Plane & Pilot
Tuesday, March 12, 2013

Lovely And Lively

The G-700S is resurrected as the AT-4, but still friendly as ever

What Is An LOA?

One cool and progressive thing about the Special Light-Sport Aircraft (S-LSA) category is how owners and mechanics can make major upgrades, repairs and alterations to their aircraft. These can include changes such as oil heaters, modified wing tips and changing the wheel to a different size. The key to making sure it all stays kosher with the FAA is the Letter Of Authorization (LOA).

Here's a quick tour of how it's done, as laid out by ASTM, (American Society for Testing and Materials), the independent body that establishes standards of airworthiness for LSA:

Any major repair, alteration, or maintenance refers to those for which instructions to complete the task are excluded from the maintenance manual(s) supplied to the consumer.

Minor repairs, alterations, or maintenance are those which are provided for in the maintenance manual(s).

The manufacturer must identify in writing the instructions for the modification, who is authorized to perform it, and that person's level of certification.

The manufacturer must provide directions to accomplish the task, detailed instructions and diagrams, methodology to test/inspect for proper completion, and an affidavit stating the modification, repair or alteration will not change the aircraft flight characteristics and applicable ASTM design and performance specifications.

The instructions must include ground and flight testing that complies with the original ASTM production acceptance testing standard, as appropriate, to verify the alteration was performed correctly and the aircraft is safe to operate.

Major repairs and alterations may only be accomplished on S-LSA by a light-sport aircraft repairman with a maintenance rating, a certificated mechanic with A&P ratings, or a certificated repair station.

The manufacturer must provide the level of certification required to perform the task and the technical data for such a repair or alteration and identify the training required, if any, to perform that repair or alteration.

Labels: LSAs


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