Flight History
On 8 August 2007, the pilot of Piper PA-24-260 Comanche G-ATIA departed from Leicester Airport for a private flight. Three days earlier, the pilot had found the battery discharged and had it replaced. On the day of the accident, the engine started normally and the ammeter indicated charging. After departure from Runway 33, the pilot noticed the low voltage warning light illuminated and decided to return for a precautionary landing. While on short final, he observed a tractor and trailer combination near the runway threshold, reduced his rate of descent to clear the vehicles, and landed further along the runway than intended. The aircraft bounced twice on touchdown, prompting a go-around.
During the climb, the pilot heard an "odd pop" from the engine and made a PAN call reporting rough engine operation. The engine then became very rough, and the pilot announced he would land in the middle of the aerodrome, acknowledging it would be downwind. He began descending early. A witness in a helicopter estimated the aircraft turned left onto an easterly heading at about 100 ft above ground level. Another witness, an instructor in another aircraft, judged the turn occurred at about 200 ft. The aircraft appeared to approach to land on Runway 10 but was too high and fast. At a point south of the Runway 28 threshold, descending to within 50 ft, the pilot attempted to turn onto a right base leg for Runway 33. The aircraft climbed very slowly, then adopted a nose-down attitude and rolled to the right. The pilot reported the engine had ceased to produce power. He applied nose-up elevator, resulting in a nose-up attitude but no decrease in descent rate. The aircraft impacted the ground heavily, and a fire broke out in the engine bay.
The pilot suffered facial injuries from striking the control yoke and back pain. He vacated the aircraft without assistance and did not shut off fuel or electrical power. A helicopter landed nearby and its occupants assisted; one used a fire extinguisher on the engine fire. The aerodrome fire and rescue service arrived and extinguished the fire. The pilot was taken to hospital.
Pilot and Aircraft Information
The pilot, aged 74, held a Private Pilot's Licence and had 1,222 total flying hours, with 200 hours on type. His recent flying included 37 hours in the last 90 days and 4 hours in the last 28 days.
The aircraft, registration G-ATIA, was a 1964 Piper PA-24-260 Comanche powered by a 260 hp Lycoming IO-540-D4A5 piston engine driving a three-bladed constant-speed Hartzell propeller. It featured retractable tricycle landing gear. At its last annual inspection on 4 May 2007, the airframe had 5,492 hours, the engine 81 hours, and the propeller 240 hours. The engine had been overhauled on 15 April 2006. During the last inspection, oil pipes and a fuel hose between the injector and fuel flow manifold were replaced.
Accident Site and Wreckage
The accident site was a wheat field approximately 600 metres south-east of Runway 10. Ground impact marks indicated a nose-first impact with a slight left bank. The aircraft bounced, travelled 30 metres, and came to rest upright, oriented at 187° magnetic. The initial impact track was about 245° magnetic. Significant fire damage affected the engine bay and engine, which was forced to the right and lying on its left side. A 10-metre scorch mark led from near the impact point to about 20 metres short of the wreckage. All three landing gear legs were extended and had separated during impact. The flaps were retracted. The majority of damage was forward of the firewall, with crushing and wrinkling to wing skins and under-fuselage skin. The three propeller blades showed leading edge gouges and chordwise scratches consistent with rotation at impact; blade tips were intact, with one blade bent forward at mid-span and two bent aft.
The fuel tank selector was set to the right main tank, and the electric fuel pump switch was on. Recovered fuel totalled 69 US gallons across all tanks. Samples tested consistent with 100LL AVGAS, with minor soil debris in some samples but otherwise free of contamination. Fuel was found in the line to the engine firewall but none forward of it due to fire.
Recorded Data
A GPS unit from the aircraft provided track log data recorded at 30-second intervals. The data showed the takeoff from Runway 33, a circuit, and an aborted approach to the same runway. After the aborted landing, the final two recorded data points placed the aircraft in a left turn. One point, just beyond Runway 33, showed height about 70 ft agl and groundspeed 47 kt. The next point, about 200 metres south-west of Runway 10 threshold, recorded track 136° and groundspeed 75 kt. The final data point, about 200 metres beyond Runway 10, indicated groundspeed 72 kt. Neither final point included altitude information.
Powerplant Examination
The engine was strip-examined at an approved overhaul facility. Internals were in good condition with no heat distress, all mechanical components moved freely and were lubricated. Cam lobes were satisfactory, and oil filter and inlet screen were debris-free. The oil scavenge pump rotated freely. All spark plugs were in good condition; plugs from left-side cylinders (2, 4, 6) were coated in oil, consistent with the aircraft lying on its left side after impact. The ignition lead to plug 5 was slightly loose; other connectors were tight.
Throttle and mixture control linkages had separated from the fuel injector, consistent with impact damage. The propeller speed control linkage remained connected. The fuel hose between the engine-driven fuel pump and fuel injector had separated from the injector (this hose was not among those replaced during the last inspection). The manifold valve showed signs indicative of sticking, but this could be due to post-impact heat. Injector nozzles were tested; all had flow rates within specification except nozzle No. 4, which had a slightly low flow rate. After cleaning oil from that nozzle, its flow rate was within specification, suggesting contamination from the engine's position after impact.