Story ID: 004
Accidents: October 2021
By: David Jack Kenny
Caption: Preliminary and final accident reports, October 2021
Word Count: 1609
Preliminary Reports
Challenger Accident Claims Six

Bombardier CL-600-2B16, July 26, 2021, Truckee, California – The twin-engine jet was destroyed during an attempted circling approach to the Truckee-Tahoe Airport, killing the two pilots and four passengers.  Prevailing weather included 11-knot west winds gusting to 16, broken clouds at 2,300 feet above ground level, and four miles visibility in the smoke from nearby wildfires.  The Part 91 flight had departed from Couer d’Alene, Idaho, about 90 minutes earlier and proceeded uneventfully through its arrival into the airport environment.

Descending through FL 260, the crew was told to expect the RNAV approach to Runway 20 and requested a circle to the longer Runway 11, though winds from 280 degrees would make this a downwind landing.  They were told to expect that, then cleared for the approach after one turn in a hold north of the initial approach fix.  The tower controller offered the option of crossing the field to enter a left downwind for Runway 29, then cleared them to land on Runway 11 after they reported the runway in sight.

Radar data show that the Challenger flew a very close-in base leg, then overshot the runway.  Surveillance footage confirmed witness accounts of its “low altitude and abnormal flight path;” one described it passing just 20 feet over the trees.  It entered a steep left bank in a nose-low attitude before striking trees and then the ground, igniting a fire that consumed the aircraft.

Four Fatalities in California R66 Crash

Robinson R66, August 1, 2021, Colusa, California – The pilot and three passengers were killed when the helicopter crashed into an open field in clear weather during daylight hours.  A witness driving south about half a mile from the site reported seeing it flying straight and level eastbound at an estimated 50 to 100 feet above ground level, so low that he thought it might have been a cropduster.  It made an abrupt left turn, briefly disappeared behind trees, and then descended into the ground.

Recorded ADS-B data provided by the FAA showed that the helicopter took off from Willows at 12:07, flying west toward the foothills before turning south over the towns of Lodoga and Stonyford, then turning east again.  Altitudes were not captured.  It flew east for about 12 minutes, turned to the southeast for two minutes, then turned east again about 0.7 miles from the accident site.

Conquest Succumbs to Dual Engine Failure

Cessna 425, August 11, 2021, Helena, Montana – The pilot and two passengers suffered serious injuries when the airplane went down short of the airport in Helena, Montana.  The flight was en route from Faribault, Minnesota, to its planned destination of Missoula, Montana, at FL 240 when the pilot reported that the left engine had lost power and requested a diversion to Helena.  He advised Helena approach control that they were 16 miles from the airport, descending through FL 190, and might “need to lose altitude to land on Runway 27.”  The controller cleared the pilot to maneuver north of the airport before entering the traffic pattern on a right base leg.

Eight minutes after the initial power loss, the pilot reported that the right engine had also flamed out.  The airplane was about eight miles north of the airport at 7,900 feet msl, roughly 4,000 feet above airport elevation, but struck trees after turning back towards the airport.  The empennage and left wing were separated from the fuselage.

The pilot reported having filled the tanks with 207 gallons of Jet-A immediately before the flight.  The airplane’s most recent annual inspection was completed in March 2021, about 10 flight hours before the accident.

Turbine Commander Destroyed Departing Thunder Bay

Rockwell 690B, August 16, 2021, Thunder Bay, Ontario, Canada – The twin turboprop went down immediately after takeoff, killing the solo pilot.  A brief statement from the TSB indicated that immediately after rotation it entered “an extreme bank to the left” that continued until it crashed inverted onto Runway 07.

New Owner Loses Control of TBM 700

Socata TBM 700, August 20, 2021, Urbana, Ohio – The airplane was destroyed, killing the solo pilot, when it crashed in a nearly vertical descent from 12,100 feet.  The pilot checked in with Cincinnati Approach Control while descending from FL 200 en route from the Erie-Ottawa Airport in Port Clinton, Ohio, to Cincinnati Municipal Airport (Lunken Field), then entered an unexpected left turn.  The pilot did not respond to the controller’s inquiries and radar contact was lost.

A witness roughly two miles from the accident site described seeing the airplane “at a high altitude in a nose-dive descent toward the terrain…not turning or spinning…headed straight down.”  He did not see “signs of distress, such as smoke, fire, or parts coming off the airplane, and he stated the airplane’s engine was at full throttle.”

According to acquaintances, the pilot had bought the airplane about nine days before, during which time he had logged “several hours” of ground training and about 15.5 hours of dual instruction in the airplane.  Whether this was the pilot’s first solo flight in the airplane has not been reported.

No Injuries in G-IV Nose Gear Collapse

Gulfstream G-IV, August 21, 2021, Fort Lauderdale, Florida – The pilots aborted the takeoff in response to an intensifying shimmy during the takeoff roll, and all 14 onboard evacuated the aircraft without injury after it veered off the right side of the runway and struck a concrete slab supporting main approach lighting equipment.  Both the pilot and co-pilot reported that the shimmy “progressively got worse and worse” as the airplane accelerated to 100 knots, an account corroborated by a third pilot (not type-rated) in the jump seat.  The pilot immediately aborted the takeoff and applied brakes and reverse thrust, but the nose gear collapsed during deceleration.  The jet veered right and departed the runway.  The four flight crew members and ten passengers deplaned through the main cabin door.

An FAA inspector found the pip pin normally situated in the nose landing gear torque link on the runway some 2,215 feet from the main wreckage.  The bulk of the nose landing gear assembly was some 900 feet further down the runway.  The safety pin normally installed through the pip pin was intact and still attached to its lanyard cord. 
Final Reports
Inadequate Training Faulted in Loss of Helo

MD Helicopters 600N, June 14, 2018, Ngamatea Station, North Island, New Zealand – The pilot’s reluctance to fly the helicopter using manual throttle control—a procedure in which he’d never received formal training—left him unable to correct excessive variations in main rotor rpm following the failure of the full-authority digital engine control (Fadec) system.  He instead attempted a forced landing in rough terrain.  The helicopter landed hard, bounced, and rotated 90 degrees, during which the main rotor severed the tailboom.  Violent vibrations destroyed the airframe and a catastrophic overspeed of the engine caused an uncontained failure of the power turbine, igniting a fire in the engine compartment.  None of the five occupants were wearing helmets.  Three, including the pilot, suffered severe head injuries, and one passenger died in hospital the following day.

The helicopter was one of only two MD 600N helicopters in New Zealand at the time, and had a history of electronic control unit (ECU) anomalies that could not be replicated during troubleshooting.  The system’s logic responded to detected abnormalities in the ECU’s primary channel by transferring control to the reversionary governor; subsequent failure of the reversionary governor caused it to revert to a fixed fuel flow to keep the engine running.  Moving the collective would change main rotor rpm; to control this, the emergency procedure required the pilot to switch Fadec to manual mode and use the twist throttle to compensate.

The pilot had begun training for his type rating just two months before the accident. Both he and his instructor reported that they did not practice this procedure in the aircraft due to concern about possible engine overspeed during the transition to manual control.  The TAIC found that his answer to the question regarding an ECU failure on his written exam “made no mention of the correct actions required” and had been graded incorrect but not subsequently corrected.  They also reported that the manufacturer claimed to have a procedure for training pilots to use manual throttle control, but it was considered proprietary and only offered in its own training facilities.

Severe Gust Caused Dynamic Rollover

Airbus Helicopters AS 350B3, April 6, 2020, Skjelbreitjørna, Skagnes Municipality, Rogaland County, Norway – A stiff gust “at the worst possible time, as the longline was being pulled taut” banked the helicopter past its critical rollover angle during external load operations in support of powerline construction.  The resulting crash destroyed the helicopter, but the Norwegian Safety Investigation Authority credited the pilot’s helmet with helping him avoid serious injury.

Forecast winds exceeded the operator’s 30-knot limit for sling load work, but actual conditions varied considerably.  The two-meter-tall equipment container was attached to the helicopter by a 15-meter line with a six-meter extension, requiring a minimum altitude of 24 meters (79 feet) to lift it.  In-cockpit video showed that the pilot’s foot slipped off the right pedal as he corrected an initial roll to the left, leading to a left yaw.  The bank angle reached 31 degrees as the cargo hook load indicator showed two green lights, corresponding to a load of at least 100 kilograms (220 pounds).  The left roll became a right roll as the helicopter continued to rotate; the pilot attempted to release the load, but 12 seconds after the initial bank, the main rotor blades struck the ground.