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61-107B - Aircraft Operations at Altitudes Above 25,000 Feet Mean Sea Level or Mach Numbers Greater Than .75/ with Change 1

Date Issued
March 29, 2013
Responsible Office

This advisory circular (AC) alerts pilots transitioning from aircraft with less performance capability to complex, high-performance aircraft that are capable of operating at high altitudes and high airspeeds. In particular, this AC stresses special physiological, equipment, and aerodynamic considerations involved in these kinds of operations. It also provides information to aid pilots in becoming familiar with the basic phenomena associated with high-altitude and high-speed flight.

Title 14 of the Code of Federal Regulations (14 CFR) part 61 prescribes the knowledge and skill requirements for the various airman certificates and ratings, including category, class, and type ratings authorized to be placed thereon. The civil aircraft fleet consists of numerous aircraft capable of high-altitude flight. Certain knowledge elements of high-altitude flight are essential for the pilots of these aircraft. As required by 14 CFR § 61.31, pilots who fly at altitudes at or above FL250 in a pressurized aircraft must receive training in the critical factors relating to safe flight operations under those circumstances. These critical elements include knowledge of the special physiological and/or aerodynamic considerations that should be given to highperformance aircraft operating in the high-altitude environment. High-altitude flight has different effects on the human body than those experienced during lower altitude flight. An aircraft's aerodynamic characteristics displayed in high altitude flight may differ significantly from those experienced when penetrating at a lower altitude. Knowledge of and skill in operating high-performance aircraft will enhance the pilot's ability to easily transition into aircraft capable of high speed, high altitude flight.