NTSB Factual Report

HISTORY OF FLIGHT

On December 13, 2000, at 2050 central standard time, a McDonnell Douglas DC-9-31, N9342, operating as Northwest Airlines flight 142, sustained minor damage when its tail was struck by the wing of an Airbus A-340, TC-JII, operating as Turkish Airlines flight 6. The A-340 sustained minor damage. The incident occurred during taxi operations at O'Hare International Airport (ORD), Chicago, Illinois. At the time of the incident, Northwest Airlines flight 142 was stopped on taxiway B, just short of taxiway A-10, awaiting clearance to proceed to gate E-11, following landing. Turkish Airlines flight 6 was taxiing the opposite direction on taxiway A, and turned via taxiway A-9 to proceed to runway 09R, for departure. Night instrument meteorological conditions prevailed at the time of the incident. Northwest Airlines flight 142 was conducting scheduled domestic passenger service from Minneapolis, Minnesota, to Chicago, and operating on an instrument flight rules flight plan, under 14 CFR Part 121. Turkish Airlines flight 6 was conducting scheduled international passenger service from Chicago to Istanbul, Turkey, and operating on an instrument flight rules flight plan, under 14 CFR Part 129. No injuries were reported by the 4 crew and 81 passengers on Northwest Airlines flight 142. There were no reported injuries to the 14 crew and 150 passengers on Turkish Airlines flight 6. Following the incident, both airplanes were towed to their respective gates where the passengers deplaned normally.

In his written statement, the captain of Northwest Airlines flight 142 said that after a normal landing on runway 9L, they received taxi instructions from the ORD Air Traffic Control Tower (ATCT) to taxi to gate E-11 via taxiway H and B. The captain said his taxi speed was slow due to snow covering the taxiways and blowing snow. The captain said that passing taxiway A-9, the first officer contacted ramp control for clearance into the ramp. The captain said they were told that an aircraft was blocking the taxiway A-10 entrance to the ramp and waiting for a tug to assist them. The captain said, "ATC asked us if we could use txy (taxiway) A-9 and we advised that we had passed A-9 and were committed to entering the ramp at A-10. ATC then asked if we could enter [the] ramp at A-10 behind the disabled aircraft. We responded negative, txy (taxiway) A-10 was blocked and we had to wait until [the] disabled aircraft was moved. We advised ATC we were stopped on txy (taxiway) B between A-9 and A-10. ATC instructed us to hold our position until [the] aircraft at A-10 was moved. Our aircraft was stopped with the parking brake set." The captain said, "[The] First officer and I both noticed the Turkish Airways Airbus A340 taxi past us on the inner taxiway A in the opposite direction. Three to five minutes later, our DC-9 made an abrupt, sliding left turn towards the taxiway edge lights. I grabbed the throttles and nose tiller to confirm the brakes were set." The captain said that shortly afterward the aft flight attendant called the lead flight attendant and told him "our tail was struck by another aircraft. We notified ATC we were struck by the Turkish Airways A340."

In his written statement, the captain of Turkish Airlines flight 6 said that after de-icing, they pushed back and were positioned facing west for a runway 09R departure. The captain said that ORD ATCT gave them taxi instructions, "alpha, mike-two, mike, tango". "We were told to hold short of alpha-ten. Then changed, continue [to] alpha-nine. We stopped at alpha-nine. We saw the Northwest DC-9 on taxiway bravo. The tail [of Northwest Airlines flight 142] was off of [taxiway] bravo and on [taxiway] alpha." The captain said that they were then instructed to "use alpha-nine to tango to cross runway 14. We told them we were unable to move ahead. The Northwest tail was very close. Ground control told us, go ahead join tango. They were persistent that we join tango. I can't see back there. Plus, another plane is on [taxiway] bravo to cross in front of us. We started, then said no, not possible. We stopped but we slipped. Our wingtip touched their tail."

The ground controller on duty at ORD ATCT said that Turkish Airlines flight 6 was taxiing northbound for runway 9R. He said that Turkish Airlines flight 6 was instructed to use taxiways alpha, A-9 and tango. The controller said, "I observed THY6 (Turkish Airlines flight 6) holding by A10 and I again restated my instructions. THY6 acknowledged and continued taxiing toward A9. THY6 turned at A9 and clipped the rudder of a NWA (Northwest Airlines) DC9 on Taxiway Bravo."

METEOROLOGICAL CONDITIONS

At 2056, the automated surface observation system (ASOS) at O'Hare International Airport reported few clouds at 1,700 feet msl, a broken ceiling at 2,500 feet msl, and an overcast ceiling at 5,500 feet msl. The reported visibility was 1/2 mile with light snow and mist. The runway visual range for runway 14R was reported as 4,000 feet variable 6,000 feet. The temperature was 23 degrees F, dew point 21 degrees F, winds 070 degrees at 6 knots, and an altimeter of 30.12 inches of mercury.

WRECKAGE AND IMPACT INFORMATION

The Safety Board's on scene investigation began on December 14, 2000, at 0900.

Northwest Airlines flight 142

The DC-9-31 airplane was examined in Northwest Airline's ORD maintenance hangar. The left side of the airplane's rudder showed longitudinally running dents and scratches at approximately 2/3rds span up from the base. The dents and scratches were confined to an area approximately 10 inches wide. The dents and scratches spanned the entire width of the rudder. The trailing edge of the rudder was bent right at the end of the dented area. The rudder hydraulic actuator was broken off from its mount on the aft bulkhead, forward of the tailcone seal, and was pushed through the upper right side of the fuselage. No other damage was observed.

Turkish Airlines flight 6

The A340 airplane was examined at gate M-17 at the ORD International Terminal. The airplane's left outboard leading edge slats showed two inward dents, one in the leading edge of each, at approximately 11 feet and 14 feet inboard of the wingtip. No other damage was observed.

ADDITIONAL INFORMATION

Parties to the investigation were the Federal Aviation Administration Flight Standards District Office, Schiller Park, Illinois, and Northwest Airlines.

NTSB Probable Cause

Failure of the pilot of the other airplane to maintain clearance. Factors relating to this accident were the snow-covered taxiways and the ground controller disregarding the pilot of the other airplane's warning of the unsafe/hazardous situation of being unable to taxi around the standing Northwest Airlines DC-9 airplane.