N9156Z

HISTORY OF FLIGHTOn August 7, 2021, about 1740 central daylight time, a Mooney M20M airplane, N9156Z, was destroyed when it was involved in an accident near Victoria, Minnesota. The private pilot and two passengers (one of whom was a student pilot) sustained fatal injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

A review of automatic dependent surveillance-broadcast (ADS-B) information revealed that the airplane departed Chandler Field Airport (AXN), Alexandria, Minnesota, about 1654 on an instrument flight rules (IFR) flight plan and climbed to 5,000 ft mean sea level (msl) while en route to Flying Cloud Airport (FCM), Minneapolis, Minnesota. After the pilot descended the airplane to 3,000 ft msl, he was cleared to fly the instrument landing system (ILS) approach to runway 10R at FCM. At 1738:39, the pilot contacted the FCM tower controller and stated, “Mooney 56 Zulu…ah…with you.” The pilot did not respond, so the controller repeated the clearance; the pilot did not respond to this transmission as well.

About 10 miles from the runway while on final approach, the airplane tracked left of the ILS course and descended below 2,700 ft msl. At 1739:22, the controller again provided the landing clearance, to which the pilot stated, “ah 56 Zulu.” The airplane then made a right turn back toward the approach course and continued to descend, which triggered a low-altitude alert to the FCM tower controller. The controller transmitted the low-altitude alert to the pilot, which he acknowledged. No further transmissions were received from the pilot. The airplane subsequently made an abrupt left turn and began a rapid descent, during which radar contact was lost. The airplane subsequently impacted the ground, and a postimpact fire ensued.

Several witnesses heard a loud popping noise and observed the airplane in a rapid descent with at least one of the wings “folded up.” Review of a doorbell security video near the accident site revealed that the airplane was upright and in a nose-high attitude at ground impact and that both wings and the right stabilizer were deflected upward in a vertical position (see figure 1). A King Air pilot who heard the accident pilot’s communications with the controller stated that the pilot sounded “stressed” and “confused.”

Figure 1. Screen capture of airplane just before impact (Source: doorbell security video). PERSONNEL INFORMATIONThe pilot transitioned from a paper to an electronic logbook in February 2021. No instrument approach procedures were logged in the pilot’s electronic logbook, and the last instrument approach procedure in the pilot’s paper logbook was November 2020.

The pilot’s most recent flight review was conducted with visual procedures only; no instrument approach procedures were flown. The flight instructor reported the pilot was “very safety conscious” and “detail oriented.” The flight instructor was not aware of a safety pilot who flew with the accident pilot (to log instrument time) during the 6 months before the accident.

A friend of the accident pilot, who had accumulated about 3,000 hours of flight experience, stated that he flew frequently with the accident pilot. The pilot’s friend reported that the accident pilot flew with a yoke-mounted Garmin 650 that he used as an electronic flight bag for navigation purposes. The friend was “confident” that the accident pilot would have attempted to have the autopilot engaged during the accident instrument approach because the airplane was operating in instrument conditions at the time. The friend was also “certain” that the pilot would not have allowed the passenger who was a student pilot to fly the airplane while in instrument conditions.

The pilot’s friend described that, in Mooney airplanes, airspeed increases fairly rapidly when the airplane is pitched nose down and that pitch control is “challenging.” The accident pilot and his friend discussed using pitch trim to adjust the airplane’s attitude to facilitate pitch control while flying in instrument conditions. They also discussed making half-standard-rate turns primarily with rudder control, which the friend described as “pedal turns.” The friend was “fairly certain” that the pilot used these two methods during instrument flight. A review of ADS-B data from a January 2021 flight by the accident pilot revealed that he made a series of shallow turns for about 50 minutes. The friend reviewed the data for this flight and thought the pilot was likely practicing “pedal turns.”

The pilot’s friend often acted as the safety pilot when the pilot practiced instrument approaches, but both pilots had not flown together in 2021 due to the COVID pandemic. The friend stated the accident pilot’s personal weather minimum was an 800-ft ceiling and that, during practice instrument flying, the accident pilot usually flew GPS approaches and did not frequently fly ILS approaches. The friend was not aware of another safety pilot with whom the accident pilot flew in 2021.The friend was also not aware of the accident pilot using a flight simulator during the years preceding the accident. AIRCRAFT INFORMATIONThe Limitations section of the Airplane Flight Manual lists the maximum positive load factor with flaps up as 3.8 Gs. The airplane’s maneuvering speed (VA), which is the speed above which full deflection of any flight control should not be attempted because of the risk of damage to the aircraft structure, is listed as between 111 and 126 knots calibrated airspeed.

In 2017, the pilot reported to his insurance company that he lost directional control during landing and that the airplane subsequently struck runway edge lights, which resulted in damage to the right horizontal stabilizer. (The NTSB did not investigate this event.) The damage was repaired in 2018. The pilot’s friend stated that the runway excursion was due to “a distraction during the landing rollout.” METEOROLOGICAL INFORMATIONThe pilots of a King Air that landed immediately before the accident were interviewed about the conditions that the airplane encountered. The pilot who flew the approach and landing stated that the airplane entered the clouds at an altitude of about 4,500 ft msl and broke out of the clouds on final approach at an altitude of about 1,000 ft above ground level. The pilot who monitored the approach recalled that the airplane entered and broke out of the clouds at altitudes similar to those reported by the pilot flying. . The monitoring pilot reported that no turbulence was occurring while the airplane was in the clouds. AIRPORT INFORMATIONThe Limitations section of the Airplane Flight Manual lists the maximum positive load factor with flaps up as 3.8 Gs. The airplane’s maneuvering speed (VA), which is the speed above which full deflection of any flight control should not be attempted because of the risk of damage to the aircraft structure, is listed as between 111 and 126 knots calibrated airspeed.

In 2017, the pilot reported to his insurance company that he lost directional control during landing and that the airplane subsequently struck runway edge lights, which resulted in damage to the right horizontal stabilizer. (The NTSB did not investigate this event.) The damage was repaired in 2018. The pilot’s friend stated that the runway excursion was due to “a distraction during the landing rollout.” WRECKAGE AND IMPACT INFORMATIONThe airplane impacted the ground on a northerly heading (see figure 2). The left horizontal stabilizer and left elevator were found about 720 and 800 ft southwest of the accident site, respectively. A 6-inch section of the main wing spar upper cap splice plate was found about 300 ft southwest of the accident site.

Figure 2. Airplane at accident site with parametric data overlaid.

Postaccident examination revealed the flap actuator jackscrew threads were consistent with the flaps in the retracted position. The speedbrakes extended and retracted freely and had no deformations.

Both vacuum pumps were disassembled, and all components were accounted for. The vanes and drive couplers were intact, and the attitude gyro and turn/slip rotors showed indications of rotation at impact.

The propeller had separated from the crankshaft due to impact damage. All three blades exhibited chordwise and leading-edge scaring.

The left horizontal stabilizer separated about 10 inches outboard of the airplane centerline. The left elevator was separated from the horizontal stabilizer and fractured into two pieces. The left elevator hinges were intact on the horizontal stabilizer, and the hinge blocks were pulled from the elevator. The damage and deformation of the left horizontal stabilizer and elevator was consistent with separation in an upward direction.

The left elevator control rod attach bolt remained installed in the left elevator but was deformed inboard about 45°. The bolt threads had some smearing, and the nut and cotter pin were not located in the recovered wreckage. No evidence indicated fretting on the elevator around the bolt location.

Both wings were fractured near the outboard ends of their respective main landing gear wheel well. The lower spar cap on both wings showed no deformation adjacent to the main spar fracture locations, whereas the upper spar caps exhibited S-bending. All the examined fractures had a dull, grainy appearance consistent with overstress separation, and no evidence indicated corrosion or pre-existing fractures.

No preaccident mechanical failures or malfunctions with the airplane or engine were observed that would have precluded normal operation. ADDITIONAL INFORMATIONSpatial Disorientation

The Federal Aviation Administration’s (FAA) Airplane Flying Handbook (FAAH80833B) described some hazards associated with flying when the ground or horizon are obscured. The handbook states, in part, the following:

The vestibular sense (motion sensing by the inner ear) in particular can and will confuse the pilot. Bec...