Engines General

1: Introduction

To permit any engine to continue in service, the continuing airworthiness of the engine must be assessed at specified intervals and the results of that assessment recorded in appropriate documentation. 

For the purpose of establishing the airworthiness of a piston engine, an assessment of the engine condition shall be carried out in accordance with approved maintenance data, and any variation to published criteria shall be subject to a maintenance action carried out in accordance with approved maintenance data. 

Note 1:  CAR 42V (1988) requires; when carrying out maintenance on an aircraft and/or components of that aircraft, whether the maintenance is a periodic inspection or an engine change, the maintenance must be carried out in accordance with approved data.  Examples of approved data are; the manufacturer’s maintenance manual, service bulletins relating to the maintenance being carried out and data approved by a person authorised by CASA (CAR 35). CAR 2A (1988) refers.

2: Periodic Inspection Intervals

2.1. Private operations

At next scheduled engine inspection and thereafter at intervals not to exceed 12 months time in service.

2.2. Aerial work operations

At the next scheduled engine inspection and thereafter at intervals not to exceed 110 hours time in service or 12 months, whichever occurs first.

2.3. Charter operations

At the next scheduled engine inspection and thereafter at intervals not to exceed 110 hours time in service or 12 months, whichever occurs first.

3.1. In accordance with approved maintenance data:

a. Drain and replace the engine oil.

b. Inspect the engine oil filter elements or pressure screen, as applicable for evidence of contamination.

c. Inspect the crankcase assembly externally for condition, cracks, oil leaks, and missing or loose cylinder hold down studs/nuts/bolts.

d. Inspect all cylinders externally for condition, cracks, leaks, and missing or loose manifold attachment studs/nuts, paying particular attention to the cylinder to crankcase interface.

e. Disassemble all mufflers and stack shrouds from the exhaust system and inspect the exhaust system externally, and internally via outlet openings, for evidence of leaks, loose connections, corrosion and cracking.

f. Inspect the engine air induction system filter, alternate air door, air inlet manifolding for security, leaks and condition.

g. Inspect all engine and propeller controls and control mounting hardware for condition, freedom of operation and full travel, security and correct locking of connections.

h. Inspect all engine-mounted accessories for condition, security and leaks.

i. Inspect the engine mount(s) for cracks, security and condition.

j. Inspect all engine compartment flexible hoses for security, evidence of leakage, chafing and condition of hose fire sleeving.

k. Remove all spark plugs and inspect for condition. Replace spark plugs as required.

l. Inspect the ignition harness for security and condition.

m. Carry out a magneto to engine timing check.

n. Replace or service the fuel and air filter elements as detailed in approved maintenance data.

o. Inspect the fuel system components for condition and leaks.

p. If applicable, inspect the turbocharger, turbocharger accessories, plumbing and associated hardware for condition.

A calculation of the engine oil consumption rate over the preceding 20 hours time in service shall be assessed in accordance with approved maintenance data.

3.3. Engine performance

Carry out a static engine run to determine the engine performance is in accordance with approved maintenance data.  Engine and aircraft details and parameters achieved during the engine run are to be recorded and certified on CASA Piston Engine Condition Report Form 728. 

Note 3:  Where possible, maximum RPM is to be attained with the aircraft stationary.  However, where the aircraft manufacturer details in approved maintenance data that maximum RPM can only be achieved during take-off or climb, or the aircraft type does not permit maximum RPM to be safely obtained whilst the aircraft is stationary, an entry on the aircraft maintenance release by the pilot in command of the maximum RPM during the last flight prior to the periodic engine inspection is acceptable data.

Engine run parameters to be recorded include:

a. Take-off power.  Take-off power shall be:

(i) For a fixed pitch propeller aircraft - static RPM.

(ii) For a constant speed propeller, normally aspirated engine aircraft, take-off power shall be maximum RPM at a manifold pressure within 2" of static manifold pressure.

(iii) For a turbocharged/supercharged engine aircraft, take-off power shall be maximum RPM at the manifold pressure detailed in the aircraft flight manual.

(iv) For a rotary wing aircraft, take-off power shall be determined by the ability of the helicopter to hover in accordance with the parameters detailed in the approved flight manual.

b. With the engine at operating temperature:

(i) Oil pressure at idle and at take-off power

(ii) Oil temperature at idle and at take-off power.

c. Cylinder head or exhaust gas temperature at take-off power.

d. Fuel pressure/flow at take-off power.

e. Ambient temperature and location altitude.

a. Compliance with the requirements of this periodic inspection shall be recorded and certified by an appropriate person in the engine log book; and

b. The aircraft and engine details, engine performance parameters, cylinder leak rates, oil filter inspection results and a certification that the engine is airworthy and fit for continued service are to be certified by an appropriate person on CASA Piston Engine Condition Report Form 728.  The certified form is to be retained as an aircraft record.

Following completion of the engine manufacturer’s published TBO period, any engine defect which requires the separation of the crankcase parting flange or removal of the crankshaft shall require the engine to be disassembled to a level which will permit all internal parts to be inspected, including the magnetic particle inspection of ferrous parts.   All parts shall be in accordance with in-service limits, dimensions and tolerances detailed in approved maintenance data. 

5: In Service Maintenance

5.1. Cylinder leaks checks

At intervals not to exceed 110 hours time in service, carry out a cylinder leak check in accordance with: 

a. The procedure published by the engine manufacturer; or 

b. In the absence of a current engine manufacturer cylinder leak check procedure; carry out a cylinder leak check in accordance with the procedure detailed in Airworthiness Advisory Circular 6-32 Amdt.1. 

The results of each cylinder leak check are to be recorded in the engine logbook.

5.2. Engine oil system maintenance

The engine oil and engine oil filter shall be replaced at intervals as published by the engine manufacturer with a planning tolerance of plus or minus 10%.  A pilot, other than a student pilot, may carry out replacement of the engine oil and engine oil filter.  CAR 42ZC (4) and Schedule 8 refer.

5.3. Engine oil uplifts

All oil uplifts are to be recorded.  Oil uplift records are to be made available at the time of the engine periodic inspection.