Aviation Accident Summaries

Aviation Accident Summary ANC05FA121

Denali Park, AK, USA

Aircraft #1

N912DB

Beech V35B

Analysis

The private pilot was operating his airplane under Title 14, CFR Part 91 as a personal cross-country flight. He was participating in a group flight-seeing trip touring Alaska, that departed the state of Washington several days earlier. Each of the group's ten participants had provided their own airplanes for the tour. Prior to the accident flight, the group had been briefed by the group leader, an experienced commercial pilot with significant Alaska mountain flight experience, on the suggested route and altitudes through mountainous terrain to a rendezvous at another airport. An FAA inspector also made a presentation to the group that morning on some of the hazards associated with flying in the mountains. The group departed in small groups at close intervals. The accident pilot and two other pilots elected to initially fly a course parallel to the one suggested, up a different drainage/canyon. The intent was to join the suggested route later in the flight. A pilot flying above and behind the accident airplane noted that there was steeply rising terrain at the end on the canyon, and he started his climb before the accident pilot to clear a saddle between two peaks. He stated that the accident pilot, who was about 700-1000 feet lower than him, started his climb too late, and collided with a rock face, about 300 feet below the 5,000 feet msl saddle. The airplane was destroyed by impact and a postcrash fire. Inspection of the airplane disclosed signatures on the propeller and associated components consistent with a high power setting at impact. The pilot flying behind the accident pilot stated that there were no distress calls from the pilot prior to impact, and that the weather was not a factor in the accident. Other pilots flying in the vicinity noted that the wind was either calm or light, with no associated turbulence, with ample clearance between the ridges and the higher cloud layers.

Factual Information

HISTORY OF FLIGHT On August 5, 2005, about 1236 Alaska daylight time, a wheel-equipped Beech V35B airplane, N912DB, was destroyed by impact and postcrash fire when it collided with rising terrain while climbing, about 16 miles south-southeast of the McKinley Park airstrip, Denali National Park, Alaska. The private pilot and sole passenger were fatally injured. The 14 CFR Part 91 personal flight operated in visual meteorological conditions, and a VFR flight plan was filed. The flight departed Fairbanks, Alaska, about 1150, with an intended destination of Anchorage, Alaska. The airplane was owned and operated by the pilot. The accident airplane was part of a group of ten airplanes flying from Washington and California on an aerial tour of Alaska. The group leader had taken several previous pilot groups in their own airplanes on flights to Alaska. He had also flown commercially in Alaska for several years, and at the time of the accident, operated a tour group business called "Let's Fly Alaska", in which pilots provided their own airplanes, and traveled as a group throughout Alaska before returning to their respective bases in Washington and California. The group initially met in Puyallup, Washington, and left for Alaska on August 1. Most members of the group had attended a preflight safety briefing given the morning of the accident at the Fairbanks transient pilot's lounge by the group leader and an FAA aviation safety inspector. The FAA inspector was the designated area safety program manager for the Fairbanks Flight Standards District Office. According to the group leader and the FAA inspector, during the briefing, the group leader established a preferred route and recommended altitudes from Fairbanks following the well-defined Nenana River drainage, George Parks Highway, and the Alaska Railroad tracks, through Windy Pass via Healy and McKinley (Denali) National Park, to a group landing at Talkeetna, prior to the remaining 75 statue mile flight to Merrill Field, Anchorage. The FAA inspector also gave a safety briefing regarding the hazards of flying from visual flight rules weather into instrument meteorological conditions in mountainous terrain. The group leader, in a postaccident interview with the NTSB investigator-in-charge (IIC), indicated that the accident pilot did attend the voluntary briefing. He also noted that the accident pilot was the pilot he had been most concerned with throughout the flight, as he perceived him as reluctant to follow directions, that he flew low and close to terrain, and often made abrupt pull-ups and steep turns. A copy of the group leader's statement is included in the docket of this report, as is the IIC's digest of an interview with him, and those of other group pilots interviewed. According to the group leader, and other members of the group, they left Fairbanks at closely staggered intervals, in one group of two, and then two groups of four. The accident pilot was in the first group of four, with one airplane ahead of him, and two behind. The pilot of the airplane immediately behind the accident airplane was in a Piper Comanche 250. He indicated that he and the accident pilot elected to deviate to the west and parallel to the planned route, up a broad valley (Riley Creek drainage area). He said he was about 3,500-4,000 feet msl, and the accident pilot was a mile or so ahead of him, and about 700-1000 feet lower. The Piper pilot said he initiated a climb as the valley narrowed into a box canyon, and they approached rising terrain with a saddle between two peaks. He said the accident pilot below and ahead of him started his climb slightly later. Shortly after the accident pilot initiated his climb, he said it appeared that the accident pilot tried to initiate a left turn away from the steeply rising terrain/saddle area, and moments later he saw a plume of smoke. He continued his climb, and said that while he does not have a lot of experience in mountain flying, he came closer to the saddle ridge then he was comfortable with. After crossing the ridge, he turned around, and attempted to locate the wreckage site, but could not. He stated that weather was not a factor in the crash, that there were a few scattered thin clouds near the ridges, with light wind and no appreciable turbulence. The Piper pilot alerted the remainder of the group, and they located the general vicinity of the accident site, and relayed that information to a FAA flight service station specialist, who alerted a search and rescue team. An Alaska Air National Guard 210th Rescue Squadron helicopter and crew from Anchorage reached the accident site about 1500, and recovered the remains of the pilot and passenger. According to the helicopter commander, the pilot and passenger were lying outside the wreckage, down slope of the main wreckage point of rest. He noted there appeared to have been a localized postcrash flash fire. He estimated the accident site elevation as approximately 5,000 feet msl. PERSONNEL INFORMATION The pilot held a private pilot certificate with airplane single engine land privileges. Neither the airplane's maintenance logs, or the pilot's personal flight logbook, was discovered at the accident site, and family members indicated that they also were unable to locate the airplane's or pilot's logbooks. The flight time noted in the data fields of this report is based upon information the pilot provided in his last application for an FAA medical certificate, dated December 19, 2003, and the undated questionnaire he completed for Let's Fly Alaska. His FAA medical noted his flight experience as 6,400 hours plus, and his Let's Fly Alaska Questionnaire listed 6,600 hours plus. It could not be determined if the pilot had completed a biennial flight review. On his Let's Fly Alaska Questionnaire, the area requesting the date of his last flight review was left blank. The IIC interviewed two certificated flight instructors who had flown with the pilot during a flight review and training seminar sponsored by the American Bonanza Society. The accident pilot flew with the initial instructor for approximately 2.5 hours on April 17, 2004, for the purpose of obtaining any remedial training and a biennial flight review. The instructor indicated that the pilot had difficulty completing the basic private pilot flight maneuvers, and after 2.5 hours, the pilot told him he didn't wish to continue the flight. The instructor suggested that perhaps he'd like to fly with another instructor, to see if he could complete the biennial review. According to the instructor, the pilot reluctantly agreed. On April 18, the accident pilot flew with another instructor. That instructor related comments similar to the first instructor, and noted that the pilot was making a lot of fundamental errors, and had difficulty flying a standard traffic pattern. He stated that the pilot became frustrated, and stopped the flight review prior to completion. A review of the pilot's FAA flight records/history disclosed that on September 18, 2003, the pilot successfully completed an oral examination with a Van Nuys Flight Standards District Office aviation safety inspector, following an inadvertent gear-up landing. The FAA inspector spoke with the NTSB IIC on September 23, and noted that he did not give the pilot a flight evaluation, but said that they sat in the pilot's airplane while it was stabilized on jack stands, undergoing repairs to damage incurred during the gear-up landing. The inspector indicated in his report that the examination took 1.5 hours, and during the conversation with the NTSB IIC, said that the pilot seemed to have good knowledge about how his airplane and its emergency systems functioned. AIRCRAFT INFORMATION The airplane was a V35A, 1975 model year Beech Bonanza, registered to the pilot. It was equipped with a 285-rated horsepower Continental IO-520BB engine, and a 3-bladed Hartzell propeller. As noted, no current aircraft logbooks were discovered. A maintenance invoice/work order indicated that on July 23, 2002, a factory "zero time" rebuilt IO-520BB engine, serial number 825816-R, was installed, and other maintenance work performed. The work order reflected that at the time of installation, the tachometer time was 1485.3, and the total engine time was 4198.3. The last work order discovered was dated March 5, 2003, and indicated that the tachometer time was 1557.5 hours, or 72.2 hours since the factory rebuilt engine was installed. An aircraft annual inspection was also completed on that date. METEROLOGICAL INFORMATION Witnesses related that weather was good visual flight rules at the time of the accident, with visibility in excess of 20 miles, a few scattered clouds at 7,000 feet, and a higher overcast. They reported light or calm winds, and no significant turbulence. The closest weather reporting point to the accident site is McKinley Park, Alaska, approximately 16 miles north-northwest. At 1256, the reported weather was: Sky, 5,000' broken, 7,000' broken; visibility, 10 miles; wind, calm; temperature 16C, dew point 08C; altimeter, 29.97. COMMUNICATIONS There are no known relevant communications from the accident airplane prior to the accident. The pilot had reportedly had been in intermittent radio contact with other members of the group, but never indicated there were any problems with his airplane, and did not issue a distress call prior to the accident. WRECKAGE AND IMPACT INFORMATION The on-site investigation began on August 8. The IIC was accompanied by an Anchorage FAA Flight Standards District Office aviation inspector, two Denali National Park rangers, a representative from the airplane manufacturer, Raytheon Aircraft, and a representative from the engine manufacturer, Teledyne Continental Motors. The accident site was reached by the use of the Denali Park contract helicopter. The accident airplane was located in mountainous terrain on a steep rock face, on a saddle between two higher ridges. The elevation of the crash site was approximately 4,700 feet msl, about 300 vertical feet below the top of the 5,000 feet msl saddle, near 63:30 degrees north latitude, and 149:00 degrees west longitude. A postcrash fire had partially consumed the cabin and portions of the wings. The helicopter with the investigation team landed about 1,000 vertical feet below the wreckage site. The entire team attempted to reach the wreckage site, but due to falling rocks and the steep, ice and scree-covered terrain, the IIC requested that the remainder of the team remain below the wreckage. Due to the hazardous terrain, the IIC was only able to access the lowest section of the crash site, abeam a roughly 6 feet long section of the right wing and a portion of the left ruddervator. The propeller assembly, and a portion of the engine cowling, were about 50 feet higher. About 15 feet higher than the propeller assembly was a roughly 20 feet by 20 feet area of rock that had been charred from the postcrash fire, and whose location was consistent with the initial point of impact. Wreckage debris, consisting principally of windshield glass, and light, aluminum fragments of the fuselage, were located about 75 feet upslope of the propeller assembly. The propeller assembly had separated from the engine at the crankshaft, and the engine had separated from the fuselage. All three propeller blades were still attached to the propeller hub. All three propellers exhibited pronounced "S" bending and distortion, along with leading edge gouges and deep, chord-wise scratches on the blade faces. The majority of the airplane was either consumed by a postcrash fire, or fragmented/crushed during impact. Because of the unstable conditions, it was decided to postpone further examination of the wreckage until it was recovered from the mountain by an insurance adjuster's recovery team. The wreckage, including the engine and propeller assembly, were relocated to a storage facility in Wasilla, Alaska, by an agent for the pilot's insurance company. The IIC examined the wreckage and noted that due to severe fragmentation of the airframe and postcrash fire, flight control continuity could not be established. The engine case had been broken during impact, and damaged by the postcrash fire, but otherwise was essentially complete and intact. There was no evidence of any preimpact catastrophic engine failure. MEDICAL AND PATHOLOGICAL INFORMATION A postmortem examination was performed on the pilot by the State of Alaska, Office of the State Medical Examiner, 4500 Boniface Parkway, Anchorage, on August 8, 2005. The cause of death was attributed to multiple traumatic injuries. Toxicological samples were forwarded to the FAA's Civil Aeromedical Institute for testing. The results were negative for drugs or alcohol. FIRE There was a localized, postcrash fire, which self-extinguished. ADDITIONAL INFORMATION The pilot of the airplane immediately behind the accident airplane continued on a short distance, turned around, and attempted to locate the wreckage. His passenger took a short video tape (about 30 seconds) of the general accident area about 15 minutes after the accident, but no wreckage and no smoke or fire could be seen in the video. The IIC viewed the video tape, and returned it to the owner. During the climb to the wreckage site, a camera data card was found lying in the scree field without the camera. The data card was sent to the NTSB's vehicle recorder laboratory for review and duplication. According to family members of the passenger, the data card likely belonged to the passenger. The four photographs appeared to have been taken the morning of the accident, as the airplane entered the Riley Creek drainage, and ends a few miles from the accident site. The last photograph places the accident airplane on the left side of the drainage, close to rising terrain. The data card was returned to a family member. No parts of the airplane wreckage or components were retained by the NTSB.

Probable Cause and Findings

The pilot's failure to maintain altitude/clearance from mountainous terrain while climbing, and his improper in-flight decision making by electing to fly at a low altitude toward rising terrain. A factor associated with the accident was mountainous terrain.

 

Source: NTSB Aviation Accident Database

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