Editor's Log

November 2005 Issue




Editor’s Log: 11/05

Weather And GA
It should come as no surprise that weather-related general aviation (GA) accidents continue to take their toll. For example, the AOPA Air Safety Foundation’s (ASF) 2004 Nall Report found that only 2.8 percent of all accidents involving single-engine fixed-gear airplanes were weather-related, but that weather was involved in 12 percent of fatal accidents involving these aircraft. The ASF’s report goes on to note, “The overwhelming majority resulted from continued VFR into IMC; quite simply, a pilot flying by reference to outside visual cues flew into low visibility conditions and lost control of the aircraft or hit terrain.”

In September, the National Transportation Safety Board (NTSB) adopted a safety study that examined the risk factors associated with GA and bad weather and poor visibility. Mirroring the ASF’s numbers, the NTSB noted that only six percent of GA accidents are weather-related, but they account for more than one in four of the fatalities.

For the study, NTSB investigators collected data from 72 GA accidents occurring between August 2003 and April 2004. Using flight-tracking software, the study compared the accident flights to other, “non-accident” flights involving the same types of aircraft flying in the same general area and at the same time. Pilots flying the non-accident aircraft were contacted and interviewed, most of the time within 72 hours.

Also of no great surprise is that the study’s results suggest that a pilot’s performance history, including previous aviation accidents or incidents, and FAA knowledge or practical test failures are associated with an increased risk of being involved in weather-related GA accidents.

But there were some surprises, at least to us. For example, the NTSB found that pilots who learned to fly prior to age 25 were at the lowest risk for a weather-related accident, regardless of their age when the study was conducted. The accident risk was found to be approximately four times greater for other pilots. Another example involves a bar chart showing that aircraft owners were more likely to be involved in a weather-related accident than renters.

The NTSB defines a weather-related accident as one “that occur[s] in weather conditions characterized by instrument meteor-ological conditions (IMC) or poor visibility.”

Based on the study’s results, the NTSB made several recommendations to the FAA. They include identifying “at-risk” pilots and developing a program to reduce that risk, improving weather information presentation and delivery for flight service stations—including increased use of graphical data—and revising FAA weather-briefing guidance materials to include Internet, satellite and other data sources suitable for meeting the agency’s pre-flight briefing requirements.

Materials describing the study are on the NTSB Web site at <www.ntsb.gov>. The complete report will be released at a later date.


—Jeb Burnside