History of Flight
On October 7, 2017, about 1345 eastern daylight time, a Piper PA-25-235 airplane, registration N90866, was destroyed when it impacted terrain during initial climb after takeoff from runway 28 at Front Royal-Warren County Airport (FRR) in Front Royal, Virginia. The airline transport pilot was fatally injured. The airplane was owned and operated by the Skyline Soaring Club under 14 CFR Part 91. Visual meteorological conditions prevailed, and no flight plan was filed for the local glider tow flight.
The glider flight instructor reported that the takeoff was normal. He looked away to adjust a video camera, and when he looked back, the tow plane was below and to the right of the glider. The tow rope had slack. He released the tow rope, turned the glider 180°, and landed uneventfully. While approaching the runway, he saw a fireball from where the tow plane had been descending. Witnesses reported the tow plane pitched down, descended below the glider, and turned right before impact.
Personnel Information
The tow plane pilot, age 76, held an airline transport pilot certificate and a commercial pilot certificate with multiengine and single-engine land ratings, respectively. He also held a flight instructor certificate. His most recent FAA second-class medical certificate was issued October 1, 2015, at which time he reported 11,953 total flight hours. His logbook was not recovered.
The glider flight instructor held a commercial pilot certificate with ratings for airplane single-engine land, sea, multiengine, instrument airplane, and glider, and a flight instructor certificate with a glider rating. His most recent second-class medical was issued March 30, 2017, and he reported 1,580.2 total hours, including 107.7 hours in gliders.
Aircraft Information
The single-seat, low-wing, fixed-tailwheel airplane was manufactured in 1981. It was powered by a Lycoming O-540, 235-horsepower engine and equipped with a Hoffman four-blade, fixed-pitch wooden propeller. The most recent annual inspection was completed February 2, 2017, at which time the airframe had about 8,265 total hours and the engine 468 hours since overhaul.
Meteorological Information
Recorded weather at FRR at 1355 included wind from 230° at 10 knots, gusting to 15 knots; visibility 10 statute miles; clear sky; temperature 29°C; dew point 14°C; altimeter 30.01 inches of mercury.
Wreckage and Impact Information
The wreckage was consumed by a postcrash fire and located in a residential backyard about 1,600 ft northwest of the departure end of runway 28. A small crater consistent with engine contact was observed, with propeller fragments nearby. The main wreckage came to rest upright about 65 ft north of the crater. The tow rope was along the debris path. The left main landing gear had separated; the right main and tailwheel remained attached. All major components were accounted for.
Control cable continuity was confirmed from ailerons, elevator, and rudder to the cockpit. No readable instruments were recovered. The engine had separated and was resting forward. All four wooden propeller blades had separated from the hub; two blade roots remained attached. Engine continuity was confirmed, and thumb compression was attained on all cylinders. The engine-driven fuel pump screws were finger tight; internal components showed disintegration consistent with thermal damage. The carburetor floats were melted; the fuel inlet screen had some debris. Oil filter showed no contamination. Both magnetos had thermal damage and did not produce spark. Oil suction screen was clean.
About 145 ft of tow rope was recovered; 5 ft at the Tost reel and 10 ft aft of the tow plane were presumed consumed by fire. The glider end of the tow rope appeared separated; the Tost weak link ring assembly was not located. No guillotine marks were noted on the tow rope.
The pilot's seat had a four-point inertial reel harness system with impact and fire damage. The lock control was in the full-aft position and would not move. The cable was fully retracted and separated at the 90° pulley wheel. No evidence of preimpact malfunctions was found.
Additional Information
According to the FAA Glider Flying Handbook, a dangerous occurrence during aerotow is when the glider flies above and loses sight of the towplane, causing the towplane's tail to be pulled up and its nose lowered. The glider pilot should release immediately upon losing sight of the towplane.
Medical and Pathological Information
An autopsy of the tow pilot determined the cause of death as blunt force trauma to the neck, torso, and extremities, thermal injuries, and blunt force trauma. The pilot's heart weighed 560 grams (average for a 190-lb man is 367 grams). He had mild-to-moderate atherosclerosis: 50% stenosis in the proximal and 75% in the distal right coronary artery, and 50% in the left anterior descending coronary artery. No evidence of heart attack was noted.
Toxicological testing detected atorvastatin in blood and liver, a non-impairing cholesterol-lowering drug.
At his last medical examination in October 2015, the pilot reported hypertension, high cholesterol, and coronary artery disease (diagnosed by catheterization in 2004 as nonocclusive and mild to moderate). His personal records indicated annual cardiac calcium scoring, and a 2015 thalium stress test showed transient ischemic dilation.
Tests and Research
The glider flight instructor recorded two videos. The first ended with the glider at about 890 ft msl (200 ft agl) and airspeed 60 knots in a high-tow position. A second video began about 5 seconds later, showing the tow plane not visible. After 5 seconds, the glider's spoiler handle was nearly full aft, yaw string 45° right, altitude 940 ft msl, airspeed 70 knots. The tow plane's right wing came into view below and right. The glider yawed right, then the tow rope release handle moved aft. A snapping sound was heard, and the release handle extended about 6 inches. In the last frame with the tow plane, its elevator appeared up. The glider turned left and returned. About 13 seconds elapsed between videos; the glider climbed 50 ft while the tow plane descended 63 ft relative to the glider.
Microscopic examination of the tow rope separation showed features of overstress, consistent with breaking while the glider was attached. A dark band with metallic sheen near the separation indicated the point was near the Tost weak link.