Preliminary Reports
No Injuries in EMS Forced Landing
Bell 206, March 4, 2020, Clark, Missouri – During a patient transport in visual conditions at night, the pilot of an EMS helicopter elected to make a forced landing after indications of a partial loss of engine power. The pilot, two crew members, and the patient were uninjured. The flight was en route from the Northeast Regional Medical Center near Kirksville to the Boone Hospital Center outside Columbia.
The pilot reported that the helicopter abruptly yawed right, accompanied by the low RPM warning light and audio signal. The engine continued to run, but RPM dropped below 90 percent. RPM recovered to 97 percent during the approach to a field, but the pilot continued the landing, initiating a cyclic flare five to ten feet above the ground. The helicopter’s tailboom was wrinkled during the touchdown, and subsequent examination found that a pneumatic line had separated “near its filter connection.”
Eight Deaths in Departure Crash of Philippines Air Ambulance
IAI 1124A Westwind II, March 29, 2020, Manila, Philippines – All eight on board, including three members of the flight crew, three medical crew members, the patient, and a companion were killed when their IAI 1124A Westwind jet crashed during an attempted takeoff from Manila’s Ninoy Aquino International Airport. According to press reports, tower controllers became alarmed when the airplane hadn’t lifted off well beyond its expected ground roll and alerted airport firefighting and rescue services a few seconds before the actual crash.
Final Reports
Double Flame-Out Traced to Airspeed Discrepancy
Bombardier CL604 Challenger, March 11, 2018, near Shahr-E Kord, Iran – The pilots’ misinterpretation of divergent airspeed indications led them to reduce thrust to idle while trying to climb, causing both engines to flame out. The airplane entered a deep stall and the crew was unable to restart either engine. All 11 on board were killed when it crashed in the vicinity of Helen Mountain 70 nautical miles southwest of the city of Shahr-E Kord at an elevation of 7,500 feet. The final report of Iran’s Aircraft Accident Investigation Board, published on March 10, suggested that engine damage sustained during the flame-out and stall sequence may have made a restart impossible in any case.
The flight entered Iranian airspace en route from Sharjah Airport in the United Arab Emirates to Istanbul Atatürk Airport and was cleared to climb as filed to FL 360. After about one hour, in level cruise flight, it was handed off to a different sector of the Tehran Area Control Center. Just over three minutes later, the captain requested a climb to FL 380. Both the cockpit voice and flight data recorders showed that the left and right airspeed indicators had begun to diverge, with the left remaining steady at an indicated 256 knots and the right decreasing to 250 as groundspeed also decreased from a maximum of 403 knots to 391. The AAIB concluded that the request to climb was part of an attempt to resolve the airspeed indication discrepancy by determining which instrument showed the expected reduction while climbing.
As the jet began to climb, its airspeed comparator alerted the crew to a difference of more than 10 knots between the two indicators. The reading on the left side actually began increasing as the right’s dropped to 241 knots. Climbing through FL 370 the left indicator hit 270 knots while the right fell to 228, and the captain reduced thrust on both engines to idle. The airspeed discrepancy reached 90 knots (277 vs. 187) as the airplane reached its maximum pressure altitude of 37,872 feet. The overspeed clacker sounded 20 seconds before the stall warning and stick shaker activated.
While the crew requested progressively lower altitudes, the airplane began to descend at approximately 10,000 feet per minute. The right engine flamed out passing through FL 315 with the airplane at a 32-degree angle of attack, which reached 35 degrees when the right engine flamed out 12 seconds later. Indicated airspeed on the right channel dropped to zero 16 seconds before the FDR recording ended; the last recorded groundspeed was 148 knots.
The CVR showed that the crew never ran the quick reference handbook’s emergency procedures for an indicated airspeed discrepancy; the first officer began it several times only to be interrupted by the captain. The captain apparently relied on the left airspeed indicator, which drove the overspeed warning, to the neglect of both airspeed reconciliation and stall recovery procedures.
Hypoxia Not Confirmed in Loss of Ferry Flight
Cessna 208B, September 27, 2018, 260 km northeast of Narita International Airport, Japan – The disappearance of a Cessna Caravan on an intercontinental ferry flight was “almost certainly” due to the pilot’s incapacitation, but the precise cause could not be pinpointed because only one fragment of the airplane was recovered. The airplane entered an uncontrolled descent from FL 220 nearly nine hours into a planned ten-hour leg from Saipan in the Northern Marianas Islands to Hokkaido, Japan, and more than five hours after passing its second mandatory reporting point without establishing radio contact. Radar data recorded by Japanese air traffic control showed that it reached a descent rate of 23,000 feet per minute by the time of the last radar hit at 11,500 feet. The Caravan crashed into the Pacific less than two minutes after beginning its descent.
In a final report published on March 18, the Australian Transport Safety Bureau concluded that the pilot became incapacitated between the TEGOD and SAGOP reporting points. The airplane is presumed to have continued operating on autopilot until all usable fuel in the selected tank had been consumed and the engine stopped from fuel starvation. Because the pilot was flying solo in an unpressurized airplane and was known to prefer receiving supplemental oxygen from a nasal cannula, a practice not authorized by the airplane’s operator above 18,000 feet, the ATSB classified him as being at increased risk for hypoxia. Since his body was not recovered, however, “a medical event could not be ruled out.”
The accident occurred on the fourth leg of a planned nine-leg ferry from Jandakot, Western Australia, to Greenwood, Mississippi. The airplane had been fitted with a ferry tank providing an additional 1,635 pounds of usable fuel that had to be transferred to the right main tank periodically by one of two pilot-operated electric pumps. The 66-year-old, 13,600-hour pilot was reported to be a non-smoker, in good health, and the veteran of more than 200 ferry flights “including multiple recent Pacific crossings.” Six months earlier, he’d ferried the same airplane from Canada to Western Australia. Although two of the preceding three legs had been flown at or above FL 200, witnesses in Saipan confirmed that the microphone-equipped oxygen mask supplied by Cessna was still in its unopened original package. The airplane was grounded there for more than a week waiting for a technician to arrive and replace a damaged propeller de-icing boot.
The accident flight departed in clear weather. About an hour after takeoff the pilot reported being level at FL 220 with a true airspeed of 167 knots and a tailwind. An hour and ten minutes later he contacted Tokyo Radio via high-frequency radio to report passing TEGOD, estimating one hour and 23 minutes to reach SAGOP. The airplane passed SAGOP three minutes early but the pilot did not report and repeated calls from Tokyo Radio over the next hour and 15 minutes were not answered. Two Japan Air Self Defense Force aircraft intercepted the Caravan nearly two hours later but the pilot did not rock the wings or turn to acknowledge the intercept; they paced it for about 30 minutes before it descended into a cloud. Search-and-rescue efforts were initiated immediately and within two hours the airplane’s rear passenger door was found, but no other wreckage was recovered before a typhoon required suspension of the search. Further efforts through the following month failed to find the pilot or any other fragments of the aircraft.
Training Accident Ascribed to Spatial Disorientation
Beech C90, December 8, 2017, Geneva, Florida – In a finding of probable cause released on April 8, the NTSB ascribed the fatal crash of a King Air C90 into Florida’s Lake Harney to spatial disorientation on the part of the 243-hour commercial pilot receiving instruction, also noting that the 4,800-hour instructor’s toxicology results were positive for oxycodone. Both, along with a second commercial pilot enrolled in the L3 Academy's High-Performance Aircraft course, were killed when the turboprop stalled into the lake during an attempted ILS approach to Orlando Sanford International Airport’s Runway 27R. The flight was the students’ first in the King Air. Actual instrument conditions prevailed, including a broken ceiling at 800 feet above ground level and an overcast layer at 1,600 feet.
After a low approach to Runway 9L, the airplane climbed to 800 feet on runway heading. The pilot requested two more ILS approaches to the same runway and was instructed to maintain 3,000 feet. As the Central Florida TRACON controller began vectoring them for the second approach, the airport changed runway directions and the controller advised them to expect the ILS to Runway 27R instead. The pilot requested “extended vectors … one minute to set up” and the controller issued a series of gentle turns and a descent to 1,600 feet, which the pilot was instructed to maintain until established on the localizer.
Radar track data showed “a smooth and consistent flightpath … consistent with autopilot use until the final turn to intercept the localizer course.” After turning westbound, the aircraft began descending while turning south and then southeast, reaching a minimum altitude of 300 feet as the controller issued two low-altitude warnings and instructed the pilot to “maintain 1,600 immediately.” The pilot responded, “Yeah, I am, sir, I am, I am.” The King Air climbed from 800 to 1,700 feet in 10 seconds, then descended to 1,400 before disappearing from coverage. A witness in a boat on the lake saw it flying below the ceiling at an altitude of about 300 feet, climb steeply into the clouds, then “dive vertically into the lake.”