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Further to Herb's message above, the Supplemental Inspection Document addresses inspections and modifications required for aging aircraft to remain airworthy. The most infamous is the one for 402 Cessnas, which for aircraft with over 15,000 hours requires the installation of wing-spar straps in a procedure that is so expensive that it threatens grounding much of the fleet. Cessna is now working on other models, including the 337.
But please note:
1. The 402s are low-wing aircraft with wing mounted engines and some have a dry wing with the fuel in tip tanks, so the loads at the root of the wings are quite different than for a 337.
2. Many (most?) of the 400s have spent much of their life in charter operations, accumulating thousands of hours per year, so fatigue cycles are much greater than for the typical 337.
It's possible that the difference in loads and designs will result in an SID for the 337 which is considerably less costly and may be applicable even later in life (say, 25,000 hours). Since most 337s have far less hours, few aircraft may be affected over the next decade.
But we need to stay on top of this.
Ernie Martin
Last edited by Ernie Martin : 08-21-09 at 09:32 AM.
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