N3937MPiper PA-12

On August 11, 2022, at 1152 Alaska daylight time, a Piper PA-12 airplane, N3937M, was substantially damaged when it was involved in an accident near Arctic Village, Alaska. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The pilot was on a solo hunting trip and was returning home when the accident occurred. On the morning of the accident, the pilot sent messages between 0930 and 1030 that he was preparing to depart the area. There were no reported distress calls or other communications from the pilot. The following day, about 1140, a pilot spotted the wreckage about 2 nm west of Marsh Strip, a gravel airstrip located next to the Marsh Fork of the Canning River. The pilot who discovered the wreckage stated that on the afternoon of the accident, there was significant wind shear with sustained wind at least 20 kts and gusting to at least 30 kts. He stated that the wind gusts were violent, which made him park his airplane on an airstrip about 15 miles east of Marsh Strip and wait for the wind to subside. He added that another pilot who flew northbound over Marsh Strip about 1430 on the day of the accident reported that the wind was very turbulent.

A review of the data from the pilot’s GPS revealed that at 1149 the airplane departed Marsh Strip to the south and then made a right turn into the valley, as seen in Figure 1. The flight track continued west up the valley about 300 to 400 ft agl for about 2 nm, then made a sharp left turn and descended to the ground. Figure 1 shows the end of the GPS flight track and the estimated accident location overlaid onto Google Earth.

Figure 1. GPS flight track and accident location on Google Earth showing time (coordinated universal time [UTC]), ft above mean sea level (msl), and knots groundspeed.

A witness stated that the accident pilot had fuel stored at the Chandalar Lake Airport (PALR), Chandalar Lake, Alaska, for his hunting trip into the mountains. The pilot stated to him that he was going sheep hunting and would return when he got a sheep. On August 7, 2022, the pilot arrived at PALR and refilled the airplane with two 5-gallon containers of fuel (10 gallons total). There were three remaining 5-gallon containers full of fuel. The containers were covered and in good condition.

Based on the GPS flight data and known fuel information, the estimated fuel onboard during the accident takeoff was about 14.15 gallons.

The most recent weight and balance completed for the airplane was on February 18, 2020. The empty weight was measured as 1,191.00 lbs. The mechanic who completed the weight and balance stated that he transposed the maximum gross weight of 1,838 lbs from previous weight and balance paperwork. He added that he was not aware of any modifications to the airplane that would have increased the maximum gross weight; therefore, the maximum gross weight should have been 1,750 lbs.

A postaccident weight and balance calculation, including fuel, revealed that the accident flight payload was about 620 lbs. The airplane’s useful load was actually 559 lbs, and not 647 lbs as listed in the most recent weight and balance; therefore, the airplane was 61 lbs over maximum gross weight during the accident flight.

A witness stated that the accident pilot had fuel stored at the Chandalar Lake Airport (PALR), Chandalar Lake, Alaska, for his hunting trip into the mountains. The pilot stated to him that he was going sheep hunting and would return when he got a sheep. On August 7, 2022, the pilot arrived at PALR and refilled the airplane with two 5-gallon containers of fuel (10 gallons total). There were three remaining 5-gallon containers full of fuel. The containers were covered and in good condition.

Based on the GPS flight data and known fuel information, the estimated fuel onboard during the accident takeoff was about 14.15 gallons.

The most recent weight and balance completed for the airplane was on February 18, 2020. The empty weight was measured as 1,191.00 lbs. The mechanic who completed the weight and balance stated that he transposed the maximum gross weight of 1,838 lbs from previous weight and balance paperwork. He added that he was not aware of any modifications to the airplane that would have increased the maximum gross weight; therefore, the maximum gross weight should have been 1,750 lbs.

A postaccident weight and balance calculation, including fuel, revealed that the accident flight payload was about 620 lbs. The airplane’s useful load was actually 559 lbs, and not 647 lbs as listed in the most recent weight and balance; therefore, the airplane was 61 lbs over maximum gross weight during the accident flight.

The accident site featured an initial impact crater about 20 yards west of the airplane and the wreckage path was on a heading of 064°. On the right side of the impact crater was a disturbance in the ground that contained an inspection panel from the right wing. The main wreckage came to rest facing southeast and remained mostly intact (Figure 2).

Figure 2. Aerial view of accident site.

Examination of the wreckage at the accident site revealed that the cockpit area was crushed upward and aft. The airplane was canted left with the left wing folded back underneath the fuselage. The left wing sustained leading crushing to the wing tip. The right wing sustained outboard leading edge damage and was bent upward near midspan. Flight control continuity was confirmed from all flight control surfaces, through a few impact separations, to the cockpit controls. The flaps were partially extended. The pitch trim jackscrew position corresponded to a full nose-up position. The payload/cargo onboard the airplane at the time of the accident became dislodged, and the exact preimpact location/station of the cargo could not be determined.

The pilot’s seat floor mounts were separated from the fuselage. The pilot’s restraint was a 3-point lap belt and shoulder harness and was found secured at each anchor. The lap belt was positioned around the pilot and each of the tongues was secured by the one-stroke release buckle. The shoulder harness was still attached to the roof mount, but the strap was pulled loose at the Y junction stitching and the rest of the shoulder harness was found loose around the pilot. The first responders observed the shoulder harness loose when they arrived at the scene.

There was a strong smell of fuel near the front of the airplane and the fuel tanks and fuel lines were compromised. The gascolator was intact and about half full of fuel, which tested negative for water contamination.

The engine remained partially attached to the engine mounts and firewall, and the cowling had separated. The engine had sustained minimal impact damage. The two-bladed propeller remained attached at the crankshaft flange. The propeller blades remained attached to the propeller hub and displayed leading edge gouging, torsional twisting, chordwise striations across the cambered surface and trailing edge “S” bending.

Examination of the airframe and engine did not reveal any preaccident mechanical malfunctions or failures that would have precluded normal operation.

Garmin aera 660 GPS

The GPS was in good condition and the data was downloaded normally using the manufacturer’s procedure. The data extracted included 27 track logs from June 12, 2022, through August 11, 2022. The accident flight was recorded starting 19:46:31 UTC and ending 19:52:52 UTC on August 11, 2022. The GPS stored several user-set waypoints, of which one was “MSHFRK 02”, which is located near the beginning of the accident flight recording. The GPS began recording at 19:46:31 UTC and data consistent with a taxi lasted about half a minute between a GPS altitude of 2,780 and 2,790 ft. The GPS recorded an increase in speed beginning at 19:49:07 UTC. The airplane departed to the south and made a sharp right turn west. Throughout the flight, the airplane maintained a GPS groundspeed of between 40 and 50 kts. The airplane reached a maximum GPS altitude of 3,412 ft at 19:52:06, and then made 2 turns before the end of the data, which include an increase in recorded groundspeed to 70 kts at 19:52:21 before decreasing to 0 kts. The data ceased recording at 19:52:52 UTC, about 2.25 nautical miles west of the initial data point.

JPI Engine Data Monitor EDM-700

The device sustained minor impact damage to the exterior casing, but it was in operable condition and the data was downloaded normally using the manufacturer’s procedure. The EDM recording contained a number of hours of data over multiple power cycles. The accident flight was the last flight of the recording. The data showed a constant and steady increase in cylinder head temperatures (CHT) and exhaust gas temperatures (EGT) until the end of the recording. There were no anomalies noted in the data.

The pilot reported that, while landing off airport on an upslope of a ridge, the tailwheel-equipped airplane "touched down harder than preferred". He applied full throttle, initiated a go-around, and attempted to turn towards the downslope side of the hill. The airplane briefly became airborne but then aerodynamically stalled and nosed down into the tundra.

The airplane sustained substantial damage to the engine mount.

The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.