Aviation Accident Summaries

Aviation Accident Summary LAX01FA270

Weaverville, CA, USA

Aircraft #1

N1109T

Beech B36TC

Analysis

According to ground witnesses at the airport, the pilot departed uphill on runway 36 into rising terrain, and collided with trees just beyond the runway's departure end. Runway 36 is 2,980 feet in length with a 50-foot pavement width, and has a 3.5 percent uphill gradient with steeper rising terrain to the north of the airport. An airport warning sign states in red "This R/W Closed for takeoff use R/W 18." On the day of the accident, the pilot contacted the FAA Rancho Murieta Automated Flight Service Station at 0823. The pilot questioned the briefer about the takeoff procedure and an "X" that was marked on the runway. A discussion ensued, and the briefer told the pilot to takeoff on runway 36 (uphill), contrary to the intent of signage at the airport and FAA Airport/Facility Directory remarks. According to the briefer, his source of information for questions relating to airport procedures and operations came from the FAA Airport/Facility Directory. The entry for the airport in the FAA Airport/Facility Directory was examined. The first portion of the entry stated: "Airport closed to touch and go; go arounds; takeoff from runway 36 and landings on runway 18." Toward the end of the entry following some intervening information another note stated: "Land runway 36 takeoff runway 18 due to steep 3.5 percent uphill airport gradient and steeper rising terrain to the north." The maximum gross weight of the airplane is 3,850 pounds. Based on known and estimated weights, the weight of the airplane at the time of the accident was about 3,939.0 pounds, or 89 pounds above the maximum takeoff weight. According to the POH and best available information, the airplane would have required 3,750 feet of level, paved, and dry runway surface for takeoff with zero flaps to clear a 50-foot obstacle at the end. Witnesses at the airport estimated that the temperatures were in the mid 90's to over 100 degrees, and the wind was out of the south. Based on information provided by the witnesses, the density altitude was estimated between 4,000 and 4,800 feet mean sea level (msl).

Factual Information

HISTORY OF FLIGHT On August 5, 2001, about 1415 Pacific daylight time, a Beech B36TC, N1109T, collided with trees and rising terrain during the takeoff initial climb at the Weaverville Airport (O54), Weaverville, California. The airplane was owned and operated by the certificated private pilot as a personal flight under 14 CFR Part 91. The pilot and one passenger received serious injuries; one passenger sustained minor injuries; and one passenger received fatal injuries. The airplane was destroyed. Visual meteorological conditions prevailed and no flight plan had been filed. The cross-country flight was originating at the time, and was destined for San Jose, California. The purpose for the trip to O54 was to attend a family event. According to a witness who was at the event, and who is associated with the airport, the takeoff and landing procedures at the airport were discussed. The statement is attached. The acting airport manager for Trinity County (O54) reported that he had given an airport briefing telephonically to a pilot about the landing and takeoff procedures the day before the accident. Based on the limited information given to the manager, he concluded that it was the accident pilot who had called. On the day of the accident, the pilot contacted the Federal Aviation Administration (FAA) Rancho Murieta Automated Flight Service Station at 0823. The pilot questioned the briefer about the takeoff procedure and an "X" mark on the runway. He also filed an instrument departure flight plan from O54. A discussion ensued, and the briefer told the pilot to takeoff on runway 36 (uphill), contrary to the intent of signage at the airport and FAA Airport/Facility Directory remarks. The briefer's source of information for questions relating to airport procedures and operations came from the FAA Airport/Facility Directory. A transcript of the conversation is attached to this report. According to ground witnesses at the airport, the pilot departed uphill on runway 36 into rising terrain, and collided with trees. The FAA Airport/Facility Directory entry for the O54 contains the cautionary warning, "Takeoff runway 18, due to steep 3.5 percent uphill runway gradient and steeper rising terrain to the north." Airport signage and flight guides also reference this procedure. The airport is unattended. Witnesses at or near the airport said the temperature was over 90 degrees, and the winds were from the south at the time of takeoff. One witness attempted to run out to the runway and stop the departure when he realized what was about to happen but was unsuccessful. AIRCRAFT INFORMATION According to logbook information, the last documented annual inspection occurred on October 12, 2000, at 388.5 total flight hours. During the post accident examination, the Hobbs hour meter indicated 485.4 hours. According to the Pilot Operator Handbook (POH), the maximum gross weight of the airplane is 3,850 pounds. Based on known and estimated weights, the weight of the airplane at the time of the accident was about 3,939.0 pounds, or 89 pounds above the maximum takeoff weight as established in the (POH). The fuel tanks were last filled on August 3, 2001, at San Jose. According to the POH and best available information, the accident flight would have required 3,750 feet of level, paved, and dry runway surface for takeoff with zero flaps to clear a 50-foot obstacle at the end. PERSONNEL INFORMATION The certificated private pilot was rated for single and multiengine land airplanes and instruments. At the pilot's last documented third-class flight physical on October 8, 1999, he reported a total flight time of 4,000 hours, with 30 hours in the last 6 months. METEOROLOGICAL INFORMATION No official local area weather information was available for O54. According to local airport observers, the temperature estimates were in the mid 90's to over 100 degrees, and the wind was out of the south with visual meteorological conditions. Based on information provided by the witnesses, the density altitude was estimated between 4,000 and 4,800 feet mean sea level (msl). AIRPORT INFORMATION The Weaverville/Pool (O54) public owned airport is categorized as a basic utility airport with oversight provided by The California Department of Transportation (Caltrans). According to the FAA Airport Master Record, form 5010-2, dated June 18, 1997, runway 36/18 is 2,980 feet in length with a 50-foot pavement width at an elevation of 2,350 feet msl. The runways are designated 36 and 18. Runway 36 has a 3.5 percent uphill gradient and is listed as the landing runway due to the steep uphill gradient with steeper rising terrain to the north. Runway 36 also has a displaced threshold of 90 feet. About 200 feet north of the runway 36 designated threshold, on the west side, an airport warning sign states in red "This R/W Closed for takeoff use R/W 18." Runway 18 is designated the takeoff runway, though it is not marked as runway 18, and displays a large yellow "X" before a threshold line and a large white "X" after the threshold line. On the FAA form 5010-2, airport layout plan sketch, a note pointing to the threshold line notes it to be a relocated nonstandard threshold with no distance noted prior to the threshold. Airport remarks for O54, found in the FAA Airport/Facility Directory and on the FAA form 5010-2 state: "Airport closed to touch and go; go arounds; takeoff from runway 36 and landings on runway 18." Additionally, it states: " Runway 18 no numbers marked, white 'X' on approach end of runway 18. Land runway 36 takeoff runway 18 due to steep 3.5 percent uphill airport gradient and steeper rising terrain to the north. Significant variations in wind direction and intensity can occur at the approach to runway 36." WRECKAGE AND IMPACT INFORMATION The fuselage was located about 124 feet north, or beyond the runway 36 pavement end, in heavy forestation. Multiple tree strikes fragmented the wings into several sections strewn between the fuselage and the beginning of the forest. The rubber leading edge fuel cells were torn and scattered with no sign of post accident fire. The empennage was twisted to a point of separation from the fuselage with tree impact signatures. The propeller displayed rotational signatures with leading edge gouges and chordwise striations and severed tips. The engine was shipped to the manufacturer, Continental Motors, Mobile, Alabama, for a teardown inspection under the supervision of Safety Board investigators. The engine was impact damaged and the crankshaft flange was cracked. The engine exhibited normal operating signatures internally. The fuel system components were flow tested, and all components flowed to specifications. ADDITIONAL INFORMATION The wreckage was released to the insurance company representative on July 24, 2003.

Probable Cause and Findings

the pilot's selection of the wrong runway, which resulted in an attempted takeoff uphill in a prevailing tailwind toward rising terrain and high obstacles. Also causal was the pilot's loading of the airplane above maximum gross weight and his failure to properly interpret the aircraft performance charts, which showed the airplane required more runway and distance to clear a 50-foot obstacle than existed for the ambient conditions. Factors in the accident were the high density altitude and the confusing and contradictory information in the Airport Facility Directory.

 

Source: NTSB Aviation Accident Database

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