I recently was asked if the Regulations required the operator to comply with a newly revised Aircraft Flight Manual Supplement that affected his aircraft. The issue here was that the original Supplement that accompanied a STC that altered the aircraft allowed for a GTOW of 3,800 pounds and was without any restrictions. The new Supplement which was issued at a later date now imposed a landing weight restriction, which would have an adverse affect on his operations.
This is very similar to my blog about the maintenance requirements, but is on the operations side. That is titled Turbine Operators Get Some Relief on Their Maintenance Program. I suggest reading this as it will give a better understanding of FAA's reasoning.
The FAA issued a Memorandum dated December 5, 2008 to clarify their definition of the word current as used in different areas of the Regulations. This specifically addressed the issue of maintenance but also describes how this is relative to the operations side. The exact same reasoning is applied to the operations of an aircraft wherein one must comply with the operation limitations as set forth in the approved Flight Manual. Again they address that a current Flight Manual is one that was issued at the time of delivery of the aircraft, not one that is current “as of today”. Following this logic would dictate that a Supplement issued to a Flight Manual is also under the same rules.
A summary conclusion is that if an aircraft were altered in accordance with a FAA approved STC and said STC had incorporated a Flight Manual Supplement which imposed certain flight limitations, then the operator of the aircraft would be bound by that Supplement that was current at the time of delivery. If then, at some later date, the STC holder decides to revise the Supplement, the operator may elect to incorporate that new revision into his limitations or may elect to ignore it. Remember the real point here is all about who can and cannot implement law and policy. The manufacturer can make recommendations, but only the FAA can impose legally binding requirements.
