The document points out that the FAA should be contacted prior to any alterations on airplane to insure that airworthiness of the airplane is not violated.
A.It is stated int the document that you should inform the FAA about the alterations you'll perform on the airplane to insure the airworthiness of the airplane. B.The document says that the FAA should be involved in any alterations on airplane so to insure that the airplane will not violate any airworthiness regulations. C.The document sets forth that you should contact the FAA before any alterations on airplane to make sures that the airplanel is airworthy continuously.正确答案C
