OPS25LA054

On July 16, 2025, about 1542 eastern daylight time (EDT), SkyWest Airlines (SKW) flight 3751, a Bombardier CL-600-2D24, N833SK, departed from a closed runway at MBS International Airport (MBS), Freeland, Michigan. The flight continued without further incident to its intended destination of Detroit/Wayne County International Airport (DTW), Romulus, Michigan. The 2 flight crewmembers, 2 cabin crewmembers, and 61 passengers deplaned at the gate without any injuries. The flight was operated as a Title 14 Code of Federal Regulations Part 121 scheduled domestic passenger flight. The National Transportation Safety Board (NTSB) was notified by the Federal Aviation Administration (FAA) and, in response, began an incident investigation. History of Flight According to SKW, the incident flight’s dispatch release was 20 pages in length and indicated a departure time of 1533. The release also indicated an 18-minute taxi out at MBS and an estimated time of arrival at DTW of 1622. According to the captain, he flew in from DTW as a dead-heading crewmember and met the crew at the gate. Prior to departure the first officer, who was to be the pilot flying (PF), conducted the threat briefing. Both pilots discussed the storms in the vicinity and decided that if they received good takeoff data, they would perform the departure from runway 14 and that would keep them clear of the line of storms. The flight crew read the taxiway closures provided to them from the dispatcher with the flight release, and the captain highlighted the applicable ones on the airport diagram. The crew received the flight’s takeoff data for runway 14, and considering the potential for windshear, the crew agreed to use normal takeoff performance numbers. The MBS air traffic control tower (ATCT) was closed via a notice to airmen (NOTAM) at the time the flight was pushed back from the gate. After completing the engine start checklist, the first officer contacted Great Lakes approach control to obtain their air traffic control clearance to DTW. The flight crew reported they made the appropriate advisory transmissions on the MBS common traffic advisory frequency (CTAF) as they taxied to runway 14 via taxiway “C” and taxiway “A.” During the taxi out to runway 14 the crew reported there “were no visible cues indicating a closure of the taxiways or runways.” As the flight was holding short of runway 14, the first officer contacted Great Lakes approach control and informed the controller that they were number one at runway 14 and ready for departure. The controller issued the flight a release of “fly runway heading maintain 4,000.” The flight crew reported that “were no obstructions or airport personnel present” at the time of their departure. According to ADS-B data, the flight became airborne about 1542:39. The flight crew stated that the flight was uneventful and there was no indication they had departed from a closed runway. According to ADS-B data, the flight landed at DTW about 1607. A review ofthe NOTAMS for MBS revealed that there were 18 NOTAMs in effect at the time of the incident. One of the NOTAMS specified that runway 14/32 was closed from July 16, 2025, beginning at 0600 until July 16, 2025, at 1800. On page 14 of the flight’s dispatch release, under the section titled “Origin Airport NOTAMS,” the NOTAMs were broken down into six sections. Three of those sections were titled “Aerodrome/RWY/FICON NOTAMS,” “Taxiway and Airport Lighting NOTAMS,” “Radio/Communication NOTAMS.” There were five NOTAMS under “Aerodrome/RWY/FICON NOTAMS” section, which included the runway 14/32 closure NOTAM, five NOTAMS under the “Taxiway and Airport Light NOTAMS” section, and one NOTAM under the “Radio/Communication NOTAMS” section. Airport Information MBS was located about 9 miles to the northwest of Saginaw, Michigan at an elevation of 668.2 ft msl. The airport had two paved landing surfaces, 05/23 and 14/32. Runway 05/23 was 8,002 ft long and 150 ft wide. Runway 14/32 was 6,399 ft long and 150 ft wide. The FAA Chart Supplement provided that the MBS ATCT operated daily from 0700 until 0000. At the time of the incident, the ATCT was closed via NOTAM from July 16, 2025, at 0957 until July 16, 2025, at 2300. NOT FOR NAVIGATION Figure 1: MBS Airport Diagram (Source: Jeppesen)