History of the Flight
On 14 April 2008 at 17:44 local time, a Piper PA-28R-200 aircraft, registration EC-FHZ, departed from Cuatro Vientos Airport for a local two-hour training flight. Onboard were an instructor and two students, one of whom was in the left-hand seat. The flight plan listed only two occupants. According to the pilot in command, the fuel tanks were full and a pre-flight check was conducted.
The flight proceeded toward El Tiemblo (Avila) then onward to El Escorial (Madrid). During this leg, the crew noted a sudden increase in engine speed and a drop in propeller pitch. The instructor took control and attempted to keep the engine running, but it eventually stopped. Occupants reported a burnt smell in the cabin.
Unable to restart the engine, the instructor performed the engine failure procedure and prepared for an emergency landing. The rough terrain offered no suitable field, so at low altitude he aimed for a tree-covered hillside. The aircraft struck the top of a large pine tree and fell to the ground around 18:20. All three occupants were seriously injured.
Emergency services were notified; the aircraft was located at 20:05. The occupants were taken to hospitals in the Madrid area.
Damage to Aircraft
The aircraft structure was seriously damaged by the initial impact with the tree and then with the terrain. The wreckage did not scatter; the right horizontal stabilizer was damaged, part of the right wing’s lower surface was missing, and the wing roots had broken.
Personnel Information
The instructor (pilot in command) held a valid ATPL(A) and PPL(A) with appropriate ratings, and a valid Class 1 medical certificate. He had about 25,000 total flight hours, with over 4,000 hours on type.
The pilot in the left-hand seat had an expired Private Pilot License (PPL(A)) and expired Class 1 medical certificate; he was receiving training to renew his Single Engine Piston rating on his first instructional flight.
Aircraft Information
The aircraft was a 1971 Piper PA-28R-200 (serial 28R-7135127) with 7,758 total hours. It was owned and operated by Centro Tecnológico Are, S.L. The airworthiness certificate was valid until 7 June 2008. The Lycoming IO-360-C1C engine (serial L-7850-51A) had 7,733 total hours; its last 100-hour inspection was on 23 August 2007 at 7,694 hours.
Communications
ATC did not record any radio emergency from the aircraft. The instructor stated he used frequencies 121.5 MHz, 118.7 MHz, and 131.97 MHz. The Air Traffic Service Reporting Office (ARO) informed ATC after receiving a phone call from the instructor.
Wreckage and Impact Information
After the engine stopped, the pilot attempted but failed to restart it. He made two or three 360° turns searching for a landing area before heading toward a hillside with large trees. The aircraft “landed” on a treetop about 15 m high, absorbing most kinetic energy, then fell to the ground on a stream bank. The on-site inspection noted: propeller impacted at zero rpm, broken propeller pitch control, starting gear engaged, gascolator without internal filter, clean oil and filter, no air intake obstructions, ignition system working, and a broken crankshaft discovered when disassembling the no. 2 cylinder. The ELT battery had expired (May 2001) and was not armed.
Survival Aspects
The cockpit did not crush, and safety harnesses functioned as designed. All occupants suffered severe trauma, but the treetop impact had a positive effect on survival. Search and rescue efforts were hampered by a wide search area and wooded terrain; the pilot called 112 and the ARO office. The aircraft was located at 20:05 via telephone and visual contact with a helicopter. The lack of an ELT signal further complicated location.
Engine Inspection and Metallurgical Analysis
The engine was examined in a workshop. Findings included: a broken crankshaft between the central support and the aft part of the no. 2 cylinder crankpin; a circular crack between the front support and front part of the no. 1 crankpin; fretting on central crankcase supports; orange coating on through-studs (like plastic sealant); similar layer at the base of the no. 3 cylinder; improper lubricant residue; worn half bearings from overloading; crankshaft central support showing pile-up; and a different piston in the no. 3 cylinder (not from the overhaul).
Metallurgical analysis showed the crankshaft fractured from simultaneous fatigue in two areas, with multiple developing fatigue cracks. High loading was evidenced by deformations in the central support and half bearings, including erosion, fretting, and edging. Fatigue cracks appeared in both half casings.
Overhaul Documentation Issues
The engine had 1,687 hours since its last overhaul at the operator/owner’s maintenance center. The run-in deficiency log noted oil loss at the no. 3 cylinder base, corrected by re-tightening bolts. Post-accident inspection revealed abundant sealing material at that location. Additionally, the structural inspection of critical components used liquid penetrant testing per Lycoming’s manual, but there were date inconsistencies in overhaul reports.