ENG26LA011

On November 23, 2025, about 0950 central standard time (CST), SkyWest Airlines flight 4229, an MHIRJ Aviation Group CL-600-2C11 (CRJ550), N707EV, experienced a restriction in nose-up pitch control during the flare while landing at Range Regional Airport (KHIB), Hibbing, Minnesota. Despite the control issue, the airplane touched down and taxied to the gate with no further issues. The flight was operated as a Title 14 Code of Federal Regulations Part 121 scheduled domestic flight from Minneapolis-Saint Paul International Airport (KMSP), St. Paul, MN to KHIB. There were no injuries to occupants and there was no damage to the aircraft. SkyWest Airlines maintenance found that the elevator autopilot servo control cable (part number BA670-93710-13) was broken, and that the slack in the broken cable was wrapped around the autopilot servo mount in such a way that it caused the pitch restriction. Previous events investigated by the National Transportation Safety Board (NTSB) (see NTSB Investigation Number ENG25LA009) found that when this cable fails, the slack in the broken cable bound between the elevator autopilot servo mount and the cable guide pins. The bound cable interfered with the rotation of the servo mount, which remained connected to the aft side of the elevator control quadrant by the intact aft cables. This condition resulted in the limited rotation of the elevator control quadrant in one direction. The broken cable was sent to the NTSB Materials Laboratory for further examination. The construction of the cable was 7x7 and made from carbon steel. The fracture occurred 14 inches from the elevator autopilot servo mount end. Examination revealed that the individual wires near the fracture were worn and exhibited features consistent with cyclic fatigue. SkyWest Airlines reported that the airplane had accrued 44,643 flight hours and 33,624 flight cycles at the time of the cable failure. The cable was last inspected per MRB Task 273000-201A in May of 2016, 11,915 flight hours prior to the failure. SkyWest Airlines stated that the cable had not been replaced since they acquired the airplane in June of 2020. Additional Reported Cable Failures On January 31, 2026, SkyWest Airlines maintenance personnel found the elevator autopilot servo control cable (part number BA670-93710-13) broken on a CRJ700 (registration number N707SK). The report that prompted maintenance to troubleshoot the airplane stated that greater than normal elevator back pressure was needed to control aircraft pitch. The airplane had accrued 51,171 flight hours and 34,606 flight cycles at the time of the cable failure. The cable was last inspected per MRB Task 273000-201A in April 2025, 1,802 flight hours before the failure occurred. SkyWest Airlines stated that the cable had not been replaced since they acquired the airplane in May of 2005. The NTSB did not request the failed cable for laboratory analysis due to its similarities with the incident cable failure and the failuresdocumented in NTSB Investigation Number ENG25LA009. Corrective Actions MHIRJ released service bulletins SB 670BA-27-078 and SB 601R-27-167, both dated 01 October 2025, to provide instruction to replace the affected cables on CRJ 200/550/700/900/1000 based on accrued flight hours of the cables. Transport Canada released Airworthiness Directive number CF-2025-63 with effective date of 1 December 2025 to mandate compliance with the MHIRJ service bulletins. The Federal Aviation Administration released Airworthiness Directive number 2026-02-03 with effective date of 5 February 2026 to require replacing the elevator autopilot servo control cables on affected airplanes.