Safety Publications/Articles

Air Safety Institute Safety Spotlight

Some things are best avoided

With the thunderstorm season here, it's important for pilots to understand the characteristics of thunderstorms -- and avoid them. On June 14, 2002, the pilot of a Piper Malibu and his two passengers were killed after the airplane entered an uncontrolled descent while trying to navigate through convective activity near Osteen, Florida.

On the day of the accident, the pilot contacted flight service to obtain a briefing for a flight from Salisbury, North Carolina, to Raleigh-Durham, then on to Marco Island, Florida. The forecast for along the route predicted thunderstorms and cumulonimbus clouds with tops to 45,000 feet. The briefer focused on the weather in Florida because "that was where the activity was."

At about 6:50 p.m. the pilot contacted Jacksonville Center and was cleared direct to Marco Island. At 8:02, the pilot requested and was granted permission to leave the frequency to contact Flight Watch. He was advised of cells east of St. Augustine moving east at 20 knots, as well as sigmets related to the convective activity over Florida. Flight Watch suggested that a routing toward the Tampa-St. Petersburg area and then south would avoid an area of thunderstorms.

At 8:06, the pilot reported back with Jacksonville Center. At 8:27, he requested a deviation to the west to avoid weather, saying that he wanted to "fly through a little hole." The deviation was approved, and the Malibu turned about 20 degrees to the right. At 8:29, the pilot was instructed to switch to the next sector controller. The pilot replied "OK....[unreadable]...and a little hole here." Radar plots showed that the Malibu was in the vicinity of both light- and heavy-intensity returns. It appeared the pilot was trying to fly through a three- to five-mile gap between two thunderstorm clusters.

Radar contact was lost six minutes later. Witnesses reported hearing the engine make a winding noise, then observed the airplane -- with the right wing missing -- come out of the clouds about 300 feet agl in a nose-low spiral. The NTSB determined the cause of this accident to be the pilot's inadequate weather evaluation and his failure to maintain control of the airplane after entering an area of thunderstorms, resulting in an in-flight separation of the right wing and horizontal stabilizer.

The instrument-rated private pilot had 2,800 total hours, all of which were in single-engine airplanes, and 380 hours in the Piper Malibu. The pilot received his initial training in the Malibu in 1996. The CFI who conducted the pilot's initial training and subsequent refresher courses noted, "The pilot pushed himself dangerously close when making weather decisions in this class of airplane. He seemed to lack a healthy respect for the destructive forces of thunderstorms, and seemed to take delight in how close he could come in pushing the envelope." The CFI had cautioned the pilot as recently as two weeks before the accident to exercise greater care when flying around adverse weather systems.

Trying to "pick your way" through a weather system without the appropriate equipment can be deadly. According to the AOPA Air Safety Foundation's Weather Wise Safety Advisor, which you can download from the AOPA Online Safety Center, pilots should stay at least 20 nautical miles away from any part of a thunderstorm. Wind shear, gust fronts, turbulence, and hail can all occur within this distance. Most small GA aircraft shouldn't be anywhere near these incredible forces of nature.

Kristen Hummel manages the GA accident database for the AOPA Air Safety Foundation. She holds a commercial pilot certificate with multiengine and instrument ratings.

By Kristen Hummel

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