Story ID: 004
Business Aircraft Accident Reports: January 2023
By: David Jack Kenny
Caption: Preliminary and final accident reports, January 2023
Word Count: 1619
Preliminary Reports
Six Escape Cascading In-flight Emergencies, Agusta AW139, Sept. 24, 2022, Houma, Louisiana
Both pilots and all four passengers were able to evacuate the aircraft without injury after the crew successfully managed a series of equipment failures that first filled the cockpit with smoke, then obstructed operation of the flight controls while simultaneously rendering engine controls inoperative, leaving both engines running at maximum continuous power. The Part 135 charter flight was just seven minutes from landing at Houma Airport in Louisiana when the smell of burning plastic was noticed throughout the helicopter. Initially, no smoke was apparent, there were no caution lights or abnormal instrument indications, and flight characteristics remained normal. The pilots turned off the air-conditioning in case that was the source of the smell.
A few minutes later they heard “a loud ‘whoof’ noise” and “thick orange/brown smoke” began pouring from the aft portion of the overhead circuit breaker panel, quickly filling the cockpit and reducing visibility to zero. An audible low rotor warning sounded, accompanied by a rapid overspeed of both engines, as the collective spontaneously moved upward and the cyclic moved left. Opening the small ventilation window in the left cockpit door failed to clear the smoke and the helicopter’s airspeed prevented opening the door, but the left-seat pilot was able to remove his cockpit window, allowing the smoke to clear. “Significant force” was required to push the collective back down and center the cyclic. With the collective fully down, the helicopter quickly climbed 3,500 to 4,000 feet as main rotor speed (NR) gradually recovered to 100 percent, both engines indicating 145 percent power. “Full body weight” was required to keep the collective down. Unable to make the helicopter descend with normal control inputs, the crew switched one engine to flight idle. NR decreased from 100 percent to the upper 70s.
Switching the engine back to flight condition helped restore main rotor rpm, but made forward cyclic the only way to force the helicopter to descend. This in turn built indicated airspeed to 170-186 knots during the descent from 6,000 to 1,000 feet. The left-seat pilot declared an emergency and requested fire and emergency medical services. Still unable to control engine power in manual mode, the crew set up for an autorotation with the No. 2 engine in idle mode. NR rapidly decayed to 75 percent after No. 1 was also switched to idle, so the pilots broke off the first approach, returned No. 1 to flight status, and went around. On the second approach, they switched No. 1 back to flight status each time NR dropped to 70 percent and then back to idle when it reached 85 percent, thereby slowing to a safe speed while descending to 50 feet. They then entered autorotation with both engines at idle, landed on the runway with forward airspeed, and skidded off into the grass.
Subsequent examination found chafing and burned insulation on a 30-volt, 300-amp cable in the overhead panel that had been incorrectly routed above rather than below its support bracket, exposing it to contact with rivets on the C3 collective torque tube. In response, the manufacturer issued Emergency Alert Service Bulletin No. 139-731 calling for borescope inspections to identify misrouted cable assemblies, inspection of any affected cables and associated torque tubes, and replacement of any support brackets with incorrectly oriented retaining clips. The following day, EASA issued an AD mandating compliance with this service bulletin.
No Obvious Clues to Ferry Accident, Bell 206B, Oct. 6, 2022, near Maitland, New South Wales, Australia
The Australian Transport Safety Bureau's (ATSB’s) preliminary report offered no clear insights into why the helicopter crashed onto the bank of the Hunter River, killing the solo pilot and destroying the aircraft. The accident occurred in good visibility during daylight hours, well under the lowest reported cloud layers, with winds of eight knots. Initial examination of the wreckage found no pre-impact defects in the powerplant, flight controls, or airframe; a fuel spill at the accident site ruled out fuel exhaustion, and the fuel filter bowl showed no evidence of contamination. A series of course reversals and both lateral and vertical excursions from the charted VFR corridor remain unexplained.
The 1970-model helicopter, registered in Australia since 1986, was being returned to its owner in Warnerville, NSW after extensive maintenance at the Casino Airport to repair hail damage and replace life-limited components. The ferry pilot, holder of a commercial certificate with low-level helicopter rating, a current Class 1 medical, and current flight review, lifted off from Casino at about 1350 local time. At Wirragdurie, he entered the charted VFR corridors through restricted areas R583B and R578E, which provide 2-3 nm lateral clearance under ceilings of 2,500 and 1,600 feet, respectively. At 15:47, approaching the border between the two, he answered a phone call from a relative and said the helicopter was flying well, operations were normal, and he was five minutes from the Maitland airport and 20 minutes from Warnerville.
Nine minutes later and about 4 nm from the end of the corridor, the helicopter made a hard right 180-degree turn and backtracked northbound while climbing into restricted airspace, reaching 3,100 feet before descending back to 1,100. At Hilldale it made another right turn, departing the west side of the corridor in a climbing turn around a hill and reaching 2,900 feet while crossing through the corridor to the west. It descended to 120 feet agl over the town of Vacy before climbing once again and turning south parallel to but still outside the VFR corridor. At 1616 it cleared a ridge by about 200 feet, then began a shallow descent toward the Hunter River. Six witnesses described seeing it roll hard and descend into the riverbank. Examination of the wreckage and a tree struck by the helicopter indicated that it crashed in an 80-degree right bank and 60-degree nose-low attitude.
King Air Crashes into Parking Lot, Beech E90, Oct. 18, 2022, Marietta, Ohio
Both pilots, the airplane’s only occupants, were killed when the twin-engine turboprop crashed into the parking lot of an automobile dealership near the end of a short Part 91 positioning flight. All communications with air traffic control were normal during the 75-nm flight from Columbus, Ohio, to Parkersburg, West Virginia. The King Air was on a three-mile final on the RNAV approach to Runway 21 and cleared to land when eyewitnesses saw it abruptly depart from controlled flight into a near-vertical spin into the ground. Security camera footage corroborated those accounts.
Numerous pilot reports of trace to moderate icing were recorded in the area, and satellite data indicated supercooled water droplets in clouds from about 1,300 to 8,000 feet above the ground. A post-crash fire “totally consumed” the fuselage above the floorboards, making it impossible to determine the status of the pneumatic anti-icing system.
Final Reports
Forced Landing Precipitated by Windshield Ice, Airbus Helicopters AS350B2, March 17, 2022, Sept-Îles Airport, Quebec, Canada
The helicopter struck the frozen surface of the Baie des Sept Îles while attempting a precautionary landing after the windshield abruptly frosted over at an altitude of 300 feet. The helicopter had been parked outside overnight with the windshield uncovered; before takeoff, a combination of hot air from the cabin heat and one-third of a gallon of automotive windshield washer fluid were used to clear the rime ice that had accumulated. The pilot was attempting to maneuver closer to the Île du Père-Conan when the helicopter hit the ice, pitched forward, and rolled onto its left side. The pilot and passenger were able to evacuate the wreckage without injury and were rescued by snowmobile after the pilot contacted family members via mobile telephone.
Autopilot Disconnect Suspected in Cheyenne Disaster, Piper PA-31T, June 5, 2020, Eatonton, Georgia
Radar track data suggest that “the airplane likely was not being actively controlled” when it diverged from a gentle left turn in instrument conditions to a hard right bank that reached 120 degrees and entering a descent that eventually accelerated to 7,000 fpm. Turbulence from nearby convective activity likely delayed the pilot’s recognition that the autopilot had disengaged and “made it difficult for the pilot to recognize and recover from the fully developed unusual attitude.” He, the student pilot in the right seat, and three passengers were killed when the airplane plunged to earth from its cruising altitude of 26,000 feet. Witness statements, some corroborated by cell phone footage, described the airplane descending “in a flat-spin-type of motion” with fire “occurring on both sides of the fuselage near both wings” and parts of the airplane separating during the descent. Fire subsequently destroyed most of the fuselage, including the autopilot controller. Both outer wing sections had separated during the descent.
The accident occurred just over one hour into a planned two hour 36-minute flight from Williston, Florida, to New Castle, Indiana. The pilot filed an IFR flight plan and obtained a weather briefing via ForeFlight about an hour and a quarter before departure; the briefing included convective Sigmets along its route of flight over central and northern Georgia and Airmets for instrument conditions and turbulence. It did not include assessments of current or future icing potential, which predicted a high probability of icing conditions including supercooled liquid droplets around the time of the accident. Archived weather radar showed that in the three minutes before the upset, the Cheyenne was operating in an area of supercooled droplets and ice crystals, creating “the potential for moderate to severe icing conditions,” as well as “general air-mass thunderstorms with the potential for structural icing above the freezing level at 15,000 feet.”