Pilatus Accident Claims Four Generations
Pilatus PC-12, November 30, 2019, Chamberlain, South Dakota
Nine members of a prominent Idaho family were killed when their single-engine turboprop went down immediately after takeoff. Three other family members were rescued and hospitalized with injuries initially described as critical. The victims, ranging in age from seven to 81, represented four generations of the Hansen family of Idaho Falls. The ages of the survivors were given as 17, 27, and 28.
The accident site was barely a mile beyond the departure end of Chamberlain Municipal Airport’s Runway 31. A winter storm warning was in effect at the time, with snow accumulating at up to one inch per hour. An NTSB press release issued on December 2 cites Chamberlain’s automated weather observation station as having recorded conditions including “one-half mile visibility in moderate snow and icing, low-level windshear, and clear-air turbulence conditions” under a 500-foot overcast. Reported winds were only six knots, but gusts as high as 40 knots were recorded in Pierre at about the same time, leading some meteorologists to question the accuracy of the Chamberlain reading.
The family arrived on the morning of November 29 for an annual pheasant hunt and refueled the airplane after landing, parking it on the ramp overnight. Eight to nine inches of snow had reportedly accumulated in the interim. It is not known what the pilot did to try to remove the accumulated snow or any ice or frost that had formed underneath, but the Chamberlain airport offers only self-service fuel with no fixed-base operator, making it unlikely airport-based deicing services were available.
RFS Helicopter Pilot Unhurt in Hard Landing
Bell UH-1H, December 7, 2019, Crawford River, New South Wales, Australia
New South Wales’s Rural Fire Service temporarily grounded its remaining helicopters after impact forces separated the main rotor and gearbox from the Bell Iroquois in what was officially described as a “hard landing.” The solo pilot extricated himself from the wreckage and was pronounced uninjured after a precautionary exam at a Newcastle hospital. The aircraft had been conducting water drops on one of many brushfires wracking much of eastern Australia.
No information on the status of the investigation or possible causes of the downing had been released at press time. Aerial operations were suspended until the RFS could complete safety checks on its other rotorcraft. This was the second accident of this type in the region in less than four weeks. On November 13, a 70-year-old pilot was hospitalized after a hard landing in a fire zone west of Brisbane, Queensland.
Cause of Approach Crash Remains Mysterious
Cessna 510 Citation Mustang, December 14, 2017, near Waldburg, Germany
German investigators have been unable to determine why an Austrian-operated Cessna Mustang lost control and crashed while intercepting the localizer for the ILS approach to Runway 24 at Friedrichshafen. Two pilots and their only passenger were killed when the six-seat jet crashed into a forest after initially striking trees 1,000 meters (0.6 miles) away. Its wreckage was strewn through a 140-meter debris field, with many components from the right side of the airplane found on the left side of the ground scar and vice versa. Investigators were able to determine that at the time of impact, the landing gear, flaps, and speed brakes were all retracted.
The flight departed from Frankfurt Egelbach Airport at 5:43 p.m. local time and proceeded uneventfully through the handoff to Zurich Arrival at 6:05, reaching a maximum altitude of FL210. Zurich Arrival issued a series of vectors and descent clearances to align the aircraft for the approach. At 6:13 the crew leveled the airplane at 4,000 feet and read back an instruction to fly a 215-degree heading until established on the localizer. After a slight overshoot, it corrected back to the right at an indicated speed of 240 knots, crossed the localizer to the northwest, and descended rapidly until radar contact was lost.
The airplane’s G1000 avionics suite was not equipped with a flight data recorder, and the panel’s SD memory cards were destroyed in the crash. Based on the flight’s radar track, investigators concluded that it was almost certainly operating on autopilot, but this could not be confirmed directly. The jet was also certified for flight in known icing conditions, and its airspeed at the time of the accident was well above the 160-knot minimum Cessna specifies for flight in icing conditions but almost 100 knots faster than its published stall speed in a 60-degree bank in its high-stall-speed configuration.
Conditions along the route were conducive to icing, with precipitation, abundant humidity, and below-freezing temperatures. The captain of a transport-category aircraft reported severe icing between 15,000 and 7,000 feet during an approach to Stuttgart. Another Mustang flown by the accident aircraft’s operator reported only light icing during an approach to Friedrichshafen 10 minutes before the crash, but a Beech 1900 that arrived 45 minutes later “had been covered with massive layers of clear ice.” A frontal boundary had moved farther north than forecast, increasing the possibility of moderate to severe icing during descent, but the German Federal Bureau of Aircraft Accident Investigation (BFU) was unable to positively attribute the loss of control to a roll upset from asymmetric ice accumulation, overcontrol following an uncommanded autopilot disconnect, or a tailplane stall—or to exclude any of those possibilities. The BFU did note that excessive speed during the approach almost certainly increased pilot workload, a tendency noted in other approaches to the Friedrichshafen airport.
Equipment Status Uncertain in Apparent Missed Approach Accident
Socata TBM 700, February 18, 2018, Evanston, Wyoming
In a probable cause report published on November 6, the NTSB attributed the pilot’s loss of control during the apparent initiation of a missed approach to spatial disorientation but was unable to determine whether the pilot was attempting to fly using his standby instruments due to a failure of his primary flight display. The pilot and only passenger were killed when the airplane crashed just after initiating a climbing left turn from the final approach course for the ILS 23 approach to the Evanston-Uinta County Airport. The accident occurred in gusty winds and reduced visibility due to snow and mist with ceilings of 700 to 1,400 feet and the potential for low-level wind shear and clear air turbulence. There is no evidence the pilot had updated his only documented weather briefing, obtained 17 hours before the flight.
The pilot changed his requested destination three times in the course of the nearly four-hour flight, which departed from the Tulsa, Oklahoma International Airport at 11:10 Mountain Standard Time with a filed destination of Englewood, Colorado’s Centennial Airport. About 20 minutes after takeoff, he requested a change to Pueblo, Colorado, then, an hour and 20 minutes later, to Provo, Utah. At 2:53 he requested routing to Evanston, citing improved weather since his departure. The airplane dropped as much as 600 feet below its assigned altitude during the transition to the initial approach fix for the ILS to Evanston’s Runway 23; the pilot acknowledged several low-altitude alerts, saying that the airplane was “bouncing around” as the autopilot tried to maintain altitude.
Tracking the final approach course, it dipped just below the 7,343-foot (MSL) decision height 1.6 nautical miles from the runway threshold and then climbed to 7,700 feet. This was consistent with the published missed approach procedure, which calls for a climb to 7,700 before turning slightly left to intercept the 213-degree radial from the Evanston VOR and continuing the climb. The left turn continued through 270 degrees before the airplane began descending and turned right; radar contact was lost at 7,900 feet.
The Evanston airport manager recalled the pilot telling him that several months earlier the TBM’s flight display had gone blank during an instrument approach; he’d completed the approach by referring to information displayed by the ForeFlight app on his iPad. There is no record of any subsequent troubleshooting. The TBM’s standby instruments were located on the far right side of the instrument panel, outside the normal scan of a left-seat pilot. At the time of the accident, surface conditions recorded at the Evanston airport included winds from 350 degrees at 14 knots, one-half mile visibility in snow and freezing fog, and vertical visibility of 800 feet.
Conquest Trim Malfunction Not Confirmed
Cessna 441 Conquest II, February 22, 2018, Rossville, Indiana
Fragmentation of the wreckage made it impossible for investigators to determine which trim system, if any, was malfunctioning during a flight from Indianapolis to Green Bay, Wisconsin, in night instrument conditions. The pilot initially reported control problems about one minute after checking in with Indianapolis departure control and requested a 90-degree heading with a block altitude of 4,500 to 5,000 feet. Following a handoff to the Chicago ARTCC and a clearance to climb to FL 230, the pilot transmitted “my trim kind of going out on me.” The airplane dropped off radar after a last hit at 18,300 feet in the vicinity of the accident site. The pilot and both passengers were killed when the airplane hit a plowed field in a near-level attitude, leaving a 250-foot ground scar. Crucial components of its elevator, aileron, and rudder trim systems were either not recovered or too badly damaged for meaningful examination, leaving investigators unable to determine the role of any possible mechanical malfunction.
Two friends of the pilot recalled his expressing concern about the airplane’s avionics and “temperamental” autopilot. Both urged him not to fly it until those problems had been addressed. The airplane’s maintenance manager had no record of any discrepancies beyond erratic oil pressure readings on the right engine, which had tended to resolve after about 20 minutes of flight. The pilot had completed unusual attitude recovery training just over two years before the accident.