HIGH SPEED TAXI TESTS
1. OBJECTIVE. To determine the aircraft’s high speed handling and braking parameters.
a. Propeller rotation will determine which rudder pedal is pressed to compensate for the
asymmetrical thrust of the propeller blades.
b. Each taxi run should be 5 mph faster than the last run until the aircraft is within 80 percent
of the predicted stall speed. Prior to reaching the predicted stall speed, the pilot should test aileron
effectiveness by attempting to rock the wings slightly. As taxi speeds increase, the rudder becomes
more responsive and directional control will improve.
(1) In a nose gear aircraft, the pilot should be able to raise the nose of the aircraft to a take off attitude
at 80 percent of the stall speed. If the nose cannot be raised at this speed, the weight and balance and
CG range should be rechecked. Most likely there is a forward CG problem or the main gear is too far
aft.
c. If runway conditions permit, duplicate each taxi test with the flaps in the take-off and landing
configuration.
d. Determine the approximate point on the runway where lift-off will occur and mark it with a green
flag if no other existing reference is available.
e. Determine how much runway the pilot will need if it becomes necessary to abort the take-off.
This is usually accomplished by accelerating to 80 percent of lift off speed, bringing the engine back
to idle, and applying heavy braking action to bring the aircraft to a full stop. After each take-off/abort
test, the brakes must be allowed to COOL DOWN. The lining must be examined carefully and replaced
if necessary.
f. After determining the distance required to come to a full stop after aborting, add 30 percent to the
distance. Measure that distance from the OPPOSITE end of the active runway which will be used. If no
existing reference is available, mark it with a red flag. The taxi tests are completed when the test pilot
is satisfied with both the aircraft’s and his/her individual performance. Prior to the first flight, the
aircraft should be thoroughly inspected with special attention given to the flight controls, landing gear,
brake system, fuel system, engine, and propeller.
g. During this inspection all discrepancies must be fixed. Examine the screens/filters for metal,
flush the fuel system, and clean all the screens/filters. Perform a leak check on the engine and the fuel
system by running-up the engine.
h. Notes.
(1) The first high speed taxi tests should be made in a no wind or a light head wind condition.
The pilot should ensure that the tests will not interfere with the normal airport operations or create a
safety hazard for other aircraft.
Annual inspection must be performed as per Table #1 in the Maintenance Manual before first
flight.
BEFORE FLYING, THE PILOT MUST BE SIGNED-OFF IN A SIMILAR AIRCRAFT
DESIGN TYPE BY A FLIGHT INSTRUCTOR. FOLLOW THE PILOTS OPERATING
HANDBOOK.
FOR FLIGHT TEST, USE THE ZODIAC“FLIGHT TEST CHECK LIST”
Request this form from the manufacturer.
Appendix 1 NOV 09
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