DCA23LA185

The interruption of the local controller’s workflow due to the necessitated management of a go-around of a third airplane that was approaching a different runway. Contributing to the incident was: 1) the controller’s decision to continue the landing of ASH5826, likely without a re-assessment of its distance from the departing SKW5326, after the interruption, and 2) the lack of surface detection equipment at the Bob Hope Airport to aid the controller with traffic management.

This incident occurred after the local controller (LC) cleared SkyWest Airlines (dba United Express) flight 5326 (SKW5326) for takeoff from runway 33 at Bob Hope Airport (BUR) and instructed Mesa Airlines (dba American Eagle) flight 5826 (ASH5826) to continue its approach to land on the same runway. At the time of takeoff clearance, ASH5826 was 1.6 miles from the threshold of the same runway. Shortly after SKW5326 began its takeoff roll, the flight crew of ASH5826 determined the separation was insufficient and initiated a go-around. At this time, SKW5326 was at a groundspeed of 27 kts and accelerating across the runway threshold, and ASH5826 was 4,200 ft from the threshold at an altitude of 300 ft above ground level (agl). The LC instructed ASH5826 to climb and maintain 4,000 ft, and fly the runway heading, which put their airplane on a converging course with SKW5326, who was on the assigned standard instrument departure (SID) heading of 270. Twenty-seven seconds later, the LC instructed ASH5826 to turn right, heading 270 then changed it to turn left, heading 270 which put the two airplanes on parallel headings. Forty-seven seconds later, the crew of ASH5826 reported they were responding to a TCAS RA [traffic alert and collision avoidance system resolution advisory], and the LC instructed them to turn right 30 degrees, then changed the instruction to a left 30-degree turn. The airplanes’ closest point of separation was 1,680 ft during the left turn. After that, the separation began to increase and both airplanes were handed off to Southern California Terminal Radar Approach Control. Federal Aviation Administration (FAA) Order 7110.65Z, Air Traffic Control, Chapter 2, section 1, paragraph 2-1-6, Safety Alert, requires controllers to “issue a safety alert to an aircraft if they are aware the aircraft is in a position/altitude that, in your judgment, places it in unsafe proximity to terrain, obstructions, or other aircraft.” However, for this event, the local controller did not issue a traffic advisory or safety alert, as required, to either of the flight crews immediately after ASH5826 reported going around, or during the following minutes when both airplanes were in an unsafe proximity to each other. Prior to the incursion, at 18:53:06, the LC instructed SKW5326, which was on the ground departing Burbank, to turn right onto runway 33 and to Line Up and Wait (LUAW). The aircraft performance study found that at this time, ASH5826, was 7.9 NM (9 statute miles) from the threshold, at 2,800 ft above ground level (agl), and approaching runway 33 at BUR. According to FAA Order 7110.65Z, Air Traffic Control, Chapter 3, section 9, paragraph 3-9-4, the intent of LUAW” is to position aircraft for an imminent departure.” About 19 seconds later, ASH5826 checked in with BUR tower, and the local controller advised the crew that traffic (SKW5326) was holding in position on runway 33, and they were instructed to continue their approach. SKW5326 entered runway 33 and by 1854:30 the airplane was aligned with the runway heading and stopped behind the runway threshold waiting for a takeoff clearance. Around this time, the LC instructed an uninvolved visual flight rules (VFR) Cirrus airplane to perform a go-around on runway 26. During a postincident interview, the LC stated the go-around was issued because the airplane was too high for the approach. However, the LC did not inform the Cirrus pilot of the reason for the go-around, but the pilot complied immediately with ATC instructions. The LC then instructed the Cirrus pilot to turn base for runway 33 and follow a regional jet (ASH5826) on a 2-mile final. Several transmissions were conducted between the Cirrus pilot and the LC because there was confusion on which cross wind traffic pattern leg the pilot should fly. The LC’s communications with the Cirrus may have been a distraction that delayed the takeoff clearance for SKW5326, which would have reduced separation between the two airplanes. Further, the focus on the Cirrus may have prevented the LC from performing an adequate scan of the runway and airport environment to determine the positions of SKW5326 and ASH5826 before issuing a takeoff and landing clearance, respectively. FAA Order 7110.65Z, paragraph 3-10-3, Same Runway Separation, instructed a controller to “separate an arriving aircraft from another aircraft using the same runway by ensuring that the arriving aircraft does not cross the landing threshold until…the other aircraft has departed and crossed the runway end.” At the time of the incident, the BUR airport traffic control tower did not have surface detection equipment which would have allowed air traffic controllers to track the movement of aircraft and vehicles on airport surfaces and on final approach. This type of system would provide controllers with visual and aural warnings when a potential conflict existed. Had BUR tower been equipped with this technology, it would have alerted the controller to the reduced separation between the two airplanes prior to the SKW5326 takeoff clearance. It likely would have also detected the potential conflict during the initial portion of the ASH5826 go-around. These warnings would have likely allowed the controller to prevent these conflicts altogether or reduced their severity.

On February 22, 2023, about 1855 pacific standard time (PST), Mesa Airlines (ASH5826), N954LR, a MHI (Mitsubishi Heavy Industry) RJ CRJ-900 and SkyWest Airlines (SKW5326), N619UX, an Embraer ERJ 170-200, were involved in a runway incursion at the Bob Hope Airport (BUR), Burbank, California. The airplanes’ closest point of separation was 1,680 ft which occurred as SKW5326 was departing, while ASH5826 was performing a go-around. There were no injuries reported to the 73 passengers and crew onboard the SkyWest airplane or to the 41 passengers and crew members onboard the Mesa airplane. ASH5826 was operating under the provisions of Title 14 Code of Federal Regulations Part 121 as a scheduled domestic passenger flight from Phoenix Sky Harbor International Airport (PHX), Phoenix, Arizona to BUR. SKW5326 was operating under the provisions of Title 14 Code of Federal Regulations Part 121 as a scheduled domestic passenger flight from BUR to San Francisco International Airport (SFO), San Francisco, California. About 1853, the BUR local control (LC) controller transmitted SKW5326’s callsign to determine if they had switched from ground control frequency to the LC frequency. The crew responded that they were on the frequency. The LC controller then instructed SKW5326 to turn right on runway 33, back taxi if necessary, and line up and wait (LUAW) for runway 33. The crew read back the instructions as issued. According to the Aircraft Performance Study, at the time SKW5326 was provided LUAW instructions, ASH5826 was 7.9 nautical miles (nm) from the threshold, at 2,800 ft above ground level (agl), and approaching runway 33 at BUR. Figure 1. BUR Airport diagram depicts the location of runway 33, (purple rectangle) and the air traffic control tower (light blue circle). Figure 2 provides information on the aircraft locations and associated ATC communications for specific times indicated. The Automatic Dependent Surveillance-Broadcast (ADS-B) flight path data for ASH5826 are shown in orange and SKW5326 are noted in blue. Figure 2. ADS-B flight paths for ASH5826 (orange) and SKW5326 (blue). Selected times and ATC communications are shown. At 1853:25, the crew of ASH5826 contacted the BUR airport traffic control tower (ATCT) and reported they were on the visual approach to runway 33. At 1853:36, the LC advised the crew of ASH5826 that traffic, SKW5326, was holding in position on runway 33 and instructed them to continue the approach. The crew read back the instructions as issued. SKW5326 entered runway 33 about 1853:45, back taxied, and by 1854:30 the airplane had made a 180° turn, aligned with the runway 33 heading, and stopped behind the runway threshold. According to the SKW5326 captain’s statement, they only had performance data for the full length of the runway, so they back taxied to the beginning of runway 33, did a 180-degree turn, and held at the threshold. They were aware that there was an aircraft on approach to runway 33; however, they did not visually acquire the traffic while back taxiing on runway 33. They were in position and held for what seemed to be a couple of minutes. At 1855:38, the LC cleared SKW5326 for takeoff from runway 33. The crew read back the takeoff clearance for runway 33, as issued. At this time, ASH5826 was 1.6 miles from the threshold and at 500 ft agl. At 1855:43, the LC cleared ASH5826 to land runway 33. According to the first officer of ASH5826, he contacted the LC again to confirm they were cleared to land, as the LC had just cleared another aircraft for take-off. At 1855:50, SKW5326 began its take-off roll, and then at 1855:53, the LC responded to the crew of ASH5826, “… affirmative, runway 33 cleared to land.” According to FAA Order 7110.65Z, the controller was required to apply a 6,000 feet separation between a departing aircraft on its takeoff roll and an arriving aircraft on final approach. The NTSB’s aircraft performance study showed that ASH5826 was 1.6 miles from the runway 33 threshold when SKW5326 was cleared for takeoff. At 1855:55, one of the pilots on ASH5826 asked if SKW5326, was clear of the runway yet, and subsequently, the other pilot of ASH5826 stated, “no he...we’re going around.” According to the flight crew members of ASH5826, they determined the separation was insufficient and initiated a go-around. At this time, SKW5326 was at a groundspeed of 27 kts and accelerating across the runway threshold, and ASH5826 was 4,200 ft from the threshold and at 300 ft agl. At 1856:00, the LC stated “roger” and then instructed ASH5826 to climb and maintain 4,000 ft, and fly runway heading. The crew of ASH5826 did not respond. The airplanes were 4,000 ft apart at this time. At 1856:14, the crew of ASH5826 asked the LC for the altitude, and the LC stated 4,000 ft. The crew acknowledged and read back 4,000 ft. At 1856:27, the LC then instructed the ASH5826 to turn right, heading 270°, and subsequently corrected that instruction by stating “left 270°”. The crew acknowledged and readback left 270°. Both airplanes began a left turn once past the runway’s surface. According to the first officer of ASH5826, as they made the turn, he saw SKW5326 climbing underneath them and they received an audible alert from their onboard traffic alert and collision avoidance system (TCAS). At 1856:57, the LC instructed the crew of SKW5326 to continue on the standard instrument departure route (SID). The crew read back the instructions as issued. At 1857:02, the LC instructed ASH5826 to continue their climb. The crew read back the instructions as issued. At 1857:12, according to the Aircraft Performance Study, and as indicated in figure 3, the minimum separation of 1,680 ft horizontally occurred between ASH5826 and SKW5326. Figure 3. Flight paths for ASH5826 (orange) and SKW5326 (blue) with times and altitudes. At 1857:14, the LC asked the crew of ASH5826 if they had the Embraer in sight at 2,500 ft off to their right. The crew stated negative and reported that they were responding to and complying with a resolution advisory (RA). The LC controller responded “roger, turn right 30°”, then corrected that instruction and stated, “left 30°”. The crew acknowledged and readback left 30°. No further relevant ATC communications occurred between the crew of SKW5326 and BUR. Both airplanes were equipped with Flight Data Recorders (FDRs) and Cockpit Voice Recorders (CVRs). The FDR data was obtained for both airplanes, but the incident was overwritten on both airplanes’ two-hour CVRs. The FDR recorded airplane flight information in a digital format using solid-state flash memory as the recording medium. FDRs receive data in the ARINC 573/717/747 configurations and are required to record a minimum of 25 hours of flight data. FDRs are configured to record a set number of 12-bit words of digital information every second. The NTSB Vehicle Recorder Division received a L-3/Fairchild FA2100 FDR having part number 2100-2045-22 and serial number 00904855 from Mesa Airlines. Additionally, an electronic file containing the FDR data was received from SkyWest Airlines. The L-3/Fairchild FA2100 FDR (ASH5826) was configured to record 512 12-bit words of digital information every second and was designed to meet the crash-survivability requirements of TSO-C124b. The FDR was in good condition and the data were extracted normally from the recorder using instructions provided by the recorder manufacturer. The FDR recording contained approximately 154.9 hours of data. The incident flight was the eighth to last flight of the recording, and its duration was approximately 1 hour and 25 minutes. The parameters evaluated for the purpose of this report appeared to be in accordance with federal FDR carriage requirements. The FDR file obtained from SKW5326 was configured to record 512 12-bit words of digital information every second. The FDR recording