Operational Necessity: A mission associated with war or peacetime operations in which the consequences of an action justify accepting the risk of loss of aircraft and crew. (OpNavlnst 3710.7Q)
The term "operational necessity" is one of the most often quoted yet truly ambiguous concepts contained in OpNavInst 3710.7Q Naval Aviation Training and Operating Procedures Standardization (NATOPS) General Flight and Operating Instructions. Although the definition is easily grasped, there is an ever-present question concerning just who can authorize such missions.
Disagree? Ask ten different junior officers who can authorize an operational-necessity mission and you will likely get three or four different answers—or even a blank stare. This exercise can be entertaining and enlightening in a benign environment, but imagine the frustration of a young aircraft commander trying to make the same determination on a dark night in bad weather during peacetime.