N964RSAvipro Aircraft BEARHAWK PATROL · 2020

On October 29, 2022, about 1452 eastern daylight time, an experimental amateur-built Bearhawk Patrol airplane, N964RS, was substantially damaged when it was involved in an accident near Hanover Township, Pennsylvania. The pilot and pilot-rated passenger were fatally injured. The airplane was operated by the pilot as a Title 14 Code of Federal Regulations Part 91 personal flight.

Witnesses reported that the pilot and pilot-rated passenger departed Farmers Pride Airport (9N7), Lebanon County, Pennsylvania, earlier in the day. They reported that the pilot was functioning well, happy, and looking forward to participating in a holiday airport event. The pilot and his pilot-rated passenger flew to the Hazleton Regional Airport (HZL), Hazleton, Pennsylvania, then on to the Wilkes-Barre Wyoming Valley Airport (WBW), Wilkes-Barre, Pennsylvania. At WBW, the pilot told a friend that the airplane had a rigging issue that seemed to cause the airplane to “kick” laterally during turns. He suggested that his friend fly the airplane to see what he thought. The friend performed a 10-minute flight and reported that he noticed the odd yawing moment in the turns. The pilot responded that he would address the issue “this winter.” After lunch and fueling the airplane, the pilot and pilot-rated passenger intended to return to 9N7. Witnesses reported that the pilot sat in the front seat and fastened his seatbelt and shoulder harness while in their presence.

Automatic dependent surveillance - broadcast (ADS-B) data revealed that the airplane departed runway 25 at WBW about 1448. After departure, the airplane turned slightly left, flew in a southwesterly direction, and climbed to an altitude of 1,700 ft mean sea level (msl). The recorded data indicated a 35-second level-off, followed by a descent to about 1,500 ft msl where the airplane’s altitude varied slightly over about two minutes. In the final seconds of the flight, data indicated a 400-ft descent in fewer than 2 seconds. At this same time, witnesses reported that the airplane “rolled” then “bucked” as its nose “dipped down initially,” then pitched up “quickly.” Several witnesses reported seeing the pilot out of the airplane at this time. One heard the pilot impact the airplane’s tail, and another observed the pilot impact, then “spiral” off, the airplane’s tail. The witnesses then observed the pilot and airplane descend to the ground.

The airplane was composed of a fabric-covered steel tubular fuselage and tail, and an aluminum strut-braced wing.

The airplane was composed of a fabric-covered steel tubular fuselage and tail, and an aluminum strut-braced wing.

The airplane impacted a grass field about 5.2 nautical miles southwest of WBW. A linear ground scar, consistent with the length of the left wing, extended from the center of the wreckage with the scar oriented toward a magnetic heading of 338°, and the wings came to rest oriented on a magnetic heading of 319°. All major airplane components were located on site; however, paint chips, the airworthiness certificate, and portions of the cockpit ceiling or side window Plexiglas were the first items along the 1,900-ft-long debris path leading to the main wreckage, followed by a portion of a tail rib at 900 ft and the pilot at 530 ft from the main wreckage (see figure 1.)

Figure 1 - Flight path (yellow line) with annotated position, time, altitude, ground speed, and path heading. The locations of recovered debris are also plotted.

Both wings were accordion-crushed aft and remained attached to the fuselage, which came to rest adjacent to the right wing. The airframe structure aft of the cockpit was intact to the tail area, where the forward attachments of both the vertical and horizontal stabilizers were fractured. The tail section was largely destroyed, except for the left horizontal stabilizer, to which its elevator and elevator trim tab remained attached. The engine was partially attached to the engine mounts and embedded in an impact crater.

The propeller hub remained attached to the crankshaft flange, and both propeller blades were impact separated from the propeller. A ground scar consistent with a propeller blade strike was found near the impact crater, where one blade was located. The other propeller blade was recovered about 100 ft from the main wreckage. Both blades

showed light rotational chordwise scratches from dirt, and minimal damage to the blade

leading edges. There was no evidence of fire on any portion of the airplane. There was

evidence of fuel blight in the field and a witness reported smelling fuel.

The engine was hoisted from the remaining engine mount, and the rocker box covers removed to facilitate examination. The crankshaft rotated when the propeller was rotated by hand, and continuity of the crankshaft to the camshaft was confirmed. Thumb compression was established on cylinder Nos. 1, 2, and 4, and on cylinder No. 3 after the impact-damaged exhaust valve pushrod was removed. Borescope inspection of all cylinders revealed no anomalies. The carburetor, with throttle and mixture control cables attached, was impact separated from the bottom of the sump housing and located next to the engine at the accident site. Liquid consistent with fuel was noted inside the carburetor bowl and in the fuel pump. Both magnetos displayed impact damage to the mounting flanges. The left magneto was not capable of producing spark due to the capacitor being impact separated from the unit. The unit was opened for further examination and the points opened and closed as expected when the shaft was rotated. The right magneto produced spark at all four leads when rotated with a drill. The oil filter element appeared clean. Examination of the engine revealed no pre-impact anomalies that would have prevented normal operation.

Examination of the airframe revealed that the wing spars remained attached to the fuselage structure and both wing fuel tanks were breached. All flight control cables and tubes were connected at their associated cockpit controls. Aileron continuity was established from the cockpit control stick to the aileron control surfaces. Left rudder continuity was established from the cockpit rudder pedals to the rudder control horn; however, right rudder continuity could only be established from the cockpit rudder pedals to the cable end loop, which was not attached to the clevis at the rudder control horn. The clevis was opened and hanging from the control horn, and the clevis pin was located nearby. Examination of the elevator trim cables revealed that both cables were continuous from their attachment points at the cockpit trim control lever, through broom-strawed fractures consistent with tensile overload above the rear pilot seat, to each control surface; however, the right elevator trim tab had separated from the elevator at the two hinged attachment points.

A detailed examination of the tail tube structure by the NTSB Materials Laboratory revealed that all fractures to the tail section displayed features that were consistent with overstress. A tube that formed the trailing edge of the vertical stabilizer fractured with aft bending overstress, and the carry-through tube for mounting the aft edge of the horizontal stabilizer to the fuselage fractured in downward bending overstress, both consistent with impact with the pilot during flight.

The pilot seats remained attached to their rails, and the seatbelts remained attached to their mounts. The rear pilot’s seat was equipped with the lap belt, which was cut to assist in the recovery of the pilot-rated passenger. The forward pilot’s seat was equipped with a lap belt and shoulder harnesses, which were intact, unlatched, and undamaged.

According to the autopsy report prepared for the Luzerne County Coroner’s Office, Hanover Township, Pennsylvania, the pilot’s cause of death was multiple traumatic injuries, and the manner of death was accident.

Toxicology testing performed by the Federal Aviation Administration (FAA) Forensic Sciences Laboratory detected the antidepressant citalopram in the pilot’s heart blood and in his urine. Citalopram’s metabolite, n-desmethylcitalopram, was detected in his heart blood and in his urine. The high cholesterol medication atorvastatin and the high blood pressure medication terazosin were detected in the pilot’s heart blood and urine; these two medications are generally considered non-impairing. Citalopram was a prescription antidepressant medication marketed under the trade name Celexa. N-desmethylcitalopram is the active metabolite of citalopram. Both carry the warning that their use may impair mental of physical ability for performing hazardous tasks. The FAA will consider a special issuance of a medical certificate for depression after 6 months of treatment if the applicant is clinically stable and using only one approved treatment medication; however, the pilot had not applied for a special issuance. Citalopram is one of the FAA-approved antidepressant medications.

According to the autopsy report, the cause of death of the pilot-rated passenger was multiple traumatic injuries, and the manner of death was accident. Toxicology testing was negative for ethanol in the pilot-rated passenger’s vitreous fluid and tested-for-drugs in his liver tissue.