History of Flight
On February 20, 2012, at about 1936 central standard time, a Piper PA-24-250 single-engine airplane, registration N7147P, impacted terrain near Albany, Texas. The flight departed Abilene Regional Airport (ABI) at 1920, destined for the University of Oklahoma Westheimer Airport. Dark night visual meteorological conditions prevailed, and no flight plan was filed. The pilot reported a loss of suction and attitude indicator and requested to return to Abilene. Radar data showed the airplane climbing and then descending rapidly. The wreckage was located the following morning.
Pilot Information
The 48-year-old private pilot held a certificate for airplane single land, initially issued in 2007. His most recent third-class medical certificate, with limitations, was issued on May 10, 2010. The pilot logged 502 total flight hours, including 186 hours in the Piper PA-24 and 68 night hours. He had 3.6 hours of simulated instrument instruction, with no instrument flights logged after December 31, 2006.
Aircraft Information
The 1960 Piper PA-24-250, serial number 24-2312, was equipped with a 250-horsepower Lycoming O-540 engine. The vacuum pump, Airborne part number 211CC, was installed on January 21, 2000, and had accumulated an estimated 639 hours of operation since overhaul. Manufacturer service letters specified a mandatory replacement time of 500 hours or 6 years, which this pump exceeded.
Wreckage and Impact
The main wreckage impacted in a nearly vertical nose-down attitude on rocky terrain. The right wing outboard section, including the aileron, was found approximately one mile southeast of the main site. Impact signatures indicated a high-energy collision. The landing gear and flaps were retracted; the stabilator trim was set to about 3 degrees nose-up.
Tests and Research
Examination of the vacuum pump revealed thermal damage to the internal shear coupler, consistent with continued engine rotation after fracture. Fatigue features were present but not definitive due to damage. The attitude gyro exhibited circumferential scoring, indicating rotation at impact. No other preimpact mechanical failures were identified.
Meteorological Conditions
At 1852, ABI reported wind from 300 degrees at 12 knots, visibility 3 miles in haze and blowing dust. Sunset occurred at 1827, and the moon had set. A pilot in the area reported in-flight visibility of 1 to 3 miles and difficulty distinguishing ground from sky due to dust and darkness.