SEA99LA114

Witnesses observed the cropduster execute a second pass to a potato field from east to west. During the pull-up the aircraft failed to clear a bank of deciduous trees. Broken tree limbs and a portion of the aircraft's spray boom were found immediately west of the tree line. The aircraft impacted the ground approximately 0.15 miles further west of the tree line.

History of flight

On July 12, 1999, approximately 1040 mountain daylight time, an Air Tractor AT-502, N90807, registered to and being operated by Queen Bee Air Specialties, Inc., and being flown by a commercial pilot, was destroyed during an uncontrolled collision with terrain following an in-flight collision with trees while maneuvering. The aircraft crashed three nautical miles north-northwest of Shelley, Idaho, and the pilot sustained fatal injuries. Visual meteorological conditions existed, and no flight plan had been filed. The flight, which was engaged in crop dusting over a potato field, was to have been operated under 14CFR137, and originated from Rigby, Idaho, approximately 1020.

A witness, located one half mile south of the accident site, reported observing the aircraft mark the intended spray field with smoke markers from west to east, reverse course and initiate a spray run to the west. The witness stated that "the next pass from East to West was more difficult as it was between two houses with trees. He made his drop successfully but on his way up he banked to the left to miss the trees and house and hit part of the trees by the west house. The plane continues [sic] to climb to the left and then gradually turn - to the right, descending & crashing on his right wing & motor" (refer to STATEMENT S-I).

A second witness, located along the east/west spray track and on the west edge of the spray field, reported observing the aircraft and stated "I looked out the east window to see a crop dusting plane flying just above the potatoes flying directly toward our house. I could see the plane through some large trees between the plane and the house. I felt the plane could never clear the trees and was afraid it would surely hit the house. The plane rose sharply and turned to the south but hit some of the trees. I heard the impact and saw branches break. A few seconds later I heard a second impact sound" (refer to STATEMENT S-II).

A third witness, located one mile northeast of the accident site, reported observing the aircraft on what he thought was the aircraft's second pass from the east. Although he was unable to see the aircraft until the last few seconds of flight, he stated that "when I did see him he came up from below the Woodville Canal bank in a steep climb reaching approx. 150' - 200' rolled over on his right wing and went straight down" (refer to STATEMENT S-III).

Personnel information

The operator reported that the pilot had approximately 4,850 total flight hours of which 1,000 were in the accident aircraft make/model, and 110 of those hours were logged within the 90 days previous to the accident. The pilot's most recent second class medical examination was completed November 23, 1998, and contained the limitation "holder shall wear corrective lenses." It was not known whether the pilot was wearing such lenses at the time of the accident.

Aircraft information

The aircraft, an Air Tractor AT-502 (serial number 502-0191), was equipped with a Pratt & Whitney PT6A-34 turboprop engine. The aircraft was engaged in the dispensation of a fungicide over potato crops.

Meteorological information

The 1043 aviation surface weather observation taken at the Idaho Falls airport, six nautical miles north-northeast of the accident, recorded winds of four knots and variable direction with no gusts.

Wreckage and impact information

The aircraft crashed in an agricultural field along the southern edge of County Line Road and slightly east of Interstate 5 (refer to CHART I). The accident site coordinates were estimated to be 43 degrees 25.47 minutes north latitude and 112 degrees 08.34 minutes west longitude. On site examination was conducted by an inspector from the Federal Aviation Administration's (FAA) Salt Lake City Flight Standards District Office (FSDO) on July 13, 1999 (refer to attached Inspector's Report).

The inspector reported that the first evidence of aircraft impact with objects/terrain was noted in the tops of a deciduous tree line at a residence situated just south of the east/west oriented County Line Road (refer to photographs 1 and 2). Tree limbs and debris were observed hanging from the impacted trees and scattered across the lawn west of the trees (refer to photographs 2 and 3). A section of aircraft spray boom was observed lying on the ground in the garden just west of the tree impacts.

The aircraft's engine and propeller were observed embedded in the soil at the initial (most easterly) ground impact site. The distance between this impact site and the tree line was measured via an automobile odometer and reported to be 0.15 miles (refer to photograph 5).

The fuselage, wings, empennage and horizontal/vertical control surfaces came to rest as a single unit approximately 60 feet west of the initial ground impact site (refer to photographs 6 and 7, and DIAGRAM I).

During wreckage recovery, the engine was lifted from its impact crater and examined. Two of the three propeller blades remained attached at the hub assembly and displayed bending deformation (refer to photograph 8). One of these two blades displayed extensive chordwise scoring (refer to photograph 9). The third propeller blade was observed embedded in the soil and detached from the hub. When it was removed from the crater and examined, it displayed extensive tip curl (refer to photograph 10).

Medical and pathological information

Post-mortem examination of the pilot was conducted by Gary Ellwein, M.D., at the facilities of the Eastern Idaho Regional Medical Center, Idaho Falls, Idaho, on July 12, 1999 (case number A99.0033).

Toxicological evaluation of samples from the pilot was conducted by the FAA's Toxicology Accident and Research Laboratory, Oklahoma City, Oklahoma. All findings were negative (refer to attached report).

Additional information

On-site examination of the wreckage was conducted by an inspector from the FAA Salt Lake City FSDO on July 13, 1999, and the inspector subsequently released the wreckage to the aircraft operator.