Preliminary Reports
Deaths in New York Ditching Linked to Unapproved Restraints
U.S. Eurocopter AS350B2, March 11, 2018, New York, New York—The off-the-shelf safety harnesses used to allow passengers to leave their seats during a doors-off photo flight appear to have kept them from escaping after the helicopter overturned after a ditching in the East River. All five passengers drowned after the Liberty Helicopters sunset sightseeing flight ditched, following a total loss of engine power, rolling inverted after touchdown. Statements by both the surviving pilot and first responders cited in an NTSB preliminary report described aftermarket fall-protection harnesses fastened to nylon lanyards by locking carabiners behind the passengers’ backs; a second set of locking carabiners secured the lanyards to hard points inside the fuselage. The carabiners were normally unscrewed by ground personnel after landing and could not be released by the wearers. Emergency egress required cutting the webbing with a knife retrieved from an attached pouch. The pilot reported having briefed his passengers on this procedure, but none were able to accomplish it.
The pilot also recalled that the power failure came immediately after the front-seat passenger slid backwards across the bench seat to photograph his feet hanging outside the helicopter. While securing the aircraft for impact during autorotation he found that the passenger’s tether had snagged the emergency fuel shut-off lever; he turned it back on and attempted to restart the engine, but concluded that it “wasn’t spooling up fast enough” to recover in the remaining altitude. Salvagers found the shut-off lever’s witness wire broken, confirming that it had been moved, and also noted that the right skid’s emergency floats had not fully inflated, causing the helicopter to roll over immediately.
Following the accident the FAA issued Emergency Order No. FAA-2018-0243 prohibiting “the use of supplemental passenger restraint systems that cannot be released quickly in an emergency” in commercial doors-off operations, and requiring passengers on these flights to be “properly secured using ..FAA-approved restraints” at all times. Families of the victims have filed suit against multiple defendants including Liberty, Airbus Helicopters, and Dart Aerospace.
Fifty-Two Fatalities in Nepalese Dash-8 Crash
de Havilland Canada DHC-8-402Q, March 12, 2018, Kathmandu, Nepal—All four crewmembers and 48 of the 67 passengers were killed when U.S.-Bangla Airlines Flight 211 crashed on approach to the Kathmandu-Tribhuvan Airport. The crew broke off their initial approach to Runway 02 and circled, requesting clearance to land on Runway 20; subsequent communications between the pilot and tower controller revealed some confusion, with the pilot’s readback of a clearance to land on “Runway 02” followed by the controller’s warning another aircraft of traffic landing on Runway 20. Witnesses described the approach as “much too low,” and a surviving passenger recalled the airplane “wobbling” before crashing into a field near the airport. Thunderstorms were reported in the vicinity, and other pilots operating nearby described visibility over the hills as “poor.”
This is only the second fatal accident involving the DHC-8-400 series. On February 12, 2009, Colgan Air Flight 3407 crashed near Buffalo, New York, killing one person on the ground as well as all 49 on board. The NTSB attributed that accident to pilot inattention during an instrument approach in freezing rain at night, followed by the captain’s inappropriate response to indications of an impending stall.
Two Killed in Indiana Runway Collision
Cessna 525C Citation and Cessna 150, April 2, 2018, Marion, Indiana—Two members of the Pipe Creek Township Volunteer Fire Department died after their 1958 Cessna 150 struck the tail of a Cessna 525C Citation during a late-afternoon takeoff attempt. Reports from the scene suggest that the 150 began its takeoff roll on Runway 15 of the Marion Municipal Airport just as the Citation was landing on Runway 22; the collision occurred at the intersection. The 150 came to rest in the grass and was partly consumed by fire. The Citation remained on the runway, its vertical stabilizer completely severed by the impact. None of the five people on the jet was injured.
Marion Municipal is one of the thousands of airports not served by control towers; pilots communicate via a published radio frequency and maintain visual lookout for conflicting traffic. This was the first fatal aircraft collision in the United States since April 1, 2017, when both pilots were killed in the midair collision of two small airplanes near Edgewater, Florida.
Final Reports
Autopilot Error by Inexperienced Crew Blamed for Indian King Air Crash
Beechcraft B200 King Air, Dec. 22, 2015, Delhi, India—The Board of Inquiry convened by India’s Air Accident Investigation Bureau determined that a catastrophic loss of control resulted from the pilots’ failure to engage the autopilot’s heading mode before takeoff in below-minimums visibility. The airplane was destroyed after crashing into the airport’s perimeter road and boundary fence, then the holding tank of a water treatment plant, killing all 10 on board. The investigation further cited the pairing of two relatively inexperienced pilots as just one example of the lack of safety culture within India’s Border Security Force, the airplane’s operator.
The flight was intended to be a round trip between New Delhi and Ranchi, taking technicians to carry out maintenance on a BSF Mi-172 helicopter. The King Air took off in visibility of half a mile; then, at 400 feet above the ground, began a descending left turn. Twenty-one seconds before the crash, the pilot flying realized that the autopilot hadn’t been set to heading mode, disconnected it, and tried to recover the aircraft by hand. Bank angle, altitude, and stall warning alarms sounded continuously for the last eight seconds of the flight.
The investigation found that both pilots held the necessary certifications to act as pilot-in-command but had limited experience in that role. The pilot flying had slightly less than 1,000 hours of total experience, just 77 of which were as PIC of a King Air B200. He had also logged 620 hours as second-in-command. The pilot monitoring had less than 900 hours of total time; his B200 experience included 183 hours as SIC and 196 hours as PIC. The independent pilot examiner who’d conducted their check flights eight months earlier approved both, but recommended that each “fly under supervision of a suitably experienced senior commander” until they had amassed “a good amount of experience and training.” Two more senior captains—the internal pilot examiner and a former India Air Force pilot—were on the BSF’s roster.
The report notes that although the operator’s organizational chart included chiefs of flight safety and safety management systems, both positions were frequently vacant. The chief of flight safety at the time of the accident “had not undergone any safety training” and was serving a six-month interim appointment. Staff were generally unaware of the provisions of the SMS manual and safety policy, which the Board concluded “were prepared for fulfilling the regulatory requirements only.”
Pilot, Passenger Escape On-ground Mast-bumping Episode
Bell 206B, Sept. 12, 2016, Rockport, Washington—The pilot''s “failure to maintain helicopter control while on the ground” was the probable cause of a mast-bumping incident, according to the NSTB. After the helicopter landed on Mount Prospect in the North Cascades National Park, a “series of oscillations” prompted the pilot to shut down the engine and inspect for possible damage. The helicopter was conducting “call-when-needed” external load operations for the National Park Service (NPS) and had landed to disembark the sole passenger, a NPS employee tasked with attaching the long line and receiving the cargo. The oscillations began when he climbed out and secured the cabin door. The passenger said that the helicopter “bounced and lurched,” but the tail rotor did not strike the ground.
The pilot’s inspection revealed enough damage to require the aircraft’s extrication as an external load by a larger helicopter. An Interior Department airworthiness inspector examined it at the operator’s hangar, and while “not given full access...to conduct a thorough airframe and engine inspection,” he documented damage to the main drive shaft’s forward coupling and main transmission. The main rotor mast had made contact with the rotor’s static stops, an event known as “mast bumping” that can fracture the mast and separate the main rotor from the fuselage. The pilot reported variable winds of five to ten knots at the time of the accident.
Hard Landing Attributed to Bearing Failure
Sikorsky S-92A, Dec. 28, 2016, West Franklin Oil Platform, North Sea—A total loss of yaw control while landing on th oil platform was caused by the failure of the tail rotor pitch change shaft (TRPCS) bearing, which in turn damaged the tail rotor pitch change servo, according to the UK's Air Accidents Investigation Branch The pilots immediately entered autorotation and landed “expeditiously, but heavily, on the helideck.” The craft rotated through another 180 degrees, nearly sliding off the deck before the crew shut down the engines. There were no significant injuries to the two pilots or nine passengers on board
The aircraft’s health and usage monitoring system (HUMS) had registered excessive vibration in the TRPCS and tail rotor gearbox the previous day. This data was downloaded during scheduled maintenance overnight; however, the analysis software didn’t identify the source of the exceedences, and the helicopter was released for service without further investigation. The HUMS recorded additional exceedences on earlier flights the day of the accident, but the system does not present this information to the flight crew.
The first leg from the company’s base in Aberdeen was uneventful. On takeoff for the second leg the helicopter experienced an uncommanded right yaw of some 45 degrees, but control response seemed normal after a precautionary landing and the excursion was blamed on wind conditions. The accident sequence occurred at the end of the five-minute flight to the West Franklin platform. Sikorsky’s response to the event included improved diagnostic capabilities and user interfaces for the HUMS software and tighter manufacturing and assembly tolerances for the TRPCS bearing.