(14) Remove the tape and cardboard from the brush block. (14a) Check that the gap between the brush block and the commutator ring is 1/32" at the forward end and 3/32" at the aft end relative the rotation of the commutator ring. (14b) As Illustrated (Figure 203), a 40 bit drill placed immediately above and a 30 bit drill placed immediately below the brush (placement relative to direction of ring rotation) will assure the correct gaps. (14c) Check that the brushes are aligned with the commutators so that the entire face of each brush is in contact with the commutator rings throughout the 360° rotation (see MM 61-10-30, Figure 201). (15) Install the beta tube and thread 16 turns. (16) Zero the protractor. (17) Place the power lever in the flight idle position. (18) Move the starter/unfeather test switch to the unfeather position. WARNING: DO NOT MOVE THE SWITCH TO THE STARTER TEST POSITION. SERIOUS INJURY TO THE PERSON CHECKING THE BLADE ANGLES COULD RESULT. (19) Using the protractor, measure the propeller blade angle at the 30 inch station. The correct blade is 13.0º ± 0.2º. (20) If the blade angles are incorrect, adjust as follows: (20a) Remove the beta tube retainer bolt. (20b) Rotate the beta tube clockwise to decrease blade angle or counterclockwise to increase. (20c) Install the beta tube retainer bolt and torque to 40 inch-pounds. (21) Check propeller for safety and clearances between fixed and moving parts. (22) Align the spinner mark with the mark made on the propeller blade and reinstall it with one screw between each blade. (23) Check spinner trueness (Figure 203). (23a) Place a jack or other stationary object adjacent to the spinner.
(14) Remove the tape and cardboard from the brush block. (14a) Check that the gap between the brush block and the commutator ring is 1/32" at the forward end and 3/32" at the aft end relative the rotation of the commutator ring. (14b) As Illustrated (Figure 203), a 40 bit drill placed immediately above and a 30 bit drill placed immediately below the brush (placement relative to direction of ring rotation) will assure the correct gaps. (14c) Check that the brushes are aligned with the commutators so that the entire face of each brush is in contact with the commutator rings throughout the 360° rotation (see MM 61-10-30, Figure 201). (15) Install the beta tube and thread 16 turns. (16) Zero the protractor. (17) Place the power lever in the flight idle position. (18) Move the starter/unfeather test switch to the unfeather position. WARNING: DO NOT MOVE THE SWITCH TO THE STARTER TEST POSITION. SERIOUS INJURY TO THE PERSON CHECKING THE BLADE ANGLES COULD RESULT. (19) Using the protractor, measure the propeller blade angle at the 30 inch station. The correct blade is 13.0º ± 0.2º. (20) If the blade angles are incorrect, adjust as follows: (20a) Remove the beta tube retainer bolt. (20b) Rotate the beta tube clockwise to decrease blade angle or counterclockwise to increase. (20c) Install the beta tube retainer bolt and torque to 40 inch-pounds. (21) Check propeller for safety and clearances between fixed and moving parts. (22) Align the spinner mark with the mark made on the propeller blade and reinstall it with one screw between each blade. (23) Check spinner trueness (Figure 203). (23a) Place a jack or other stationary object adjacent to the spinner.
61.908%20Propeller%20Installation%20(Hartzell).docx