Significant Consequences to Severe Actions?
Monday, March 23rd, 2009
Or are they going overboard? From Aviation Industry Press – Daily Newsletter Wednesday 18 February 2009
Ground all twin turboprops?
The former chairman of the US National Transport Safety Board (NTSB) has stunned the aviation community with his recommendation to ground all twin-engine turboprop passenger aircraft until the end of the on-going investigation into a recent fatal accident of a Bombardier Q400 near Buffalo, New York. He argues that due to the lower speed, ice can build up quicker on turboprops than on jets and can lead to greater ice accumulation.
Icing may have been a factor in the Buffalo crash - the pilots reported “significant” icing on the approach to the airport. Other flight crew reported icing conditions on the night of the accident, including pilots of similar types to the Q400, none of which were considered “severe”.
Aside from possible ice build-up, controversy surrounds whether or not the pilots should have had the autopilot engaged before the crash. While current regulation requires the flight crew to disengage the autopilot only in “severe” icing conditions, the NTSB has in the past recommended to the FAA that it may be advisable to fly the aircraft manually in light-to-moderate icing conditions. This point, however, comes back to the question of whether or not the ice-build up was “severe”. The NTSB investigation team has thus far denied allegations the Colgan Air were acting incorrectly by keeping the autopilot engaged.
It is no wonder the FAA and industry have dismissed the radical recommendation to ground all twin-engine turboprop aircraft. However that it came from the former chief accident inspector himself - while the investigation is still going on and no clear indication of the cause has been given - is a surprise indeed.
- Michael Gubisch, staff writer, Aircraft Technology Engineering & Maintenance
Is this another instance of targeting what is the most visible and not focusing on the real problem, the root cause? Or is it simply reacting to the public’s perception so it appears that action is being taken. Aviators and non-aviators, let me know what your opinion is on this topic.

