C. FLIGHT TEST.
WARNING
ENGINE TEST CLUBS MUST BE REPLACED WITH APPROVED FLIGHT PROPELLERS BEFORE FLYING AIRCRAFT.
1. Start the engine and perform a normal preflight run-up in accordance with the engine operator’s manual.
2. Take off at airframe recommended take off power, while monitoring RPM, fuel flow, oil pressure, oil temperature and cylinder head temperatures.
3. As soon as possible, reduce to climb power specified in operator’s manual. Assume a shallow climb angle to a suitable cruise altitude. Adjust mixture per pilot’s operating handbook (POH).
4. After establishing cruise altitude, reduce power to approximately 75% and continue flight for 2 hours. For the second hour, alternate power settings between 65% and 75% power per operator’s manual.
NOTE
If the engine is normally aspirated (non-turbocharged), it will be necessary to cruise at the lower altitudes to obtain the required cruise power levels. Density altitude in excess of 8,000 feet (5,000 feet is recommended) will not allow the engine to develop sufficient cruise power for a good break-in.
5. Increase engine power to maximum airframe recommendations and maintain for 30 minutes, provided engine and aircraft are performing within operating manual specifications.
Page 3 of 7
CAUTION
AVOID LOW-MANIFOLD PRESSURE DURING HIGH ENGINE SPEEDS (UNDER 15” HG.) AND RAPID CHANGES IN ENGINE SPEEDS WITH ENGINES THAT HAVE DYNAMIC COUNTERWEIGHT ASSEMBLIES. THESE CONDITIONS CAN DAMAGE THE COUNTERWEIGHTS, ROLLERS OR BUSHINGS, THEREBY CAUSING DETUNING.
6. Descend at low cruise power while closely monitoring the engine instruments. Avoid long descents at low manifold pressure. Do not reduce altitude too rapidly or the engine temperature may drop too quickly.
CAUTION
AVOID ANY CLOSED THROTTLE DESCENTS. CLOSED THROTTLE OPERATION DURING DESCENTS WILL CAUSE RING FLUTTER CAUSING DAMAGE TO THE CYLINDERS AND RINGS.
7. After landing and shutdown, check for leaks at fuel and oil fittings and at engine and accessory parting surfaces. Compute fuel and oil consumption and compare the limits given in operator’s manual. If consumption exceeds figures shown in manual, determine the cause before releasing the aircraft for service.
8. Remove oil suction screen and oil pressure screen or oil filter to check again for contamination. NOTE
To seat the piston rings in a newly overhauled engine, cruise the aircraft at 65% to 75% power for the first 50 hours, or until oil consumption stabilizes.
