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Experience no match for the stormExperience no match for the storm

(NYC08FA260)(NYC08FA260)

Air Safety InstituteBy David Kenny

Each season brings its own hazards to aircraft. In the southeastern states, thunderstorm season begins in early spring, before the risk of icing is a comfortably distant memory. By summer, convective activity is common in much of the country, but the warmer, damper regions continue to get an especially heavy dose. On a late-July afternoon in the Carolinas, thunderstorms should scarcely come as a surprise—even without a warm front passing through a mass of very moist, unstable air.

That was the situation on July 29, 2008, when a Piper PA23-180 broke up at 9,800 feet msl near Highlands, N.C., killing both on board. Surface analysis showed the front running from central Virginia to the accident site just north of the South Carolina-Georgia border, then due west into Tennessee. The National Weather Service’s convective outlook warned of “general air mass thunderstorms.”

The pilot had some reason not to be intimidated. He was an airline captain, type-rated in the Boeing 757 and 767, with almost 12,000 hours in his logbook. He’d bought the Apache two weeks earlier and was flying it home to Florida from Louisville, Ky. His son, a 255-hour single-engine private pilot, took the left seat. It was their first flight in the airplane.

No doubt his professional experience had gotten him used to flying in almost any weather. He only requested an abbreviated briefing when he filed his instrument flight plan, acknowledging the convective sigmet already in effect for western Florida. More convective sigmets were issued just about the time the two took off from Louisville. They covered most of the planned route to an intermediate stop in Hazelton, Ga., but the pilot never contacted Flight Watch or flight service for weather updates.

If he was used to working his way around storms, he was also used to relying on better tools while doing it: on-board radar, advisories from company dispatch, and, most importantly, the power to climb above most of the weather. Motoring along at 9,000 feet, he had none of these (though the airplane was equipped with a Stormscope), and radio transcripts and witness reports both suggest that he was in and out of the clouds.

The flight began deviating for weather under the control of Knoxville Approach and continued after the hand-off to Atlanta Center. The Atlanta controller warned the pilot that “an area of heavy to extreme precipitation at your twelve o’clock and two zero miles … extends approximately 15 miles south of that position and it’s about 15 to 20 miles wide.” Its direction of movement wasn’t clear, so the controller authorized the pilot to deviate as needed. He chose to turn left, heading southeast, and then six minutes later turned east to try to skirt around what the controller described as “another build-up.”

In fact, that heading took the airplane just north of another large area of heavy to extreme precipitation. As the turbulence got worse, the pilot told the controller he was reversing course. After flying west along the edge of that same cell, he turned right to a 330 heading, then left again. The airplane tracked southwesterly for the last minute before it disappeared from radar. Witnesses saw it fall out of the clouds in pieces; the tail was found a quarter mile from the fuselage and the left engine another half mile further on. The left wing was separated at the root and again mid-span.

The NTSB cited the controller’s informal description of the last cell as contributing to the accident, but attributed it primarily to the pilot’s decision to fly into an area of thunderstorms in the first place. It’s hard to argue. Expertise is an enormous asset, but even the best of us have to tailor our plans to the capabilities of the aircraft we’re actually flying.