Quantcast Touchdown - P-330_wch50135


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Touchdown. The touchdown is the setting of the aircraft gently onto the runway
from a landing attitude.  As the aircraft settles, the landing attitude must be
maintained with backstick as necessary. If the landing attitude is not maintained, the
nosewheel will contact the ground with or before the main gear and the aircraft will
probably bounce back into the air. If the aircraft is flown onto the ground with
excessive speed in a flat attitude, the same thing will occur. These situations call for
immediate pilot action.  A very hard or high bounce has only one remedy --
application of full power to execute a waveoff. A moderate skip or bounce can
usually be corrected by raising the nose to the landing attitude and re-landing the
aircraft. Failure to take any corrective action or the use of improper technique such as
chasing the nose will result in a "porpoise." A porpoise is a condition where the
aircraft oscillates in successive bounces, which usually results in an eventual severe
nose-wheel-first landing with probable damage to the nose gear.
The landing transition and touchdown should be made with the PCL approaching
idle, and the airplane at an airspeed approximately 10 percent above stall, so that the
airplane will touch down on the main gear. As the airplane settles, the proper landing
attitude must be attained by application of whatever back elevator pressure is
Some pilots may try to force or fly the airplane onto the ground without establishing
proper landing attitude. It is paradoxical that the way to make an ideal landing is to
try to hold the airplane's wheels a few inches off the ground as long as possible with
the elevators. In most cases, when the wheels are within about two or three feet of
the ground, the airplane will still be settling too fast for a gentle touchdown;
therefore, this descent must be retarded by further back pressure on the elevators.
Since the airplane is already close to its stalling speed and is settling, this added back
pressure will only slow up the settling instead of stopping it. At the same time,
though, it will result in the airplane touching the ground in the proper landing attitude.
The T-34C should contact the ground in a nose-high attitude, with the main wheels
touching down first. After the main wheels make initial contact with the ground,
back pressure on the elevator control should be held to maintain a positive angle of
attack until it is certain that the aircraft is on the deck. Then back pressure may be
gradually relaxed to allow the nosewheel to gently settle onto the runway. This will
cause a low angle of attack on the wings to prevent floating or skipping, and will
allow the full weight of the airplane to rest on the wheels for better braking action.
The airplane should never be "flown on" the runway with excess speed.
It is extremely important that the touchdown occur with the airplane's longitudinal
axis exactly parallel to the direction in which the airplane is moving along the
runway. Failure to accomplish this not only imposes severe side loads on the landing
gear, but imparts groundlooping (swerving) tendencies. To avoid these side stresses
or a ground loop, the pilot must never allow the airplane to touch down while in a
crab or while drifting.

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