August 2, 1993 (the "Schwab opinion"), reproduced in Jackson and Edwards, Federal Aviation Regulations Explained, Parts 1, 61, 91, 141 and NTSB 830 (Jeppesen, 2009). Letter from Rebecca MacPherson, Assistant Chief Counsel, FAA Regulations Division, to James W. Dymond, Esq. dated March 9, 2007, reproduced