Aero Propeller & Accessories Inc., with guidance from the FAA, has developed the "Prop Saver Program" for the Part 91 General Aviation Operator. As the Part 91 Operator is not required to perform any major inspections unless mandated by an AD, there is a tendency for the propeller to be neglected. Annual aircraft inspections do not adequately address propeller airworthiness, or safety.
"See FAA Advisory Circular AC20-37E." As the GA fleet ages, the problems associated with corrosion will become more and more problematic. Normal operation such as going to altitude where it is cold, and returning to warmer temperatures, coastal operations, improper cleaning procedures, all cause moisture and corrosion problems. The grease manufactures also recommend replacing lubricants on a regular basis, as they absorb moisture, and cause corrosion. Corrosion concentrates stresses that if neglected, can lead to component failure. As propellers, are one of the most highly stressed components on an aircraft, neglect should never be a consideration. With approximately 20 to 40 thousand pounds of pressure on the blade shank and hub assembly, blade tips reaching the speed of sound, vibratory, bending and twisting stresses, engine harmonics, vibration, and incorrectly calibrated tachometers, all can lead to propeller failure.
The "Prop Saver Program" is an affordable option, that is approximately one half the cost of an overhaul. This inspection includes disassembly of the propeller, removal of old lubricants, visual inspection of components for corrosion, excessive wear, and unairworthy conditions that may exist inside the hub unit. The blades are stripped of the old paint, leading edges are lightly dressed, new corrosion protection and paint are then applied. The customer will be notified of any unairworthy conditions, and advised of the options. The propeller is then reassembled with new seals, lubricants, and statically balanced. This inspection program can add years of reliability and safety to your propeller by minimizing the environmental and operational effects on your propeller.
As this is not an overhaul, the following procedures will not be accomplished.
1) Blade width and thickness will not be measured unless requested by the customer.
2) Service Letter and Service Bulletin updates will not be accomplished.
3) Magnetic Particle and Penetrant inspections will not be performed.
To meet the program minimum standards, the propeller must be up to date with all AD’s, and be undamaged.