Late last month, the FAA released an Information for Operators (InFO) notice warning against the dangers of pilots inhibiting terrain avoidance and warning systems (TAWS) aural alerts. According to the notice, “Alerts from TAWS can become a nuisance or a distraction to pilots when flying at altitudes below the alerting threshold of the system. This may result in the pilot’s decision to inhibit the system. Inhibiting warning systems and ignoring warnings, combined with deteriorating weather conditions leading to loss of visual surface reference and situational awareness, has been found to be the cause of some CFIT [controlled flight into terrain] accidents.
“This InFO serves to inform operators about the risks associated with distraction and complacency brought about by routine use of the TAWS’ terrain inhibit feature. It is also intended to ensure operators understand the importance of having procedures and training for the use of the terrain inhibit aural warning switches associated with nuisance alerts.”
The FAA recommends that directors of operations for charter providers (Part 135), private flight department managers (Part 91) and fractional ownership program managers (Part 91, subpart K) “should review their approved training programs to ensure procedures for the use of the terrain warning system inhibit switch is adequately addressed.”