DCA25LA163

The captain’s failure to recognize that the airplane’s location did not agree with the assigned departure runway as required per the Southwest Airlines Airplane Operating Manual, and the captain’s plan continuation error when he missed several cues that would have informed him that he was not on the assigned departure runway when he initiated takeoff.

On March 20, 2025, about 0930 eastern daylight time (EDT), Southwest Airlines (SWA) flight 3278, a Boeing 737-8H4, N8315C, taxied onto and initiated a takeoff roll from taxiway “H” at Orlando International Airport (MCO), Orlando, Florida. SWA flight 3278 discontinued its takeoff roll and subsequently returned to the gate area. The flight was operated under Title 14 Code of Federal Regulations Part 121 as a scheduled domestic passenger flight to Albany International Airport (ALB), Albany, New York. All 158 occupants (2 flight crew members, 4 cabin crew members, and 152 passengers) deplaned at the gate without any injuries. According to an Aircraft Communication Addressing and Reporting System (ACARS) message, at 0917 the L1 door was closed and at 0922 an “out gate message” was sent, and the flight began pushback from gate 103. According to the first officer, they had started both engines during the pushback. About 0925, the first officer contacted the Airport Traffic Control Tower (ATCT) ground control to request taxi clearance and was told to taxi to runway 17R via the ramp and taxiway H2. Subsequently, the flight began to taxi on the airside 2 ramp (see figure 1). Figure 1: Airport diagram showing Airside 2 and 4 gates, G and H taxiways, and runway 17R (Source: Jeppesen) About 0927, the airplane stopped taxiing abeam the taxiway H1 entrance from the ramp. According to crew statements the flight stopped in this area due to a company aircraft that had pushed back from a gate, and there was not room to taxi around the airplane. The captain stated the crew completed the Before Takeoff checklist while waiting for the airplane to clear their taxi path. Additionally, the crew stated that taxiways G and H1 were closed due to construction, and men and equipment were present and working on taxiway H1. Once the company airplane taxied out, the first officer informed ATCT that they were clear. About 0929, the flight crew was issued a clearance for takeoff on Runway 17R at H2 while they were in the ramp area holding short of H2. Subsequently, the flight data recorder (FDR) data showed N1 for both engines increased to 38.8%. Subsequently, FDR data indicated that both engines N1 increased to at or above 40% for the remainder of the taxi and commencement of the takeoff roll. The event flight turned left on taxiway H2 from the airside 2 ramp area with a recorded ground speed of 9 kts. The event flight taxied on taxiway H2 crossing taxiway G (see figure 2). The first officer stated that as they were crossing taxiway G, the captain stated that the final approach was clear and that runway 17R was verified. According to the flight crew, about this time the captain asked the first officer to confirm they had run the Before Takeoff checklist. The first officer stated that the airplane was still headed straight towards the runway 17R and taxiway H2 intersection and momentarily looked up to scan the overhead panel to ensure that the bleed switches and packs were in the proper position, and confirmed that the checklist was completed. As the first officer finished his scan, the first officer felt the airplane turning as the captain turned the airplane onto taxiway H. The captain stated that before he finished the right turn, he announced that he was setting takeoff thrust and selected the take-off/go-around (TOGA) switch while advancing the thrust levers. About 0930, when the flight approached taxiway H and subsequently made a right turn onto taxiway H, the recorded ground speed was 14 kts, the engine N1 speed increased to about 90.6%, and the takeoff roll began. The captain stated that after the turn the airplane wasn’t centered on the surface, and he applied rudder to maintain the centerline. The captain stated that maintaining the centerline required full attention and he didn’t notice the airplane was on a taxiway. The first officer stated that he had momentarily looked down, saw the thrust levers moving up, and then looked outside the aircraft and realized that the airplane was on a taxiway. The first officer stated he was startled when he saw this, and it took a few seconds for the first officer to vocalize “we are on the taxiway-reject.” About the same time as the first officer commanded the reject, the ATCT controller instructed “southwest 3278 stop, southwest 3278 stop, stop stop southwest 3278 stop cancel takeoff clearance you’re on hotel taxiway southwest 3278.” The highest recorded automatic dependent surveillance broadcast (ADS-B) ground speed the flight obtained was 66 knots, the crew stated that the flight’s airspeed did not exceed 80 kts, and the flight data recording indicated the maximum speed of 71 kts computed airspeed. FDR data also showed the airplane had traveled about 800 feet down taxiway H before the groundspeed began to rapidly decrease. After the flight crew aborted their takeoff, they turned right on to taxiway H3. Figure 2: Incident flight's taxi and attempted takeoff route. (Source: ADS-B data) After turning right on to taxiway H3, the ATCT queried if the crew wanted to taxi back and takeoff. The crew informed the ATCT controller that they would need to return to the gate after the brake cooling time had completed. About 0931, the flight turned right onto taxiway G, and about six minutes later the flight taxied onto the Airside 2 ramp at taxiway G1. In post-accident statements and interviews, the captain stated that as they had turned onto taxiway H2, he did a scan of the final approach to 17R for traffic, and he noted an airplane landing on 17L. Both crew confirmed that the airplane in sight was landing on 17L, after which he stated final is clear, and recalled seeing the 17R sign straight ahead. The captain stated that after clearing and passing taxiway G, he had mistakenly turned right onto taxiway H thinking it was runway 17R. The captain also stated after turning, he was occupied with centering the airplane on the surface and did not realize they were on a taxiway until the error was identified by both the first officer and ATCT. The captain was asked in a post-accident interview how he verified the surface he was on. He stated that for a H2 departure he would not be able to see the numbers on the runway itself but could use the lighting and magnetic course. He also mentioned that he had been using a moving map display during the taxi out to identify the taxi route but was not referencing it while approaching the runway. The Southwest Airlines Aircraft Operating Manual provided the following guidance, in part, as it pertained to taxiing onto the departure runway: Both Pilots crosscheck all available references and confirm that the aircraft’s location is in agreement with the assigned departure runway. Use all available references to confirm that the aircraft is at the assigned departure runway. The references may include: Aircraft heading indicators (including HGS) Navigation display Runway signage Painted runway designation (may not be visible for displaced thresholds or intersection takeoffs) Jeppsen -9 page Runway lighting (expected lighting versus actual lighting) Verify the aircraft is on the assigned runway for takeoff using all available references. (CA) Verbally verify the aircraft is on the assigned runway. Verify that the aircraft is on the assigned runway and state, “Runway _____, Verified.” Warning: If there is any doubt that the aircraft is on the correct runway, do not takeoff and notify ATC immediately… The captain failed to follow these standard operating procedures when he did not verbally verify the aircraft was on the assigned runway and initiated the takeoff without verifying the aircraft was on the assigned runway. The captain exhibited a plan continuation error when he entered the taxiway, thinking it was the assigned runway, and ignored several cues that indicated his incorrect location; to include the presence of a yellow taxi c