TSB reiterates warning about risk of unstable runway approaches

The Transportation Safety Board of Canada has reiterated its call for commercial aviation operators to have a flight data monitoring program in order to assess the risk posed by unstable approaches.

TSB released March 9 an investigation report into an incident at Sault Ste. Marie Airport Feb. 25, 2015. A Jazz DHC8-100 touched down about 500 feet short of the runway threshold and was damaged.

There was reduced visibility due to blowing snow and the airplane “struck one of the runway approach lights before coming to a stop approximately 1.500 feet past the threshold,” TSB stated in the report.

TSB, a separate agency from Transport Canada, investigates incidents in aviation, marine, rail and pipelines.

In its report into the Feb. 25, 2015 incident, TSB noted that weather forecast initially called for “generally good conditions,” with visibility reduced to 3 statute miles in light snow showers.

But while on approach, the crew received aerodrome special meteorological reports. The first “indicated that the ceiling was reduced to 2,000 feet” with one statute mile of visibility. Another, two minutes later, indicated that the ceiling “was further reduced to 300 feet” with visibility at one-quarter of a statute mile.

TSB also made three findings as to risk.

“If guidance provided to flight crews allows for large tolerance windows, and crews are not trained to recognize an unstable condition, then there is a continued risk that flights that are unstable will be continued to a landing,” TSB concluded. “If crews do not report unstable approaches and operators do not conduct flight data monitoring but rely only on safety management system reports to determine the frequency of unstable approaches, there is a risk that these issues will persist and contribute to an accident.”

Unstable approaches was one of three aviation issues on TSB’s watch list, released Oct. 31, 2016.

The watch list is a list of issues that TSB says need to be addressed. Unstable approaches will remain on the watch list until “major airlines track stable-approach policy compliance through their safety management systems, and take action to reduce unstable approaches that continue to landing,” TSB stated last fall.

“The tools being used by some airlines to improve flight crew compliance include flight data monitoring, flight operations quality assurance programs, explicit standard operating procedures, and non-punitive go-around policies,” TSB said in its investigation report into the 2015 incident in Sault Ste. Marie. “However, major airlines need to expand the use of these tools, evaluate them to confirm that they are effective at reducing the number of unstable approaches continued to a landing, and integrate them fully” into their safety management systems.