NTSB Factual Report

On April 8, 2008, approximately 1205 mountain daylight time, a Bombardier, Inc. CL-600-2B16 business jet, N483BA, sustained substantial damage when it impacted birds during initial climb after takeoff from Colorado Springs Municipal Airport (COS), Colorado Springs, Colorado. The captain, first officer, cabin attendant, and two passengers were not injured. The airplane was operated by The Boeing Company Executive Flight Operations, Gary, Indiana, and registered to CEF 2002 Aircraft LLC, Danbury, Connecticut. Visual meteorological conditions prevailed, and an instrument flight rules flight plan was filed for the Title 14 Code of Federal Regulations Part 91 business flight. The flight was originating at the time of the accident.

The captain and first officer reported the sky was clear and light winds were from the south. Prior to departure, the crew had not received any advisories regarding bird activity in the area. On takeoff, the crew was given a clearance to a 150-degree heading and a climb to 10,000 feet mean sea level (msl). The takeoff was normal and in accordance with company procedures. Approximately 2 minutes after takeoff and passing through 8,000 feet msl and 230 knots, the crew noticed "large white birds." Immediately thereafter, the airplane impacted the birds. "At first there was a loud bang, followed by a moderately loud wind noise." The crew realized at least one bird had penetrated into the cockpit; they declared an emergency and requested to return to COS. The captain performed a few control checks and verified they could maneuver the airplane. The captain slowed the airplane to 200 knots to reduce noise and wind in the flight deck. The control checks were good and they turned back to COS.

The crew then took a minute to assess the damage to the airplane. The left engine had high vibration (4.0 mils); however the engine instruments matched with the right engine and the throttles were not split. In addition, the N2 gauge REV (thrust reverser) light was very intermittent in amber. The captain elected to turn off the left thrust reverser for the remaining portion of the flight, and the crew elected not to shut down the left engine due to weight, high airport altitude and visibility considerations. On the downwind leg, the crew selected flaps 20 degrees and an airspeed of 170 knots on the speed bug. The crew noted no problems with aircraft control after the configuration changes. During the downwind to base turn, the crew then selected flaps 30 degrees, landing gear down, and airspeed 150 knots. After turning final for runway 17R, the crew selected flaps 45 degrees and airspeed 150 knots (Vref for the landing was 142 knots). The captain continued the landing from the left seat and the first officer provided visibility assistance due to bird matter on the windscreen. The airplane landed uneventfully and taxied to a COS fixed based operator. The crew decided no evacuation of the airplane was required.

On April 9th to the 12th, representatives of the NTSB, operator, and airframe manufacturer examined the airplane. Examination of the airframe revealed a hole in the aircraft's forward fuselage below the cockpit windows. The fuselage skin and forward pressure bulkhead were penetrated and contained bird matter. The left engine fan blades were damaged and the spinner was buckled and collapsed. The thrust reverser torque box assembly and pylon tracks were bent, and the engine cowl supports were broken. The right engine inlet cowl leading edge was dented at the 12 o'clock position. Small bird matter remains were noted on fan blades, inlet skin and the fan spinner. Bird matter was noted on the cockpit windows, fuselage, and vertical and horizontal stabilizers.

On May 20th and 21st, the left engine was examined at General Electric's engine maintenance facility, Arkansas City, Kansas. During the examination, bird remains and feather fragments were collected from within the aft spinner, fan blade roots, and the fan exit area. All the fan blades were intact; however, most of the fan blades had damage to the leading edges and/or corner tips.

Bird remains were removed from the cockpit and left engine areas. The bird remains were collected and submitted to the Smithsonian Feather Identification Laboratory, Washington, DC. The bird remains were identified as American White Pelican (Pelecanus erythrorhynchos), and the average mass for the bird is approximately 7,000 grams (15.4 pounds). The state of Colorado is located in the migratory path of the American White Pelican. The birds usually travel from Montana/South Dakota to Mexico, paired up for mating, and travel in flocks of 4 to 12 birds.

The United States Air Force's Bird Avoidance Model (BAM) is used as a key tool for analysis, predictability, and correlation of bird habitat, migration, and breeding characteristics, combined with key environmental, and man-made geographic data. The BAM, based on historical data, has three risk classes: Low, Moderate, and Severe. These classes are based upon the bird mass in ounces per square kilometer. At the time of the accident, the BAM risk class was moderate for the Colorado Springs area.

NTSB Probable Cause

the impact with a bird during initial takeoff climb.