Piper PA-25 Pawnee — Airworthiness Directives

This document is a comment letter from the Soaring Society of America (SSA) regarding a proposed Airworthiness Directive (AD) for the Piper PA-25 Pawnee aircraft, particularly those used for glider towing. The SSA represents a significant number of Pawnee operators and seeks to provide feedback on the proposed AD based on operational experience and safety analyses. The letter argues that the proposed inspection protocols are overly stringent and not necessary for Pawnees used exclusively for glider towing, which experience significantly lower stress compared to those used for agricultural purposes. The SSA suggests alternative inspection methods that would maintain safety while reducing operational costs and disruptions to glider towing operations. The document emphasizes the absence of spar failure issues in the U.S. and calls for a more tailored approach to inspections for glider-towing Pawnees.

• Piper PA-25 Pawnees used for glider towing experience significantly lower operational stress compared to those used for agriculture.
• The SSA represents 143 Piper Pawnee aircraft currently used for glider towing in the U.S.
• The proposed AD includes overly stringent inspection protocols that may not be necessary for glider-towing operations.
• The SSA recommends using non-destructive borescope inspections instead of eddy current inspections to reduce costs and risks.
• There have been no recorded accidents in the U.S. due to wing spar failures in Piper Pawnees.