Maintenance Quiz

1. Some airlines are trialling the use of sustainable aviation fuel (SAF); SAF is: 

1. not a clean substitute for fossil jet fuel
2. refined from higher grade petroleum
3. produced using mainly carbon by-products
4. produced from resources such as waste oil, agricultural residues and non-fossil CO2

2. Piston-engine fuels rely heavily on having a high tetraethyl lead (TEL) content:

1. TEL is needed as an anti-detonation product
2. Aviation piston engines must operate with fuels that contain high levels of TEL
3. Aviation fuel not containing TEL is suitable for high-powered turbocharged engines as the possibility of detonation is reduced
4. New fuels containing little or no TEL are still experimental and unlikely to receive certification by US federal authorities

3. In recent years, propeller manufacturers have produced many new designs for light aircraft including 5-blade models: 

1. Five-blade designs are a powerful marketing tool, but do not enhance aircraft performance
2. Five-blade propellers are usually smaller diameter than 3- or 4-blade designs, which assists in reducing stone damage
3. Five-blade propellers are inherently smooth in operation and do not require dynamic balancing
4. All five-blade designs are manufactured from composite material

4. General Aviation Manufacturing Inc (GAMI) designed a fuel nozzle for Continental and Lycoming piston engines that has a different size orifice depending on which cylinder they are installed in. They are often called ‘tuned injectors’:

1. GAMI injectors result in having a larger EGT spread during the leaning process
2. GAMI injectors provide more fuel to the engine and thus lower the EGT
3. To take advantage of the GAMI design features, each cylinder must have the correct GAMI injector in the correct cylinder
4. GAMI injectors provide less fuel to the engine and increase EGT and CHT

5. Normally aspirated (non-turbo) Cessna 210 aircraft are factory fitted with rounded prop blade tips, while turbo-charged and pressurised versions of the Cessna 210 have square prop blade tips: 

1. The shape of the blade tips makes no difference to aircraft performance
2. If turbo and pressurised aircraft were fitted with rounded tip prop blades, aircraft performance would be increased
3. Cessna allows either rounded or square blade propellers to be fitted to all their 210 models
4. The square-tipped propellers perform much better at altitude where turbo and pressurised aircraft cruise

6. If a tyre shows severe material loss deep into the tyre case in one spot: 

1. This may be caused by a wheel lock-up on landing
2. The anti-skid system could not have caused it
3. Aquaplaning on landing would not cause this kind of damage
4. An out-of-balance tyre would put the heavy spot at the bottom for each landing and multiple landings would cause the tyre to wear in the same spot

7. In light turbo-prop engines such as the PT6A-series, the manufacturer calls out 2 types of in-service compressor cleaning – a de-salination wash and a power recovery wash:

1. A de-salination wash is required when engine performance begins to degrade
2. A de-salination wash is not required when operating in a coastal area or when flying in a polluted area
3. A power recovery wash is required when engine performance degrades or when called out by the manufacturer
4. A power recovery wash only requires a motorised rinse with de-mineralised water

8. On Learjet 35/36 models, the nose-wheel tyre has a moulding on each side called chines or deflectors. Their purpose is to:

1. deflect standing water outwards to reduce water spraying onto the main wheels and brakes
2. deflect water, keeping the nose wheel straight when taking off on a wet runway
3. deflect water, keeping the nose wheel straight when the drogue chute is deployed
4. deflect standing water outwards to reduce water ingestion into the engines

9. Oil types for piston engines are advertised differently by manufacturers. The correct oil to use is: 

1. the same oil as installed when the engine was new (or overhauled) 
2. the oil specified by the pilot operating handbook (flight manual) or maintenance manual
3. any aviation brand of oil
4. single-weight oils in Australia because the climate isn’t cold enough for multigrade oils

Answers:

1. d
2. a
3. b
4. c
5. d
6. a
7. c
8. d
9. b