17.7 Propeller Storage & Preservation

Question 1

What manual will you find a procedure for storage and preservation of uninstalled propellers?

Answer 1

Propeller maintenance manual. (PMM)

Question 2

From what storage period is deemed ‘long term’ for propellers?

Answer 2

6 months

Question 3

What is the ideal storage temperature for fixed wooden propellers?

Answer 3

Between 10 - 20 degrees C

Question 4

How should an installed fixed wooden propeller be stored to ensure even moisture distribution for a period of 3 months?

Answer 4

Horizontally

Question 5

On completion of a ground run, what should be done to the propeller?

Answer 5

Washed with mild solution of of soap and clean water and inspected for corrosion.

Question 6

For storage periods in excess of 3 months, what should be done to the pitch change mechanism?

Answer 6

Flushed with inhibiting oil and covered with waxed paper.

Question 7

What should external parts be treated with?

Answer 7

Lanolin or approved anti-corrosive.

Inspect regularly for corrosion

Question 8

For short term storage of 3 months, uninstalled wooden propellers with an automatic pitch control system will require?

Answer 8

Filling up with oil, turned every 2 weeks.

Question 9

For metal variable pitch propellers the procedure is the exact same as short term with one acception. What is this?

Answer 9

If the propeller blades have pre-loaded bearings, must be rotated every 6 months to prevent brinelling.
(Leave 1 inch from original position after check)

Question 10

What should happen at the 6/9 month stage of propeller storage?

Answer 10

Exercising the blades.

Question 11

At the 12 month stage of propeller storage, what should be done?

Answer 11

• Bearing inspection and removal.

- re-inhibiting

Question 12

What should take place at the 3rd year of propeller storage?

Answer 12

Sent for overhaul - hub/blade inspection as required by AWN75

Question 13

If the propeller is dismantled and remains in the manufactures packaging, what is required every 12 months?

Answer 13

Nothing if the bearings are un-loaded.

- pre-loaded bearings still require annual inspection.

Question 14

What types of corrosion inhibitor can be used for storage?

Answer 14

Mineral jelly, storage wax compound

Question 15

How is the pitch change mechanism prepared for storage?

Answer 15

Immersed in inhibiting oil and drained. Wrapped in wax paper

Question 16

How should the propeller blades be prepared for storage?

Answer 16

Coated in lanolin and wrapped in greaseproof paper.

Question 17

What should electrical connections and slip rings be coated in before storage?

Answer 17

Petroleum jelly and labelled

Question 18

What EASA form should stored parts have accompanied with them?

Answer 18

EASA form 1

Question 19

What should not come into contact with the de-icer boots when storing a propeller for up to 6 months?

Answer 19

Lanolin

Question 20

When storing a propeller with pre-loaded bearings for a time period of up to 6 months, what must be done to prevent the bearings from brinelling?

Answer 20

At the 6 month point, rotate the propeller 3 full rotations and should be left at least 1 inch away from its original position

Question 21

What must happen to a propeller in storage at each 12 month point?

Answer 21

It requires re-inhibiting at each 12 month point

Question 22

What should lanolin never come into contact with?

Answer 22

The de-icer boots

Question 23

What must happen to an uninstalled wooden propeller with an automatic pitch change mechanism prior to storing?

Answer 23

It must be filled with normal oil prior to storing

Question 24

What must happen to an uninstalled metal propeller with a variable pitch change mechanism prior to storing?

Answer 24

The oil must be drained and re-filled with inhibiting oil