Part 91 operators use of Minimum Descent Altitude as a Decision Altitude
Part 91 operators use of Minimum Descent Altitude (MDA) as a Decision Altitude (DA) Many navigation systems permit operators to fly non-precision approaches with GPS lateral and vertical navigation guidance. FAA Order 8900.1, Volume 3, Chapter 18, Section 5, paragraph C073 provides guidance on how an MDA may be used as a DA when using vertical navigation (VNAV). Operators must be authorized with a Letter of Authorization (LOA) C073 in order to use an MDA as a DA with VNAV. This information was originally published in Notice, N 8900.248, dated 12/11/13. The Notice expired 12/12/14 and the information incorporated in