Hartzell CD15K - 8.4 1000-HOUR OR 4 YEAR HEATER SERVICE, INSPECTION AND SUBSEQUENT 250-HOUR INTERNAL SERVICE AND INSPECTION (as contained in the Instructions for Continued Airworthiness, MM10001 Maintenance Manual); 8.5 2000-HOUR OR 10 YEAR OVERHAUL (to be accomplished in accord with MM10001 sections 8-11.)

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MM10001
Dated 1/1/08
Rev L dated 5/21/15
8.4 1000-HOUR OR 4 YEAR HEATER SERVICE, INSPECTION AND
SUBSEQUENT 250-HOUR INTERNAL SERVICE AND INSPECTION (as
contained in the Instructions for Continued Airworthiness, MM10001 Maintenance
Manual)
NOTE: This inspection must be recorded in accordance with FAR43.9 and maintained as required by
FAR 91.417.
At the end of 1000 hours or 4 year heater operation time* and thereafter at intervals not to exceed
250-hours* (or four years whichever comes first) perform the following checks:
 Complete Pressure Decay Test as outlined in MM10001 Section 8.6.
 Complete the 250hr/2yr service inspection
IMPORTANT: IF LEAK IS DETECTED DURING PDT, THE COMBUSTION TUBE
ASSEMBLY HAS FAILED. PRIOR TO FURTHER FLIGHT,
OVERHAUL ANY HEATER THAT DOES NOT PASS THE
COMBUSTION TUBE PRESSURE DECAY TEST REQUIRED BY THIS
INSPECTION. IT IS RECOMMENDED THAT THE OVERHAUL BE
PERFORMED BY THE HARTZELL ENGINE TECHNOLOGIES LLC
SERVICE CENTER.
8.5 2000-HOUR OR 10 YEAR OVERHAUL (to be accomplished in accord with
MM10001 sections 8-11.)
NOTE: This procedure must be recorded in accordance with FAR43.9 and maintained as required by
FAR 91.417.
NOTE: IT IS RECOMMENDED THAT THE OVERHAUL BE PERFORMED BY THE
HARTZELL ENGINE TECHNOLOGIES LLC SERVICE CENTER.
NOTE: *If an hour meter is not used, count one (1) heater hour for every two (2) flight hours of
normal aircraft operation. Consideration should be given for any excessive ground operation
or geographical operation of the heating system.
 Overhaul of the combustion heater and all accessories are recommended at 2000-hours or
10 years. If wear is evident, it is recommended to replace the combustion chamber. If a
new combustion tube is installed at overhaul, the heater may operate to the 1000-hour
inspection interval at which time the pressure decay test is required. Thereafter the
pressure decay test is not to exceed each 250-hours or four years (whichever occurs first).
If the combustion tube is found to be serviceable and is reused at the overhaul time,
the 250-hour/4 year repetitive pressure decay test is still required.