NTSB Factual Report

On August 23, 2014, about 1210 eastern daylight time, a Piper PA-28-180, N9095J, registered to and operated by Old Cherokee LLC, was substantially damaged during a forced landing at Montgomery County Airpark (GAI), Gaithersburg, Maryland. The commercial-rated pilot, the sole occupant sustained serious injuries, and the airplane was being operated under the provisions of 14 Code of Federal Regulations (CFR) Part 91 as a personal flight. Visual meteorological conditions prevailed at the time and an instrument flight rules flight plan was filed for the flight to Essex County Airport, Caldwell, New Jersey. The flight was originating at the time of the accident.

The pilot stated that in preparation of the flight he performed a preflight inspection of the airplane using a laminated Piper checklist which he followed step by step. He then had the left fuel tank fueled, which he watched. About 20 to 25 minutes after fueling he checked both fuel tank sump drains and the fuel strainer for contaminants; none were found.

He started the engine, obtained his IFR clearance, and taxied to the run-up area of runway 14. While there with full fuel tanks, he performed systems checks (run-up) using the laminated checklist, and noted everything was normal. He reported the magneto drops were normal with one drop slightly greater than the other with the difference being within the normal range. He obtained his IFR departure clearance, taxied onto the runway and being aware of the new engine, he applied partial power then released the brakes. He then added full power, and with the fuel selector positioned to the right tank believed the tachometer indicated 2,475 to 2,500 rpm. He reported that the airplane accelerated normally and noted that all instruments were in the green and indicating normal. He allowed the airplane to fly off the runway but could not recall the point along the length, but did state that the takeoff roll seemed normal. After becoming airborne he accelerated to and was climbing at Vy speed, and when the flight was about 100 feet above ground level, the engine surged only once. He stated that he was asked by the FAA inspector if he felt or heard the surge and he reported telling the FAA inspector that he heard the surge. He equated the surge to be similar as if the fuel to air ratio was leaned before shutdown.

He leveled off, where the engine operated normally and the engine did not surge again. He also stated that when he leveled the nose "everything [was] as it should be." He was asked if the surging evidenced itself on the tachometer and he reported he was not sure because he was looking outside. He allowed the airplane to accelerate, "to good forward speed." He stated that at the point where the surge occurred there was insufficient runway remaining to land, and he was cognizant of needing to land if the engine quit. He allowed the speed to build and he relaxed the forward pressure on the control yoke allowing the airplane to climb. During a climb about 100 feet more, the engine "failed" or quit suddenly. At that point with trees, houses, and a road ahead he decided that an on-airport landing would be best. He reported trouble shooting procedures consisted of switching tanks, but this did not restore engine power. Following the loss of power he called on the radio to announce the engine failure and turned left towards an area north of the runway. At some point he turned off the fuel selector, but when asked if the propeller stopped he said he did not believe it did. He bled off airspeed, and recalled the airplane impacted the ground with the left wing first followed by the left main landing gear, and responded that he believed he was in controlled flight when the airplane impacted and he had not stalled the airplane. He did not believe he lost consciousness, and was assisted from the airplane.

Two witnesses were interviewed by a NTSB National Resource Specialist (Aviation Systems Engineer) at GAI several hours after the accident. One witness who was located at a hangar at the departure end of runway 14 and is a pilot and airframe and powerplant mechanic reported hearing the engine hesitate, then pick up again. The witness reported the engine sputtered again, and then quit. He reported the airplane banked to the left impacting the ground left wing low. The other witness who was in an airplane reported the accident airplane flew over him at 100 feet. He then heard the engine go to idle. The witness noticed the left wing drop and the airplane descended in a steep constant spiral to the ground. The witness secured the airplane he was in and ran to the accident site to render assistance.

According to the NTSB National Resource Specialist (Aviation Systems Engineer) who inspected the wreckage and the accident site, he reported that the airplane was heading 220 degrees magnetic, or roughly perpendicular toward runway 14. The wreckage location was to the left of the departure end of the runway, in an area bounded by the final taxiways and run-up area. The left wingtip was found nearest the runway, 63 feet to the front of the resting position of the engine. The wingtip was 23 feet from the heavy ground scar of fuselage width and clear plastic window material was near this ground scar. The magnetic heading from the wingtip to the front of the engine was 100 degrees.

Inspection of the wreckage revealed the main landing gear had remained attached to each wing and the nose landing gear was separated, laying between the airplane nose and heavy ground scar. The tip of the right wing was oriented upward; the wing remained attached to the fuselage. The left wing was only connected by control cables and found inverted. Witnesses reported moving the wing to help extricate the pilot. The baggage door was open with one or two large black fabric suitcases visible inside.

Substantial fuel was found in both wing fuel tanks and a heavy smell of fuel was in the area. From pilot's perspective, the propeller was found in orientation of 2 to 8 o'clock. The leading edges of the propeller blades were not damaged, and one blade was bent back beneath the engine cylinders. Impact damage was noted in the area where the gascolator was installed; inspection of it revealed the metal bowl and fuel drain were found loose and contained a small amount of dirt and paint chips.

Inspection of the cockpit revealed the fuel selector was found at the 9 o'clock position of left fuel tank. Witnesses related having turned off any switches appearing to be in the ON position and the initial inspection was that all switches were in the OFF position. Both cockpit yokes were bent downward. The flap handle was in the UP position. A statement from the NTSB National Resource Specialist (Aviation Systems Engineer) is contained in the NTSB public docket.

A mechanic who helped recover the airplane reported that approximately 26.5 gallons of fuel were drained. The right wing was 3/4 full and the left wing which was nearly inverted and sheared off had 10 gallons; the left wing remained connected by one flight control cable. No fuel contamination was noted in the drained fuel. The ELT had activated, and the boost pump which was still operating was turned off. The battery was physically disconnected because the master switch was impact damaged. The stall warning light bulb was sent to the NTSB investigator-in-charge for inspection, which revealed no stretching of the bulb filament.

Inspection of the airplane and engine by a representative of the engine manufacturer was performed with oversight by either a Federal Aviation Administration (FAA) inspector or a mechanic with Inspection Authorization (IA) who had never maintained the airplane. At the start of the inspection, the wings had been previously removed. With respect to the cockpit, the as-found positions were:

Carburetor Heat-Off

Throttle-Full Forward

Mixture Control-Idle Cut-off

Fuel Selector-Off

Tachometer- 3003.74

Further inspection of the cockpit revealed the pilot's shoulder harness was still attached to the left side of the lapbelt. The pilot's seat was broken loose, and the pilot's floor boards were displaced up. Additionally, an Insight G2 Graphic Engine monitor was installed and a 2 GB SD card was noted in the slot for the device. The SD card was later removed by a NTSB investigator and provided to the NTSB Vehicle Recorder Laboratory for read-out.

Inspection of the engine revealed the throttle, mixture, and carburetor heat controls were connected in the engine compartment. The positions of the carburetor heat control on the airbox, throttle and mixture control levers of the carburetor matched the as-found positions in the cockpit. Visual inspection of the crankshaft revealed it was slightly bent and cracked about half the diameter at the nose seal, which precluded an engine run. Crankshaft, camshaft, and valve train continuity was confirmed during hand rotation of the propeller. Thumb suction and compression was noted in each cylinder and valve train continuity was noted for the intake and exhaust valves of all cylinders. Continuity was noted to the magnetos drive gears, and during hand rotation of the propeller, both magnetos operated. Because the starter ring gear was broken, the magneto to engine timing could not be conclusively determined; however, the magnetos were timed between 25 and 30 degrees BTDC (specification is 25 degrees BTDC). No obstructions of the air induction system were noted; the bracket air filter appeared to be freshly oiled. Inspection of the engine-driven fuel pump revealed it operated satisfactory when operated by hand; no defects were noted. Residual fuel was noted inside the pump and in the inlet and outlet flexible fuel lines to the engine-driven fuel pump. The fuel was consistent with 100 low lead. The AVSTAR carburetor was removed and inspection of the inlet screen revealed it was clean. The carburetor was disassembled and there were approximately 5 ounces of fuel in the carburetor bowl; the metal floats were not crushed. The fuel in the carburetor bowl was tested using water finding paste and no water was detected. The float height was not measured. The accelerator pump checked good when the throttle lever was actuated, and the needle valve and seat checked good during hand movement of the float. The carburetor was retained for further inspection at the manufacturer's facility.

The magnetos were removed, spun by a mechanical device and noted to spark at all ignition leads. The spark plugs were checked for gap, wear, and color using the Champion Aviation Check-A-Plug chart and all were normal. There were no indications of rich or lean condition. Each P-Lead were tightly installed; no issues were identified with either P-Lead. The ignition key was not found therefore a check of ignition switch could not be performed at the time of the engine examination.

Inspection of the gascolator revealed the bowl was broken and the screen was clean. The housing was broken at the inlet to the strainer. From the firewall forward to the carburetor inlet there was no blockage of any fuel supply lines noted.

The fuel selector was in the off detent when first viewed. Impact damage to the surrounding area precluded full rotation of the fuel selector handle. Detents were felt at the fuel selector for the left and right positions. With a mechanic present and the fuel selector placed to the left tank detent, air was blown in the left tank supply line at the wing root and no obstructions were noted to the fuel strainer; no air was felt at the right fuselage root. The fuel selector was then positioned to the right tank position and air was blown in the right fuel supply line at the wing root and no obstructions were noted to the fuel strainer; no air was felt at the left fuselage root. The fuel selector was then placed in the off position, and air was blown in the left and right fuel supply lines at each wing root, no air was noted at the fuel strainer. The detents were audible and could be felt. The fuel supply and vent lines in both wing fuel tanks were free of obstructions.

Inspection of the two-bladed fixed pitch propeller revealed one blade was bent aft approximately 20 degrees beginning about 8 inches from the hub, and exhibited chordwise scratches on the cambered side of the blade, while the other blade was not damaged, and did not exhibit any scratches.

Inspection of the maintenance records revealed the engine was factory overhauled and was shipped in November 2013. It was installed in the accident airplane in March 2014. At the time of the accident, the engine had accrued approximately 30 hours since factory overhaul.

Data downloaded from the Insight G2 Graphic Engine monitor revealed the accident flight was recorded. A review of the data revealed that data for the following parameters were recorded: carburetor temperature (degrees Fahrenheit), buss voltage, cylinder head temperature (CHT) and exhaust gas temperature (EGT) for all cylinders (degrees Fahrenheit), outside air temperature (degrees Fahrenheit), and fuel flow. The data downloaded from the unit indicated that with respect to fuel flow, it showed a rapid decrease from about 10 gallons-per-hour (GPH) to 4 GPH, with a corresponding decrease in exhaust gas temperature (EGT) readings for all cylinders. The fuel flow then sharply increased to about 6 GPH, with corresponding increase in EGT readings from all cylinders. The fuel flow again then sharply decreased to about 4 GPH, with a corresponding decrease in EGT readings from all cylinders.

According to the airplane type certificate data sheet (TCDS), the maximum permissible takeoff rpm is 2,475, and for all other operations the maximum permissible rpm is 2,700.

Inspection of the carburetor at the manufacturer's facility revealed the float height was slightly less than specified during physical inspection; however, the float height was determined to be within limits during bench testing. The unit was placed on a test bench with airflow and found to pass all test points. The unit was disassembled after testing and the needle seat was found to slightly less than specification. A report of the carburetor testing is contained in the NTSB public docket.

According to a surface aviation observation report taken at GAI at 1215, or approximately 5 minutes after the accident, the temperature and dew point were recorded to be 20 and 18 degrees Celsius, or 68 and 64 degrees Fahrenheit, respectively.

A review of FAA Special Airworthiness Information Bulletin (SAIB) associated with carburetor ice prevention, indicates that based on the reported temperature and dew point readings taken 5 minutes after the accident, the conditions were favorable for serious icing at glide power. A copy of the FAA SAIB is contained in the NTSB public docket.

NTSB Probable Cause

The loss of engine power due to fuel starvation for reasons that could not be determined during postaccident examination of the fuel supply and fuel vent systems.