O.S. Engine OS29709000 GT55 Propeller Retention Washer for RC Models  [OS29709000]

Precision prop washer for model aircraft

This O.S. Engine OS29709000 propeller washer GT55 is an RC-scale accessory made to locate and retain a propeller on a model aircraft shaft. It is a simple mechanical washer designed to sit between the propeller and the securing nut or spinner assembly to provide repeatable seating and consistent contact through maintenance cycles.

Installation is straightforward: remove the prop nut or spinner, place the washer on the shaft against the propeller hub, then reinstall the nut or spinner and tighten to your normal secure fit. Verify shaft flats and propeller seating so the washer lies flat and does not introduce misalignment. No special tools or torque figures are required beyond standard propeller installation practice.

For tuning and routine maintenance, a dedicated propeller washer helps preserve consistent prop seating after repeated removals, which can reduce balance shifts and simplify vibration troubleshooting. Include it in your regular checks when swapping props, bearings, or if you notice subtle vibration during run-up.