INSTALLATION OF PROPELLER

The method of installation will depend on the type of propeller, and all instructions detailed in the appropriate AMM should be carefully followed; these will include any special checks to be carried out, and details concerning lubrication, torque loading and locking or retaining parts. The following procedures are applicable to most propellers:

• Remove all protective covers and plugs, and clean parts which have been treated with a protective coating. Lubricate specified parts with the recommended grease or oil before installation.

• Fit the electrical brush gear housing to the engine reduction gear casing, and check that it is square with the engine shaft, using a dial test indicator clamped to the shaft.

• Fit the sling to the propeller, lightly smear the front and rear cone seatings with engineers' blue, and temporarily fit the propeller to check the contact area of the cones. Tighten the hub retaining nut by hand, rotate the propeller at least one revolution, then remove the propeller and check the extent of blueing of the cones. If the contact area is less than 80%, high stops may be removed by light stoning, or where permitted, by lapping on a suitable mandrel. Clean the cones and cone settings.

• With hydraulically-operated propellers, fit and lock the oil tubes in the engine shaft.

• Refit the propeller, lightly lubricate the splines, cone bore and threads with specified lubricants. Cone faces should not normally be lubricated, as this may result in looseness of the propeller when the oil film is lost. Lubricating the propeller bore, rather than the shaft will prevent any lubricant from being displaced on to the cone face when the propeller is installed.

• Turn the blades to the feathered angle, and fit the pitch-change mechanism.

• Install the brush gear, and check for correct contact between the brushes and the slip rings.

• Fit the spinner, and turn the blades through their full pitch range, to check for fouling.