CHI99FA102

The airplane was cleared to land on runway 19R at the Kansas City International Airport. The first officer said that the airplane was on speed and on course for the visual approach. 'The captain had just called the 1,000 feet [above the ground] call when a flock of snow geese suddenly illuminated in our lights, engulfing us from below, flying into us. No birds hit the windshields, but it was immediately apparent they had flown into the engines.' The captain said that he had the airplane, advanced the power on both engines, and ordered the first officer to reset the flaps to 30 degrees, the single- engine flap position. 'The number one engine continued to compressor stall. The number two engine went to a sub-idle run condition.' The captain reduced the power on the number one engine 'enough to lessen the surge/stall condition to a rate of once every two seconds, which allowed just enough thrust to maintain the approach and to lower the vibration. The number one engine continued to compressor stall/surge to touchdown.' The touchdown was normal. Examination of the airplane revealed bird remains and substantial damage to both engines. No other anomalies were found.

History of flight

On March 4, 1999, at 2200 central standard time, a Douglas DC-9- 15F, N195US, operated by USA Jet Airlines, Incorporated, encountered a flock of large birds, while on final approach for landing at Kansas City International Airport, Kansas City, Missouri. During the encounter, several birds were ingested into both engines, resulting in a severe power loss. The pilot managed to regain enough thrust on one engine to continue the approach and land the airplane without further incident. Night visual meteorological conditions prevailed at the time of the encounter. The flight was being conducted under 14 CFR Part 121, non-scheduled, domestic air cargo service. An IFR flight plan was on file. The captain and first officer reported no injuries. The flight originated at Los Angeles, California, at 1825 pacific standard time (pst), and was en route to Kansas City, Missouri.

In her written statement, the first officer said that she was the flying pilot for this leg of their trip. Kansas City International Airport was conducting visual approaches to runways 19L and 19R. The airplane was cleared to land on runway 19R (10,801 feet by 150 feet, dry concrete). The first officer said that the airplane was on speed and course for the visual approach. "The captain had just called the 1,000 feet [above the ground] call when a flock of snow geese [was] suddenly illuminated in our lights, engulfing us from below, flying into us. No birds hit the windshields, but it was immediately apparent they had flown into the engines." The captain said that he had the airplane and directed the first officer to set the flaps to 30 degrees. The first officer said that she notified the Kansas City Air Traffic Control Tower (ATCT) of the bird strike. "When asked by [the] tower if we wanted to go around, we responded, negative.

The number two engine showed about 30 percent N1. The number one engine, when full thrust [was] applied, responded with fluctuating EPRs (engine pressure ratio gauge indications) and violent vibrations. We were able to land and taxi to the ramp with the thrust from [the] number one engine."

In his written statement, the captain said that on the descent into Kansas City international Airport, they received the current airport Automatic Terminal Information System (ATIS) broadcast. The ATIS information included the note, "migratory bird activity reported in the vicinity of the airport." Descending through 10,000 feet mean sea level (msl), the airplane's ground flood lights were turned on. Descending through 5,000 feet msl, the airplane's landing lights were turned on. The captain said that the first officer was flying the airplane on a 150 degree magnetic heading for the visual approach. The first officer intercepted the localizer inbound course for runway 19R, just inside the final approach fix. Ten miles from the airport, the landing gear was extended and the flaps lowered to 40 degrees. At 1,000 feet above ground level (agl), the captain said he made the call, "on localizer, on glide path, on speed." "At 800 feet agl, we hit with no warning, a large flock of snow geese." The captain said that the airplane was three miles from the runway threshold. "Both engines compressor stalled, and I took control of [the] aircraft." The airspeed decayed and the airplane descended below the glide path. The captain advanced the power on both engines and ordered the flaps reset to 30 degrees, the single-engine flap position. "The number one engine continued to compressor stall. The number two engine went to a sub-idle run condition." The captain said that the number one engine compressor stalled at a rate of a surge/stall per second, and vibrated violently. The number two engine remained at 30 percent N1 with no response to the throttle position. The captain reduced the power on the number one engine "enough to lessen the surge/stall condition to a rate of once every two seconds, which allowed just enough thrust to maintain the approach and to lower the vibration... The number one engine continued to compressor stall/surge to touchdown." The touchdown was normal.

Personnel information

The captain holds an airline transport pilot certificate with single-engine land, multi-engine land, and instrument airplane ratings. The captain reported having over 16,000 total flight hours, and over 10,000 hours in the DC-9. In the 30 days prior to the flight, he had logged 60 hours, all in the DC-9.

USA Jet Airlines, Incorporated, stated the captain underwent a flight proficiency check in the DC-9 on December 19, 1998.

The first officer holds an airline transport pilot certificate with single-engine land, multi-engine land, and instrument airplane ratings. The first officer reported having over 4,000 hours total flight time, and over 400 hours in the DC-9. In the 30 days prior to the flight, she had logged 60 hours, all in the DC-9.

USA Jet Airlines, Incorporated, stated the first officer underwent a flight proficiency check in the DC-9 on August 20, 1998.

Aircraft information

The airplane was a Douglas DC-9-15F, N195US, serial number 47017, owned and operated by USA Jet Airlines, Incorporated, of Belleville, Michigan, and was used for commercially transporting manufactured parts for automobiles, and other on-demand cargo.

The airplane had undergone a company continuous airworthiness inspection, "C" check," on February 4, 1999. The total airframe time at the inspection was 68,213.5 hours. The airframe time at the time of the bird encounter was 68,261.2 hours.

The airplane underwent a standard preflight by the crew prior to departing Los Angeles on March 4, 1999.

Airport information

Kansas City International Airport (MCI) is located at Latitude 39 degrees, 17.86 minutes north, and Longitude 94 degrees, 42.84 minutes west. The airport center is located approximately 15 miles north-northwest of the Kansas City metropolitan area, and 11 miles due north of the Missouri River. The Missouri River runs west-southwest to east through the north part of the city.

The FAA operates a class B airspace over the airport which extends radially from the airport center, out to 20 nautical miles. Requirements for operating with a mode C transponder extends radially for 30 nautical miles.

Airport Remarks listed for Kansas City International Airport in the Airport/Facilities Directory, North Central U. S., covering Missouri, include an advisory for "Waterfowl on and in vicinity of airport from October 1 to December 15, and April 1 to May 30."

Wreckage and impact information

On March 5, 1999, at 0930 cst, Federal Aviation Administration (FAA) inspectors examined the airplane at Executive Beechcraft, Kansas City International Airport.

The airframe showed no damage. Traces of bird remains were found along the front and top of the left nose gear door, and the left nose gear brace strut.

The left engine (number one engine), serial number 649193, showed traces of bird remains on the nose dome. Traces of bird remains were also observed adhering to the front ring and inside wall of the engine's nose cowl. The inlet guide vanes showed some minor inward denting along the leading edges. All of the first stage compressor fan blades were bent and broken. The second stage compressor fan blades were also bent and broken. Bird remains were observed adhering to the inner wall of the engine's exhaust pipe.

The predominately intact carcass of a large white-feathered bird was found embedded on the inboard inlet guide vanes of the airplane's right engine (number two engine), serial number 654749. Traces of bird remains were observed at the base of the nose dome, next to the bird carcass.

Flight control continuity was confirmed. Examination of the airplane's remaining systems revealed no anomalies.

The engines were retained for further examination.

Tests and research

The left eng