Aviation Accident Summaries

Aviation Accident Summary CHI06LA038

Chicago, IL, USA

Aircraft #1

N359FE

McDonnell Douglas MD-10

Analysis

The airplane contacted a 747 crew stair structure with the underside of the left wing while taxiing. The stairs were located on the left edge of the taxiway, partially on the grass. The captain, who was a company line check airman (LCA), was sitting in the right seat during the flight. This LCA was conducting upgrade training for a captain trainee who was sitting in the left seat. In addition, an FAA inspector who was observing the training was sitting in the cockpit jump seat during the flight. While taxiing the LCA became occupied with an auxiliary power unit (APU) warning light in the cockpit. The crew was unaware that the airplane contacted something until they were informed of the damage by maintenance personnel when they reached their destination. On the night of the accident, the stairs were located at the edge of the taxiway, partially on the grass. The location of the stairs was reported to air traffic control by another airplane that taxied out after the accident airplane. Three days after the accident, the damaged stairs were located against a hangar. The damage to the underside of the left wing consisted of a series of parallel scratches and gouges from the leading edge of the wing to the trailing edge of the aileron. The scratches and gouges contained areas of red, white, and yellow paint transfers. These paint transfers matched the color of the stairs. The LCA and the captain trainee both reported that they never saw the stairs. The FAA inspector stated he saw the stairs, but thought the airplane had cleared them. None of the three reported feeling the impact with the stairs. The operator of the stairs reported that the stairs were secured against a hangar after they last used them on the day prior to the accident. The only lights near the area where the stairs were located were the taxiway lights. The accident occurred on an overcast night. The winds at the time of the accident were gusting to 27 knots.

Factual Information

On November 28, 2005, at 2153 central standard time, a McDonnell Douglas MD-10, N359FE, operated by Federal Express Corporation (FedEx) as flight 1205, contacted an air stair assembly while taxiing to runway 27L for takeoff at the O'Hare International Airport (ORD), Chicago, Illinois. The captain, first officer/captain trainee, a Federal Aviation Administration (FAA) inspector, and two jump seat passengers on board were not injured. The airplane received substantial damage to the underside of its left wing. The Title 14 Code of Federal Regulations Part 121 cargo flight was operating in visual meteorological conditions at the time of the collision. The flight continued on to its planned destination of Memphis International Airport (MEM), Memphis, Tennessee, were it landed uneventfully at 2236. The flight crew was unaware of the damage until maintenance personnel informed them of the damage after they had landed in MEM. The captain, a company line check airman (LCA), was sitting in the right seat during the flight. This LCA was conducting captain upgrade training for a trainee who was sitting in the left seat. In addition, a FAA inspector, who was observing the training, was sitting in the cockpit jump seat during the flight. The LCA stated the sky condition was overcast and it was "very dark" at ORD. They had the nose taxi light illuminated while they were taxiing. He reported their taxi instructions were to use taxiways Lima, Kilo, Tango 12 and to hold short of the runway. He reported that while on taxiway Lima, they received an "APU Door DISAG" light in the cockpit indicating that the auxiliary power unit (APU) door had not closed properly. The LCA stated he began to trouble shoot the problem and the captain trainee continued to taxi the airplane. The LCA stated that during this time, he periodically looked up to make sure the captain trainee was keeping the airplane on the centerline. He did state that because of the APU warning, he was not as focused on the surrounding area as he normally would have been. The LCA stated they resolved the APU issue and continued the flight uneventfully. He reported that after they landed in MEM, two mechanics came into the cockpit and informed the flight crew of the damage on the underside of the left wing. The captain trainee reported that winds were gusty and the lighting conditions were dark at ORD. He reported they sat on the FedEx ramp until they received their taxi clearance, which was taxiways Lima 2, Lima, Kilo, Tango 12, and to hold short of runway 32L. He reported that after leaving the ramp they taxied east on taxiway Lima. He reported that there were lighted ramp areas on the right side of the airplane near Lima 3, but the area on the left side of the airplane consisted of a dark grassy area bordering the taxiway and runway. The captain trainee reported he continued to taxi; however, he slowed down as the LCA was working on the APU door problem. The captain trainee stated the LCA resolved the APU issue and he continued to taxi, turning onto taxiway Kilo. He reported they were then cleared to taxi to runway 27L, which they used for takeoff. The captain trainee stated the flight was normal and they were unaware of the damage to the left wing until after the flight. The FAA inspector who was in the cockpit reported using the same taxi route at ORD as reported by the captain and captain trainee. The inspector reported the flight to MEM was uneventful, and they were informed of the damage after landing. The inspector reported the damage might have occurred while taxiing on taxiway Lima at ORD. He reported, "There was an airstair type of ground service equipment parked well off the taxiway into the grass area, left of taxiway Lima. ... I did not mention it to the crew because from my position in the Jump Seat it was not an issue because of its position and height. If this is were [sic] the damage occurred it was not felt or heard by any of the crew in the flight deck, or by the two dead heading crew members sitting in the supernumerary area." The inspector continued to report that there was ramp lighting only on the right side of the airplane and that only taxiway lights lighted the left side. He stated the crew used normal taxi lights on the airplane during the taxi. On the same night, another FedEx flight crew, FedEx 1606, reported pushing back off the FedEx cargo ramp at 2154. This crew stated they were taxiing along taxiway Lima when they saw a set of crew stairs off the left side of their airplane. This crew stated the stairs were between the taxiway way lights with one of its wheels on the grass. The crew veered their airplane to the right to avoid the stairs and notified ground control of the position of the stairs. ORD ground control reported that at 2201 the crew of FedEx 1606 reported, "Switching tower FDX 1606 Heavy and ah the problem for 1606 at our current position as there's an aircraft boarding ladder over in the grass ah just off the taxiway." According to air traffic control, the tower supervisor immediately notified ORD operations about the stairs. ORD operations reported that at 2205 they received a call from Swissport stating that one of their stair carts had blown across taxiway Lima adjacent to the United Airlines cargo ramp, and they wanted to retrieve it. They were informed that they needed to wait until an airport operations vehicle arrived to escort them across the taxiway. In addition, at 2208 airport operations received a call from the air traffic control tower informing them of the position of the stairs. According to airport operations, their vehicle was already en route to the location when this call was received. At 2210, airport operations closed Lima taxiway between Lima 2 and Lima 3 so that the stairs could be removed. Airport operations reported the stairs were half off the taxiway and standing upright when they arrived. At 2228, the stairs were removed and the NOTAM (notice to airmen), which closed the taxiway, was canceled. The damage to the underside of the left wing on N359FE consisted of a series of parallel scratches and gouges. The damage was primarily contained in an area between 19 feet and 8 feet from the wingtip. The damage consisted of a 2'6" by 5 1/4 " open gouge in the left-hand outboard aileron, a broken rib in the aileron, open gouges in 2 of the trailing edge wing panels, an open gouge in one of the lower wing skin panels, holes in the #7 and #8 leading-edge slats, scrapes across the fuel tank skin panels one of which resulted in a fracture and a small fuel leak, and several other scratches from the leading edge of the wing to the trailing edge of the aileron. The scratches and gouges contained areas of red, white, and yellow paint transfers. According to Swissport, the stair unit was properly stowed and secured up against a hangar on the United Airlines cargo ramp after they last used it on November 27th. The next flight they had scheduled which would have required the use of the stair unit was on November 30th. Swissport suggested that another operator on the airport might have used the stairs without them knowing it. On December 1, 2005, FedEx personnel located a 747 stair unit up against a building on the United Airlines cargo ramp. The rails at the top of the stair stand were bent in one direction. The rails were painted white and a rusty red primer was visible under the paint where it had been scratched off. A yellow crank handle at the top of the stairs was also damaged. The height of the stair rails was approximately 17 feet 9 inches high. Including the height of the crank handle the structure was approximately 18 feet 2 inches high. The height of the wing at the most outboard scratch was 15 feet 4 inches high.

Probable Cause and Findings

The failure of the flight crew to see and avoid the crew stairs and the failure of unknown persons to properly secure the stairs after use. Factors associated with the accident were the dark light conditions and the gusty winds.

 

Source: NTSB Aviation Accident Database

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