Preliminary Reports
Rescue Flight Escapes After Rotor Strike
Leonardo Helicopters AW139, August 12, 2020, 21 km west-southwest of Caboolture Airport, Queensland, Australia – The main rotor of a Queensland government helicopter struck trees during a medical evacuation at night, damaging “at least three” blades. After climbing away from the surface, the pilot conducted a control check and did not detect any unusual vibrations; the crew alerting system likewise flagged no abnormalities. The pilot nevertheless took the precautions of immediately returning to the helicopter’s base at the Archerfield Airport, limiting airspeed to 100 knots and performing a run-on landing. No injuries resulted.
The flight was dispatched to rescue a horseback rider who’d been injured in a fall. A ground-based paramedic in a four-wheel-drive vehicle reached the patient first but was unable to perform the evacuation due to the patient’s suspected injuries and the ruggedness of the terrain. The flight was conducted in dark night conditions in rain; the crew located the accident site using night vision goggles. The lack of a suitable landing zone necessitated two successive winching operations, one to lower the rescue crew officer (RCO) to the site and the second to extract both him and the patient.
During the extraction, with the cyclic and pedals controlled by the flight director-autopilot system, the helicopter drifted left and forward while descending from about 65 to 50 feet above the ground. The right rear quadrant of the main rotor disc struck trees and the medical officer saw a branch fall to the ground. The pilot raised collective while the patient and RCO were still on the winch; they were dragged through the trees during the climb, then were spun by the rotor wash until they were recovered into the helicopter. Postflight examination found that one main rotor blade had lost a section of its tip cap estimated as weighing 50 grams (1.76 ounces), while two others showed “evidence of damage to the abrasion strip on the outermost edge of the tip cap.” Those blades were returned to the manufacturer for further examination.
Main Rotor Struck by Cabin Door
Eurocopter AS 350, September 6, 2020, Fort Greely, Alaska – The pilot made a successful emergency landing and both crew members escaped without injury after the left passenger door abruptly separated from the airframe and struck a main rotor blade. According to the pilot, they were in cruise flight at 700 feet above ground level at 110 knots when an uncommanded left yaw accompanied a sudden loud bang. He told investigators that the door, which both he and a mechanic had checked during their preflight inspection, went from “fully secured to gone instantly.”
Except for the preflight, the door had not been opened that day. The pilot landed the helicopter in a grassy area nearby. Both the door and the airframe were recovered for examination.
TBM Crashes in Upstate New York, Killing Two
Socata TBM 700, October 2, 2020, Corfu, New York – A prominent personal injury attorney and his niece, an assistant regional counsel with the U.S. Department of Health and Human Services, were killed when their single-engine turboprop spiralled in from 11,000 feet. While following vectors for the ILS approach to Runway 23 at the Buffalo Niagara International Airport in New York, the airplane entered a descending right turn and rapidly disappeared from radar coverage. The last two radar hits show its rate of descent increasing from 4.760 to 11,667 feet per minute as it descended through 11,000 feet. Local sources described an impact crater ten feet deep at the accident site.
During the flight from Manchester, New Hampshire at FL 280, the pilot lost communications with Boston Center. Forty seconds after he checked in with Buffalo Approach, the approach controller asked, “Everything okay up there?” The pilot responded, “Yes, sir, everything’s fine.” About one minute later the pilot acknowledged the controller’s explanation of their routing to the final approach course. The airplane began turning right a minute later and the pilot did not respond to multiple transmissions from Approach Control, including instructions to “Stop your descent, maintain one zero thousand” and to “Stop your descent, level your wings, maintain any altitude.”
Final Reports
Switching Error Leads to Fuel Exhaustion
Beech C90A, February 14, 2017, Rattan, Oklahoma –The NTSB concluded that a complete loss of electrical power in IMC resulted from the pilot accidentally switching the three-position “ignition/engine start/starter only” switches to the ON position, thereby switching the starter/generators to starter operation and taking the generators off-line. The left engine subsequently lost power as the pilot searched for an opening in the clouds. The nose gear collapsed during a precautionary landing in a field. No patients were on board the air ambulance at the time, and the pilot and two medical crew members escaped without injury.
The airplane was based at McAlester, Oklahoma. The flight was intended to pick up a patient in Idabel, Oklahoma for transport to Paris, Texas. The pilot recalled lowering the engine ice vanes and activating the de-icing system during ground operations, then raising the ice vanes for takeoff. After reaching their cruising altitude of 7,000 feet, Fort Worth Center advised of heavy rain showers in the vicinity of Idabel and the pilot “put the ice vanes down.” The airplane’s electrical system went through two quick “fluctuations” in which “everything went away and then came back. Seconds later, the entire system failed.” His efforts to navigate by compass references to an area where his preflight briefing led him to expect better weather were complicated by conflicting suggestions from the medical crew, who had contacted company dispatch by cell phone.
Investigators found no visible fuel in either wing tank, none in the left nacelle tank, and about one quart in the right nacelle tank. Both ignition/engine start/starter only switches and both engine anti-ice switches were set to ON. Battery voltage was measured at 10.7.
The airplane’s operator reported that 1,720 pounds of fuel were on board at dispatch, good for 2.7 hours at maximum cruise power and 4.2 hours at maximum economy. The accident flight lasted 3.65 hours, which the NTSB interpreted as showing that the flight departed without the required IFR fuel reserves. However, the combined straight-line distance from McAlester to Idabel to Paris is only 107 nautical miles, well under an hour in a King Air at any reasonable power setting.
Unauthorized Maneuvering End in Wire Strike
Hughes 369, August 21, 2018, Granger, Texas – A special operations pilot from the Jordanian Air Force and his instructor, a retired U.S. Army helicopter pilot with 7,000 hours of experience, were killed when their helicopter collided with a steel wire power distribution line strung between 36-foot-high poles. Low-altitude maneuvering was not part of the curriculum for the flight, which was intended to be an initial orientation to the local airports and practice area as part of annual refresher training in emergency procedures which the operator provided under contract with the U.S. Army.
A witness saw the helicopter flying towards his house at high speed in a nose-low attitude and an altitude of 30-40 feet before making a quick climb to clear power lines along his street. Radar track data showed its altitude varying between 25 and 125 feet, with the last hit coming at 58 feet. Investigators found that the cable had been pulled from the three poles south of the wreckage that were bent toward the site, and 1,300 feet of cable ran from the next pole to the scene. The cable was severed at a point between two stands of trees which, on the helicopter’s heading, would have obscured the poles from view.
The contractor’s Chief Operating Officer reported that the Jordanian pilots “often wanted to fly low-level, high-speed maneuvers outside the airport environment,” which he regarded as “serious transgressions.” He was not aware of any such offenses by the accident instructor during his tenure with the company.
Ergonomics Faulted in DC-3 Ditching
Douglas DC-3C Basler turbo conversions TP67, June 21, 2019, Eabamet Lake, Ontario - TSB investigators concluded that the simultaneous loss of power in both engines immediately after takeoff “may have” been caused by the airplane’s captain, who was the pilot not flying, having accidentally moved the condition levers while twisting around to reach the safety latch control handle and gear handle to raise the landing gear. Both handles are located between the two pilot seats in a location that can be difficult to reach. No handle or support surface is provided other than the throttle quadrant, and testing demonstrated that the condition levers are more easily displaced by the pilot in the left seat.
The freighter ditched in the lake after both engines shut down while climbing through 200 feet; both altitude and airspeed were too low to make a restart feasible. Both pilots escaped without injury and swam to shore, where they were rescued by an officer of the Nishnawbe Aski Police Service.
Engine Shut Off During Practice Autorotation
Aerospatiale AS350 B2, February 18, 2020, Tampa, Florida – FINAL. The instructor accidentally moved the helicopter’s throttle lever from “idle” to “off” during a practice 180-degree autorotation, causing a complete loss of engine power. The instructor took over the controls and landed the helicopter on a taxiway, where it skidded 180 feet before sliding into the grass and coming to rest in a drainage ditch. No injuries resulted.
The student was attempting to practice a 180-degree autorotation to the runway. The instructor moved the throttle lever from “fly” to “idle” as they passed abeam their target point. The student overshot the turn, instead lining up with the taxiway, and was initiating a go-around when power was lost.