Aviation Accident Summaries

Aviation Accident Summary SEA97LA077

WENATCHEE, WA, USA

Aircraft #1

N826PH

de Havilland DHC-8

Analysis

After an uneventful landing, the pilot was cleared to taxi to the terminal. During the taxi, a ground marshaller signaled for the airplane to be turned (left) toward the northwest. The flight crew initiated a left turn. During the turn, the right wing tip of the airplane collided with a wing deicing cart. The cart tumbled and bounced back toward the trailing edge of the right wing. A portion of the cart impaled the right aileron, causing substantial damage. The captain and first officer did not see the deice cart in time to stop the right wing from striking it during the turn. Subsequent investigation revealed that the marshaller was using a spot on the ramp to park the accident airplane that was intended to be used for a smaller aircraft. Also, the ramp area at the airport did not have any lead-in lines or markings to provide taxi guidance, nor was a 'safe movement' zone designated. Additionally, the decing cart had been noted as a potential hazard by the previous station manager; however, it was not moved because of its needed proximity to an electrical source.

Factual Information

On March 26, 1997, about 0950 Pacific standard time, N826PH, a Dehavilland DHC-8 airplane, operating as Horizon Airlines Flight 2157, collided with ground equipment during taxi in Wenatchee, Washington, and was substantially damaged. The airline transport pilot (captain), commercial pilot (first officer), flight attendant, and all 9 passengers were not injured. Visual meteorological conditions prevailed and an instrument flight rules flight plan had been filed. The air carrier flight departed from Moses Lake, Washington, at 0925 and was destined for Wenatchee. The flight was conducted under 14 CFR 121. According to representatives of Horizon Airlines, the airplane had landed uneventfully on runway 30 at the Pangborn Memorial Airport in Wenatchee and was cleared to taxi to the terminal. As the airplane taxied toward the terminal, a ground marshaler signaled to have the airplane turn toward the northwest. The flight crew initiated a left turn. During the turn, the right wing tip of the airplane collided with the rising structure of a United Express wing de-icing cart. The cart tumbled and bounced back toward the trailing edge of the right wing. A portion of the cart impaled the right aileron, causing substantial damage. A review of maintenance records revealed that the aileron received extensive structural damage and required replacement. According to a written statement (attached) by the captain that was submitted to the Safety Board, the captain stated: After landing on [runway] 30 at [Wenatchee], we cleared the runway on the last taxiway before the end of the runway. While taxiing eastbound on the taxiway, we saw the marshaller indicating that we were to park parallel to the terminal building pointing west. As we made the 180 [degree] turn towards the marshaller, our right wingtip impacted the ladder on the United Express de-icing cart. The aircraft was immediately stopped and engine shut down.... The marshaller said she lost site of the de-ice cart due to the position of the aircraft. The first officer was watching the right wingtip while the aircraft was making the turn. Because of the position of the de-ice cart relative to the aircraft, it did not come into his view until it was too late to warn me or to stop the aircraft. The captain also stated that there were no lead-in lines to guide him into the ramp, and that the marshaller gave no turn signals to him as he was turning the airplane. According to a written statement (attached) by the first officer that was submitted to the Safety Board, the first officer stated: As we entered the ramp area, I placed my thumb on the glareshield and monitored the movement of the right wing. From an easterly heading, we made an approximate one hundred and eighty degree turn towards the left to line up with the marshaller. As we rolled out of the left turn, the right wing struck the upper portion of the United Express decing equipment.... At no time did I neglect to do my duty of monitoring the movement of the right wing. I simply did not have enough time to warn [the captain] of the impending collision. According to a written statement (attached) by the Horizon Airlines Station Manager in Wenatchee that was submitted to the Safety Board, the station manager stated: "After investigating I found our agent to be 75 % - 80 % at fault. She was on the Metro mark and not on the Dash 8 Mark when marshalling aircraft in. Pilots could have made slower approach however, when turning the aircraft at the angle it was that wing comes around very, very fast...." Further investigation by the Safety Board revealed that the marshaler was using a spot on the ramp to park the accident airplane that was intended to be used for Horizon's Swearingen SA227 "Metro" aircraft, and not a Dehavilland DHC-8. Also, the ramp area for commuter aircraft at the Pangborn Memorial Airport in Wenatchee did not have any lead-in lines or markings to provide taxi guidance, nor was a "safe movement" zone designated. Additionally, the decing cart that was owned and operated by United Airlines had been noted as a potential hazard by the previous Horizon Airlines Station Manager at Wenatchee; however, it was not moved because of its needed proximity to an electrical source.

Probable Cause and Findings

failure of the ground marshaller to marshal the airplane into a correct parking place on the ramp, her failure to verify clearance between the right wing of the airplane and the ground de-ice cart, and failure of the flight crew to ensure clearance of the right wing as the airplane was being taxied into the parking place. Factors relating to the accident include: a congested ramp facility, and inadequate ramp markings.

 

Source: NTSB Aviation Accident Database

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