History of Flight
On June 10, 2015, about 0909 Pacific daylight time, a Beech F35, N4224B, was substantially damaged during a forced landing following a loss of engine power during takeoff initial climb from the Snohomish County Airport (PAE), Everett, Washington. The airplane was registered to and operated by the pilot under 14 CFR Part 91. The private pilot receiving instruction sustained serious injuries and the flight instructor was fatally injured. Visual meteorological conditions prevailed, and no flight plan was filed for the personal flight, which was originating at the time of the accident with an unknown destination.
The pilot receiving instruction reported that he had recently purchased the accident airplane and had not flown it yet. He contacted the flight instructor for a familiarization flight. After an uneventful preflight inspection, they boarded and taxied to taxiway Alpha 4 at runway 16R for an engine run-up. Magnetos drops were normal, the propeller operated normally, and no engine issues were noted. Cleared for takeoff, the flight instructor taxied onto the runway and initiated the takeoff.
Once airborne, the flight instructor retracted the landing gear, and the airplane began a slow climb, but it seemed to have no power to climb. The pilot saw the flight instructor managing the fuel and verifying the throttle position as the airplane began to descend. Subsequently, the airplane impacted a grassy wetland area on the departure end of runway 16R. The pilot stated he did not think the engine completely stopped until impact, but it lacked a strong powerful sound.
FAA Air Traffic Control Tower records showed the pilot was cleared for takeoff at the Alpha 4 intersection, and no further radio transmissions were heard. Airport security camera footage captured the taxi and takeoff; the airplane became airborne between Alpha 6 and Alpha 7 taxiways (about 2,400 feet from Alpha 4), then descended out of view beyond the departure end of the runway.
Personnel Information
Pilot Receiving Instruction
A 72-year-old private pilot with an airplane single-engine land, single-engine sea, and instrument airplane ratings. He held a third-class medical certificate issued October 14, 2013, with no limitations. He reported 1,096 hours total flight time, of which 1 hour was in the accident make and model.
Flight Instructor
An 80-year-old airline transport pilot with commercial and flight instructor certificates. He held a third-class medical certificate issued December 21, 2014, with the limitation "must wear lenses for distant, and have glasses for near vision, not valid for any class after 12/31/2015." His logbook showed 10,049.1 hours total flight time as of June 7, 2015, with 5.4 hours in the previous 30 days.
Aircraft Information
The four-seat, low-wing, retractable-gear airplane (S/N D-4191) was manufactured in 1955. It was powered by a Continental Motors E-225-8 engine (S/N 40044-D) rated at 225 horsepower, equipped with a Hartzell model HC A2V20 2-bladed constant speed propeller (S/N AK1346). No shoulder restraints were installed for any seats.
Maintenance records showed a Bendix Fuel Injection system was installed on September 22, 1976 (airframe total time 3,210.0 hours). The most recent annual inspection was completed March 11, 2015 (airframe time 4,745.69 hours; engine time since major overhaul 540.69 hours). The previous annual was August 13, 2013 (airframe time 4,743.58 hours). The most recent maintenance on the fuel injection system was March 22, 2006, installing an injector and line on the #5 cylinder.
Airport refueling records showed the airplane was refueled with 47.4 gallons of 100 low lead fuel on June 8, 2015.
Meteorological Information
Recorded data from PAE automated surface observing station at 0853: wind from 280 degrees at 4 knots, visibility 10 statute miles, clear sky, temperature 15 degrees Celsius, dew point 10 degrees Celsius, altimeter 29.98 inches of mercury.
Wreckage and Impact Information
The airplane impacted heavy vegetation about 1,921 feet south of the departure end of runway 16R, coming to rest upright on a heading of about 230 degrees magnetic. The first point of contact was disturbed vegetation in a marshy area, extending about 88 feet to the main wreckage on a heading of about 160 degrees.
The engine remained attached to the fuselage, slightly displaced downward. All fuel and oil lines remained attached. The left wing was bent downward about 5 feet inboard from the wing tip on the leading edge, with 45-degree buckling extending from leading to trailing edge. The right wingtip fuel tank was impact damaged and separated in half. The fuselage exhibited buckling. Flight control continuity was established to all primary surfaces; rudder pedals could not be moved due to floorboard impact damage. The landing gear was in the up position; the cockpit gear handle was up.
The cockpit was intact, with left and right seats equipped only with lap belt restraints. The left seatbelt was clasped and cut on the outboard side; the right seatbelt was unclasped. No shoulder harnesses were installed.
Examination of the engine revealed all accessories attached. Spark plugs: #2 and #6 had black deposits; #1, 3, 4, 5 had gray deposits. Fuel injector nozzles #1 and #4 were partially obstructed. A fuel system functionality check using an alternate fuel source showed erratic fuel expulsion and fuel pressure/flow of 13 psi initially, then 8 psi after swapping injectors.
Additional Information
A JPI EDM 700 engine monitoring unit recorded data spanning about 19 minutes of the accident flight. Data showed a rise in exhaust gas temperatures (EGT) and cylinder head temperatures (CHT) for all cylinders, followed by two decreases consistent with an engine run-up. About 13 minutes after data start, EGT values became erratic. Cylinder #5 EGT decreased from about 1,400°F to about 400°F over 1 minute, then increased back to 1,400°F, while CHT decreased from 360°F to 270°F.
Medical and Pathological Information
An autopsy on the flight instructor conducted June 11, 2015, determined the cause of death as "blunt-force injuries of the head and chest." Toxicological testing by CAMI detected Acetaminophen, Ibuprofen, Terazosin, and Warfarin in urine and/or blood.
Tests and Research
Engine examination at Continental Motors Inc. on November 18, 2015, revealed the fuel servo inlet fuel screen was installed 180 degrees opposite to manufacturer's instructions, allowing debris to flow unfiltered. About one-quarter to one-half teaspoon of dark colored debris was found in the screen and housing. Corrosion was present. During test cell runs, the engine would not fire on all cylinders and could not exceed 1,500 RPM. After replacing spark plugs, adjusting magneto timing, and switching the fuel flow divider, the engine still ran on partial cylinders. The fuel servo was removed and a carburetor installed; the engine then ran successfully at various power settings for about 23 minutes.
Further examination of the fuel system at Precision Air Motive on January 4, 2016, found significant debris in two fuel diaphragm housings and on diaphragm assemblies. The mixture control valve and idle valve exhibited corrosion; the idle valve was seized. Debris appeared as pliable gray material (similar to paste) or brittle white material (similar to aluminum oxide corrosion). Analyzed by the NTSB Materials Laboratory, grey white particles were aluminum alloys (heavily oxidized), and dark brown particles were low alloy steels (heavily oxidized). The source of the debris was not determined.