Aviation Accident Summaries

Aviation Accident Summary OPS10IA163

Burbank, CA, USA

Aircraft #1

N953SW

BOMBARDIER INC CL-600-2B19

Aircraft #2

N29LW

AMERICAN EUROCOPTER LLC AS350B2

Analysis

A Canadair CRJ-200 and an American Eurocopter AStar 350, operating as a news helicopter, were involved in a near mid-air collision while the CRJ was on the left base leg of the landing pattern for a visual approach to land. As the CRJ was descending through 1,500 feet, the helicopter was conducting operations two miles southeast of the runway at 1,400 feet. The crew of the CRJ received and complied with a traffic alert and collision avoidance system resolution advisory directing a climb to maintain separation from the helicopter. The helicopter was operating under visual flight rules in the southeast portion of the airport’s Class C airspace. The event occurred at dusk under visual meteorological conditions. There was no damage to either aircraft, and no reported injuries. This incident resulted from the local controller not maintaining positive control/standard separation of aircraft within the Class C airspace. As the controller did not issue any control instructions to establish and maintain separation, neither visual separation nor target resolution procedures were being applied before the incident occurred. Consequently, the flight crew of the CRJ received a resolution advisory and had to maneuver to resolve the conflict.

Factual Information

On Thursday, April 29, 2010, at approximately 1942 Pacific daylight time, N953SW, a Canadair CRJ-200 Regional Jet operating as SkyWest flight 5945 (SKW5945), and an American Eurocopter AStar 350, N29LW, operating as TV2, were involved in a reported near mid-air collision at Bob Hope Airport (BUR), Burbank, California. SKW5945 was on a left base for a visual approach to runway 33 descending through 1,500 feet, and TV2 was conducting operations two miles southeast of the runway at 1,400 feet. The crew of SKW5945 received and complied with a Traffic Alert and Collision Avoidance System (TCAS) resolution advisory (RA) directing a climb to maintain separation from the helicopter. SKW5945 was on a regularly scheduled passenger flight from San Francisco International Airport (SFO) to BUR, and was operating on an instrument flight rules (IFR) flight plan under 14 Code of Federal Air Regulations Part 121. TV2, a news helicopter, was conducting visual flight rules (VFR) operations in the southeast portion of BUR class C airspace under the provisions of 14 Code of Federal Regulations Part 91. The event occurred during at dusk under visual meteorological conditions. There was no damage to either aircraft, and no reported injuries. History of Flight TV2 was operating inside the BUR class C airspace and was already on local control (LC) frequency when the incident occurred. At about 1941, the pilot of SKW5945 contacted BUR air traffic control tower reporting approximately five miles southwest of the airport on a left base for a visual approach to runway 33. The local controller directed the CRJ to reduce to final approach speed and square his base in order to clear a departing aircraft for takeoff before SKW5945's arrival. Approximately one minute later, TV2 called BUR tower with a “request.” The local controller immediately directed TV2, which had been had been eastbound approximately two miles south of BUR at 1,400 feet, to remain east of the approach end of runway 33 for inbound traffic. The pilot responded that he had the inbound traffic in sight, would remain east of the extended centerline, and asked to work in the area just to the west side of the extended centerline once the traffic landed. At approximately 1942, when SKW5943 was descending through 1,500 feet, the local controller advised the pilot of helicopter traffic off to his left side, “…low level at 1,400 feet.” The pilot responded that he had received a TCAS alert on that traffic and would have to go around because he had to climb in response a resolution advisory. The local controller issued missed approach instructions, and transferred the aircraft to Southern California Terminal Radar Approach Control (SCT) for vectors back to BUR. TV2 remained in BUR’s airspace for approximately five more minutes before departing toward Whiteman Airport (WHP). SKW5945 returned to BUR for a visual approach, and landed on runway 33 without further incident. Radar Data Radar data for this report was obtained from the ASR-9 sensor located at BUR. Two graphics showing an overview of the paths of the two aircraft and a close-up view of their minimum separation have been entered in the docket. The applicable separation standard between VFR and IFR aircraft in class C airspace is visual separation, 500 feet vertical, or target resolution. At closest point of approach, the aircraft were separated by approximately .77 nautical mile laterally and 100 feet vertically; as the controller did not issue any control instructions to establish and maintain separation, neither visual separation nor target resolution procedures were being applied before the incident occurred. ATC Facility Information BUR was a level 7 tower with radar facility responsible for ATC services in the Class C airspace 24 hours a day, seven days a week. BUR averaged 110,000 operations per year as of calendar year 2009. The tower was responsible for providing class C services to aircraft operating within the charted inner ring of the class C airspace. The remainder of the class C area was under control of SCT. Personnel Interviews Front Line Manager (FLM) The FLM was in charge of the tower cab operation at the time of the incident. He was generally monitoring all of the control positions, but had been specifically listening to a training session in progress at the CD/FD position. He assessed the tower’s workload at the time as moderate, and was aware of the helicopter traffic operating in the vicinity of the airport but characterized it as nothing unusual. He heard the LC clear a Southwest flight for immediate takeoff. He said this clearance caught his attention, so he looked out of the southern tower window for traffic and saw SKW5945 turning on a two mile final but climbing. The FLM then heard the LC issuing traffic. The LC then coordinated the go around on SKW5945 with SCT and transferred the flight back to SCT. The aircraft returned a few minutes later and landed without further incident. Controllers had many options when handling helicopters operating near the airport, and had to use their best judgment. In this particular case the LC restricted the helicopter to remain east of the final approach course for runway 33, which "should have worked." However, the FLM said that LC could have exercised more positive control over the helicopter. Local Controller (LC) SKW5945 reported on a left base to runway 33, and LC cleared the pilot to land. He instructed TV2 to remain east of the extended final for runway 33, and based on an earlier traffic call made regarding a different aircraft in the area, believed that TV2 had reported the inbound CRJ in sight. Shortly afterward, he saw SKW5945 fly through the runway 33 final and provided a traffic advisory about the helicopter traffic operating east of the final approach course. The pilot of SKW5945 then reported responding to a TCAS RA. The CRJ executed a go-around and LC transferred the flight back to SCT. He believed that the helicopter’s proximity to the runway 33 final extended centerline was safe because he had instructed the helicopter to remain clear of the final. In other circumstances, he had issued pilots specific distances to remain clear of the final approach course, and in retrospect thought that may have been beneficial in this situation. Local Assist (LA) Just before the incident, the LA controller looked out the window and saw SKW5945 east of the runway 33 final approach course. She heard the pilot say that he was going around, so she called the SCT Fillmore sector to coordinate the missed approach. SCT told her to put SKW5945 on a 270-degree heading and climb him to 4000 feet. Facility Corrective Actions As a result of this incident BUR tower controllers were provided refresher training on Visual Separation (FAA 7110.65, 7-2-1), Traffic Advisories (FAA 7110.65, 2-1-21) and Safety Alerts (FAA 7110.65, 2-1-6.)

Probable Cause and Findings

The local controller’s failure to issue control instructions necessary to ensure positive control/standard separation of traffic operating within the Class C airspace.

 

Source: NTSB Aviation Accident Database

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