Coldfoot, AK, USA
N4827K
RYAN NAVION A
The commercial pilot was conducting a 14 Code of Federal Regulations (CFR) Part 135 commercial air tour flight with three passengers onboard when the airplane impacted rising terrain below the entrance of a high mountain pass. The airplane was substantially damaged, and the pilot and his three passengers were seriously injured. Thirty-five days later, one of the passengers died as a result of his injuries. The pilot initially reported to first responders that he had encountered a severe downdraft while approaching the high mountain pass, which caused the airplane to lose altitude. Review of reported weather conditions at the time of the accident in the area of the pass indicated that the wind speed was 4 to 7 knots, and no indications of sudden downdrafts were discovered. When interviewed by investigators about 2 weeks after the accident, the pilot stated that the right front seat passenger was not wearing his shoulder harness and had slumped onto the flight controls and become unresponsive after taking a motion sickness drug. The pilot further stated that the two rear seat passengers (who had also taken the drug) were also unresponsive when this occurred. However, none of the three passengers recalled this, and the front seat passenger was found with his seatbelt and shoulder harness on when first responders arrived on scene. In a written statement dated about 2 months after his interview, the pilot stated that a propeller blade had separated in flight, as one propeller blade was missing and not recovered from the accident site. The passengers did not recall that this had occurred, and postaccident examination of the propeller hub, propeller blade pilot tubes, propeller blade clamps, and the remaining propeller blade indicated that the missing propeller blade had separated during the impact sequence. Evidence that the missing propeller blade separated on impact included the existence of power signatures on the remaining propeller blade and the presence of a large amount of grease in the hub, which was not thrown out in a centrifugal pattern from the missing propeller blade side of the hub as it would have been if the blade had separated in flight. Further findings indicating that the missing propeller blade separated on impact were a broken clamp bolt head found lying inside the clamp bolt cup of the clamp from the missing propeller blade, impact damage on that same clamp, and a shiny-crescent shaped contact mark on the hub butt in the aft quadrant where the trailing edge of the missing propeller blade would have been located; the crescent-shaped contact mark, which was indicative of aluminum transfer from the missing blade to the hub butt, is typically seen when propeller blades separate during impact. Additionally, metallurgical testing showed that the impact-damaged clamp from the missing propeller blade as well as both of the propeller blade tubes had failed due to overload, and no evidence of fatigue cracking was found. Postaccident examination of the airframe and engine found no evidence of preimpact mechanical malfunctions or anomalies that would have precluded normal operation of the airplane. Several discrepancies were noted with the engine, including the presence of metallic particulates within the oil filter, contamination of the fuel inlet screen with a rubber-like material, and damage to the oil pump consistent with hard particle passage; however, none of these discrepancies would have prevented the engine from producing power. Witness statements, passenger statements, photographs taken during the flight by one of the passengers, and GPS data recovered from a GPS receiver onboard the airplane indicated that, after takeoff, the pilot did not climb to a safe cruising altitude to cross through the mountain pass but instead remained at low altitude. After circling a town, he proceeded up a valley that led to the high mountain pass, flying below the tops of the surrounding mountains in close proximity to terrain and obstructions about 500 feet above ground level. This low altitude flying resulted in the airplane reaching the area of the pass, being boxed in by the surrounding terrain, and not having enough energy or performance to climb up and cross over the pass as the terrain at that point was rising faster than the airplane could climb. Examination of weight and balance information indicated that the pilot had taken off with the airplane loaded over maximum gross weight and that the airplane was near its maximum gross weight when the accident occurred. The pilot's decision to operate the airplane near its maximum gross weight likely contributed to the accident because it reduced the margin of power available for climb. Review of Federal Aviation Administration (FAA) records revealed that, from 2007 to 2012, the pilot had a history of accidents, incidents, reexaminations, and checkride failures. Despite the pilot's history and concerns voiced by numerous FAA personnel during the certification process, the FAA issued a certificate to the pilot in 2012 to conduct commercial air transportation pursuant to 14 CFR Part 135.
HISTORY OF FLIGHTOn August 24, 2014, about 1305 Alaska daylight time, a Ryan Navion A, N4827K, was substantially damaged when it impacted terrain while maneuvering in mountainous terrain, approximately 56 nautical miles north-northeast of Coldfoot, Alaska. The airplane was operated by Kirst Aviation, as an on-demand sightseeing flight under the provisions of 14 Code of Federal Regulations (CFR) Part 135. The commercial pilot and the three passengers were seriously injured during the accident. The right-front seat passenger died 35 days after the accident as a result of his injuries. Visual meteorological conditions prevailed, and a visual flight rules (VFR) flight plan was filed for the flight, which originated at Fairbanks International Airport (PAFA), Fairbanks, Alaska about 1003. According to Federal Aviation Administration (FAA) records, earlier that day the pilot filed a VFR flight plan indicating that he intended to depart from PAFA, stop at Bettles Airport (PABT), Bettles, Alaska; Deadhorse Airport (PASC), Deadhorse, Alaska; and Barter Island LRRS Airport (PABA), Barter Island, Alaska, before returning to PAFA. He indicated that the airplane had approximately 7 hours and 20 minutes of fuel on-board. The accident occurred during the flight between PABT and PASC in Atigun Pass, which is a high mountain pass that crosses the Brooks Range at an altitude of 4,739 feet above mean sea level (msl), at the head of the Dietrich River, where the Dalton Highway and the Trans-Alaska Pipeline, cross the Continental Divide. Review of the Fairbanks Sectional Chart and the World Aeronautical Chart for the area around Atigun Pass that was published by the FAA effective at the time of the accident revealed that it contained a warning that stated: "RAPIDLY RISING TERRAIN" and advised to "USE CAUTION DURING PERIODS OF LOW CEILING AND VISIBILITY." Pilot Interview On September 9, 2014, NTSB investigators conducted an interview with the pilot. During the interview, the pilot stated that he had received a call about 2 weeks prior to the accident flight from the male passenger inquiring about flightseeing and observing polar bears at Barter Island. Originally, the flight was to be for two passengers who were from a group that was traveling on a cruise ship, but was later changed to three passengers. He recalled departing PAFA about 1000 for PABT and recalled that the 1.5-hour flight to PABT was uneventful. The male passenger was seated in the airplane's right front seat, and the two female passengers were seated in the airplane's two rear seats. The pilot stated that the male passenger weighed 262 pounds and had positioned his seat to its rearmost position. During the flight, one woman became queasy but not sick. Motion sickness pills were offered by the male passenger but were declined since they induce sleep. They stopped in PABT for a bathroom break and a brief walk around. The pilot reported he did not purchase fuel at PABT. The flight from PABT to Atigun Pass took about 20 minutes. During this segment of the trip, the pilot reported that the three passengers seemed much more subdued. The pilot stated that, to facilitate moving around the cabin for taking pictures, the available four-point harnesses were not being used by the passengers. He advised that he was climbing through 5,500 to 5,700 feet with a target altitude of 6,000 feet around Chandalar Shelf, when the male passenger slumped into the yoke and blocked the throttle and landing gear controls as they encountered rising terrain and a downdraft. The inflight cruise speed of 130 knots then increased to 160 knots, near the airplane's placarded never exceed speed (Vne). The pilot yelled at the unresponsive passenger and attempted to push him away from the engine controls and off the yoke. The pilot advised that he was pinned by the unresponsive passenger and that the back seat passengers were unresponsive during the entire time that the male passenger was unresponsive. The pilot lowered the wing flaps half way and opened the canopy 6-inches to facilitate a post-crash exit. Postimpact, the pilot was able to shut off the fuel, master switch, and magnetos, remove his seatbelt, open the canopy, and exit the airplane. The three passengers were unresponsive after the crash and remained in the airplane. When Alyeska Pipeline personnel arrived, they informed the pilot that the three passengers were in the airplane and that the airplane was not stable and could slide down the embankment. One of the female passengers was airlifted from the accident site to Fairbanks by helicopter. The pilot and two remaining passengers were transported to Galbraith Lake for subsequent medical air transport. When asked, the pilot reported that there were no mechanical malfunctions or anomalies that would have precluded normal operation of the airplane. Pilot's NTSB Form 6120.1 Approximately 2 months after the interview, on November 7, 2014, the pilot submitted a signed Pilot/Operator Aircraft Accident/Incident Report (NTSB Form 6120.1). On the form, the pilot stated the following: "Part 135 flight with three passengers. Standard pre-flight before take-off, including proper weight and balance calculation-about 70 gallons for flight. Flight from Fairbanks to Bettles was uneventful. Stopped and took a break at Bettles and then proceeded to Prudhoe Bay via Atigun Pass. While operating at approximately 5,600', encountered abrupt and unexpected aircraft instability. Took steps to correct but actions were ineffective. Made decision to protect passengers and myself in light of conditions. Aircraft hit the ground nose up and came to rest on side of hill. Made my way out of aircraft and was rescued. Have strong feelings about what happened but am awaiting the results of ongoing investigation, will reconsider providing further info after receiving results." He checked the box indicating a mechanical failure and stated that there was a "propeller bolt failure causing blade to become unindexed and blade separation in flight." Passenger Interviews According to the right front seat passenger, who was interviewed by FAA inspectors on August 27, 2014, after stopping in PABT, they proceeded up the valley. The air was smooth, under a "clear blue sky." Everyone had their shoulder harnesses on. Enroute to PASC, the pilot provided wildlife photo opportunities before the accident occurred. He could not remember the impact or the details leading up to it. According to one of the rear seat passengers, who was interviewed by a Transportation Safety Board of Canada investigator on September 12, 2014, they departed PABT and flew about 1 hour. They followed a pipeline with everyone taking photographs. A moose was observed at a lake, and photographs were taken while they circled the moose. After circling the moose, all three passengers took motion sickness pills (Gravol) that were given to them by the front right seat passenger. They proceeded into a mountain valley approximately 20 minutes later, and she remembered entering the mountain valley halfway between the tops of the mountains and the ground. Just prior to the accident, the passenger felt the airplane bank slightly and then drop as if "into an air pocket." She described it as "when it drops and you feel your tummy rise up." The rear seat passenger did not remember hearing anything unusual, observing or hearing the pilot struggling, or hearing anything that would have indicated any concern by the pilot regarding the front seat passenger. Immediately prior to the accident, she remembered that the pilot was flying a relatively straight course. Her next memory was waking up after the accident. According to the other rear seat passenger, who was interviewed by FAA inspectors on September 8, 2014, after stopping at PABT, they followed the pipeline. She started feeling queasy and took a motion sickness pill. About 10 minutes later, they "hit an air pocket," and she felt her body being pressed into the seat in a "downward pull." She did not recall hearing any different or unusual sounds and was not aware that anything was wrong before the impact. Witness Statements According to several witnesses, just prior to the accident, they observed the airplane flying slowly in a northerly direction in the vicinity of Atigun Pass. The airplane was flying at low altitude, following the contours of the surrounding terrain, "like he was looking for game." As the airplane passed over a work truck at an estimated altitude between 500 and 800 feet above ground level (agl), the engine sounded like it was "running strong." Moments later, the airplane impacted sloping terrain at an elevation of approximately 4,600 feet on the east side of the Dalton Highway. It then slid about 35 feet across the loose rock of the slope and came to rest. When witnesses and first responders reached the airplane, all the occupants were in the airplane and conscious. The pilot instructed the first responders on how to unlatch the canopy and open it. Their first attempts to get the pilot out of the airplane were unsuccessful as the pilot discovered that his leg "wasn't working right." They lifted the pilot out and found a place for him to sit as they went back to the airplane to get the passengers out. As the pilot sat on the rocks the pilot stated, "What happened? What the hell happened?" He also made a comment about his business stating something similar to, "Well, I guess I'm out of business" or "Well there goes my business." He later was heard to say, "I don't know what happened – I guess I was too low, I don't know." Later, the pilot advised a first responder that he was flying at an altitude about 1,000 feet over the top of the pass, when a strong downdraft caused the airplane to lose altitude. The pilot elaborated that he had tried to compensate by adding power and lowering the flaps to half. First responders also noted that the front seat passenger had his shoulder harness and seatbelt on when they reached the airplane, and they had to remove the harness and seat belt in order to extricate him from the airplane. PERSONNEL INFORMATIONThe pilot held a commercial pilot certificate with ratings for airplane single-engine land, airplane single-engine sea, and instrument airplane. He also held a flight instructor certificate with ratings for airplane single-engine and instrument airplane, as well as a mechanic certificate with ratings for airframe and powerplant, and an inspection authorization. His most recent FAA second-class medical certificate was issued on April 3, 2014. On the NTSB Form 6120.1 completed by the pilot, he reported that he had accrued 4,759 total hours of flight experience, 657 of which were in the accident airplane make and model. Review of FAA and NTSB aircraft accident records revealed that the pilot had been involved in two previous accidents. On December 26, 2007, the pilot was involved in an accident (NTSB Case No. ANC08LA030) while providing flight instruction to a student pilot in a Piper PA-22 during civil twilight. While on approach to an unlighted, snow-covered gravel runway, the pilot instructed the student pilot to go-around when he realized that the airplane was not lined up with the runway. He said that his verbal command to immediately apply full engine power and initiate a go-around was followed, but the engine did not respond. According to the pilot, he then took control of the airplane, confirmed that the throttle was at maximum, and then landed the airplane in the deep snow. As the main and nose wheels touched down in the deep snow off the left side of the runway, the airplane decelerated rapidly, and the nose landing gear collapsed. The airplane sustained substantial damage to the fuselage and wings. An FAA airworthiness inspector reported that his postaccident inspection of the airplane disclosed a number of maintenance deficiencies, but found none that would have accounted for the loss of engine power. The NTSB determined that the probable cause of the accident was a loss of engine power for an undetermined reason during an attempted go-around, resulting in a forced landing and a collision with snow-covered terrain. The NTSB also determined that a factor associated with the accident was the lack of suitable terrain for a forced landing. On November 14, 2008, the pilot was involved in another accident (NTSB Case No. ANC09LA011A) while providing instruction to a student pilot in a Cessna 152 in day visual meteorological conditions. The Cessna 152 was on the right downwind leg for landing behind a Cessna 182R that was on final approach. The Air Traffic Control Tower (ATCT) specialist asked the Cessna 152 pilots if they had the landing traffic in sight, and the pilot said that they did. Review of radar data and radio communications from the ATCT revealed that the Cessna 152 joined the final approach course slightly behind and above the Cessna 182R. As the two airplanes continued toward the runway, the ATCT specialist issued instructions to the Cessna 152 to make a right 360-degree turn. According to the pilot, at about the same time the nose of the Cessna 182R appeared under his Cessna 152 and he applied full power and began a left climbing turn while advising ATCT of his actions. The left wingtip of the Cessna 152 collided with the top right side of the Cessna 182R's rudder. The pilot of the Cessna 182R reportedly never saw the other airplane. Both airplanes landed without further incident. The NTSB determined that probable cause of the accident was the failure of the instructor in the Cessna 152 [the pilot] to maintain separation from another landing airplane and his failure to follow the tower controller's instructions. AIRCRAFT INFORMATIONThe accident aircraft was a single-engine, four-seat, low-wing airplane of conventional metal construction. It was powered by a 225 horsepower, Continental E-225-4 engine, driving a two-blade Hartzell, variable pitch, constant speed propeller. According to maintenance records, the airplane was manufactured in 1949. Its most recent annual inspection was completed by the pilot on June 14, 2014. The records indicated that, at the time of the inspection, the airplane had accrued 4,027.4 total hours of operation, and the engine had accrued 334.1 hours since major overhaul. The records showed that the pilot had been conducting the majority of the maintenance on the airplane, engine, and propeller since June 2011. Review of maintenance records further indicated that the propeller was overhauled on May 31, 2011, by a certified repair station and installed on the airplane by the pilot on June 6, 2011, approximately 3 years prior to the accident. According to the records, since the June 2011 installation, the propeller had been removed and remounted three times by the pilot to inspect and/or replace the propeller hydraulic bladder diaphragm, as required by Hartzell Alert Service Bulletin No. HC-ASB-61-338. The most recent removal and reinstallation of the propeller was on February 1, 2013. Weight and Balance Information On the NTSB Form 6120.1 completed by the pilot, he reported that he completed a "standard pre-flight before take-off, including proper weight and balance calculation-about 70 gallons for flight." When the pilot was interviewed on September 9, 2014, he stated that he calculated the weight of fuel, bags, and people to be "about 40 pounds below gross weight" before he departed PAFA. Review of published fuel flow data for the Continental E-225-4 engine indicated that, at 65% power, fuel flow would have been about 76 pounds (lbs) of fuel per hour, which equated to a minimum fuel load of approximately 100 gallons (not including fuel for taxi, takeoff, and climb) in order to have 7 hours and 20 minutes fuel onboard on departure from PAFA as listed on the pilot's flight plan. Weight calculations were performed using estimated weights of 160 lbs for the pilot, 230 lbs for the right front seat passenger, 180 lbs for one of the rear seat passengers, 150 lbs for the other rear seat passenger, 30 lbs of baggage, and 100 gallons of fuel on departure from PAFA. The calculations indicated that the airplane was approximately 187 pounds above maximum gross weight on takeoff from PAFA, approximately 37 pounds over maximum
The pilot’s improper inflight planning and improper decision to deliberately operate the airplane at low altitude in close proximity to obstructions and rising terrain. Contributing to the accident were the pilot’s improper preflight planning and the Federal Aviation Administration’s inappropriate decision to issue a 14 Code of Federal Regulations Part 135 certificate to the operator despite the pilot’s history of accidents, incidents, reexaminations, and checkride failures.
Source: NTSB Aviation Accident Database
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