WPR09FA154

The pilot's failure to maintain clearance from trees and terrain while maneuvering at a low altitude.

The pilot was on a cross-country flight during daytime visual meteorological conditions. A witness near the accident site reported observing a high-wing airplane similar to the accident airplane flying about 20 to 30 feet above the ground at a high rate of speed. The witness stated that the airplane was low enough to startle a herd of elk near the airplane's flight path. The witness continued watching the airplane as it pitched up and to the left, making a 180-degree turn steep enough to allow him to see the tops of both wings. There were no known witnesses to the accident sequence. The wreckage was located near the base of a mountain range about 2 days later, after being the subject of a missing airplane alert notice. Accident site documentation of the ground scars, contact evidence on the trees, and impact damage to the airplane were indicative of a high-speed controlled flight collision with trees and, subsequently, the ground. Examination of the airframe and engine revealed no evidence of any preimpact mechanical anomalies.

HISTORY OF FLIGHT On March 17, 2009, about 1445 mountain daylight time, a Cessna 180F airplane, N2698Y, was substantially damaged when it impacted terrain while maneuvering near Townsend, Montana. The airplane was registered to Mountain Flying, LLC of Helena, Montana and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91. The airline transport pilot, sole occupant of the airplane, was killed. Visual meteorological conditions prevailed in the area of the accident and no flight plan was filed for the personal flight. The cross-country flight originated from the Gallatin Field Airport, Bozeman, Montana, about 1411 with an intended destination of Helena, Montana. Family members of the pilot contacted the Federal Aviation Administration (FAA) on the evening of March 17, 2009, after becoming concerned when the pilot had not arrived at his intended destination. The FAA subsequently issued an Alert Notification. The Montana Aeronautics Division and United States Air Force, and the United States Customs and Border Protection commenced search and rescue operations throughout the area of the pilot's intended flight path. The wreckage was located by aerial units on the morning of March 19, 2009. A witness located about 2 miles northeast of the accident site reported that on March 17, while watching two people trespass on private property, he observed a high wing airplane similar to the accident airplane flying on a northerly heading, west of a set of power lines that were adjacent to a main railroad crossing. The witness stated that the tops of the wings were below the power lines and he estimated the airplane was 20 to 30 feet above the ground traveling at a high rate of speed. He added that the airplane was low enough, that it spooked a herd of elk near the airplane's flight path. The witness continued watching the airplane as it pitched up and to the left, making a 180-degree turn near the Kelly Gulch area to a southerly heading. He added that as the airplane pitched up, he was able to see the tops of the wings. The witness further stated that he stopped watching the airplane to continue observing the trespassers. There were no known witnesses to the accident sequence. PERSONNEL INFORMATION The pilot, age 64, held an airline transport pilot certificate with airplane single-engine land, multi-engine land, and instrument airplane ratings. The pilot also held a flight instructor certificate with airplane single-engine, multi-engine, and instrument ratings. A first-class airman medical certificate was issued March 19, 2008, with the limitations stated "must wear corrective lenses and possess glasses for near and intermediate vision." The pilot reported on his most recent airman's medical application that he had accumulated 20,045 total flight hours. The pilot's personal logbooks were not located during the course of the investigation. AIRCRAFT INFORMATION The four-seat, high-wing, fixed-gear tailwheel equipped airplane, serial number (S/N) 18051198, was manufactured in 1962. It was powered by a Teledyne Continental Motors IO-520-D (142), serial number 632509-R. The engine was modified to an O-520-F, rated at 280 horse power and equipped with a three bladed Hartzell constant speed propeller. According to FAA records, the pilot had recently purchased the airplane on December 30, 2008. Review of copies of maintenance logbook records showed an annual inspection was completed on August 1, 2008, at a recorded tachometer reading of 221.3 hours, airframe total time of 5,221.3 hours, and engine time since major overhaul of 221.3 hours. The digital tachometer was intact and not examined to determine its current readings. A logbook entry dated June 13, 2006, stated in part "0.00 hours since factory rebuilt. Converted engine from IO-520-D to IO-520-D-C-F by installing a "F" fuel system. Reference TCM Service Bulletin M75-6, Rev 1 and TCM IO-520 parts manual. Modified engine from TCM IO-520-D-C-F to Texas Skyways O-520-F/TS." METEOROLOGICAL INFORMATION A review of recorded data from the Automated Surface Observing System (ASOS), located at the Helena Regional Airport (HLN), Helena, Montana, revealed that at 1453, conditions were wind from 260 degrees at 18 knots, gusts to 25 knots, visibility 10 statute miles, few clouds at 4,800 feet above ground level (agl), overcast cloud layer at 5,500 feet agl, temperature 4 degrees Celsius, dew point -7 degrees Celsius, altimeter setting of 30.13 inches of Mercury, remarks peek wind gust from 260 degrees at 28 knots at 1420. The ASOS at the Gallatin Field Airport, Bozeman, Montana, reported at 1456, wind from 100 degrees at 5 knots, visibility 10 statute miles, broken cloud layer at 6,000 feet agl, temperature 6 degrees Celsius, dew point -4 degrees Celsius, and an altimeter setting of 30.11 inches of Mercury. According to a witness located adjacent to the accident site, around the time of the accident, he observed a storm over the mountain range west of the accident site with visible snow precipitation. He also stated that there was about 6 to 7 inches of snow on the ground in the area of the accident and the wind was about 5 to 10 miles an hour. WRECKAGE AND IMPACT INFORMATION Wreckage debris and numerous broken tree limbs were scattered about 600 feet along an approximate 355-degree magnetic heading from a cluster of scraped and broken trees, about 15 to 20 feet in height, within the bottom of a mountain drainage. A separated section of the inboard left wing and an outboard section of the left aileron were lodged in a damaged tree near the initial point of contact. A circular impression was observed on the separated portion of the left wing structure and was consistent with a topped tree located along with the separated portion of the left wing. The outboard left wing tip and auxiliary fuel tank were located about 102 feet from the initial impact with trees. Adjacent to the left wing tip, a ground scar/track consistent with the left main landing gear was observed. About 10 feet north and 7 feet east of the left main landing gear track, a second ground scar / track was observed. It was consistent with the right main landing gear and extended about 46 feet to an area of upsloping terrain. Five ground scars, aligned perpendicular and centered between the left and right wheel mark ground impressions were observed and found consistent with propeller slash marks. The first slash mark was followed by a second slash mark about 21 inches north, a third slash mark about 44 inches north, a fourth about 60 inches north, and a fifth slash mark about 89 inches north of the first propeller slash mark. A crater approximately 8 to 12 inches deep, 10 feet long, and 4 feet wide was observed on the ground approximately 148 feet north of the initial cluster of broken trees. Various debris including Plexiglas, left wing structure, right main landing gear, and vortex generators were located throughout the wreckage debris path, which extended up a 45-degree slope. The fuselage and empennage were located approximately 123 feet upslope of the crater. The propeller came to rest about 76 feet north of the main wreckage. The right main landing gear was found about 253 feet north of the propeller. Examination of the airframe revealed that the fuselage came to rest on about a 340-degree heading. A majority of the fuselage was consumed by fire. The empennage of the airplane was separated at the baggage compartment area and was found lying inverted. The elevator and rudder remained attached to their respective mounts. The outboard tips of the horizontal stabilizer and elevators were impact damaged. The outboard tip of the right elevator was separated and located within the wreckage debris path. Rudder and elevator control cable continuity was established from the control surfaces to the cockpit controls. The righ