N23UB

HISTORY OF FLIGHTOn August 13, 2023, about 1610 eastern daylight time, a Mikoyan Gurevich MiG-23UB airplane, N23UB, was destroyed when it was involved in an accident near Belleville, Michigan. The pilot-in-command (PIC) and pilot-rated observer (PRO) received serious injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 air show exhibition flight.

The flight was performing at the Thunder Over Michigan Air Show held at the Willow Run Airport (YIP), Ypsilanti, Michigan. The accident flight was scheduled to be the second to last act. The airplane was a privately-owned, Russian-designed military fighter that employed variable geometry wings that allowed the wing sweep angle to be changed in flight. The airplane was powered by a single turbojet engine with an afterburner. The PIC was seated in the front cockpit and the PRO was seated in the rear cockpit.

The PIC reported that the flight departed from runway 23 at YIP, first using maximum power, followed by minimum afterburner, and then maximum afterburner. He then deselected afterburner as he turned the airplane onto the downwind leg of the traffic pattern. The PIC noted nothing unusual at this time.

The PIC then maneuvered the airplane for a “banana pass” (a low-level, knife-edge display pass) along runway 23. As the airplane approached for the display pass, the PRO swept the wings to the 45° position, at which time the PIC glanced at his airspeed indicator and noticed the airplane was slower than he thought it should have been, but it was still above the minimum maneuvering speed. The PIC believed this may have been the first indication that the engine was losing power, but he did not realize it at this time. To increase airspeed, he advanced the throttle and decreased pitch slightly.

About this time, the PRO announced that it was time to engage the afterburner for the display pass. The PIC advanced the throttle to the full position and pulled the afterburner paddle switch to engage the afterburner, but there was no increase in engine power. He announced to the PRO that the afterburner did not engage and that he was attempting it again. He pulled the throttle back to midrange and then readvanced it, using the same procedure to engage the afterburner, but there was still no increase in engine power.

The PIC and the PRO confirmed with each other that an emergency existed. The PIC visually located YIP and decided that he needed to continue toward the airport. About this time, the PRO announced that he had selected the wings to the 16° sweep position, which the PIC acknowledged. The PIC maneuvered the airplane back toward YIP using the angle-of-attack indicator to keep the airplane from entering an aerodynamic stall. He stated that his intention was to place the airplane into an area away from the public, at just above stall speed.

The PIC located an area that met these criteria and was maneuvering the airplane toward that location. He also noted that the engine was running above idle and was still producing some thrust, but not enough to maintain airspeed and altitude. The PIC believed that the airplane would have been able to descend to a large field, just past a large highway but short of the runway. About this time, the PRO stated that flap deployment was needed, which the PIC delayed to maintain a better glide ratio. He believed he later selected the takeoff flap position when the airplane was about 190 kts, which was the lowest airspeed he remembered. The PIC stated that the flight controls were operating during the entire flight and that the airplane never approached an aerodynamic stall.

The PIC stated that once the airplane was established in the glide to the selected landing area, he then had time to attempt to diagnose the loss of engine power. He first activated the emergency nozzle control but did not feel any immediate response from the engine. About that time, that the PRO stated, “We need to get out of the jet,” to which the PIC responded, “No.” The PIC stated he was surprised by the PRO’s statement, as he had not considered ejecting and did not thereafter. After attempting to reestablish engine power using the emergency nozzle control, the PIC intended to use the emergency engine control, which bypasses the automatic fuel control, to reestablish engine power; however, he did not remember if he was able to activate the switch before the ejection seat fired and he departed the cockpit.

The PRO stated that while the airplane was descending and accelerating for a display pass, he swept the wings back to 45°. As they approached the air show line and the PIC moved the throttle forward into the afterburner range, the thrust from the engine dropped to near zero and the airplane began to decelerate. The PRO stated that the deceleration was such that he was pulled forward against his shoulder straps. The descent reached 500 ft agl, and the PIC began a climbing left turn. The PIC said that they had a problem, and the PRO agreed.

The PIC moved the throttle to idle, then forward to the maximum without afterburner, and then into the afterburner range. The PRO stated that there was no change in engine rpm, no restoration of thrust, and no change in engine noise. The PRO stated that the PIC attempted this throttle movement at least three more times. As the airplane climbed, the airspeed decayed, and the PRO stated that he made airspeed callouts as the airplane slowed. The PRO told the pilot, “We need the wings to 16°,” and the PIC agreed. The PRO selected the 16° wing position, and the wings moved to that position. The PRO said that the airspeed decreased below 200 kts and he declared an emergency over the air show communication frequency.

The PRO said they briefly discussed the engine power loss, and the PIC asked if they could make it to runway 27, to which the PRO replied, “No.” He said that the altitude peaked at 900 ft agl, and the PIC then began trading altitude to maintain airspeed. He said the airplane was in and out of the stall buffet, and he asked the PIC if they needed flaps. He stated that the PIC said, “Yes,” the PIC selected takeoff flaps, and the PRO confirmed the flap and slat deployment. The PRO stated that the airplane was in a descending left turn and the trajectory would intersect terrain outside the airport perimeter and over 2 miles south of runway 27 at YIP. He stated that he communicated the need to eject with the PIC. After several seconds without a response, as the airplane was descending below 350 ft agl, the PRO activated the ejection sequence and both occupants were ejected from the airplane.

Video evidence indicated that the airplane was in a left bank when the ejection seats fired. The airplane continued in the left bank and descended into the ground about 1.7 miles south of the approach end of runway 27 at YIP. The wreckage path was about 600 ft long on a heading of about 35°. There was a postimpact explosion and fire. The fuselage section that contained the tail surfaces and engine came to rest adjacent to an apartment building. The remainder of the airplane was fragmented and distributed along the wreckage path. Both occupants landed in a lake and received serious injuries. There were no reported injuries on the ground. PERSONNEL INFORMATIONThe PIC, who was the owner of the airplane, held an airline transport pilot certificate with type ratings for Airbus 320, Boeing 757, Boing 767, Boeing 777, Aero Vodochody L39, and MiG 23 airplanes. He reported having a total of 21,296 hours of total flight experience, including 42 hours in MiG 23 airplanes. In addition to his civilian flight experience, the pilot previously served as a United States Naval Aviator. During his military career, he accumulated 2,500 hours flight experience, including 47 combat missions, and 250 aircraft carrier landings.

The rear-seat PRO held an airline transport pilot certificate with type ratings for Boeing 777, Airbus 320, McDonnell Douglas DC-9, Bombardier Canadair Regional Jet CL-65, Saab 340, Embraer 500, Embraer 505, SIAI-Marchetti S.211, and Aero Vodochody L-39 airplanes. He reported having a total of 15,000 hours of flight experience, including 12 hours in MiG 23 airplanes. He was an active Lieutenant Colonel in the Air National Guard. He reported having over 2,400 hours of military jet flight experience, including 50 combat missions. He also reported having formal training on ACES 11 (F-16), Northrop Seat (T-38), and Martin Baker Mk 16 (T-6A) ejection seats. WRECKAGE AND IMPACT INFORMATIONThe airplane impacted the ground about 1.7 miles and 160° from the approach end of runway 27 at YIP, and the main part of the wreckage came to rest about 600 ft and 35° from the initial impact point. The airplane was resting near an apartment building with damage to the exterior west wall of the building evident. Examination of the airplane’s flight control system was not performed, as the pilot reported no flight control difficulties during the flight. Further examination consisted of a tabletop review of the aircraft and engine logbooks provided by the PIC, the PIC’s formal statement following the accident, and photos taken of the accident scene.

The PIC provided a written statement to the NTSB after the accident that described the events of the day as well as a previous loss of engine power event in 2018, after which he replaced the fuel control unit (FCU).

A review of aircraft and engine logbooks provided by the PIC revealed an engine logbook entry for the installation of a new FCU on a page dated with the year 2018. The PIC stated that his mechanic purchased three new FCUs on his behalf, one of which was then installed on the airplane. It is not known whether the term ‘new’ meant recently manufactured or manufactured years ago with no operating time. According to the PIC’s postaccident statement, replacement of the FCU was thought to have fixed the engine anomaly experienced in 2018. The accident FCU had accumulated about 13 flight...