Aviation Accident Summaries

Aviation Accident Summary ANC03FA061

Skagway, AK, USA

Aircraft #1

N736QK

Cessna 172

Analysis

The certificated private pilot departed on a VFR cross-country flight over mountainous terrain. In order for the pilot to reach his destination, the flight would need to traverse a commonly used mountain pass. Prior to departure, the pilot obtained a weather briefing that included AIRMET's for mountain obscuration along the planned route of flight. The Automated Flight Service Station (AFSS) briefer advised that there were no pilot weather reports available for the area around the mountain pass. The AFSS specialist added that weather conditions, specifically in mountain passes, were forecast to deteriorate, with marginal VFR conditions, low ceilings, rain, and fog. A road maintenance crew working on a portion of the highway near the accident site, reported low clouds, fog, and reduced visibility in the area just before the accident, and they elected to stop working due to safety concerns associated with deteriorating weather conditions. One witness reported that while sitting in his vehicle, waiting for weather conditions to improve, he heard what sounded like a low flying airplane headed towards him. He said that as he looked up, he saw the accident airplane fly out of a cloud, headed north, and parallel to the east side of the valley. As the airplane continued, he heard it "clip the side of the mountain." After the airplane contacted the mountain, the wings rocked back-and-forth, and the airplane once again entered a cloudbank. He said that just after he lost sight of the airplane for the second time, the engine speed increased significantly, followed by the sound of the airplane impacting terrain. Postaccident inspection of the airplane disclosed no evidence of any preaccident mechanical anomalies.

Factual Information

On June 25, 2003, about 1105 Alaska daylight time, a wheel-equipped Cessna 172 airplane, N736QK, sustained substantial damage during an in-flight collision with mountainous terrain in cruise flight, about 12 miles north of Skagway, Alaska. The airplane was being operated as a Title 14, CFR Part 91 visual flight rules (VFR) cross-country personal flight when the accident occurred. The private certificated pilot and the sole passenger received fatal injuries. Visual meteorological conditions prevailed at the airplane's point of departure, and a VFR flight plan was filed. The flight originated at the Juneau International Airport, Juneau, Alaska, about 1028, and was en route to the Whitehorse International Airport, Whitehorse, Yukon Territory, Canada. On June 25, 2003, at 0844, the pilot contacted the Juneau, Alaska, Automated Flight Service Station (AFSS), and requested a weather briefing. The pilot said his planned route of flight was from Juneau to Watson Lake, Yukon Territory, with a stop in Whitehorse, Yukon Territory to clear US/Canadian customs before proceeding further into Canada. The pilot said that while en route to Whitehorse, he would fly direct to Skagway, then northbound to Whitehorse, through a commonly traveled mountain pass. The AFSS specialist provided a full briefing that included AIRMETs for mountain obscuration along the flight's planned route. The AFSS specialist added that forecast weather conditions to the north of Skagway, specifically in mountain passes, were forecast to deteriorate sometime after 1000, with marginal VFR conditions, low ceilings, rain, and fog. The AFSS specialist also noted that there were no current pilot weather reports available for the flight between Skagway and Whitehorse. The pilot then filed two separate VFR flight plans. The first flight plan was filed for the flight between Juneau and Whitehorse, via Skagway, and the second flight plan was filed for the flight between Whitehorse and Watson Lake. The airplane departed the Juneau International Airport, about 1028. About 1031, the pilot contacted the Juneau AFSS and requested that his VFR flight plan be activated. No further communication was received from the pilot. During on-scene interviews conducted by the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on June 26, members of a State of Alaska road maintenance crew working on a portion of the Klondike Highway near the accident site, reported low clouds, fog, and reduced visibility in the area just before the accident. They said that while working at the 2,500-foot msl level of the mountain pass, they elected to stop working due to safety concerns associated with deteriorating weather conditions. One of the witnesses reported that while sitting in his vehicle, waiting for weather conditions to improve, he heard what sounded like a low flying airplane headed towards them. He said: "I was really surprised to hear an airplane flying since the weather was so bad." The witness said that as he looked up, he saw the accident airplane fly out of a cloud, headed north, and parallel to the east side of the valley. He reported that as the airplane continued, he heard it "clip the side of the mountain." The witness said that just after the airplane contacted the mountain, the wings rocked back-and-forth, and the airplane once again entered a cloudbank. He said that just after he lost sight of the airplane for the second time, the engine speed increased significantly, followed by the sound of the airplane impacting terrain. The witnesses reported that immediately after hearing the impact, they reported the accident to the State of Alaska / Department of Transportation dispatcher, who then contacted the Alaska State Troopers, Skagway Police, and Skagway Volunteer Fire Department. Responding rescue personnel located the inverted airplane wreckage about 1200, at the 2,900-foot msl level of Mine Mountain, in an area of steep, rock and tree-covered terrain. PERSONNEL INFORMATION The pilot held a private pilot certificate with airplane single-engine land and instrument airplane ratings. The most recent special issuance second-class medical certificate was issued to the pilot on April 24, 2003, and was valid until April 30, 2004. The medical certificate contained the limitation requiring that the pilot provide the Federal Aviation Administration's Regional Flight Surgeon, Kansas, Missouri with a current medical report, from the pilot's treating physician, with his history of elevated blood pressure treatment. According to the pilot's personal logbook that was located at the accident site, his total aeronautical experience consisted of about 1,398.4 hours. In the preceding 90 and 30 days prior to the accident, the logbook listed a total of 72.1 and 52.6 hours, respectively. The pilot underwent a biennial flight review (BFR) on November 2, 2001, and an instrument proficiency check on May 20, 2003. The last entry in the pilot's logbook was dated June 23, 2003, for a flight from Talkeetna, Alaska, to Cordova, Alaska. METEOROLOGICAL INFORMATION The closest official weather observation station is located at the Skagway Airport, about 12 nautical miles south, and 2,900 feet lower than the accident site. On June 25, 2003, at 1053, an automated weather observation system was reporting, in part: Wind, 200 degrees (true) at 14 knots; visibility, 10 statute miles; clouds, 5,500 feet overcast; temperature, 57 degrees F; dew point, 46 degrees F; altimeter, 30.05 inHg. A witness, parked in a truck along a roadway, located about one-quarter of a mile and 300 feet below the accident site, characterized the weather conditions in the mountain pass as "very low visibility with rain, fog, low ceilings, and very strong winds." He added that at one point visibility was reduced to less than 300 feet horizontally. He said there were occasional breaks in the fog as it was being blown through the mountain pass by the strong winds, allowing brief glimpses of the surrounding mountainous terrain. COMMUNICATIONS A transcript of telephone, and air to ground communications between the accident airplane, the AFSS, and Juneau Air Traffic Control Tower, are included in the public docket for this accident. WRECKAGE AND IMPACT INFORMATION The NTSB IIC examined the airplane wreckage at the accident site on June 26, 2003. The accident site was located about 2,900-feet msl in an area of about 40-degree up sloping rock and tundra, adjacent to a small mountain ravine. An area of soil disruption, located about 15 feet above the final resting point of the wreckage, appeared to be the first point of impact. The soil disruption crater measured about 5 feet across. Small portions of airplane wreckage debris, including paint chips, and broken Plexiglas, were observed within the soil disruption crater. The accident airplane came to rest inverted, with the empennage orientated downhill. The nose of the airplane was oriented uphill, on a magnetic heading of approximately 030 degrees. The wings remained attached to the fuselage, but were extensively distorted. The flight control surfaces remained connected to their respective attach points. Due to impact related damage, continuity of the flight control cables could not be established at the accident site. The two-bladed propeller assembly remained connected to the engine crankshaft. One propeller blade exhibited almost 90 degree aft bending about mid-span, with substantial leading edge gouging and chordwise scratching. The second propeller blade exhibited almost 90 degree aft bending about 5 inches from the tip, with substantial leading edge gouging and chordwise scratching. The bottom of the engine sustained impact damage. The muffler was crushed upward and flattened against the engine, as was the muffler exhaust tube. The crushed and folded edges of the muffler exhaust tube did not exhibit any cracking or breaks. No evidence of any preaccident mechanical anomalies were discovered during the on-scene portion of the investigation. On June 27, the airplane wreckage was recovered from the accident site by helicopter, flown to a roadside site, and transported by truck to a wreckage storage facility located in Skagway. MEDICAL AND PATHOLOGICAL INFORMATION A postmortem examination of the pilot was conducted under the authority of the Alaska State Medical Examiner, 4500 South Boniface Parkway, Anchorage, Alaska, on June 27, 2003. The examination revealed that the cause of death was massive blunt force injuries. A toxicological examination conducted by the FAA's Civil Aero Medical Institute (CAMI) on August 11, 2003, was negative for alcohol or drugs. TESTS AND RESEARCH After the airplane was removed from the accident site, a detailed airframe and engine inspection was accomplished on June 27, in Skagway, with representatives of all parties to the investigation present. Flight control cable continuity was established. No evidence of any preaccident mechanical anomalies was discovered. The NTSB IIC recovered a GARMIN, model 195, hand held Global Positioning System (GPS) unit from the accident site. The GPS unit was shipped to GARMIN International, Inc., to recover the accident pilot's preaccident route of flight information. A technician for GARMIN International reported to the NTSB IIC that impact related damage to the GPS unit precluded him from retrieving any stored data. WRECKAGE RELEASE The Safety Board did not take custody of the airplane wreckage. The retained GARMIN hand held GPS unit, along with the deceased pilot's personal logbook, were released to the family's representative on August 14, 2003.

Probable Cause and Findings

The pilot's continued visual flight into instrument meteorological conditions, which resulted in an in-flight collision with mountainous terrain. Factors associated with the accident were low ceilings, rain, and fog.

 

Source: NTSB Aviation Accident Database

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