The following information provides an awareness of problems that might be avoided in the future. The information is based on final reports by official investigative authorities on aircraft accidents and incidents.
Loose Fan Duct
Boeing 787-9. No damage. No injuries.
While preparing for a scheduled flight from London to New Delhi on the morning of April 29, 2017, the flight crew learned that the left air-conditioning system had been disabled in accordance with provisions of the minimum equipment list (MEL). The maintenance action had been taken because the cabin air compressor shaft in the right air-conditioning system had failed and damaged the compressor.
The MEL specified that with only one of the two air-conditioning systems functioning, the aircraft would have to remain within 60 minutes of an alternate airport throughout the flight. Compliance with this provision required, in part, a change of the flight plan and fuel load. As a result, the 787 departed from London about 30 minutes behind schedule with 124 passengers and 13 crewmembers aboard.
While climbing to Flight Level (FL) 350 (approximately 35,000 ft), the crew noticed that the cockpit temperature was higher than normal and that the airflow was lower than normal. Shortly after leveling off at FL 350, the crew saw a cabin pressure warning on the engine indicating and crew alerting system (EICAS) and noticed that the cabin altitude had climbed to 8,500 ft and was still increasing at 300 fpm although both outflow valves were closed. While diagnosing the problem the pilots saw an EICAS system-status warning about the lower recirculating fan in the right (functioning) air-conditioning system.
“The crew discussed remedial options and initially requested a descent to FL 310 to see whether the cabin altitude would stabilise,” said the report by the U.K. Air Accidents Investigation Branch. However, the cabin altitude continued to increase as the aircraft descended. The crew declared an urgency with air traffic control (ATC), manually deployed the passenger oxygen masks and advised the cabin crew of the situation.
“The crew carried out the appropriate QRH [quick reference handbook] drills in a timely and comprehensive manner,” the report said. When the cabin altitude increased to 10,000 ft, the pilots donned their oxygen masks, declared an emergency and initiated a rapid descent to 10,000 ft. “The aircraft was approximately 25 nm [46 km] east of Brussels, Belgium,” the report said. “As the aircraft descended through [25,800 ft] the cabin altitude reached a maximum value of 10,429 ft before starting to reduce. … The cabin altitude continued to reduce to about 3,700 ft, where it stabilised.”
The crew decided to return to London Heathrow Airport They jettisoned about 4,000 kg (8,818 lb) of fuel to meet landing weight requirements and subsequently landed the aircraft without further incident.
Examination of the 787 revealed that during the preflight maintenance to disable the left air-conditioning system, the lower recirculation fan in the right air-conditioning system had not been reattached correctly to the recirculation duct. “The incorrect fitment of the coupling and sleeve was partly a consequence of the inaccessibility of those components … and the lack of tactile feel enabling an incorrectly assembled coupling to be easily identified,” the report said.
Investigators determined that the loose recirculation fan detached from the recirculation duct after the aircraft departed from Heathrow. This caused a leak of cabin airflow that the right air-conditioning system alone was unable to overcome as the demand for pressurizing airflow increased during the climb, the report said.
First Officer Suffers Seizure
Airbus A320. No damage. No injuries.
The first officer felt a mild throat irritation before beginning a flight from Delhi, India, to Kolkata the afternoon of April 27, 2017, but was able to function normally during the flight. About 30 minutes after the subsequent takeoff from Kolkata with 180 passengers and six crewmembers for the return flight to Delhi, the first officer drank water to ease his throat irritation. However, he subsequently regurgitated the water, said the report by the Aircraft Accident Investigation Bureau of India.
“He again tried to have water, but again it came out,” the report said. “His hands and feet then became stiff. His body was shaking. After two or three minutes, he had blurring of vision, and thereafter he went unconscious.”
The captain was unable to rouse or communicate with the first officer. “The lead cabin attendant, along with another cabin attendant, entered the cockpit and tried to revive the first officer,” the report said. “He remained unresponsive. [His] seat was reclined and shoulder harness was put on to ensure that he did not touch the controls inadvertently. Oxygen was administered to the first officer using a quick-donning mask. … Blood was found coming out of the first officer’s mouth.”
The lead cabin attendant used the passenger-address system to inquire if there was a physician aboard, but she received no response. There also were no company pilots aboard to assist the captain. The captain declared an emergency, informed ATC of the situation and diverted the flight to Bhubaneswar. He also requested medical assistance on arrival.
The first officer regained consciousness about 10 minutes later but remained disoriented. The captain told him to relax and to continue using supplemental oxygen. The captain then landed the aircraft at Bhubaneswar without further incident. The first officer was examined by a physician in the cockpit and then taken by ambulance to a medical facility.
Further examination of the 31-year-old first officer revealed that he had suffered a seizure and an episode of syncope, or a temporary loss of unconsciousness due to insufficient blood flow to the brain. He likely had bitten his tongue during the seizure, which caused the bleeding, the report said. He also was diagnosed as having several ailments, including hypotension (low blood pressure), gallstones and cystitis (inflammation of the bladder).
The report included this message: “Flight crew incapacitation is a real safety hazard that occurs more frequently than many other emergencies. Incapacitation can occur in many forms. Sometimes the flight crew does not have any symptoms before incapacitation, [which] can occur in all age groups and during any phase of flight. Incapacitation may be obvious or subtle, so it is important to remain alert for either.”
Severe Turbulence Encounter
Airbus A319-132. Minor damage. Two serious injuries, one minor injury.
The A319 was en route with 93 passengers and five crewmembers from Phoenix, Arizona, U.S., to Denver, Colorado, the morning of April 15, 2012, and was cleared to descend from FL 390 to 17,000 ft over Buena Vista, Colorado. “The seat belt sign was on during the descent, and there were no pilot reports of turbulence in the area,” said the report by the U.S. National Transportation Safety Board (NTSB). “The captain [the pilot monitoring] turned on the weather radar and noted no returns present between the airplane and the airport.”
The airplane was descending through 32,000 ft when indicated airspeed rapidly increased. The captain disengaged the autopilot, and the first officer was reducing the A319’s nose-down pitch attitude when an overspeed warning sounded. The A319 then encountered severe turbulence that lasted 10 to 15 seconds.
“Two passengers who were not wearing their seat belts were lifted out of their seats and struck the ceiling panels during the encounter,” the report said. One of the passengers sustained minor injuries. Two flight attendants, who were sitting in jump seats in the aft galley without their seat belts on, also were thrown against the ceiling and landed on the floor. Both suffered serious injuries and were tended to by another flight attendant and two medical specialists who were among the passengers.
“The captain declared a medical emergency and arranged for emergency personnel to meet the flight on arrival [in Denver],” the report said. “At the gate, paramedics transported the two injured flight attendants and [the injured] passenger to the hospital.”
NTSB concluded that the probable cause of the accident was “an inadvertent encounter with mountain wave turbulence.”
Disoriented in Night IMC
Pilatus PC-12. Destroyed. Three fatalities.
Night instrument meteorological conditions (IMC) and moderate turbulence prevailed when the pilot and two medical crewmembers departed from Amarillo, Texas, U.S., to pick up a patient in Clovis, New Mexico, on April 28, 2017. Shortly after taking off to the northeast, the pilot was told by an air traffic controller to reset his transponder to the assigned code. The single-turboprop leveled off at about 4,500 ft (900 ft above the ground) for about 30 seconds before resuming the initial climb.
“The airplane resumed its climb at a rate of about 6,000 fpm,” the NTSB report said. After leveling off at 6,000 ft, the pilot was told to establish radio communication with the next sector controller. About a minute after communication was established, the controller told the pilot that he was no longer receiving the airplane’s transponder return on his radar display.
“The pilot did not respond,” the report said. “Radar data showed the airplane descending rapidly at a rate that reached 17,000 fpm. Surveillance video from a nearby truck stop recorded lights from the airplane descending at an angle of about 45 degrees, followed by an explosion.” The PC-12 had struck terrain in a steep nose-down and wings-level attitude about 1.5 nm (2.8 km) south of the airport.
Investigators determined that the pilot’s “limited” recent flight experience in night IMC and the “excessive pitch and roll angles, rapid climb [and] unexpected level-offs” during the accident flight were among factors indicating that the pilot experienced spatial disorientation during the flight.
The report also said that the pilot likely had engaged the autopilot during departure but subsequently did not realize that the autopilot had disengaged. “The operator reported that the airplane had experienced repeated, unexpected in-flight autopilot disconnects and, two days before the accident, the chief pilot recorded a video of the autopilot disconnecting during a flight,” the report said.
Crossed Crosswind Control
Viking Air Twin Otter. Substantial damage. No injuries.
The aircraft was en route with 17 passengers and two flight crewmembers from Tatung, Taiwan, to Lanyu, which was experiencing moderate turbulence and wind shear the afternoon of April 13, 2017. “The flight crew were still in the initial stage of accumulating flying experience in the type aircraft,” said the report by the Aviation Safety Council, an independent aviation investigation agency.
During the approach to Lanyu, the captain applied left rudder to counter a left crosswind, and the Twin Otter touched down with its nose yawed left. The aircraft began to drift left, and the captain attempted to regain directional control by applying right rudder and asymmetric reverse thrust. This would have required extracting more reverse thrust from the right engine and propeller than from the left power plant.
However, “recorded engine data … revealed that the captain inadvertently pulled back the left power lever while he was intending to apply the right-turning differential power to assist him in correcting the left drift,” the report said. “It resulted in increasing the left reverse power and intensified the aircraft’s left-drifting tendency. Though the captain attempted to [regain] direction control of the aircraft by increasing right rudder input and [applying] right wheel brake pressure, he still kept increasing the reverse power of the left engine to the maximum, not knowing that he was taking the wrong side.”
The Twin Otter veered off the left side of the runway and struck a fence. Damage was substantial, but none of the occupants was injured.
The report noted that the use of asymmetric reverse thrust for directional control is not recommended and that the flight crew had “very limited” experience, and had received no training, in applying differential forward thrust for directional control on landing. The aviation authority in Canada, where the aircraft was manufactured, recommended using only rudder — and nosewheel steering if necessary — to maintain directional control, the report said. The aircraft manufacturer recommended the use of asymmetric forward thrust only “as the aircraft slows down.”
Emergency Landing on Road
Piper Chieftain. Substantial damage. No injuries.
The flight crew was conducting a charter flight with four passengers in visual meteorological conditions from Medicine Hat, Alberta, Canada, to Calgary the morning of April 25, 2018. After leveling off at 8,000 ft, they completed the cruise checklist, which including repositioning the fuel selectors from the inboard (main) fuel tanks to the outboard (auxiliary) tanks.
The Chieftain was about 12 nm (22 km) south of Calgary International Airport when the right engine began to surge. “The captain then requested that the first officer run the engine failure in-flight checklist,” said the report by the Transportation Safety Board of Canada. “The items on the checklist were performed, with the exception of the cause check and feathering the propeller. The cause check directs the crew to check fuel flow, fuel quantity, fuel selector position, oil pressure and temperature, and magneto switches.”
The crew requested, and received, clearance from the arrival controller to land on the closest runway, Runway 35R. They reported that the right fuel pump had failed and declined the controller’s offer to have aircraft rescue and fire fighting services on standby.
About a minute later, the left engine began to surge. The crew declared an emergency with the airport traffic (tower) controller and were cleared to land on Runway 35R. “The flight crew then made a second mayday call, informing the tower controller that they would be landing on a road because they would not be able to make it to the airfield,” the report said.
The pilots landed the Chieftain on a six-lane, divided highway. “Shortly after the aircraft touched down, its right wing contacted a light standard on the right side of the road, shearing off the outer four feet [1.2 m] of the wing,” the report said. “There were no injuries to the passengers, the flight crew or any persons on the ground.”
Examination of the aircraft revealed that the fuel selector valves were positioned to the outboard fuel tanks, which were nearly empty. Each of the inboard fuel tanks contained about 40 gal (151 L) of fuel.
Engine Starved of Oil
Cessna 421C. Destroyed. One fatality.
The pilot departed from Conroe, Texas, U.S., the morning of April 25, 2017, to conduct a local post-maintenance test flight while receiving visual flight rules flight services from ATC. The airplane was at 2,400 ft about 38 minutes after takeoff when the pilot reported an “oil leak” and requested clearance to return to the Conroe airport.
The controller advised that Huntsville Municipal Airport was closer, and the pilot decided to go there instead. “The controller then issued a heading to position the airplane for a right base leg for Runway 18 and stated that the airport was at the pilot’s 1 o’clock position, 7 miles [11 km] away,” the NTSB report said. “The pilot acknowledged and turned the airplane onto the issued heading.”
A few minutes later, the controller told the pilot that the airport was at his 3 o’clock position and 3 mi (5 km) away. The pilot replied that he did not have the airport in sight. The controller lost radio and radar contact with the airplane when it descended below 2,000 ft. The controller asked the pilot of another aircraft in the area to tell the 421 pilot that he had flown past the Huntsville airport. The pilot was able to hail the 421 pilot, who said that he had a “dead” engine.
A witness saw the 421 about 150 ft above the ground and descending with the left propeller stationary and the flaps and landing gear retracted. The airplane was destroyed when it struck terrain and burned.
Examination of the wreckage revealed that a connecting rod in the left engine had failed. “The connecting rod bearings exhibited signs of heat distress and discoloration consistent with a lack of lubrication,” the report said. “The engine’s oil pump was intact, and the gears were wet with oil. Based on the available evidence, the engine failure was the result of oil starvation; however, the examination could not identify the reason for the starvation.”
Loose Cowling Hits Rotor
Eurocopter MBB BK-117. Substantial damage. No injuries.
Maintenance had been performed on the helicopter before the pilot conducted an air ambulance flight the afternoon of April 26, 2016, to transfer a medical patient and three crewmembers from a hospital in Grafton, West Virginia, U.S., to a hospital in Pittsburgh, Pennsylvania. After landing in Pittsburgh, he noticed that a cowling had partially separated from a vertical fin and had struck a tail rotor blade.
“Further examination of the helicopter revealed that the right vertical fin cowling remained secured but that eight of the 11 [Dzus] fasteners on the left vertical fin cowling were unlocked, consistent with maintenance personnel not properly securing them following the maintenance work that was performed earlier that day,” the NTSB report said.
Simulation Turns Real
Airbus Helicopters AS350-B3. Destroyed. No injuries.
During a preflight briefing for an annual proficiency check at Sola, Norway, the afternoon of April 30, 2016, the examiner told the pilot that he would simulate a hydraulic failure by activating the “HYD TEST” switch, which normally is used to check the flight controls after starting the engine, said the report by the Accident Investigation Board of Norway.
During the check ride, the pilot made a steep approach to the Sola airstrip and established a hover about 6 ft above the ground. As briefed, the examiner activated the “HYD TEST” switch to simulate a hydraulic failure. “The [pilot] then moved the ‘HYD OFF’ switch on the collective to off, most likely inadvertently,” the report said. “He then immediately switched this back on, most likely in an attempt to correct the error.”
However, the combined actions caused a loss of hydraulic pressure, and the helicopter began to drift and rotate uncontrollably. “The uncontrollable movements were so significant that the main rotor blades impacted the ground and the helicopter’s tail boom,” the report said. The AS350 was substantially damaged by the impact and ensuing fire, but the pilot and the examiner escaped injury.
Rotor Severs Tail Boom
Bell 206B-3. Substantial damage. No injuries.
The student pilot conducted an autorotational landing during a training flight in Germiston, South Africa, the morning of April 6, 2017. The flight instructor said that the main rotor was rotating slowly during the latter phase of the maneuver. The rotor blades struck and severed the tail boom when the JetRanger touched down hard. Damage was substantial, but neither pilot was injured.
The South African Civil Aviation Authority determined that the probable cause of the accident was that the main rotor speed was allowed to decrease below the prescribed minimum, which led to the hard landing and flexing of the main rotor.
|Date||Location||Aircraft Type||Aircraft Damage||Injuries|
NA = not available
This information, gathered from various government and media sources, is subject to change as the investigations of the accidents and incidents are completed.
|Feb. 3||Yorba Linda, California, U.S.||Cessna 414||destroyed||5 fatal, 2 serious|
|Shortly after taking off from Fullerton in visual meteorological conditions (VMC), the 414 entered an area with rain showers and microburst activity. The airplane descended rapidly and broke up in flight before striking terrain in a residential area. The pilot and four people on the ground were killed; two other people on the ground were seriously injured.|
|Feb. 6||Aurora, Oregon, U.S.||Piper Meridian||destroyed||2 serious|
|The single-engine airplane struck approach lights and terrain on approach.|
|Feb. 8||Billund, Denmark||Airbus A321||substantial||NA|
|No injuries were reported when the A321’s tail struck the runway during a hard landing.|
|Feb 8||Miami||Convair C-131B||destroyed||1 fatal, 1 serious|
|The Convair was en route on a cargo flight from Nassau, Bahamas, when the right engine began to surge. The flight crew shut down the engine and feathered the propeller. Shortly thereafter, the left engine began to surge, and the pilots ditched the airplane in the ocean about 32 mi (51 km) east of the destination, Miami–Opa Locka Executive Airport. The tail section separated when the airplane struck the water. The captain was killed, and the first officer was seriously injured.|
|Feb. 9||Nairobi, Kenya||Embraer ERJ-190AR||substantial||none|
|While being serviced on the ramp, the aircraft overran its chocks when an engine was started. The aircraft then collided with another ERJ-190 that was parked on the ramp. Both aircraft were substantially damaged.|
|Feb. 15||Canadian, Texas, U.S.||Cessna 421C||destroyed||2 fatal|
|The pilot was conducting a visual flight rules flight from Amarillo, Texas, to Hemphill County Airport, which had 7 mi (11 km) visibility and an 800-ft ceiling. The 421 struck terrain about 8 mi (13 km) from the destination.|
|Feb. 21||Frankfort, Kentucky, U.S.||Beech 76||substantial||1 minor, 1 none|
|Day VMC prevailed for an instructional flight that was intended to prepare the commercial pilot for a multi-engine check ride. The pilot attempted to reject a simulated single-engine approach to Capital City Airport after the approach became unstable. The Duchess veered left and struck an embankment. The flight instructor sustained minor injuries; the pilot was not hurt.|
|Feb. 22||Colby, Kansas, U.S.||Beech Queen Air||substantial||none|
|The crew door next to the left front seat opened during departure from Shalz Field Airport for a positioning flight. The pilot attempted to return to the airport and was maneuvering to remain below a 200-ft overcast when the Queen Air stalled and struck terrain.|
|Feb. 23||Houston||Boeing 767-375ER||destroyed||3 fatal|
|En route on a cargo flight from Miami, the 767 was descending to land at Houston–George Bush Intercontinental Airport when it entered a rapid descent and struck the water in Trinity Bay, about 32 nm (59 km) from the destination.|
|Feb. 26||Moscow||Gulfstream G200 Galaxy||substantial||5 none|
|Instrument meteorological conditions with light snow prevailed when the G200 slid off the left side of the runway while landing at Sheremetyevo International Airport.|
|Feb. 28||Shreveport, Louisiana, U.S.||Piper Meridian||destroyed||2 fatal|
|The pilot declared an emergency shortly after takeoff and was attempting to return to the airport when the airplane crashed into the Red River.|