ePilot ASF Accident Reports - Thunderstorms and airplanes don't mix
Thunderstorms and airplanes don't mix
Time and time again, tangles with thunderstorms yield disastrous results. On September 24, 2002, the pilot of a Piper Saratoga and his passenger were killed after their aircraft broke up during an encounter with a thunderstorm over Yeehaw Junction, Florida.
At about 1 p.m. EDT the pilot contacted the Saint Petersburg Flight Service Station (FSS) to file an instrument flight plan from Lantana, Florida, to Orlando, and return, with a departure time of 2 p.m. He requested weather information and was told about low levels of precipitation along his route with the majority of the weather east of his route. The briefer also mentioned that thunderstorm activity was reported north of Orlando.
At 1:50 p.m. the pilot contacted Miami Center's Vero Beach terminal radar controller and reported level at 7,000 feet. The controller responded with the current altimeter setting.
At 1:51 p.m. the pilot requested a 10-degree turn to the left for weather. The controller approved the turn and cleared the pilot "direct BAIRN intersection when able." At 1:53 radar indicated that the Saratoga had turned to a heading of 330 degrees, which is consistent with a heading to BAIRN intersection.
At 1:58 p.m. the controller announced on the frequency that three convective sigmets had been issued and further information could be obtained through flight watch, HIWAS, and flight service.
At 2:08 p.m. the pilot reported that he was in IMC at 7,000 feet, and asked for a descent to 5,000 feet, which was approved. Thirteen seconds later, the pilot radioed, "One oh six Juliet gulf, the gyro is out." The controller instructed the pilot to descend and maintain 5,000 feet, but there was no response. Radar data showed the airplane descending at 11,143 fpm in a tight turn to the right. The right wing, vertical stabilizer, and stabilator were overstressed and separated due to the convective activity in the thunderstorm.
The NTSB determined the cause of this accident was the pilot's continued flight into known severe weather, resulting in an in-flight separation of the right wing, vertical stabilizer, and the stabilator. Factors in this accident were heavy thunderstorms, the failure of the FAA controllers to provide the pilot information on observed weather areas, and the FSS specialist's failure to provide the pilot with forecasted adverse weather conditions.
The 397-hour private pilot held an instrument rating that was issued five months before the accident. His logbook indicated 39 hours in actual instrument conditions.
Investigation revealed that when the pilot radioed that his gyro was out, he was penetrating intense to extreme Level 5 and 6 weather echoes. The thunderstorms contained heavy rain, IMC, updrafts and downdrafts, horizontal gusts, and turbulence of at least moderate intensity. The storms began to build in intensity about 10 minutes before the accident. There were also 124 cloud-to-ground lightning strikes between 2 p.m. and 2:15 p.m. in a 15-mile radius of the last radar position of the Saratoga.
It was found that the controller did not advise the pilot of the pertinent information on observed weather areas displayed on his radarscope.
Understanding ATC's weather capabilities is imperative when trying to navigate through severe weather. They cannot always see what you're flying in, and may assume that you have in-flight weather technology on board. The ultimate responsibility to obtain all pertinent weather information (in-flight and on the ground) falls to the pilot in command; always ask ATC if you are unsure of the weather ahead of you.
For more information about how ATC can help during severe weather, take the AOPA Air Safety Foundation's online Thunderstorms: A Case Study minicourse.
Accident reports can be found in ASF's accident database.
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November 11, 2009