NPA 2017-06

Loss of control or loss of flight path during go-around or other flight phases

The objective of this NPA is to mitigate the safety risk of loss of the normal go-around (G/A) flight path, or loss of control of the aircraft during G/A or other flight phases executed at low-speed.

This NPA proposes to amend CS-25 to ensure that: 

  • the design of large aeroplanes is such that the G/A procedure with all engines operating (AEO) can be safely conducted by the flight crew without requiring exceptional piloting skills or alertness. Risk of excessive crew workload and risk of somatogravic illusion must be carefully evaluated, and design mitigation measures must be put in place if those risks are too high; 
  • the design of large aeroplanes provides an adequate longitudinal controllability and authority during G/A and other flight phases (focusing on low speed situations).

The proposed changes are expected to provide a fair safety benefit against an acceptable cost impact for large aeroplane manufacturers.