NTSB Factual Report

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 the provisions of Title 14 Code of Federal Regulations 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. The flight was originating at the time of the accident with an unknown destination.

In a written statement provided to the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), the pilot receiving instruction reported that he had recently purchased the accident airplane and had not flown it yet. The pilot stated that he contacted the flight instructor and had arranged for him to provide a familiarization flight in the accident airplane. Following an uneventful preflight inspection, the owner and the flight instructor boarded the airplane and taxied to taxiway Alpha 4 at runway 16R, and proceeded to conduct an engine run up. The pilot said that both magneto drops were within the normal range, the propeller operated normally, and no engine issues were noted. Upon receiving their clearance for takeoff on runway 16R at Alpha 4, the flight instructor taxied the airplane onto the runway and proceeded to initiate the takeoff.

The pilot reported that once the airplane was airborne, the flight instructor retracted the landing gear and the airplane began a slow climb; however, it seemed like the airplane had no power to climb. The pilot further stated he 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 added that he did not think the engine completely stopped until the airplane hit the ground; however, he felt that the engine did not have a strong powerful sound but he did not recall hearing it missing or coughing.

Information obtained from the Federal Aviation Administration (FAA) Air Traffic Control Tower (ATCT) revealed that the pilot was cleared for takeoff on runway 16R at the Alpha 4 intersection. Following an acknowledgement of the takeoff clearance, no further radio transmissions were heard from the pilot.

Review of airport security camera recordings revealed that three separate cameras captured various portions of the taxi and takeoff sequence. The recorded footage showed that the airplane taxied to runway 16R at the Alpha 4 taxiway intersection. A second camera captured the airplane during takeoff and the airplane appeared to have become airborne between the Alpha 6 and Alpha 7 taxiways, or about 2,400 feet from taxiway Alpha 4. A third camera captured the airplane descend in a shallow descent out of view of the camera beyond the departure end of the runway.

PERSONNEL INFORMATION

Pilot Receiving Instruction

The pilot, age 72, held a private pilot certificate with an airplane single-engine land, single-engine sea, and instrument airplane ratings. A third-class airman medical certificate was issued to the pilot on October 14, 2013, with no limitations stated. The pilot reported that he had accumulated 1,096 hours of total flight time, of which 1 hour was in the accident make and model airplane.

Flight Instructor

The flight instructor, age 80, held an airline transport pilot certificate with an airplane multi-engine land rating with commercial pilot privileges for airplane single-engine land and gliders. In addition, the flight instructor held a flight instructor certificate with airplane single-engine land, multi-engine land, and instrument airplane ratings. A third-class airman medical certificate was issued to the flight instructor on December 21, 2014, with the limitation stated "must wear lenses for distant, and have glasses for near vision, not valid for any class after 12/31/2015."

Review of the flight instructor's logbook revealed that as of the most recent entry dated June 7, 2015, he had accumulated 10,049.1 hours total flight time of which 5.4 hours were within the previous 30 days.

AIRCRAFT INFORMATION

The four-seat, low-wing, retractable-gear airplane, serial number (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 horse power. The airplane was also equipped with a Hartzell model HC A2V20 2-bladed constant speed propeller, S/N AK1346. The airplane was not equipped with shoulder restraints for any of the installed seats.

Review of the airframe and engine maintenance records revealed that a Bendix Fuel Injection system was installed on the engine on September 22, 1976 at an airframe total time of 3,210.0 hours per Supplemental Type Certificate SE 12 SW and SA 41 SW. The most recent annual inspection was completed on March 11, 2015, at an airframe total time / tachometer time of 4,745.69 hours and engine time since major overhaul of 540.69 hours. The previous annual was completed on August 13, 2013, at an airframe total time / tachometer time of 4,743.58 hours.

The most recent maintenance logbook entry regarding the engine fuel injection system was on March 22, 2006, at an airframe total time / tachometer time of 4,647.53 hours. The entry stated in part "…installed injector and injector line on the #5 cylinder, and tightened fittings. Installed fuel line from fuel servo to distribution spider."

Airport refueling records revealed that the airplane was refueled with 47.4 gallons of 100 low lead fuel on June 8, 2015.

METEOROLOGICAL INFORMATION

A review of recorded data from PAE automated surface observing station, revealed at 0853 conditions were wind from 280 degrees at 4 knots, visibility 10 statute miles, clear sky, temperature 15 degrees Celsius, dew point 10 degrees Celsius, and an altimeter setting of 29.98 inches of mercury.

AIRPORT INFORMATION

PAE is a tower controlled airport that operates under class Delta airspace. The airport is equipped with two runways, 16R/34L, which is 9,010 feet in length and 150-feet wide and 16L/34R, which is 3,004 feet in length and 75-feet wide. The reported field elevation for the airport is 607 feet. The distance from the Alpha 4 taxiway and the departure end threshold of runway 16R is about 5,200 feet.

WRECKAGE AND IMPACT INFORMATION

Examination of the accident site revealed that the airplane impacted an area of heavy vegetation about 1,921 feet south of the departure end of runway 16R. The airplane came to rest upright on a heading of about 230 degrees magnetic. The first identified point of contact with terrain was disturbed vegetation within a marshy area, which extended about 88 feet to the main wreckage, oriented on a heading of about 160-degrees magnetic.

Examination of the airframe revealed that the engine remained attached to the fuselage and was slightly displaced downward. All fuel and oil lines remained attached to their respective attach points.

The left wing remained attached to the fuselage via its mounts. The flap and aileron remained attached to their respective mounts. The left wing was bent downward about 5 feet inboard from the wing tip on the leading edge. 45-degree buckling extended from the leading edge to the trailing edge, about 44 inches inboard from the wing tip. The wing tip tank, aux, and main fuel tank caps remained intact and secure to the fuel tanks. The trailing edge of the left wing tip was punctured and the first responders sealed it with sealing putty. The left main fuel tank sump drain was separated from the bladder. The flap was in the up position.

The right wing remained attached to the fuselage via its mounts. The flap and aileron remained attached to their respective mounts. The right wingtip fuel tank was impact damaged and separated in half. The wing tip tank, aux, and main fuel tank caps remained intact and secure to the fuel tanks. Multiple leading edge impact marks were observed. The flap was in the up position.

The fuselage above the carry through structure exhibited vertically oriented buckling, and the fuselage on the right side exhibited horizontal buckle lines. The rear fuselage was buckled downward between fuselage stations 151 and 179. The remainder of the rear fuselage and empennage remained intact.

Flight control continuity was established from the cockpit controls to all primary flight control surfaces. Pitch control was able to be manipulated from the cockpit controls. The rudder pedals could not be moved due to floorboard impact damage. Both aileron and rudder control cables were found pinched by floorboard impact damage as they passed under the front carry through.

The landing gear was found in the "up" position. The landing gear actuator was in the retracted position and the cockpit landing gear handle was in the up position.

The cockpit was intact with the interior space not compromised. The left and right seats were equipped with lap belt restraints only. The left seatbelt was clasped, and the outboard side of the seatbelt was cut. The right side seatbelt was unclasped. No shoulder harnesses were installed. The left and right seats remained secure to their respective attach points.

The right corner of the glare shield at the windshield post was dented and pushed inward.

Examination of the Continental E225-8 engine, S/N 40044-D, revealed that all engine accessories remained attached to their respective mounts. Throttle, mixture, and propeller control continuity was established from the cockpit controls to the engine controls.

The top spark plugs were removed and the number 2 and 6 spark plugs exhibited very dark (black) deposits within the electrode area. The number 1, 3, 4, and 5 spark plugs exhibited gray colored deposits within the electrode area.

Examination of the fuel injector nozzles revealed that the number 1 and number 4 nozzles were found partially obstructed. All six fuel injector nozzles were disconnected from the cylinders in order to perform a fuel system functionality check. An alternate fuel source was attached to the right wing fuel inlet port. Electrical power was applied to the fuselage and the electrical boost pump was turned on. Fuel expelled at each fuel injector nozzle and was captured in a glass container with erratic levels noted. In addition, during the initial test, the fuel pressure/fuel flow was 13 psi. The number 1 cylinder fuel injector was swapped with number 2 injector and the number 2 was installed in the number 1 cylinder line. The fuel boost pump was turned on and the fuel flow gauge indicated 8 psi, with erratic levels of fuel captured within glass jars. See the Accident Site, Airframe, and Engine Examination Summary Report within the public docket for further details.

The engine was removed and subsequently shipped to Continental Motors Inc. for further examination.

MEDICAL AND PATHOLOGICAL INFORMATION

The Snohomish County Coroner conducted an autopsy on the flight instructor on June 11, 2015. The medical examiner determined that the cause of death was "blunt-force injuries of the head and chest."

The FAA's Civil Aeromedical Institute (CAMI) in Oklahoma City, Oklahoma, performed toxicology tests on the flight instructor. According to CAMI's report, carbon monoxide, cyanide, volatiles, and drugs were tested, and had positive results for: 39 (ug/ml, ug/g) Acetaminophen detected in Urine, Ibuprofen detected in Urine, Terazosin detected in Urine, Terazosin detected in Blood (Cavity), Warfarin detected in Blood (Cavity) and Warfarin detected in Urine.

TESTS AND RESEARCH

Further examination of the engine was conducted at Continental Motors Inc., Mobile, Alabama, on November 18, 2015. The examination revealed that the engine was received secure within its crate. The propeller and propeller governor were removed and a test propeller was installed to facilitate the engine run. The fuel servo inlet fuel screen was removed for inspection. The screen was found to be installed 180-degrees opposite of the manufacturer's installation instructions. This would allow for debris to flow throughout the system, unfiltered. About one-quarter to one-half of a teaspoon of dark colored debris was removed from the fuel screen and fuel screen housing. In addition, corrosion was observed within the fuel screen and the fuel screen housing cap. The engine was placed on an engine test cell.

During the first 5 engine run attempts, it was noted that the engine was not firing on all cylinders, and would not produce RPM over 1,500. Despite replacing the top spark plugs, changing magneto to engine timing (from 31 to 27 degrees), and switching the fuel flow divider, the engine continued to run on partial cylinders. The fuel servo unit was removed and a carburetor was subsequently installed. The engine was started and ran successfully at various power settings (maximum of 2,550 rpm) for about 23 minutes prior to being shut off utilizing the engine test cell fuel shut off.

The fuel system, which includes the fuel flow divider, fuel servo, and fuel nozzles were removed and retained for further examination at Precision Air Motive.

Examination of the fuel system was conducted on January 4, 2016, at the facilities of Precision Air Motive, Arlington, Washington. The fuel servo was disassembled and examined. A significant amount of debris was noted in two of the fuel diaphragm housings, and on the diaphragm assemblies, one of which regulates fuel to the fuel injectors. The mixture control valve and idle valve exhibited evidence of corrosion. The idle valve was found seized within its respective galley. Upon removal, corrosion was observed within the galley. All debris found appeared to be either a pliable gray material, similar to a paste, or a brittle white material, similar to aluminum oxide corrosion.

The debris observed within the fuel servo was removed and subsequently sent to the NTSB Materials Laboratory for further examination. The submitted debris from the fuel servo was visually examined and selected particulates were analyzed using a hand held X-ray Fluorescence Spectrometer (XRF). Visually, the debris was composed of two optically different particle types. The debris was predominately larger grey white particles mixed with lesser amounts of smaller dark brown particles.

XRF spectra of several different areas of the grey white particles indicated compositions consistent with aluminum alloys. The white appearance and crumbling nature of the particles was indicative of heavily oxidized aluminum. Spectra of the dark brown particles were consistent with low alloy steels. The appearance and dark color was indicative of heavy oxidization of the particles.

The source of the debris within the fuel servo was not determined.

ADDITIONAL INFORMATION

The airplane was equipped with a JPI EDM 700 engine monitoring unit. The data downloaded from the unit revealed that on the accident flight, the recorded data spanned about 19 minutes. The data showed a rise in exhaust gas temperatures (EGT) and cylinder head temperatures (CHT) for all cylinders followed by two separate decreases in the EGT recordings, consistent with an engine run up. The data further depicted that the EGT values began to be erratic about 13 minutes following the start of the recorded data. The cylinder 5 EGT value showed a decrease from about 1,400 degrees F to about 400 degrees F over the course of about 1 minute prior to increasing back to about 1,400 degrees F and a decrease in CHT from 360 degrees F to about 270 degrees F. For further information, see the JPI Engine Monitoring Unit data plot within the public docket for this accident.

NTSB Probable Cause

The partial loss of engine power during takeoff due to debris within the fuel servo, which restricted fuel flow throughout the engine fuel system and resulted in a partial loss of engine power.