Story ID: 004
Business Aircraft Accident Reports: April 2023
By: David Jack Kenny
Caption: Preliminary and final accident reports, April 2023
Word Count: 1632
Preliminary ReportsNo Survivors in King Air Crash, Beech King Air 200, Feb. 22, 2023, Little Rock, Arkansas
Five members of a North Little Rock environmental consulting firm were killed when their King Air crashed just after takeoff from Bill and Hillary Clinton National Airport. The flight was bound for Columbus, Ohio, where the occupants were to investigate a fatal explosion in a metals factory. A line of thunderstorms with 40-knot wind gusts was reportedly passing through the area at the time, and the National Weather Service had issued a Special Weather Statement about 30 minutes before the accident. Initial press reports did not include any witness accounts of the crash, which occurred within one mile of the airport.
Five Lost in Air Ambulance Break-up, Pilatus PC-12/45, Feb. 24, 2023, Stagecoach, Nevada
All five occupants, including the pilot, two medical crewmen, a patient, and the patient’s wife, perished when the single-engine turboprop crashed 14 minutes after takeoff from Reno/Tahoe International Airport. The air ambulance flight departed at 21:00 local time with a destination of Salt Lake City. Radar and ADS-B track data showed that it reached a maximum altitude of 19,400 feet before entering a spiralling descent at a rate that exceeded 30,000 fpm. No distress call was received. The last radar hit came at 11,000 feet; two hours later first responders found the main wreckage about 25 miles southeast of the airport.
In a press conference on February 26, NTSB vice chairman Bruce Landsberg cited evidence that the airplane had broken up in flight: the outboard portion of the right wing and one horizontal stabilizer and elevator were found half to three-quarters of a mile from the fuselage.
Prevailing weather included gusty winds and less than two miles visibility in snow beneath a 2,000-foot overcast with both forecasts and pilot reports of icing up to 20,000 feet and light to moderate turbulence, conditions within the Pilatus’s capabilities. Landsberg described the weather as “pretty much a normal winter evening around Reno.” He also noted that the airplane was not equipped with a flight data recorder or  a cockpit voice recorder, something the NTSB has long recommended that FAA regulations be revised to require.
Final ReportsLoose Ring Nut Precipitated, L.A. Hospital Crash, Agusta A109S, Nov. 16, 2020, Los Angeles, California
Examination of the wreckage determined that the ring nut securing the tail rotor duplex bearing had backed out of its sleeve, causing the loss of yaw control during a steep approach. The pilot and one of the two passengers suffered serious injuries when the helicopter crashed onto the rooftop helipad of the USC Keck Medical Center at the conclusion of an organ procurement flight. The pilot reported that about 40 feet above the helipad, while descending at 40-50 knots airspeed and 102 percent engine rpm, a gradual right yaw began that was not corrected by full left pedal. As the helicopter’s nose crossed over the edge of the building, the yaw accelerated dramatically. Realizing that the aircraft was becoming uncontrollable, the pilot “dumped collective” to keep it on the helipad. Footage recorded by a witness in an adjacent building corroborated his account, showing the helicopter slowly rotating clockwise during its descent and rolling left prior to impact. The main rotor blades struck first, followed by the left main landing gear and then the fuselage, and the helicopter came to rest on its left side.
All major components of the wreckage remained on the rooftop. The tail rotor assembly and 90-degree gearbox were separated from the tail boom, and examination of the tail rotor rotating controls found that the ring nut had separated from the thrust sleeve assembly, disconnecting the tail rotor control servo actuator from the pitch-change links.
The manufacturer reported four previous instances of ring nut failures attributed to installation errors, none of which had been investigated by the NTSB. These led the manufacturer to issue five successive technical bulletins, the EASA to issue Emergency Airworthiness Directive (EAD) 2012-1095E, and the FAA to issue AD 2014-02-08, later superseded by AD 2015-11-08. Among other provisions, these required daily pilot inspections of the dual safety wires securing the ring nut. Fragments of one safety wire remained attached to the ring nut, which also showed accelerated wear at the bottom edge of its outside diameter. The manufacturer has since developed an improved dual-lock bearing support retrofittable to current aircraft.
Ice Accumulation Cited in Landing Stall, Embraer EMB-500 Phenom 100, Aug. 2, 2021, Paris-Le Bourget Airport, France
Airframe ice accreted after the crew deactivated the anti-icing systems, and their decision to fly a no-ice approach profile led the light jet to stall onto the runway just before landing, shearing the nose and right main landing gear and igniting a fire after the strut punctured the right fuel tank. The airplane slid some 1,050 meters (3,445 feet), then veered off the left side of Runway 27. Airport rescue and firefighting crews extinguished the fire and the two pilots and sole passenger were evacuated without injury.
The Maltese-registered charter flight departed from Venice at 08:17, cruising at FL 340. The first officer was the pilot flying. Flight manual charts for non-icing conditions led them to calculate a final approach speed of 121 knots and reference landing speed (Vref) of 97 knots.
At 09:20, they tuned in the Le Bourget ATIS recording. The snow predicted in their departure weather briefing had not materialized and the runways were clean, but severe icing was reported between 3,000 and 5,000 feet, something the captain said was “common” at Le Bourget.
The crew activated the engine and windshield de-icing prior to descending to 5,000 feet; then, after descending to 3,000 feet with clearance for the ILS 27 approach, operated the wing and stabilizer boots for 21 seconds, deactivating them after confirming that ice along the leading edges had broken off. The approach was flown with full flaps at 135 knots indicated airspeed.
Five seconds after the radar altimeter indicated 50 feet, airspeed dropped from 94 to 90 knots and the angle of attack increased from 10 to 28 degrees. The captain took the controls and attempted a go-around as the stall warning activated, but too late. Three hours after the accident, BEA investigators found ice on the leading edges of both wings and horizontal stabilizers. The BEA also noted that the increased landing speeds and distances the manufacturer required with deicing systems in use would have precluded landing at Le Bourget due to insufficient runway length and inadequate climb performance.
Other Phenom 100 pilots interviewed acknowledged that they had “unofficially” been taught to use deicing just long enough to dislodge visible ice to avoid having to divert. The investigation also cited similar accidents in Gaithersburg, Maryland, in 2014 and Berlin in 2013 attributed to failure to properly use deicing systems.
Aggressive Takeoffs Preceded Fatal Departure Stall, Rockwell International Aero Commander 690B, Aug. 16, 2021, Thunder Bay, Ontario, Canada
The TSB’s review of radio communications between the pilot and the control tower showed that on at least his two previous departures, the accident pilot had made sharp left turns immediately after takeoff to fly in close proximity to the control tower, apparently for the entertainment of the tower controllers.
The solo pilot was killed and the airplane destroyed when it stalled into the ground from approximately 45 feet, igniting a fire that consumed three-quarters of the airframe in the less than three minutes it took airport rescue and firefighting crews to reach and extinguish the blaze.
The accident flight was the day’s third of “bird dog” firefighting operations conducted to establish entry and exit routes for water-bomber crews and coordinate operations with fire crews on the ground.
On the first two flights, the pilot was accompanied by a forestry air attack officer, as is standard for “bird dog” operations. On the first, the pilot made a steep left turn immediately after takeoff from Runway 12, passing within 200 feet of the front of the control tower. The tower controller radioed: “That was fantastic,” adding “thanks for the little show.” The pilot replied “I can get closer if you’d like,” and the controller answered, “Sure.”
Before the second takeoff, the pilot transmitted: “Get your camera ready if you’d like,” and a second (trainee) controller responded “Sure! Will do.” Asked whether he’d prefer the pilot to fly north or south of the tower, the trainee replied, “Your choice. I got the camera ready.” The pilot opted to go south, banking earlier and harder, this time passing some 600 feet behind the tower. The trainee radioed, “Thanks for the show. Next time I want to be on board.”
The accident flight was intended to reposition the airplane for maintenance at Dryden Regional Airport in Ontario, so the forestry air attack officer was not on board. The pilot was instructed to line up and wait on Runway 12 while another aircraft landed on Runway 25; the two pilots briefly conversed on tower frequency before the Commander was cleared for takeoff.
The airplane began a steep left turn immediately after rotation, rolled hard left, and crashed inverted onto the surface of Runway 07, catching fire. Examination of the wreckage found no evidence of pre-impact anomalies except a failed elevator trim cable, most of whose strands had worn through before the accident flight.
However, the trim tab was found in the normal takeoff position, and the TSB ruled out runaway trim as having played any part in the accident. The Board noted that high-energy maneuvering often required during fire-spotting flights likely desensitized the pilot to risks of accelerated stalls.