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Cases › NYC03FA039 · Part 121 airline

Boeing 757-251

Flushing, NY, USA · 2003-01-19·N550NW

0
fatal
0
serious
Serious injury
highest injury
Substantial
damage

What happened

NTSB summary, verbatim

The Boeing 757 was parked at the gate with passengers aboard when an Airbus that was being taxied struck the Boeing. The Airbus was being taxied to a gate by maintenance technicians. The taxiing mechanic reported that he activated the parking brake and waited for ground personnel and a jet way operator to arrive. After the ground personnel arrived he released the parking brake. The airplane did not move and he advanced the throttles out of their idle detents "a couple of inches, about halfway." The airplane began to move at a "fairly decent speed," and he realized the throttles were still out of the idle detent position. He pulled the throttles back and applied brakes; however, the airplane did not slow and continued until it struck the jet way. Review of the flight data recorder revealed that about 12 seconds after the parking brake was released, the thrust lever angles for both engines were increased to about 17 degrees for about 9 seconds, before they were returned to the idle position. During that time, the engines N1 and N2 speeds increased to about 71, and 85 percent, respectively. The taxiing mechanic stated he was qualified to taxi the Airbus and had taxied the airplane regularly as part of his normal work duties. Review of his training records revealed he had received approximately 5 hours of initial Airbus taxi on-the-job training. However, he did not possess an authorization to taxi the A319. Examination of airplane's brake-steering control unit, and the electronic control units from each engine, did not reveal any evidence of a system failure, which would have contributed to the accident.

Photographs

3the aircraft, and what the investigators found
Wreckage and site documentation · 3 photographs from the docket

Photographs are NTSB docket attachments — works of the US government, in the public domain. Captions are the Board’s own.

Probable cause

the Board's determination
Maintenance personnel failure to maintain aircraft control as a result of excessive throttle input.

NTSB analysis

from the final report

The Boeing 757 was parked at the gate with passengers aboard when an Airbus that was being taxied struck the Boeing. The Airbus was being taxied to a gate by maintenance technicians. The taxiing mechanic reported that he activated the parking brake and waited for ground personnel and a jet way operator to arrive. After the ground personnel arrived he released the parking brake. The airplane did not move and he advanced the throttles out of their idle detents "a couple of inches, about halfway." The airplane began to move at a "fairly decent speed," and he realized the throttles were still out of the idle detent position. He pulled the throttles back and applied brakes; however, the airplane did not slow and continued until it struck the jet way. Review of the flight data recorder revealed that about 12 seconds after the parking brake was released, the thrust lever angles for both engines were increased to about 17 degrees for about 9 seconds, before they were returned to the idle position. During that time, the engines N1 and N2 speeds increased to about 71, and 85 percent, respectively. The taxiing mechanic stated he was qualified to taxi the Airbus and had taxied the airplane regularly as part of his normal work duties. Review of his training records revealed he had received approximately 5 hours of initial Airbus taxi on-the-job training. However, he did not possess an authorization to taxi the A319. Examination of airplane's brake-steering control unit, and the electronic control units from each engine, did not reveal any evidence of a system failure, which would have contributed to the accident.