N619UX

HISTORY OF FLIGHTOn 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. ADDITIONAL INFORMATIONTCAS

The manufacturer of the ASH5826 aircraft was contacted and informed the NTSB that the aircraft contained TCAS, Traffic Surveillance System (TSS) model number 4100 and part number 822-2132-001. The system contained data concentrator unit (DCU) part number 822-1310-007. The operator confirmed this information. With this equipment, the manufacturer informed the NTSB that TCAS Vertical Resolution, which includes parameters TCAS Vertical Control, TCAS Combined Control, TCAS Up Advisory and TCAS Down Advisory, did not record data; therefore, these parameters are not provided.

FAA Order JO 7110.65Z, Air Traffic Control

Chapter 1, Section 1, General, paragraph 1–1–1, Purpose of This Order, stated in part:

This order prescribes air traffic control procedures and phraseology for use by persons providing air traffic control services. Controllers are required to be familiar with the provisions of this order that pertain to their operational responsibilities and to exercise their best judgment if they encounter situations that are not covered by it.

Chapter 2, Section 1, paragraph 2-1-1, ATC Service, stated in part:

a. The primary purpose of the ATC system is to prevent a collision involving aircraft operating in the system.

b. In addition to its primary purpose, the ATC system also:

1. Provides a safe, orderly, and expeditious flow of air traffic.

2. Supports National Security and Homeland Defense missions.

c. The ATC system must provide certain additional services to the extent permitted. The provision of additional services is not optional on the part of the controller, but rather required when the work situation permits. It is recognized that the provision of these services may be precluded by various factors, including, but not limited to:

1. Volume of traffic.

2. Frequency congestion.

3. Quality of surveillance.

4. Controller workload.

5. Higher priority duties.

6. The physical inability to scan and detect situations falling in this category

Chapter 2, Section 1, paragraph 2-1-2 Duty Priority, stated in part:

a. Give first priority to separating aircraft and issuing safety alerts as required in this order. Good judgment must be used in prioritizing all other provisions of this order based on the requirements of the situation at hand.

NOTE- Because there are many variables involved, it is virtually impossible to develop a standard list of duty priorities that would apply uniformly to every conceivable situation. Each set of circumstances must be evaluated on its own merit, and when more than one action is required, controllers must exercise their best judgment based on the facts and circumstances known to them. That action which is most critical from a safety standpoint is performed first.

Chapter 2, section 1, paragraph 2-1-6, Safety Alert, stated in part:

Issue a safety alert to an aircraft if you are aware the aircraft is in a position/altitude that, in your judgment, places it in unsafe proximity to terrain, obstructions, or other aircraft. Once the pilot informs you action is being taken to resolve the situation, you may discontinue the issuance of further alerts. Do not assume that because someone else has responsibility for the aircraft that the unsafe situation has been observed and the safety alert issued; inform the appropriate controller.

NOTE- 1. The issuance of a safety alert is a first priority (see paragraph 2-1-2, Duty Priority) once the controller observes and recognizes a situation of unsafe aircraft proximity to terrain, obstacles, or other aircraft. Conditions, such as workload, traffic volume, the quality/limitations of the radar ...