Aviation Accident Summaries

Aviation Accident Summary ANC19FA026

Seward, AK, USA

Aircraft #1

N6314V

Helio H 250

Analysis

The airline transport pilot was asked to pick up two passengers, and their equipment, from a remote unimproved, grass-covered airstrip that was surrounded by trees at the southern end of the site. After failing to return with the passengers, a friend of the pilot initiated an aerial search and found the airplane at the south end of the airstrip on the shoreline of a small river. The airplane was observed in a near vertical position and had largely been consumed by a postcrash fire. The initial impact point was marked by a fresh tree break in an area of 85 ft. tall trees at the departure end of the site. The airplane's left wing had a large elliptical-shaped impact area with fresh pieces of the broken tree wedged inside. First responders found some of the passenger's equipment/luggage on the side of the accident airstrip, which appeared to have been intentionally left. The exact takeoff weight of the airplane is unknown due to the postcrash fire.   During an NTSB postaccident examination of the airplane and engine, no mechanical malfunction or anomalies were found.  Given the lack of any mechanical deficiencies with the airplane, the grass-covered airstrip, and a stand of tall trees at the departure end of the site, it is likely the airplane collided with a tall tree during initial climb out, and subsequently the pilot lost control of the airplane.

Factual Information

HISTORY OF FLIGHTOn June 21, 2019, about 1546 Alaska daylight time, a Helio Courier H-250 airplane, N6314V, was destroyed by impact forces and a postcrash fire after a collision with tree-covered terrain about 25 miles southeast of Seward Airport (SWD), Seward, Alaska. The airline transport pilot and two passengers received fatal injuries. The airplane was registered to and operated by the pilot as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight. Visual meteorological conditions prevailed at the time of the accident, and no flight plan was filed. The flight departed from an unimproved grass-covered airstrip about 25 nautical miles from SWD, about 1546. According to a friend of the accident pilot, the purpose of the flight was to pick up two passengers from the remote unimproved airstrip in an area of Seward known as Johnstone Bay and return them to SWD. The pilot's friend, who owns and operates a 14 CFR Part 135 air taxi company based at SWD, explained that his air taxi had dropped off the couple to Johnstone Bay on June 18 and that the couple was originally scheduled to be picked up on June 25. The couple contacted the air taxi company owner via a satellite phone and asked to be picked up sooner. The air taxi company owner stated that, when the couple called for an early pickup, the air taxi airplane was configured on wheel-skis for glacier operations and would be unable to land at the unimproved airstrip until after the skis were removed. The air taxi company owner also stated that the accident pilot volunteered to pick up the couple, free of charge, and that the owner accepted the pilot's offer. The accident airplane departed SWD about 1450. The owner of the air taxi company further reported that, after the accident airplane departed from SWD en route to Johnstone Bay, he tracked the airplane's location using the pilot's GPS unit. The last "ping" from the GPS unit was about 1546 at Johnstone Bay. When the airplane failed to return to SWD by 1630, the air taxi company owner started an aerial search, and he eventually discovered burning airplane wreckage near the departure end of the airstrip. AIRCRAFT INFORMATIONThe Helio H-250 airplane was a single-engine, high-wing, tailwheel-equipped airplane. It incorporated a conventional flight control arrangement, with the flight control surfaces directly actuated by cables and tubes from the dual cockpit controls. The accident airplane's normal-category standard airworthiness certificate was issued by the Federal Aviation Administration in September 1967. The airplane was equipped with a Lycoming O-540-A1A5 direct-drive, six-cylinder engine rated at 250hp at 2575rpm, and a Hartzell HC-92WK-1D/W8847N propeller. A review of maintenance records revealed that the airplane's most recent annual inspection occurred on September 1, 2018; at that time, the airframe accumulated 6,708.9 hours total time, and the engine accumulated 1,000.4 hours since overhaul. The last entry, on June 8, 2019, showed that 29-inch Alaskan Bushwheels were installed; at that time, the airframe and engine had accumulated 10.9 hours since the time of inspection. The airplane was equipped with two Chelton Integrated Display Units, both of which were a flight/navigation instrumentation system. The units were sent to the National Transportation Safety Board's (NTSB) Vehicle Recorders Laboratory in Washington, DC, to download the data stored in nonvolatile memory, but the extent of the fire damage to the units precluded recovery of the data. The airplane was also equipped with an emergency locator transmitter (ELT), which did not broadcast after the accident. The ELT sustained post-impact fire damage, so the NTSB could not determine why the ELT did not broadcast. METEOROLOGICAL INFORMATIONAt 1553, the meteorological information that SWD was reporting included wind from 180° at 10 knots, 10 statute miles visibility, clear sky, temperature 55°F, dew point 46°F, and an altimeter setting of 30.06 inches of mercury. The air taxi owner reported that the weather at the time that he landed on the airstrip at Johnstone Bay was clear with very light wind. AIRPORT INFORMATIONThe Helio H-250 airplane was a single-engine, high-wing, tailwheel-equipped airplane. It incorporated a conventional flight control arrangement, with the flight control surfaces directly actuated by cables and tubes from the dual cockpit controls. The accident airplane's normal-category standard airworthiness certificate was issued by the Federal Aviation Administration in September 1967. The airplane was equipped with a Lycoming O-540-A1A5 direct-drive, six-cylinder engine rated at 250hp at 2575rpm, and a Hartzell HC-92WK-1D/W8847N propeller. A review of maintenance records revealed that the airplane's most recent annual inspection occurred on September 1, 2018; at that time, the airframe accumulated 6,708.9 hours total time, and the engine accumulated 1,000.4 hours since overhaul. The last entry, on June 8, 2019, showed that 29-inch Alaskan Bushwheels were installed; at that time, the airframe and engine had accumulated 10.9 hours since the time of inspection. The airplane was equipped with two Chelton Integrated Display Units, both of which were a flight/navigation instrumentation system. The units were sent to the National Transportation Safety Board's (NTSB) Vehicle Recorders Laboratory in Washington, DC, to download the data stored in nonvolatile memory, but the extent of the fire damage to the units precluded recovery of the data. The airplane was also equipped with an emergency locator transmitter (ELT), which did not broadcast after the accident. The ELT sustained post-impact fire damage, so the NTSB could not determine why the ELT did not broadcast. WRECKAGE AND IMPACT INFORMATIONThe wreckage was located south of the airstrip on the shoreline of a small river that flowed from Little Johnstone Lake into Johnstone Bay in the north Pacific Ocean. The airplane came to rest in a nose down vertical position on a heading of about 340°. The initial impact point was marked by a fresh tree break on a treetop in an area with trees that were about 85 ft tall. The distance between the initial impact point and the main wreckage site was about 125 ft. The airplane's left wing had a large elliptical-shaped impact area with fresh pieces of the nearby broken tree wedged inside. All major components of the airplane were found at the accident site but, a postcrash fire destroyed a large portion of the wreckage. The engine was still attached to the airframe, the exterior fuselage skin was burned with the main cabin frame tubing intact, and the empennage had separated and come to rest partially burned on the ground in front of the airplane. Both wings were heavily burned near the fuel tanks; only the outboard sections and leading edges of the wings were not burned. The landing gear components were found in the burned wreckage, and the horizontal stabilator was burned with only about one-half of the structure remaining. Because the engine was thermally damaged, no accessories were available for a detailed engine examination. Internal continuity of the engine was established visually using a light borescope. The postaccident examination of the airplane and engine revealed no mechanical failures or malfunctions that would have precluded normal operation. Seven bags of luggage belonging to the passengers were found on the side of the airstrip. The bag weight varied from about 9 to 60lbs. and the total baggage weight was about 238lbs. The bags appeared to have been intentionally left beside the airstrip. ADDITIONAL INFORMATIONThe unimproved airstrip consisted of short grass, with a distance of about 1,078 ft from the lake's edge to the base of the 85 ft tall trees. The airstrip had a shorter crosswind airstrip with longer grass, that roughly followed the lake shoreline and intersected the 1,078 ft airstrip about 175 ft from the water's edge. (see figures 1 & 2) The baggage was found near the intersection of the crosswind airstrip, with the remaining runway from the intersection toward the base of the trees being approximately 900 ft. Figure 1. Figure 2. A representative from Helio Aircraft LLC, the type certificate data holder for Helio airplanes, reported that the H-250 airplane, at a gross weight of 3,400 lbs. has a take-off roll of approximately 750 ft over a 50 ft obstacle. He added that, the H-250 airplane uses leading edge slats and large flaps to "help make the airplane stall proof" but that the added lift "does come with additional drag, especially at high angles of attack." The representative also stated that, if the airplane is flown at extremely high angles of attack, the drag can "overcome" the available thrust, which could be noticeable in the H-250 model because of the lower horsepower engine and static thrust. MEDICAL AND PATHOLOGICAL INFORMATIONThe State of Alaska Medical Examiner's Office, Anchorage, Alaska, conducted an autopsy of the pilot. The autopsy found that the pilot's cause of death was multiple traumatic injuries. Toxicology testing performed at the FAA's Forensic Sciences Laboratory identified no drugs, ethanol, and carbon monoxide in the pilot's specimens.

Probable Cause and Findings

The pilot's failure to maintain clearance from trees during takeoff, which resulted in an in-flight collision, a loss of control, and impact with terrain.

 

Source: NTSB Aviation Accident Database

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