt. All three crew members were uninjured.
A similar loss-of-control situation afflicted a United Airlines DC-10 at Sioux City, Iowa, in July, 1989. The airplane's tail-mounted engine exploded in flight, sending shrapnel through critical hydraulic lines, draining all hydraulic fluid from the big Douglas' three systems.
Captain Al Haynes and his crew had to learn to control the DC-10 with power from the remaining two engines, and succeeded in landing the airplane at Sioux City, though a wing contacted the ground on touchdown, and the airplane came apart in the ensuing crash. Still, 185 of the 296 people aboard survived, because the crew put the airplane down on an airport.
Most private aircraft aren't large enough to require hydraulic boost to move control surfaces, so loss of hydraulic pressure usually affects only brakes and sometimes landing gear. Control failures aren't common, but they can still be potentially dangerous. A cable can break or come off a pulley, a foreign (or domestic) object can jamb a pushrod, and there's always the chance that Murphy will find new ways to cause problems.
As the two airline crews above demonstrated, it's sometimes possible to fly an airplane with little or no aerodynamic control. In fact, a fairly adept pilot can sometimes take off and land some airplanes without using the elevators or ailerons at all.
I know one of those "adept" pilots. Back in the last century, then-TWA Captain Barry Schiff demonstrated that skill on national television. In those halcyon days, Schiff and I worked together on an ABC-TV show called Wide World of Flying. I did a series of Left Seat Checkouts, and Barry did video stories on safety, brilliantly synthesizing material that might otherwise have been a tough sell.
In one of those video articles, he demonstrated the ability to fly a takeoff and landing in a Cessna Skyhawk without touching the elevator control. Schiff employed a combination of elevator trim and power to control the airplane, flying a complete pattern, from brake release to wheels stop.
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Labels: Features, Pilot Guide, Pilot Resources, Pilot Skills, Situational Awareness, Proficiency, Pilot Safety