Nikolai, AK, USA
N2343G
CESSNA 182B
The commercial pilot and two passengers were on a personal cross-country flight that included flying through a narrow mountain pass. The typical route through the pass required making multiple turns, and the pass intersected with a box canyon. A family member reported the airplane overdue for arrival, and an alert notice was issued. The airplane's wreckage was located the following day at the bottom of the box canyon. A pilot who flew through the mountain pass on the morning of the accident reported 4,400-foot ceilings, severe turbulence, and flat light conditions. A friend of the pilot who attempted to cross the mountain pass the day of the accident reported flat light conditions and having difficulty discerning terrain features. He turned the airplane around due to the weather conditions and returned to the airport. He also stated that the accident pilot had become disorientated the previous year while flying a helicopter through the same mountain pass and had taken the wrong route. A postaccident examination revealed no evidence of a mechanical malfunction or failure with the airframe or engine that would have precluded normal operation. Given the lack of mechanical anomalies, the reported weather conditions, and the pilot statements, it is likely that the accident pilot mistakenly entered the box canyon thinking it was his route. Additionally, wreckage impact signatures and GPS data indicated that it is likely that the pilot was attempting to avoid rising terrain by entering a steep bank turn, which resulted in an aerodynamic stall.
HISTORY OF FLIGHTOn March 4, 2013, about 1117 Alaska standard time, a Cessna 182B airplane, N2343G, sustained substantial damage when it collided with mountainous, snow-covered terrain, about 65 miles southeast of Nikolai, Alaska. The airplane was being operated by the pilot as a visual flight rules (VFR) personal flight, under 14 Code of Federal Regulations Part 91, when the accident occurred. The certificated commercial pilot and two passengers were fatally injured. Visual meteorological conditions prevailed, and no flight plan was filed. The flight originated at the Merrill Field Airport, Anchorage, Alaska, at approximately 1006, and was bound for Takotna, Alaska, via Rainy Pass. According to a family friend of the pilot, the flight was scheduled to depart Merrill Field at 0900, fly via Rainy Pass to Takotna, drop off two passengers, and return to Merrill Field, where he would transport two more passengers to Takotna later that day. The family group of four had hoped to volunteer for the Iditarod sled dog race. The pilot was feeling rushed due to the late start, and was hoping to complete the round trip without stopping in McGrath for fuel. When the airplane did not return to Merrill Field, a concerned family member notified the Federal Aviation Administration who issued an alert notice (ALNOT) at 1608. After being notified of the overdue airplane, personnel from the 11th Air Force's Rescue Coordination Center initiated a search for the missing airplane along its supposed route of flight. On the morning of March 5, an Air National Guard HH-60G Helicopter located the wreckage in an area of steep mountainous terrain near Rainy Pass at the end of a box canyon, and accessed the site confirming the pilot and two passengers were deceased. Rainy Pass is a narrow mountain pass that is commonly used by Visual Flight Rules pilots to transit from the Anchorage bowl area, through the Alaska Range, to the Kuskokwim River drainage. The typical route through Rainy Pass from Merrill Field follows a path to Puntilla Lake, then northwest along Ptarmigan Pass to the mouth of Pass Creek, then northwest up Pass Creek to the summit of Rainy Pass, through the pass, southwest along Pass Fork to Dalzell Creek, north along Dalzell Creek to the Tatina River, before turning west to Rohn. The entrance to the box canyon where the accident occurred intersected with Rainy Pass and was approximately 1 mile northwest of the summit. During a telephone conversation with the NTSB IIC on March 5, 2013, a friend of the pilot, who departed Merrill Field at approximately 0951, with a planned stop in Puntilla, before continuing through Rainy Pass, stated that upon entering Rainy Pass he encountered flat light and windy conditions. He could not discern where the ground was, except for the occasional dog musher on the ground in Rainy Pass. He turned around due to the weather conditions and returned to Merrill Field. He also stated that the previous year the accident pilot had become disorientated while flying a helicopter through Rainy Pass and had taken the wrong route. During an interview with the NTSB IIC on March 7, a pilot flying thru Rainy Pass the morning of March 4, reported ceilings of 4,400 feet, severe turbulence, and flat light conditions. PERSONNEL INFORMATIONThe pilot, age 59, held a commercial pilot certificate with an airplane muilti-engine land, airplane single-engine land, rotorcraft and instrument rating. He also held a certified flight instructor certificate with airplane single-engine land, multi-engine land, and rotorcraft-helicopter rating. His most recent second class medical certificate was issued on October 13, 2012, with the limitations that he must wear lenses for distant and have glasses for near vision. According to the Pilot/Operator Aircraft Accident Report, (NTSB Form 6120.1) submitted by his employer, his total aeronautical experience was about 1680 flight hours, of which about 550 were in single-engine airplanes. In the 90 and 30 days preceeding the accident, the pilot flew a total of 20 and 15 flight hours, respectively. AIRCRAFT INFORMATIONThe airplane was a 1959 model year, Cessna 182B. At the time of the accident the airplane had a total time in service of approximately 3730.2 flight hours. A review of the maintenance records revealed that the most recent annual inspection of the airframe and engine was on August 21, 2012, about 6.4 flight hours before the accident. The airplane was equipped with a Continental Motors O-470-L engine, rated at 230 horsepower. The engine was overhauled about 1,420.2 hours before the accident. METEOROLOGICAL INFORMATIONThe area weather forecast valid through 1800 on the day of the accident was: scattered clouds at 2,000 feet, and broken to scattered clouds at 5,000 feet, broken clouds at 11,000 feet, with the tops of the clouds at 30,000 feet. The weather outlook for the Rainy Pass area valid through 2400 was: VFR. The closest weather reporting facility was Puntilla Lake, about 18 mile northwest of the accident site. At 0902, a weather observation from Puntilla Lake was reporting, in part: wind, calm; visibility, 25 statute miles; clouds and sky condition, 5,000 feet overcast, temperature, 23 degrees F; dew point 21 degrees F; altimeter, 30.35 inHg. AIRPORT INFORMATIONThe airplane was a 1959 model year, Cessna 182B. At the time of the accident the airplane had a total time in service of approximately 3730.2 flight hours. A review of the maintenance records revealed that the most recent annual inspection of the airframe and engine was on August 21, 2012, about 6.4 flight hours before the accident. The airplane was equipped with a Continental Motors O-470-L engine, rated at 230 horsepower. The engine was overhauled about 1,420.2 hours before the accident. WRECKAGE AND IMPACT INFORMATIONThe National Transportation Safety Board (NTSB) investigator-in- charge (IIC), along with a representative from Cessna Aircraft Company reached the accident site on the afternoon of March 11. The on-scene examination revealed that the airplane impacted in a near vertical attitude, on a rock and snow-covered 33 degree slope, near the bottom of a box canyon, at an elevation of about 4,386 feet mean sea level. The nose of the airplane was on approximately a 35 degree heading, and downhill (All headings/ bearings noted in this report are magnetic). All of the airplane's major components were found at the main wreckage site. The cockpit area was extensively damaged. The engine and firewall were displaced upward and aft, and the instrument panel was displaced upward, almost to the top of the windscreen. The throttle and mixture control were found in the full-forward position. The propeller control was in the near full-forward position. The carburetor heat was in the off position. The ignition switch was in the "both" position. The aft fuselage separated from the forward fuselage at the upper production joint near the forward end of the rear windows. The left door separated from the fuselage and exhibited crushing damage. The empennage was intact and relatively free of impact damage. The airplane's severed left wing was inverted and underneath the main wreckage, and exhibited spanwise upward bending. The wing's flight control surfaces remained attached to their respective attach points. The airplane's right wing remained attached to the forward wing attach point, and the aft wing spar separated approximately 4 inches outboard of the rear attach point. Extensive spanwise leading edge aft crushing was present from mid-span outboard. The wing's flight control surfaces remained attached to their respective attach points. The horizontal and vertical stabilizer, elevators and rudder remained attached to the empennage, and were relatively free of impact damage. The cowling was crushed upwards and aft. The engine had impact damage to the front and underside. The propeller bolts attaching the propeller to the engine crankshaft remained attached to the crankshaft flange, but the crankshaft was fractured aft of the flange. Both propeller blades remained attached to the propeller hub assembly and exhibited extensive leading edge gouges, substantial torsional "S" twisting and chordwise scratching. Both propeller tips separated from the propeller blades. Both flaps were in the up position and the flap handle was in the up and locked position. Due to impact damage, the flight controls could not be moved by their respective controls, but continuity of the flight control cables was established to the cockpit area. No evidence of preimpact mechanical anomalies was found. MEDICAL AND PATHOLOGICAL INFORMATIONA post mortem examination was conducted under the authority of the Alaska state Medical Examiner, Anchorage, Alaska, on March 6, 2013. The cause of death for the pilot was attributed to blunt force injuries. The Federal Aviation Administration (FAA) Civil Aeromedical Institute performed toxicology examinations for the pilot on May 7, 2013, which was negative for alcohol and drugs. TESTS AND RESEARCHAt the time of the accident, the pilot was using a Garmin GPSMAP 296 portable global positioning system (GPS) receiver, capable of storing route-of-flight data. The unit was sent to the NTSB's Vehicle Recorders Division for examination. An NTSB electrical engineer was able to extract the GPS data for the accident flight, which included, in part, time, latitude, longitude, and GPS altitude. Groundspeed and course information were derived from the extracted parameters. A flight track map overlay, and tabular data corresponding to the accident flight are available in the public docket for this accident. On October 24, 2013, an engine examination was performed by Continental Motors, Inc., under the supervision of the NTSB. No anomalies, contamination, or evidence of malfunction was found in any of the engine accessories. The cylinders, pistons, valve train, crankshaft, and other internal components were all without evidence of anomaly or malfunction.
The pilot’s failure to maintain adequate airspeed while maneuvering inside a box canyon and the airplane’s subsequent aerodynamic stall, which resulted in an in-flight collision with mountainous terrain. Contributing to the accident was the pilot’s visual disorientation in flat light conditions.
Source: NTSB Aviation Accident Database
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