N525SGCapes Greg R MURPHY MOOSE · 2019

On August 14, 2019, about 1853 Pacific daylight time, an experimental, amateur-built Murphy Moose, N525SG, was destroyed when it was involved in an accident near Marysville, Washington and south of the Arlington Municipal Airport (AWO), Arlington, Washington. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

A witness at the pilot’s departure airport reported that the day before the accident, he saw the pilot conducting high-speed taxi tests on the runway and that it did not sound like the engine was running “well.” On the day of the accident, he saw the airplane take off and that it appeared normal but that he saw black smoke emitting from the engine exhaust.

Several witnesses in the vicinity of the accident site reported seeing the airplane flying at a low altitude and banking left before it descended nose down to the ground. One of these witnesses stated that the airplane appeared to be “out of control,” and another one of these witnesses reported that the airplane was descending “at a dangerous speed.”

Three witnesses reported hearing the engine “pop loudly then rev high,” “was loud and sounded like it was possibly overrevving,” and “missing or puttering.”

Two witnesses reported seeing another airplane near the accident airplane. One witness reported that the other airplane was slightly ahead of and above the accident airplane and that the airplanes were “unusually close.” The other witness reported that he saw the accident airplane banking left and it looked like it was going to cut off another airplane. The accident airplane then “plunged toward the ground.”

A review of Seattle terminal radar approach control data, GPS, and engine monitoring data revealed that the accident airplane departed from Frontier Airpark (WN53), Lake Stevens, Washington, to the north at full engine power before it turned left while north of AWO, then continued to the south. About 3 minutes into the flight, the engine rpm fluctuated between 2,260 and 2,900 rpm for 3 minutes before it returned to full power. Concurrently, another airplane, which could not be identified because both airplanes were visual flight rules and squawking “1200,” was approaching AWO from the south. When the accident airplane was southwest of AWO, it started turning north to final approach toward runway 34 while descending about 1,000 ft per minute (fpm) and still at full power. The unidentified airplane continued flying north toward runway 34. About 1.2 nautical miles south of the runway, the accident airplane was west and slightly north of the unidentified airplane. At their closest point, the two airplanes were within 0.22 mile of each other, and both airplanes were about 500 ft above ground level. The accident airplane’s engine remained at full power and the airplane’s descent rate had increased to 4,000 fpm 7 seconds before the recorded data ended. The unidentified airplane continued north, flew over runway 34, made a left teardrop turn over AWO, and then departed the area toward the south. (see Figure 1). AWO does not have an air traffic control tower, and the common traffic advisory frequency is not recorded.

Figure 1. Accident airplane and unidentified airplane flight path

According to the Federal Aviation Administration, the pilot’s medical certificate expired on December 31, 2015. No record was found indicating the pilot had applied for BasicMed. The pilot’s logbook indicated that as of the last entry dated December 29, 2014, he had a total of 375 hours of flight experience.

Throughout the entire logbook, there were no entries related to flying a Murphy Moose. The last recorded biannual flight review in the pilot’s logbook was dated July 9, 2014 and was conducted in a Beech 19 airplane.

The pilot had recently built the airplane, and it was issued a special airworthiness certificate on June 6, 2019. The pilot’s first flight in the airplane was on July 20, 2019. During that flight, the pilot flew from WN53 to AWO and refueled, and the airplane then experienced an unspecified electrical problem. The pilot flew the airplane back to WN53. During landing, the airplane touched down hard and exited the runway.

The airplane impacted a field about 1 mile south of runway 34 at AWO. The debris path was about 334 ft long, and it was oriented on a magnetic heading of about 348°. The first identified point of contact (FIPC) was an area of displaced dirt, consistent with impact of the left float. Followed by another area of disturbed dirt, consistent with impact of the right float. A large crater, which contained wooden propeller blade fragments, was located about 61 ft from the FIPC. Portions of the propeller, front float wheel assembly, the left and right wingtips, the engine airbox assembly, and portions of the engine cowling were found at different points farther along the debris path. The main wreckage came to rest inverted about 289 ft from the FIPC, and the left and right floats had come to rest 309 and 334 ft, respectively, from the FIPC.

Both the left and right wings remained partially attached to the fuselage and exhibited extensive damage throughout. The cabin area was fragmented and torn open. The empennage exhibited impact-related damage but remained attached to the fuselage. Flight control continuity was established throughout the airframe.

The fuel system was breached. A blue liquid consistent with 100LL fuel was observed in the fuel strainer bowl, and the screen was clear of debris. The engine remained attached to its mounts and firewall. All the accessories, except the carburetor, remained attached to the engine. The throttle cable was separated from the carburetor, consistent with impact damage. Engine control continuity was established. The propeller hub remained intact. The three propeller blades were separated/splintered near the blade root. The oil lines to the oil cooler exhibited impact damage, and oil was observed throughout the accident site and wreckage. Examination of the airframe and engine revealed no preaccident mechanical malfunctions or failures that would have precluded normal operation.