History of Flight
On October 23, 2018, about 1400 eastern daylight time, a Mooney M20C, registration N9667M, was destroyed in an accident near Woodbine, New Jersey. The commercial pilot was fatally injured. The airplane was operating as a Title 14 Code of Federal Regulations Part 91 personal flight.
Data from the airplane's Appareo Stratus 2S indicated that after takeoff, the airplane accelerated to a maximum groundspeed of about 62 knots. At approximately 1359:19, the altitude was about 192 ft msl (about 151 ft above ground level) and groundspeed was about 60 knots. Over the next six seconds, the pitch attitude increased from about 11° to about 36°, with an altitude increase and groundspeed decrease. At 1359:25, the pitch began to decrease, and the airplane reached its highest altitude of about 417 ft msl, with a groundspeed of about 26 knots. The airplane then banked left, descended, and the last data point was near the main wreckage. An airport security camera showed the airplane in a nearly vertical nose-low, slight left-wing-low attitude with the landing gear extended.
A witness at the fuel terminal reported that the airplane taxied toward the approach end of runway 31. He heard engine power increase to high rpm and observed the takeoff. The airplane became airborne about 900 ft down the runway and climbed to an estimated 100 ft above the runway. The witness noted a slight climb attitude and retracted landing gear between taxiways C and D. He then heard an impact near the windsock and called 911. The engine sounded steady and constant until impact.
A mechanic who maintained the airplane was inside a hangar when he heard full takeoff power followed by an impact. The engine sound was steady before impact. He did not hear an engine run-up. He responded to the accident site and noted a small amount of smoke on the right side of the instrument panel and puddles of fuel, with a major puddle under the left wing.
Aircraft Information
The Mooney M20C has a manually operated landing gear system with a retracting handle assembly ("Johnson bar"). The system uses direct mechanical linkage and bungee springs. To retract the gear, a safety latch button is depressed and the handle is pushed aft from the downlock socket to the floor, then slid into the up-lock socket.
Friends of the pilot reported that in the 1–2 weeks before the accident, he expressed difficulty retracting the landing gear. One friend said the pilot mentioned it was easier to retract at slower airspeed. Another friend recounted a conversation where the pilot would brace himself and use one hand to operate the Johnson bar, leaving no hands on the control yoke. The mechanic who maintained the airplane stated the pilot did not express that concern to him.
The last annual inspection was performed by a mechanic using his own checklist; he did not test the force required to retract the landing gear. The Mooney 100-Hour-Annual Inspection Guide requires checking operation and rigging but does not specify measuring retraction force. The airplane was equipped with a JPI EDM 700; no exceedances of cylinder head or oil temperature were recorded.
Wreckage and Impact
The airplane crashed on airport property near the departure end of runway 31, about 2,450 ft down the runway and 200 ft southwest of the southern edge. A ground scar from the left wing was oriented on a magnetic heading of about 305°. The airplane came to rest upright with the empennage nearly separated. No fire was observed, but a burned electrical smell was noted in the cockpit; the source could not be determined.
Flight control examination revealed no preimpact failure or malfunction. The elevator trim jackscrew was extended 7 threads, correlating to takeoff trim. The empennage showed a compression wrinkle on the left side consistent with left rotation. Impact marks on the tailcone and elevators were examined but control position at impact could not be determined.
The left wing flap and aileron remained connected. The leading edge had full-span aft crushing. The main landing gear was fully extended, with the aft portion driven through the wing. The retracting bungee assembly was fractured but the spring was not. The right wing also had connected flap and aileron, leading edge crushing, and the landing gear partially extended. The bungee assembly separated with a bent cylinder and fractured rod due to bending overload.
The flap cylinder extension measured 3 1/16 inches, corresponding to flaps up, but the manufacturer cautioned that impact may have affected the system. The Johnson bar was fractured from the lever assembly, nearly vertical (gear down position) but not in its downlock socket. No pre-existing cracks were found. The nose landing gear was collapsed aft.
Engine examination revealed impact damage precluded crankshaft rotation. Cylinders 1 and 3 were removed; continuity of crankshaft, camshaft, and valve train was confirmed. No anomalies were found in cylinders 2 and 4 via borescope. Fuel, ignition, exhaust, and lubrication systems showed no preimpact failure. The propeller dome separated; one blade was rotated and curled aft about 90°, the other twisted, both with leading edge gouges and chordwise scoring.
Medical and Pathological Information
A postmortem examination by the Office of the Chief Medical Examiner, Woodbine, New Jersey, determined the cause of death as multiple blunt impact injuries. Toxicology results were negative for volatiles and carbon monoxide. Unquantified amounts of sildenafil, desmethylsildenafil, and pantoprazole were detected in liver and blood specimens. Sildenafil (Viagra) is used for erectile dysfunction; pantoprazole is for GERD. Neither is considered sedating.
Tests and Research
The airplane owner's manual stated that rapid movement of the landing gear handle makes retraction easier, and gear retracts easiest at low airspeeds, though no specific speed is given. The manual lists stall speed at maximum gross weight (2,575 lbs), no flaps, 0° bank as 67 mph (about 58 knots), and at 15° bank as 64 mph.
The airplane's certification basis was Civil Air Regulations Part 3, which had no specification for maximum force at the retracting handle. A previous flight on October 10, 2018, recorded by the Appareo Stratus 2S, showed a departure from runway 19. Between 1816:16 and 1816:21, pitch attitude increased from about 4° to 22°, with groundspeed slowing to 45 knots. With a headwind component of about 10 knots, this was within about 3 knots of the published stall speed.