Accident Details
On an unspecified date, a twin-engine aircraft owned by Lawrence R. Liptack crashed in flames in an open field located northeast of Bowie, Texas. The pilot and owner, aged 51, and his son, aged 10, were killed in the accident.
Witness Account
A witness observed the airplane at approximately 500 feet above ground level (agl) while on a left base landing approach. The airplane suddenly pointed straight down, began spinning, and made three complete rotations before impacting terrain in a partially nose-down attitude. The aircraft came to rest upright and was mostly consumed by an immediate post-impact fire.
Examination Findings
A post-accident examination of the wreckage revealed no evidence of preimpact mechanical malfunctions or failures that would have precluded normal operation. Data from an on-board GPS unit indicated that, while on the base leg of the airport traffic pattern for landing, the accident airplane's airspeed decayed 10 knots below the manufacturer's recommended approach speed for turbulent conditions.
Weather Conditions
A pilot operating another pipeline patrol airplane in the vicinity reported frequent severe-to-extreme turbulence about 1,000 to 2,000 feet above ground level.
Medical Findings
An autopsy performed on the pilot found significant existing atherosclerotic disease (60 to 80 percent) and described evidence of an acute, premortem, nonocclusive thrombosis of the left anterior descending coronary artery. The medical examiner's conclusion stated that it "appears the decedent likely suffered an acute cardiac event while piloting his aircraft" and that he "died primarily due to hypertensive and atherosclerotic cardiovascular disease and that his multiple blunt force injuries likely contributed to his death." It is likely that the pilot was incapacitated due to the acute cardiac event and lost control of the airplane during the approach to land.