PA31 STC

PA31- Spar Life Extension STC Modification – instructions for the modification to the wing main lower cap assembly in order to extend the life of a time expired wing main spar lower cap on a PA31-350 per AD/PA-31/37 Note 5. The life extension doubles the life of the wing main spar lower cap. As part of the modification, an inspection is required for continued airworthiness of the aircraft.

A structural modification to the lower spar cap will occur by replacing the original strap with an aluminium strap which extends further outboard of the wing root to increase the structural strength in the local area. The modified spar strap plate is fabricated from 2024-T3 Aluminium Alloy and is similar to the OEM spar strap plate. The only exception is that the spar strap plate extends an additional 8” outboard to a total length of 42”. The extension improves the damage tolerance of the local area of the main wing lower spar cap assembly.

We will provide the STC, the spar and all rivets.

Cost is AU$14,000 (plus GST if in Australia) plus freight.