Accidents: November 2021

 - November 1, 2021, 8:14 AM

Preliminary Reports

Challenger Crew Confronts Runaway Trim

Bombardier BD-100-1A10 (Challenger 300), Aug. 24, 2021, Edmonton, Alberta, Canada – During a flight from Edmonton to Calgary with a single passenger, the two-pilot crew experienced increasing uncommanded nose-down trim. They shut off power to the horizontal trim and executed the STAB TRIM FAIL checklist from the quick-reference handbook but were unable to neutralize pitch forces. After declaring a PAN-PAN and advising air traffic control, they shifted weight aft in the cabin and decided to continue to Calgary, where they requested a long downwind and shallow approach. 

An uneventful landing was made at VREF  plus 30 knots with 10 degrees of flaps. Maintenance staff subsequently found that the copilot’s trim switch was internally stuck in the nose-down position. At the time the TSB released its report, the cause had not been determined.

Seven Killed in Brazilian King Air Crash

Beechcraft B200GT KA 250, Sept. 14, 2021, Piracicaba, São Paulo, Brazil – All seven on board, including both pilots and five members of a prominent Brazilian family, perished when the 2019 model turboprop crashed into a eucalyptus grove and exploded just 15 seconds after takeoff. Photographs of the accident site show that the airframe was almost totally consumed by the post-crash fire. 

The airplane took off from Piracicaba’s Pedro Morganti Municipal Airport on a flight to Pará just before 9 a.m., only to go down almost immediately in woods adjacent to the São Paulo State Technical Faculty. Footage from a home security camera shows it descending in a steep, nose-low, right-wing-down attitude. Investigators from the Brazilian Air Force’s Center for Investigation and Prevention of Aeronautical Accidents (CENIPA) reached the scene about noon. 

Brakes Implicated in Citation Departure Accident

Cessna 560 Citation XLS+, Sept. 2, 2021, Farmington, Connecticut – Skid marks on the runway and a witness report of “blue colored smoke from the back side of the airplane” suggest that the airplane’s parking brake may have been engaged during the takeoff roll, impeding its acceleration until it departed the end of the 3,665-foot runway. All four on board—two pilots and two passengers—were killed when the jet continued past the threshold over a steep downslope but failed to climb, striking a utility pole 361 feet past the end of the runway. Four people on the ground were also injured, one seriously. The IFR flight was departing Robertson Field Airport in Plainville, Connecticut, for the Dare County Regional Airport in Manteo, North Carolina.

Witness accounts of unusually slow acceleration were corroborated by the flight data recorder (FDR), which showed that it took more than 40 percent longer to go from 20 to 100 knots than on its two previous flights (17 vs. 11.5 and 12 seconds, respectively). The longitudinal force was measured at .245 g compared with .365 and .35 g, respectively, a 30 percent reduction. One witness recalled seeing a puff of blue smoke when the airplane was about two-thirds of the way down the runway. A second noted that the nose wheel was still on the ground when it passed the halfway point. A third, watching from beyond the departure end, reported that the Citation left the runway in a level attitude, then pitched up as the ground dropped below it but failed to climb. It struck the pole, causing “a small explosion near the right engine followed by a shower of softball-sized sparks” before disappearing from sight. A ground scar in a grassy area 850 feet north of the damaged pole continued to the point where the airplane hit a building, igniting a fire that almost completely consumed the aircraft except for the aft portion of the tail.

Investigators found a skid mark from the right tire 2,360 feet from the runway’s approach end; a skid mark from the left tire began about 120 feet later. Both were continuous past the end of the runway and into the short stretch of grass before the hill. Examination of the wreckage found that the parking brake handle and the valve it controlled were both in the “set” position. The NTSB’s preliminary report notes that “parking brake valve position and normal brake application were not recorded by the FDR, and the airplane’s takeoff configuration warning system did not incorporate parking brake valve position as part of its activation logic.”

R66 Down in Georgia Forest

Robinson R66, Sept. 16, 2021, Monticello, Georgia – Searchers located the helicopter’s wreckage in a densely wooded section of the Oconee National Forest 16 hours after it descended into the trees, leaving a 125-foot debris path. All three occupants, initially described as two pilots and a passenger, were found dead at the scene. An NTSB spokesman described weather during the flight—which originated some 180 miles south at Thomasville, Georgia—as rainy with low clouds and reduced visibility. The flight’s destination was not initially reported.

A witness living close to the accident site recalled that it was “pouring rain” when she heard an aircraft pass “very low” over the family home at roughly 8:30 p.m. The passenger was identified as a well-known Atlanta architect, whose widow has since filed wrongful-death lawsuits against two companies associated with operating the flight.

Final Reports

ATSB Advocates Emergency Breathing Systems

Garlick Helicopters UH-1H, Jan. 9, 2020, Eden, New South Wales, Australia –  The circumstances of the pilot’s underwater escape led the Australian Transportation Safety Bureau (ATSB) to recommend equipping all crew members on overwater flights, including water drops, with emergency breathing systems (EBS). The ATSB is already on record as a strong advocate of helicopter underwater escape training (HUET), which the accident pilot had most recently completed about eight months earlier, but noted that the time required to wait for the helicopter to stop moving, release restraints, free any snagged clothing, and find an escape route can easily exceed an individual’s breath-hold capacity. Despite the increasing prevalence of HUET training, drowning remains the most common cause of death in helicopter ditchings.

While conducting water drops on a bush fire using a 1,400-liter (370-gallon) bucket on a 100-foot-long line, the pilot established a 100-foot hover over the Ben Boyd Reservoir. Hearing a grinding noise, he immediately jettisoned the bucket and applied forward cyclic, but the helicopter lost all power and descended straight into the water. Though the pilot used “all the main rotor energy available” to slow the descent, the impact burst both chin bubbles. The helicopter filled with water, rolled inverted, and sank. 

Relying on his HUET course, the pilot waited for all motion to stop before unstrapping but was unable to open either front door. Moving into the cabin, he found an air pocket and “took a couple of breaths.” The cabin sliding door also would not open, so he punched out the right sliding door’s rear window to escape, inflated his life jacket, and swam to shore. Despite his difficulty egressing, he told investigators that he “would have been dead without HUET,” describing the course as “great” and very realistic.

Following the accident, the pilot acquired a compressed-air EBS, and the New South Wales Rural Fire Service began investigating the possibility of providing all crew members with EBS and adding the EBS component to the mandatory recurrent HUET course. The cause of the power loss was found to be the failure of the number 1 and 21 bearings in the engine’s front section due to loss of lubrication. The cause of the oil-flow restriction could not be determined.

Covid Downtime Cited in Floatplane Upset

de Havilland DHC-6 Twin Otter, Oct. 5, 2020, Malé-Velena International Airport, Maldives – The Maldives Accident Investigation Coordinating Committee (AICC) identified the captain’s relatively sparse flight time following his transition back to the Twin Otter from the DHC-8 as a likely factor in his loss of control of the floatplane during a crosswind water landing. Almost immediately after touching down on the “North Right” water runway, the Twin Otter rolled hard to the right until the wingtip hit the water. The airplane slewed right 180 degrees, the left wing dropped abruptly, and the left engine and propeller impacted the water before the airplane settled back onto both floats, facing southwards. The first officer and flight attendant sustained unspecified minor injuries; the four passengers were unhurt.

The Trans Maldivian Airways flight from the Vommuli seaplane base was described as uneventful aside from en route deviations to maintain VFR. Although 20-knot winds from 280 degrees were reported at Velana, neither pilot considered the conditions too challenging for a northbound landing. They described the approach as stable and the touchdown as smooth. Following the upset, the airport’s fire-and-rescue boat assisted the Twin Otter in taxiing to the dock on a single engine.

The 42-year-old captain, who was the pilot flying, reported 12,329 hours of career experience. However, only 112 of his 3,417 hours in type had been logged since 2011. From 2011 through 2019, he had operated the DHC-8 regional airliner, then began transitioning back to the Twin Otter in January 2020. He had flown some 60 hours as PIC under supervision before being cleared for regular line flying, more than double the minimum 25 hours required by the airline. The AICC’s report notes that pilots transitioning to floatplanes “have often had difficulty in mastering the motor skills necessary to maintain the proper attitude for water landing within the time period specified in the Operations Manual.”

Shortly after his release to line flying, a national Covid-19 lockdown brought all air transportation activities to a near-total halt, greatly limiting his opportunities to maintain currency. At the time of the accident, he had flown only 37.5 hours in the preceding 90 days and just 51.4 since completing his transition training.