Aviation Accident Summaries

Aviation Accident Summary CHI98LA026

SHEBOYGAN, WI, USA

Aircraft #1

N62MB

Learjet 35A

Analysis

The airplane had just reached its rotation speed during takeoff, when a deer '...bolted across the front of the aircraft from right to left...' striking the left wing. The pilot said he had to use full right aileron and rudder to keep the airplane level until it reached a low cruise speed. The middle third of the left wing's leading edge was crushed aft. The pilot continued the flight to a larger airport and landed without further incident. The departure runway (where the accident occurred) was located between 2-wooded areas that were about 600 and 1,100-feet from its edge. The airport did not have a perimeter fence around it that would prevent deer from entering the runway environment. The Federal Aviation Administration, in concert with the accident airport's state and county authorities have agreed to install a perimeter fence that is designed to keep deer from straying onto the airport property.

Factual Information

On October 29, 1997, at 1200 central standard time (cst), a Lear 35A, N62MB, piloted by an airline transport-rated crew, was substantially damaged when its left wing collided with a deer during takeoff from runway 03 (5,399' X 100' dry concrete) at the Sheboygan County Memorial Airport, Sheboygan, Wisconsin. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 135 passenger flight was not operating on a flight plan. The flight crew and two passengers reported no injuries. The flight was departing from Sheboygan, Wisconsin, at 1200 cst. According to the pilot, the airplane collided with a deer that "...bolted across the front of the aircraft from right to left..." as the airplane reached its rotational speed for liftoff. He said the left wing struck the deer "...about 2/3 of the way outboard of the wing very near the stall fence." The pilot said they climbed the airplane slowly, noting "...it took full right aileron and almost full right rudder to keep the aircraft level. As we accelerated the control forces required reduced rapidly." The pilot said he accelerated the airplane to 200 knots and it "...flew well... ." According to the pilot, there was "...some vibration..." during the cruise portion of the flight. He said that about 1/4 right aileron was required to keep the airplane level. The pilot said he decided to fly the airplane to General Mitchell International Airport, Milwaukee, Wisconsin, because it had longer runways and "...excellent rescue equipment." N62MB was landed on runway 25L (8,011' X 150' dry concrete) at General Mitchell Airport "...without incident...," according to the pilot. Inspection of the airplane revealed that the middle-third of the left wing's leading edge was crushed aft about 3 to 4-inches. The wing fence's forward section was wrinkled to its mid-span location. The wing skin next to the leading edge damage was wrinkled to about the mid-chord area. During an interview with the airport manager (manager) it was revealed that N62MB collided with the deer about 2/3rds the way down runway 03. He said that portion of the runway is located between two wooded areas. The wooded area west of the collision point is about 1,100 feet from the runway. The wooded area east of the collision point is about 600 feet from the runway. The manager stated the deer was going from the east wooded area to the west wooded area via the clearway and runway environment. The manager said in addition to the wooded areas close to the runways, there are also wetlands and farm fields immediately adjacent to the airport property. The farm fields are usually planted with corn, soy beans and wheat, according to the manager. The manager said the airport does not have a perimeter fence to prevent deer and wild turkeys from entering the airport property. He said the county board has petitioned state aviation authorities for funding assistance to install a fence in the past. The funding has not been available for such a project, according to the manager. The manager said a fence project involving the installation of a 12-foot high fence would cost about $400,000.00. At the conclusion of discussions with the Federal Aviation Administration Airport District Office in Minneapolis, Minnesota, the Wisconsin Bureau of Aeronautics in Madison, Wisconsin, and the airport manager the installation of the deer fence at the airport has been approved and should be installed by Fall 1998.

Probable Cause and Findings

a deer that ran in front of the airplane during the takeoff phase. A factor in this accident was the lack of an airport perimeter fence to prevent deer from getting onto the runway.

 

Source: NTSB Aviation Accident Database

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