WN4805 - Incident: Southwest B737 at Portland on Jun 25th 2024

A Southwest Airlines Boeing 737-700, registration N7861J performing flight WN-4805 from Portland,ME to Baltimore,MD (USA), departed Portland's runway 29 at 05:43L (09:43Z) when both runway and tower were still closed (to be opened by 05:45L/09:45Z). The aircraft continued to Baltimore for a landing without further incident.

Airport Operations can be heard on tower frequency opening the runway about two minutes after Southwest's departure and asking tower whether they could get hold of the Southwest Airplane that had just taken off over them while they were doing a runway inspection. Tower responded they never talked to them, they weren't yet open.

According to NOTAMs only Portland's runway 18/36 would have been available at that time (Tuesday, Jun 25th 2024, 09:43Z).

The FAA released a statement on Jun 29th 2024: "Southwest Airlines Flight 4805 departed from a temporarily closed runway at the Portland International Jetport on Tuesday, June 25. An airport vehicle exited the runway before the plane began its takeoff roll. The FAA and NTSB are investigating the event, which occurred around 5:45 a.m. local time."

On Jul 12th 2024 the NTSB released their preliminary report summarizing the sequence of events:

According to SWA, the incident flight’s dispatch release, titled “release -1,” indicated that the departure time for the flight was 0540. The release also indicated a 12-minute taxi out at PWM and an arrival time at BWI of 0715.

As part of their preflight duties, the flight crew reviewed “Southwest Airlines Briefing” electronic weather packet, which was generated on June 25, 2024, at 0446. The packet contained, in part, the departure and destination weather and, notice to air missions (NOTAMs). There were 32 NOTAMs specifically for PWM, including a NOTAM for runway 11/29 being closed until 0545 on the event date. In addition, part of the weather packet included a content page that included a message that all flights departing from PWM before 0545 must call their dispatcher and receive a briefing from the Chief Pilot who was on call about departing from runway 18/36 which is one of the shortest runways within the SWA system. The flight crew did not see the content page nor did they call for a briefing.

A review of the NOTAMs for PWM revealed that runway 11/29 was closed at the time of the flight’s departure due to construction activities on or near the runway. The runway closure NOTAM was in effect from June 19 to July 24, 2024, and stipulated that the runway would be closed Monday through Friday from 2230 to 0545 and Saturday and Sunday from 0000 to 0545.

The incident flight occurred on a Tuesday.

According to the incident flight crew members, they arrived for the flight on time. The captain, who was the pilot flying, began the preflight duties by reviewing the aircraft logbook for open discrepancies, minimum equipment list items, and a maintenance release. The first officer (FO) conducted the exterior preflight duties and programmed their navigation equipment.

The crew used their respective iPads to set up five flight-related applications, including Jeppesen FlightDeck Pro, WSi, and Comply 365, which provided station-specific information.

The captain accessed the Comply 365 application and noted that the PWM tower was closed until 0545; therefore, Boston Air Route Traffic Control Center would need to be contacted on frequency 128.2 for their instrument flight rules (IFR) clearance and void time. The application also indicated that morning departures should expect to use runway 29. The captain stated that he briefed this information to the FO and then entered the departure, destination, and route into the flight management computer.

The flight crew also reviewed the NOTAMs and noted that runway 29 was closed on Saturdays and Sundays until 0545. The captain incorrectly assumed that any additional days for the runway closure would be in the same NOTAM. The flight crew members did not see the separate NOTAM addressing the runway closure on the other days of the week; the NOTAM was underneath another application.

The FO stated that, before pushback, they received performance weight and balance (PWB) takeoff data via AeroData for runway 29. Normally when a runway is closed, no takeoff data is received, only a message stating it is unavailable due to runway closure. The crew did not brief, nor were they required to, the frequency they would utilize. When the flight was ready to push back, the FO advised on the universal communication frequency (UNICOM) frequency 122.95 that they would be pushing back from gate 4. He also advised on the UNICOM frequency they would be taxing to runway 29 for departure. The flight crew completed all briefings and checklists, and the airplane pushed back from the gate normally.

The captain stated that the FO made “multiple calls to Portland Traffic” in regards to their planned taxi route to runway 29. The FO stated, to investigators, that, while taxiing he utilized the UNICOM frequency to announce their intentions. He then, just before reaching the runway, contacted Boston Center and advised that they were number one for departure from runway 29.

Boston Center gave a clearance void time with instructions to climb on the runway heading to 4,000 feet. The FO stated that he again advised, over the UNICOM, that the airplane would be turning onto runway 29 for departure. Both crewmembers indicated that they saw a truck exit the runway while the flight was holding short of runway 29. Before applying power, they both confirmed that the truck was clear of the runway; it had turned off the runway onto the taxiway and pulled up by the terminal and faced the runway.

The airplane turned onto runway 29, and the FO announced on UNICOM that the airplane would be departing from runway 29. After a visual check of the runway, the flight crew verified the runway and that it was clear of all objects. The flight crew did not observe any equipment, markings, visual closed runway lighted “Xs” designations, or any other sign indicating that the runway was closed, and all equipment and people were clear of the runway. No other traffic or communication was heard on the UNICOM frequency. The flight departed runway 29 and continued to BWI uneventfully.

Relevant NOTAM:
!PWM 06/168 PWM RWY 11/29 CLSD EXC XNG AND TAX THU FRI MON TUE WED 0230-0945
2406200230-2407310945

Related Flight: WN4805, Southwest Airlines News