On September 26, 2004, about 0800 Alaska daylight time, a McDonnell Douglas MD-82 airplane, N16894, had a partial loss of engine power during takeoff from the Ted Stevens International Airport, Anchorage, Alaska. The flight was being conducted under Title 14, CFR Part 91, as a public use flight, operated by the Department of Justice, United States Marshals Service. The purpose of the flight was to transport prisoners between Anchorage and Phoenix, Arizona. There were no injuries to the 2 pilots, 17 guards, or the 112 prisoners aboard. Visual meteorological conditions prevailed, and an instrument flight plan had been filed for the intermediate flight to Boeing Field, Seattle, Washington. Use your browsers 'back' function to return to synopsisReturn to Query Page
During an interview with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on September 29, the captain stated that during the takeoff roll on runway 32, as the airplane's airspeed increased to about 90 knots, a loud bang was heard, immediately followed by the airplane's slight veer to the left of the runway centerline. The crew aborted the takeoff, suspecting that one of the airplane's left tires had blown during the takeoff roll. The captain said that she then taxied the airplane off of the active runway, onto an adjacent taxiway to assess the situation. She said that with both engines operating at idle, while stopped on the taxiway, a maintenance technician that was aboard, deplaned to inspect the airplane's condition, specifically the condition of the airplane landing gear. When the mechanic returned to the cockpit area, he reported that no mechanical anomalies were noted with the landing gear.
The captain said that as she advanced the number one engine's throttle to about 1.4 engine pressure ratio (EPR), a slight airframe vibration was felt, along with a loud noise that "sounded like a sewing machine." She added that after the airplane was taxied to the parking area, an inspection of the number one engine revealed damage to the first stage disk.
The captain reported that the airplane had remained parked overnight, outside, prior to the incident flight, and that when the flight departed, heavy wet snow/slush was present around the parking area and on the taxiways. She said that she did not request to have chemical de-icing done during the preflight, since the outside air temperature was above freezing at the time of departure.
According to contract maintenance crews, engine inlet plugs were not used while the airplane was in Anchorage overnight. A supervisor for the contract maintenance company reported to the NTSB IIC that prior to departure, a maintenance technician visually inspected both engine inlets for any accumulation of debris.
During a telephone conversation with the NTSB IIC on September 30, 2004, a Department of Justice aviation safety officer reported that de-icing procedures are conducted in accordance with McDonnell Douglas's cold weather operating procedures outlined in the MD-80 flight crew-operating manual. The safety officer noted that the Department of Justice did not, nor was it required to use, a Federal Aviation Administration (FAA) approved de-icing program, while operating as a public use flight, under Title 14, CFR Part 91.
A review of the McDonnell Douglas MD-80 flight crew operating manual revealed a caution note stating: "CAUTION: Ice shedding from wing upper surface during takeoff can cause severe damage to one or both engines, leading to surge, vibration, and complete thrust loss." In addition, the MD-80 flight crew operating manual states: "Clear ice can also form on wing upper surface when cold-soaked fuel is in the main wing fuel tanks and the airplane is exposed to conditions of high humidity, rain, drizzle, or fog at ambient temperatures well above freezing. Even though the bottom surface of the wing is free of frost and ice, upper wing surface clear ice can form if suitable conditions exist. An accumulation of clear ice is difficult to detect visually."
According to an FAA airworthiness inspector from the Anchorage Flight Standards District Office, the incident airplane was not equipped with an inboard, over-wing heater blanket system. The inspector said that the airplane was equipped with a series of non-skid strips, and tuft triangular decal/symbol assemblies that aid in performing a tactile inspection of the upper inboard wing surface.
A Department of Justice aviation safety officer reported that during the course of his agency's investigation, it was revealed that the crew did not perform a tactile inspection of the upper wing surfaces prior to the incident departure. He noted that the captain was not willing to provide a written statement during his internal incident investigation.
The airplane was equipped with Pratt & Whitney (P&W) JT8D-219 engines. Initial on scene examination of the left engine revealed that the fan blades were heavily damaged.
The left engine was removed and shipped to TIMCO Engine Center, Inc., in Oscoda, Michigan for teardown and inspection. On November 1, 2, 3 and 4, 2004, an engine teardown and inspection was conducted under the direction of an airworthiness inspector from the FAA's Grand Rapids Flight Standards District Office. According to the FAA inspector, the damage to the low-pressure compressor (LPC) C-1 blades, as well as the damage to the high pressure compressor (HPC) C-7 stator was consistent with foreign object damage (FOD). He said that the FOD damage was consistent with soft body impact damage. Copies of the FAA airworthiness inspector's written report, along with a copy of TIMCO Engine Center's preliminary damage assessment, are included in the public docket for this incident.
The airplane's flight data recorder (FDR) and the cockpit voice recorder (CVR) were removed and shipped to the NTSB's Washington, D.C., vehicle recorder division. The FDR readout showed that the incident takeoff roll was within normal operating tolerances, consistent with the captain's reported takeoff procedure. A copy of FDR factual report is included in the public docket for this incident. The CVR did not contain any data connected with the incident takeoff.
Ted Stevens International Airport weather observation at the time of the incident consisted of: Sky conditions and ceiling, 200 feet, few, 600 feet, overcast; visibility, 10 statute mile; wind, 290 degrees at 8 knots; temperature, 37 degrees F; dew point, 37 degrees F.