Final Report: Pilot blamed in Malibu turboprop breakup

 - March 22, 2007, 9:53 AM

PIPER PA-46-310P MALIBU, OSTENN, FLA., JUNE 14, 2002–Trying to thread through a hole in an area of thunderstorms on an IFR flight from Raleigh, N.C. to Marco Island, Fla., the pilot of Malibu N9143B asked ATC for a deviation 12 miles to the west. He attempted to fly through an area of light radar echoes between the two large areas of heavier echoes. N9143B departed level flight, and radar showed that a cluster of Level Three to Four thunderstorms was present in the vicinity of its position. The airplane started an uncontrolled descent from FL260. Witnesses reported hearing the engine make a winding noise, then the airplane came out of the clouds about 300 feet above the ground, in a nose-low spiral, with the right wing missing. The right wing was found 1.62 miles from the main wreckage.

The NTSB determined the probable cause was the pilot’s inadequate weather evaluation and his failure to maintain control of the airplane after entering an area of thunderstorms, resulting in the in-flight separation of the right wing and right horizontal stabilizer and an uncontrolled descent.

The pilot had received a weather briefing, which the NTSB said did not thoroughly address hazardous weather along the route. He had contacted Flight Watch en route and was advised of “cells” east of St. Augustine and of a convective sigmet in effect for southern Florida.

Radar data indicated the airplane descended rapidly in a left-hand turn to a maximum descent rate of 20,700 fpm. The radar pod and wing panel separated at
an altitude of 26,000 feet just before the airplane’s rapid descent.

The airplane was destroyed and the private pilot and two passengers were killed. The fracture in the right wing piece and left horizontal stabilizer spar appeared to be caused by excessive upward aerodynamic loads. Initial failure was in compression buckling along the upper surface of the wing.

The pilot’s flight instructor said the pilot “pushed himself dangerously close when making weather decisions in this class of airplane” and seemed to “lack a healthy respect” for the destructive forces of thunderstorms and seemed to take “delight” in how close he could push the envelope. The CFI said he had cautioned him as late as “two weeks” before the accident that his decision-making in this respect was deficient and he needed to exercise “greater care” when flying his converted Malibu (retrofitted with a Pratt & Whitney Canada PT6A-34 turboprop engine) in and around “adverse weather systems.”