dirtstrip wrote:Following the logic of increased loads for extended wings and the relative weakening of Bushcaddy components needing to be beefed up, does the same logic apply to extended wing kits for Cessna and others especially since a rise in gross weight follows the Cessna extended wing kits and further increases stress load? If the same increased structural loads do not affect the Cessna or others then can we assume the design margin for strength is less on the Bushcaddy than on those other aircraft? It seems a logical question to ask and one I am not qualified to answer.
It's important to understand the difference between testing and certification (and modification via STC) of certificated aircraft versus the "consensus standards" applied to S-LSA aircraft.
A modifier of a Cessna wing, for example, has to demonstrate to the satisfaction of the FAA that the wing will still meet the pertinent standards of the certification category that airplane is certified under. This requires VERY rigorous engineering data and structures and loads testing.
LSA's, on the other hand, are NOT "certificated" aircraft. They are built to "consensus standards" agreed to by the industry and the FAA, but the FAA does not certify a design. It's up to the manufacturer to determine that the airplane is safe and meets the consensus standards, not the FAA. The testing done by the manufacturer is as rigorous as they feel it needs to be to meet consensus standards, but in any case, it's not as rigorous as is the testing required for certificated aircraft.
That's not to suggest that LSA aircraft are unsafe, but there have been a few in flight failures in the LSA world that probably would never have happened in a certificated aircraft. The LSA manufacturer can test the aircraft to as strict a standards in excess of the consensus standards as they like. Some of them undoubtedly do test them beyond the "minimum" requirements.
MTV