Rockwell Grand Commander 690

IRIPA - Islamic Republic of Iran Police Aviation

Commander 690 BM

Phillip R. Zeeck

Surdex Corporation

On September 28, 2021, about 0900 central daylight time, a Rockwell International 690B airplane, N690LS, was destroyed when it was involved in an accident near Hiles, Wisconsin. The pilot and two passengers sustained fatal injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 aerial imagery survey flight. According to the operator, the flight mission was to obtain aerial imagery of the forest vegetation for the Wisconsin Department of Natural Resources. Preliminary automatic dependent surveillance-broadcast information (ADS-B) revealed the airplane departed the Rhinelander-Oneida County Airport, Rhinelander, Wisconsin, about 0850. About 0858, the airplane began to level off about 15,600 ft with a maximum groundspeed of 209 knots (kts). Between 0858 and 0900, the airplane continued level flight; however, the groundspeed decreased to about 93 kts. The ADS-B data ended at 0900:56. According to air traffic control, a “mayday, mayday, mayday…we’re in a spin” transmission was broadcast. The airplane was not under air traffic control during the flight or at the time of the accident. A witness, located about one mile from the accident site, reported he heard a “loud, strange sounding airplane.” He looked up and noticed an airplane “nose down at high rate of speed spinning about its longitudinal axis at about 30 to 60 rpm.” The witness lost sight of the airplane behind some trees and then heard an impact. The airplane wreckage was located during an aerial and ground search in wetlands and wooded terrain about 10 miles east of Eagle River, Wisconsin, and 1 mile west of Butternut Lake, in the Chequamegon-Nicolet National Forest. The wreckage was distributed in a diameter of about 50 yards. A majority of the main wreckage was found beneath the water surface with some debris located in the trees.

MAG Aerospace

Shortly after takeoff from runway 12 at Thunder Bay Airport, the twin engine airplane rolled to the left and crashed upside down on runway 07, bursting into flames. The aircraft was totally destroyed and the pilot, sole on board, was killed.

Private Mexican

The aircraft was engagted in an illegal contraband flight when it crash landed in an open field located near Ahuas. No one was found on site and the aircraft was damaged beyond repair. A load of cocaine was found on board.

Mickey L. Brethower

The private pilot, who was the owner of the airplane, and a flight instructor were performing a recurrent training flight. Radar data showed that the airplane departed and climbed to an altitude about 5,000 ft above ground level. About 5 minutes after takeoff, the airplane conducted a left 360° turn followed by a right 360° turn, then continued in level flight for about 2 minutes as it slowed to a groundspeed of about 90 knots, which may have been indicative of airwork leading to slow flight or stall maneuvers. The airplane then entered a steep bank and impacted the ground in a nose-low attitude. Both engines and propellers displayed evidence of operation at the time of impact, and postaccident examination revealed no mechanical anomalies that would have precluded normal operation of the airframe or engines. The instructor had a history of obstructive sleep apnea. The investigation was unable to determine how well the condition was controlled, if he had symptoms from the condition, or if it contributed to the accident. Toxicology testing revealed low levels of ethanol in specimens from both pilots; however, it is likely that some or all of the ethanol detected was a result of postmortem production, and it is unlikely that alcohol impairment contributed to the accident. Toxicology testing also detected the primary psychoactive compound of marijuana, tetrahydrocannabinol (THC), and its metabolite, tetrahydrocannabinol carboxylic acid (THCCOOH), in specimens obtained from comingled remains; the investigation was unable to reliably determine which pilot had used the impairing illicit drug. Additionally, it is not possible to determine impairment from tissue specimens; therefore, the investigation was unable to determine whether THC impaired either of the pilots or if it may have contributed to the accident.

IRIPA - Islamic Republic of Iran Police Aviation

The twin engine aircraft was flying to Zahedan with a crew of three (two pilots and a flight attendant) and four passengers, among them General Mahmoud Sadeqi, a senior police officer who was travelling to Zahedan to investigate the circumstances of a recent attack that killed four police officers. While approaching Zahedan by night, the crew failed to realize his altitude was too low when the airplane struck the slope of a mountain located in the Sabzpushan Heights, north of the airport. The wreckage was found the following morning. All seven occupants were killed. A day later, Iranian Authorities said the accident was caused by technical flaws, darkness and the pilot’s unfamiliarity with the region.

Ellumax Leasing

The pilot was attempting a circling approach with a strong gusty tailwind. Radar data and an air traffic controller confirmed that the airplane was circling at or below the minimum descent altitude of 720 feet (708 feet above ground level [agl]) while flying in and out of an overcast ceiling that was varying between 600 feet and 1,100 feet agl. The airplane was flying at 100 knots and was close to the runway threshold on the left downwind leg of the airport traffic pattern, which would have required a 180-degree turn with a 45-degree or greater bank to align with the runway. Assuming a consistent bank of 45 degrees, and a stall speed of 88 to 94 knots, the airplane would have been near stall during that bank. If the bank was increased due to the tailwind, the stall speed would have increased above 100 knots. Additionally, witnesses saw the airplane descend out of the clouds in a nose-down attitude. Thus, it was likely the pilot encountered an aerodynamic stall as he was banking sharply, while flying in and out of clouds, trying to align the airplane with the runway. Toxicological testing revealed the presence of zolpidem, which is a sleep aid marketed under the brand name Ambien; however, the levels were well below the therapeutic range and consistent with the pilot taking the medication the evening before the accident. Therefore, the pilot was not impaired due to the zolpidem. Examination of the wreckage did not reveal any preimpact mechanical malfunctions.