Boeing 737-823 N976NN incident near Sarasota, Florida

Probable cause

The local controller’s failure to prioritize and properly monitor the runway and airport environment along with his erroneous assumption that ROU 1633 would depart from runway 14 before AAL2172 arrived to land on the same runway, which resulted in a loss of separation between both airplanes.

NTSB analysis

At the time of the incident, the flight crews of Air Canada Rouge flight 1633 (ROU1633) and American Airlines flight 2172 (AAL2172) were in communications with and were operating in the Sarasota-Bradenton International Airport (SRQ) Air Traffic Control Tower (ATCT) airspace. Two FAA controllers were on duty at the time, but one was on break, and the local control (LC) controller was the only person in the tower at that time. All ATCT positions including that of the operational supervisor were combined, and the workload was stated as normal for the time of day and for one controller being in the ATCT cab.

NTSB postincident examination of SRQ radar data revealed that AAL2172 was about twelve miles northwest of SRQ on a visual approach to runway 14 when communications were established with the FAA local controller (LC). The LC then cleared AAL2172 to land on Runway 14.

About three minutes later, the LC asked ROU1633 if they were ready for departure, and ROU1633 responded affirmatively. The LC then cleared ROU1633 for takeoff on Runway 14, with instructions to fly the runway heading, and issued ROU1633 a traffic advisory that AAL2172 was on a 3-mile final. The LC stated that he then turned while at the LC position and picked up flight strips and talked to another aircraft. ADS-B data indicated that AAL2172 was about 4.1 nm from the threshold of runway 14.

About 13 seconds later, when AAL2172 was on 3.4-mile final, the LC issued AAL2172 a traffic advisory informing AAL2172 that ROU1633 was departing runway 14. When AAL2172 was on a 2.5-mile final, ROU1633 asked the LC to confirm the departure heading, to which the LC affirmed that ROU1633 was to fly the runway heading. The LC further stated that ROU1633 had not yet started their takeoff roll. He stated that he then turned away from his position and walked to the Automatic Terminal Information Service (ATIS) equipment located on the other side of the tower cab to update the latest ATIS information. About 53 seconds later, while at the ATIS equipment, the local controller heard that AAL2172 was executing a pilot-initiated go-around, and he looked and saw that ROU 1633 was passing the intersection of runway 14/22 and climbing, and AAL2172 was abeam taxiway C2 on the go-around.

The controller relied on visually monitoring both airplanes to ensure that their courses diverged, and that lateral separation was assured. However, the local controller turned his attention to a lower priority task before confirming that ROU1633 had departed.

The estimated closest proximity between ROU1633 and AAL2172 was 0.6 miles horizontally and about the same altitude; ROU1633 was departing runway 14 and climbing through 100 feet, and AAL2172 was about 100 feet, and crossing over the runway 14 numbers.

Figure 1. Position of aircraft involved when local controller looked up and outside the ATCT cab after hearing AAL2172 report “going around”.

Text from the NTSB. Open the NTSB docket for DCA23LA179 for the full record.