Aviation Accident Summaries

Aviation Accident Summary WPR10IA135

Los Angeles, CA, USA

Aircraft #1

N226SW

EMBRAER EMB-120ER

Analysis

At the completion of a scheduled passenger flight, the airplane was taxied to the arrival gate at which point the flight crew was marshaled into the gate by a ground marshaller. The captain reported that as he taxied into the gate area at a normal speed, he observed the lead-in line, a parked fuel truck on the right side, the jet bridge on the left side, and the marshaller. He felt confident the airplane could proceed to the gate and clear all of the obstacles. As he continued to taxi, he anticipated the marshaller shortly giving the stop signal and chose to maintain visual attention on the marshaller. Just as the marshaller raised his hands to perform the stop signal, the left propeller struck the jet bridge. The first officer reported that he was looking out the right side of the airplane to make sure everything was clear of the wing and propeller. He reported that he never saw the jet bridge on the left side. He turned his attention back to the marshaller and saw his arms moving up indicating they were close to stopping. Before the marshaller crossed his day wands to indicate the stop location, the first officer felt something hit the airplane. The marshaller reported that he was concentrating on the airplane’s right side where a fuel truck was parked close to the envelope line and was concerned about the truck’s proximity to the airplane. Because of where his attention was focused, he misjudged the stop line marked for EMB airplanes and instead signaled the airplane to stop on the line marked for CRJ airplanes. Just as he crossed his wands, the left engine propeller struck the jet bridge. Postaccident examination of the airplane and surrounding parking area revealed that the airplane’s nosewheel tire came to rest about 18 feet beyond the stop line marked “EMB,” at a line marked “RJ50.” A reenactment of the incident, accomplished by towing an airplane on the taxi line toward the RJ50 stop line, determined that the flight crew had a clear view of the surroundings associated with the gate, including the jet bridge, when both occupants turned to look out the left cockpit window. In addition, it was also determined that the captain would be able to see part of the left engine and propeller as the airplane approached the jet bridge just prior to the RJ50 stop line.

Factual Information

On February 16, 2010, about 0635 Pacific standard time, an Embraer EMB-120ER, N226SW, sustained minor damage when it taxied into a jet bridge while parking at its assigned terminal gate 82 at the Los Angeles International Airport, California (LAX). None of the two flight crew members, flight attendant, or the 28 passengers were injured. There were no reported ground injuries. Visual meteorological conditions prevailed, and an instrument flight plan was filed. The airplane was registered to Wells Fargo Bank and operated by SkyWest Airlines, St. George, Utah, as United Express flight 6199 under the provisions of Title 14 Code of Federal Regulations Part 121. The scheduled domestic passenger flight originated from Carlsbad, California at 0554. The captain reported that they were taxiing at a normal speed approaching gate 82. The captain observed the lead in line, a parked fuel truck on the right side, the jet bridge on the left side, and the marshaller. The captain "felt confident" the airplane could proceed to the gate and clear all of the obstacles. The captain reported that while taxiing in and choosing to stay visually with the marshaller, he noticed the marshaller’s hands were starting to move upward to perform the stop signal, when the left propeller struck the jet bridge. The first officer reported that the captain and he saw the marshaller and the captain proceeded to follow his directions to the parking location. The first officer looked out the right side of the airplane to make sure everything was clear of the wing and propeller. He reported that he never saw the jet bridge on the left side. He then turned his attention back to the marshaller and saw his arms moving up indicating they were close to the stopping location. Before the wands crossed, he felt something hit the airplane. The marshaller reported that he was assigned to work at gate 82. As the airplane came into the alley, he was concentrating on his left side view of the airplane (right side of the airplane) due to the fuel truck being parked on the pathway that leads to the bag room, which was too close to the envelope line and he did not want to hit the wing tip. When he stopped the airplane at the line by using the customary stop signal, the left engine propeller hit the jet bridge. The marshaller reported seconds later he realized that the airplane had stopped on the CRJ line rather and the EMB line. The marshaller further reported that he misjudged the EMB line because he had been looking at the fuel truck and was concerned about its proximity to the airplane, rather than looking at the jet bridge. According to the SkyWest "Station Operations Manual," marshallers use specific hand/arm signals and hold wands while guiding airplanes to and from their gates. One of the signals used is designed to indicate to the flight deck crew that the ramp area for their arriving airplane is clear of obstructions. The incident airplane was cleared to proceed to gate 82 and received appropriate signals to move forward from the marshaller, who was the only individual in the immediate ramp area. It was consistent with company policy to use a single ground marshaller, when local conditions permit (e.g. ramp congestion and visibility). According to the station manager, SkyWest routinely uses this gate for both turboprop (Embraer) and turbojet (Bombardier Canadair Regional Jet) airplanes. The station manager stated that, at the time of the incident, the jet bridge attached to gate 82 was not in motion. The jet bridge was parked with its two wheels located within the confines of its assigned non-use box since it is not used for Embraer EMB-120ER type airplanes. A National Transportation Safety Board (NTSB) investigator examined the incident airplane and ramp area. The investigator observed that the tarmac approaching gate 82 is striped with a single yellow airplane nose wheel lead-in line. Along this line there are two specific locations marked for stopping airplanes. The stop locations are indicated by paint stripes/lines that are oriented perpendicular to the lead-in line. The perpendicular stop lines are marked with letters/numbers. These markings serve to identify to the ground personnel the location at which the different types of airplanes are to be stopped. The NTSB investigator noted that when approaching the gate, the first stop line is marked "EMB," and the second line closest to the terminal (and the jet bridge) is marked "RJ50." The distance between these two lines was about 18 feet. The NTSB investigator noted that the EMB-120ER’s nose wheel was centered on the lead in line and positioned on top of the stop line bearing the mark "RJ50.” The investigator also observed that the incident airplane's left engine was missing portions of two of its four propeller blades. An oil spray residue was observed on the left side of the fuselage, and a pool of oil was present below the left engine and wing. Portions of two propeller blades were embedded into the bottom of the dented jet bridge. Portions of the separated blades were fragmented and found beneath the left and right side of the airplane. The left engine's nacelle was bent, and multiple dents were noted in various locations on the left side of the fuselage. The dents were consistent in appearance with blade fragment impact signatures. A sensor on the jet bridge was also damaged. A reenactment of the incident was accomplished on March 1, 2010. Participants included the NTSB investigator in charge, Federal Aviation Administration inspectors, SkyWest safety managers and the station manager. An EMB-120ER airplane was actually towed into gate 82 at LAX. While moving forward on the taxi line towards the “RJ50 stop line, it was determined that the first officer seated in the front right seat and the captain seated in the front left seat had a clear view of surroundings associated with the gate including the jet bridge when both occupants turned to look out the left cockpit window. In addition, the captain seated in the front left seat would also have been able to see part of the left engine and propeller as the propeller approached and contacted the jet bridge, just prior to the “RJ50” stop line.

Probable Cause and Findings

The flight crew’s failure to maintain clearance from the jet bridge during taxi. Contributing to the incident was the ramp marshaller's diverted attention and failure to signal the flight crew to stop at the correct position.

 

Source: NTSB Aviation Accident Database

Get all the details on your iPhone or iPad with:

Aviation Accidents App

In-Depth Access to Aviation Accident Reports