Clearance Expectation Leads to Incursion

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.

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Jets

‘Hasty Judgment’

Airbus A320, Dassault Falcon 900. No damage. No injuries.

The captain of the A320 made a “hasty judgment” that a radio transmission begun by the airport traffic controller would include a takeoff clearance, and neither the first officer nor the second officer questioned his decision to begin the takeoff roll before the clearance actually was received, said the Japan Transport Safety Board (TSB).

Moreover, none of the three flight crewmembers subsequently heard or responded to the controller’s repeated instructions to stop, according to the TSB’s report on the serious incident at Naha (Japan) Airport on Okinawa the evening of March 18, 2018.

The Falcon had just landed and was still on the runway when the A320 began to accelerate behind it. However, the pilots of the business jet were able to vacate the runway before the Airbus passed by.

The A320, with 106 passengers and nine crewmembers aboard, was being taxied for departure from Naha’s Runway 18 when the airport traffic controller cleared the Falcon crew to land on the 3,000-m (9,843-ft) runway. The A320 crew was communicating with the ground controller at the time and did not hear the Falcon’s landing clearance, nor did they apparently see the aircraft on approach.

The ground controller told the A320 crew to hold short of the runway. When the A320 crew subsequently established radio communication with the airport traffic controller, the controller said, “Confirm ready for departure.” The controller planned to sequence the A320 for takeoff between the Falcon and another aircraft on approach. After the A320 crew confirmed that they were ready for takeoff, the controller instructed them to line up and wait on Runway 18. The controller then told the Falcon crew to vacate the runway on a taxiway that was about 2,250 m (7,382 ft) from the A320’s position.

The report said that the A320 captain, the pilot flying, believed that the controller’s confirmation that they were ready to take off implied that they were “expected to take off immediately, and [he] took it for granted that a takeoff clearance should be issued following the tower’s instructions to line up and wait.”

The controller began to tell the crew that they could disregard a previously issued altitude restriction, and the captain assumed that the transmission would include a takeoff clearance. “Immediately after this transmission started, the [captain increased] engine thrust and released the brakes,” the report said. “He did not visually recognize [that the Falcon was] on the runway in front when he commenced the takeoff roll.”

After the controller completed the radio transmission, the second officer, who was handling radio communications, incorrectly read back the cancellation of the altitude restriction. The controller was correcting the second officer when he noticed that the A320 was rolling for takeoff. He radioed, using the aircraft’s call sign, “DKH1332, hold. Stop. Stop immediately. DKH1332, stop immediately.”

“The [A320] continued the takeoff roll even after the tower instructed it to stop immediately,” the report said. “All of the three flight crewmembers … did not hear the tower’s instructions to stop immediately.”

Noticing that the Falcon had vacated the runway and that there was no further risk of a collision, the controller made no further radio transmissions to the A320 as it continued the takeoff roll. The aircraft subsequently completed its scheduled flight without further incident.

Uncontained Generator Failure

McDonnell Douglas MD-83. Substantial damage. No injuries.

The MD-83, with 163 people aboard, was on approach to Dayton (Ohio, U.S.) International Airport the morning of March 19, 2017, when a fire erupted in the no. 2 (right) engine. “The flight crew followed the quick reference handbook procedures, discharged both fire bottles and shut down the no. 2 engine,” said the report by the U.S. National Transportation Safety Board (NTSB).

The crew then completed the approach and landed the airplane without further incident. The MD-83 was examined on the runway by aircraft rescue and fire fighting personnel, who determined that the fire had been extinguished. The crew then taxied the airplane to the gate.

Examination of the engine revealed an uncontained failure of the generator. Metal fragments released during the failure had severed an oil line between the constant speed drive and the oil cooler. “The severed line sprayed oil onto hot generator and engine case surfaces that subsequently ignited,” the report said.

The generator’s accumulated operating time and cycles were not required to be recorded, but investigators estimated that the generator had been in service longer than the 40,000-hour overhaul limit recommended by the manufacturer, UTC Aerospace Systems. Available records indicated that the generator’s main rotor had never been overhauled or rewound, the report said.

Altitude Deviation Creates Conflict

Boeing 737-800, Embraer ERJ-135. No damage. No injuries.

Both aircraft were en route northeastbound to O.R. Tambo International Airport in Johannesburg, South Africa, the morning of March 13, 2017. The 737, with 130 passengers and six crewmembers aboard, was cruising in visual meteorological conditions (VMC) at Flight Level (FL) 410 (approximately 41,000 ft) when the flight crew was instructed by air traffic control (ATC) to descend to FL 380, said the report by the South African Civil Aviation Authority.

The 737 crew had initiated the descent when ATC issued a rerouting instruction that placed the aircraft on a flight path toward a waypoint to which the ERJ also was headed on a nearly parallel course. The ERJ, with 16 passengers and three crewmembers aboard, was in cruise flight at FL 370. Thus, the planned vertical separation between the two aircraft was 1,000 ft.

After entering the new routing into the 737’s flight management system, the crew realized that the aircraft was above the desired descent path. The first officer, the pilot flying, increased the rate of descent to capture the desired descent profile. The pilots subsequently received a traffic-alert and collision avoidance system (TCAS) traffic advisory (TA) that was followed almost immediately by a resolution advisory (RA) that told the crew to establish level flight.

The first officer disengaged the autopilot and autothrottle systems and hand flew the aircraft in compliance with the RA. He noticed that the 737 was 400 ft below the assigned altitude at the same time the captain called “check altitude,” increased thrust and pitch attitude, and established level flight at the assigned FL 380.

Meanwhile, the ERJ flight crew also had received a TCAS TA. “The PIC [pilot in command] put his hands on the controls in order to manoeuvre the aircraft should a TCAS RA occur,” the report said. “The FO [first officer] switched on the aircraft external lights as per standing operating procedure (SOP) in order to make the aircraft more visible.” The ERJ pilots saw the 737 above and to their left about the same time they received, and responded to, an RA telling them to descend.

The TAs that had been generated in both aircraft likely had been prompted by the 737’s high rate of descent. Investigators determined that the aircraft passed within 500 ft vertically and 1.6 nm (3.0 km) laterally while the crews were responding to the subsequent RAs.

The pilots of both aircraft advised ATC that they were responding to TCAS RAs. The controller handling both aircraft had noticed the 737’s altitude deviation and had questioned the flight crew about it. After confirming that a risk of collision no longer existed, the controller cleared the ERJ crew to climb back to FL 370. Both aircraft subsequently were landed at Johannesburg without further incident.

Laptop Battery Ignites

Airbus A320-216. Minor damage. No injuries.

Shortly after the A320 was landed and taxied to a stand at Helsinki-Vantaa (Finland) Airport the night of March 7, 2017, passengers seated in the front section of the aircraft detected the odor of an electrical fire and saw smoke building in the cabin. They reported this to the cabin crew, and the senior cabin attendant relayed the information by interphone to the flight crew. She then gave another cabin attendant a portable Halon fire extinguisher and told her to don a smoke hood.

After verifying the situation in the cabin, a flight crewmember returned to the cockpit and advised ATC and the ramp crew that there was a fire aboard the aircraft. “He also told the ramp crew that they were not to open the cargo doors because the source of the smoke was unknown,” said the report by the Safety Investigation Authority of Finland. The flight crew then checked the aircraft’s systems for indication of a problem but found none.

Passengers informed the cabin crew that the smoke was coming from the footwell of a seat on the right side of the aisle. The cabin attendant with the fire extinguisher found that the smoke was emanating from a nylon backpack beneath a passenger seat. “She moved the laptop with her foot so as to make it more accessible and then discharged the fire extinguisher toward it,” the report said. “In addition, she shoved the neighboring passengers’ bags and overcoats to the side and kept monitoring that the fire had been extinguished. … The sequence from the first detection of smoke to extinguishing the laptop took approximately one minute.”

The senior cabin attendant told the passengers to leave their belongings behind and to exit the aircraft rapidly. “Some of the passengers followed the instructions,” the report said. “Other passengers tried to take their hand luggage with them, which resulted in the aisle being blocked and the deplaning process being slowed down.”

None of the 167 passengers and six crewmembers was injured during the incident. Investigators determined that the fire had begun in a laptop inside the backpack and had scorched the lower cushion of the passenger seat and the floor and wall near the seat. “The laptop, the backpack and all items in it were destroyed,” the report said.

X-ray examination of the laptop revealed that the fire had originated in its 3.5-volt lithium-ion battery. The owner said that the laptop had been purchased six months before the incident and had not heated abnormally during use. “According to the laptop’s manufacturer, no quality issues had been detected in this model’s batteries,” the report said.

Thermal damage precluded a conclusive determination of the cause of the battery fire. “According to the experts [who examined the laptop] the fire was possibly caused by external damage to the battery,” the report said. “While a hole was detected on the outer surface of the battery, the investigation could not confirm whether the hole had been there prior to the fire or caused as a result of it.”

In addition to external damage, “a lithium-ion battery can be forced into thermal runaway because of, among other things, an internal or external short circuit … overcharging or exposure to high temperatures,” the report explained. “Laptop battery fires are rare in flight, but they are not altogether unheard of.”

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Turboprops

Gear Damaged on Go-Around

Beech 99. Substantial damage. No injuries.

While refueling and boarding more charter passengers in Dillingham, Alaska, U.S., the afternoon of March 29, 2018, the pilot found that the weather conditions at the next stop, Pilot Point, included 1/4 mi (400 m) visibility and a 200-ft ceiling. However, the pilot believed that, by the time he reached Pilot Point, the conditions would have improved sufficiently to conduct the global positioning system (GPS) approach to Runway 07. The published minimums for the approach are 1 mi (1,600 m) visibility and 600 ft.

The pilot told investigators that as the airplane neared Pilot Point, the automated weather observation system was reporting 1 3/4 mi (2,800 m) visibility, the NTSB report said. The pilot conducted the GPS approach and briefly saw the approach end of the 3,280-ft (1,000-m) gravel runway when the airplane reached the minimum descent altitude. However, he initiated a go-around after losing sight of the runway when the airplane entered an “isolated wisp of fog,” he told investigators.

“Seconds later, I got a solid visual on the runway,” the pilot said. “I went to a visual approach … and initiated a teardrop pattern to land on Runway 25. … As I was crossing the approach end of the runway, I felt the airplane begin to sink rapidly and slide to the left.”

The pilot initiated a go-around, but the airplane touched down hard on the left main landing gear off the left side of the runway before climbing. He said that when he attempted to retract the landing gear, he found that “the handle was locked in place.” A pilot-rated passenger visually inspected the main landing gear and found that the left gear appeared to be down and locked, and that the right gear was bent back. In addition, the right flap was damaged, and fuel was leaking from the wing.

The pilot declared an emergency and diverted the flight to King Salmon, where he conducted an instrument landing system approach. He shut down both engines and feathered the propellers before the airplane touched down on the paved runway. The pilot said that the airplane slid about 1,000 ft (305 m) before coming to a stop. The seven passengers and the pilot were not injured, but the airplane had been substantially damaged during the hard landing at Pilot Point.

Misplaced Tool Hits Prop

Swearingen Metro. Substantial damage. No injuries.

The pilot was departing from Boise, Idaho, U.S., for a positioning flight the night of March 20, 2017, when he heard a “pop” and felt a vibration. He initially thought a tire had burst but then determined that there might be a problem with a propeller. He returned to the airport and landed the Metro without further incident.

After shutdown, the pilot found that the tip of a propeller blade had separated from the left propeller and penetrated the fuselage. “Airport personnel later found additional pieces of propeller blade material on the runway, as well as what appeared to be the blade of a screwdriver and pieces of the handle,” the NTSB report said.

“Maintenance personnel reported that a mechanic had been working on the airplane just before the flight and had been called away from the task he was performing before it was completed,” the report said. “The airplane was subsequently returned to service.”

Investigators determined that the mechanic had left a screwdriver near the windshield wiper, in a position the pilot could not see, when he was called away. “It is likely that, during the takeoff roll, the screwdriver became dislodged from the area of the windshield wiper and impacted the left propeller,” the report said.

Yaw Damper on For Takeoff

Beech King Air B200. Substantial damage. No injuries.

The commander felt stiffness in the rudder controls, and the King Air veered slightly left during takeoff from Chandigarh, India, the morning of March 25, 2014. The aircraft lifted off near the edge of the runway and entered a left turn. The commander told the copilot that the rudder was “locked.” Both pilots then noticed an annunciator indicating that the yaw damper was engaged.

The commander pressed the yaw damper disengage switch on his control yoke almost the same time that the copilot pressed the yaw damper button on the autopilot. These actions resulted in the yaw damper disengaging and re-engaging, said the report by India’s Ministry of Civil Aviation.

Meanwhile, both pilots applied right aileron control in unsuccessful efforts to correct the left turn. “Within three to four seconds of getting airborne, the aircraft impacted the ground in a left bank attitude,” the report said. The King Air was substantially damaged, but the eight passengers and two pilots escaped injury.

The report said that among the probable causes of the accident were the flight crew’s “haste to take off,” the absence of the use of checklists and a pre-takeoff check, and the “failure on the part of the crew to effectively put off the yaw damp so as to release the rudder stiffness as per the emergency checklist.”

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Piston Airplanes

‘Unnecessary Risk’

Beech B60 Duke. Destroyed. Two fatalities.

The private pilot had just purchased the Duke and was receiving instruction to meet insurance requirements the afternoon of March 4, 2017. The airplane departed from Sarasota-Bradenton (Florida, U.S.) Airport and was observed maneuvering 1,000 ft to 1,200 ft above the ground in slow flight before it stalled and entered a spin. Both pilots were killed when the Duke struck terrain.

NTSB concluded that the probable cause of the accident was “the pilots’ decision to perform flight training maneuvers at low airspeed at an altitude that was insufficient for stall recovery.” The flight instructor’s “nonstandard stall-recovery techniques” were cited as a contributing factor.

“The instructor used techniques that were not in keeping with established flight training standards,” the report said. “Most critically, the instructor used two techniques that introduced unnecessary risk: increasing power before reducing the angle-of-attack during a stall recovery and introducing asymmetric power while recovering from a stall in a multi-engine airplane. Both techniques are dangerous errors because they can lead to an airplane entering a spin.”

Stall During Evasive Maneuver

Cessna 340A. Destroyed. Two fatalities.

The 340 began to roll for takeoff from Runway 04 at Peter O. Knight Airport in Tampa, Florida, U.S., about the same time that a Cessna 172M began rolling on Runway 36 the morning of March 18, 2016. A witness heard the pilots of both airplanes announce their intentions on the airport’s common traffic advisory frequency (CTAF).

Airport video showed that the 172 was airborne and crossing the runway intersection when the 340 lifted off. “Almost immediately, the Cessna 340A began a climbing left turn with an increasing bank angle while the Cessna 172M continued straight ahead,” the NTSB report said. The 340 stalled when the bank angle reached about 40 degrees; it then rolled inverted and struck the ground in a nose-low and left-wing-low attitude. The pilot and his passenger were killed.

“The Cessna 172M, which was not damaged, continued to its destination and landed uneventfully,” the report said. “Both occupants later reported that they were constantly monitoring the CTAF but did not hear the transmission from the Cessna 340A pilot [or] see any inbound or outbound aircraft.”

Tanks Runs Dry on Ferry Flight

Beech B60 Duke. Substantial damage. One minor injury.

The pilot was conducting a ferry flight from Dallas to Mexia, Texas, U.S., the morning of March 1, 2018. The Duke was cruising at 5,000 ft shortly after takeoff when the left engine surged several times. Shortly after the pilot shut down the left engine, the right engine lost power. The airplane descended, struck treetops and touched down hard in a field with the landing gear retracted. The pilot sustained minor injuries. The Duke’s wings, engine mounts and lower fuselage were substantially damaged.

“The pilot reported that he had requested 200 gallons (757 L) of fuel from his home-airport fixed base operator, but they did not fuel the airplane,” the NTSB report said. “The pilot did not check the fuel quantity during his preflight inspection.”

NTSB concluded that the probable cause of the accident was “the pilot’s improper preflight inspection of the fuel level, which resulted in a loss of engine power due to fuel exhaustion.” A contributing factor was “the pilot’s failure to lower the landing gear before the emergency landing.”

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Helicopters

‘We Lost Power’

Bell 206L-1. Destroyed. Two fatalities, one serious injury.

The U.S. Forest Service helicopter was near the end of a controlled-burn mission near Saucier, Mississippi, U.S., the afternoon of March 30, 2015, when the pilot told the two crewmembers, “We lost power.” A witness on the ground had heard a sound “that resembled an air hose being unplugged from a pressurized air tank,” the NTSB report said.

The LongRanger was about 20 ft above the treetops when the power loss occurred. “The helicopter then descended into a group of 80-ft-tall trees in a nose-high attitude and impacted terrain,” the report said. The pilot and one crewmember were killed; the other crewmember was seriously injured. The helicopter was destroyed by the impact and post-impact fire.

Refueling records indicated that fuel exhaustion was unlikely, but extensive thermal damage precluded a conclusive determination of the cause of the power loss. “Although a weather study indicated that smoke and particulates were present in the area before, during and after the accident, witnesses reported an absence of smoke near the area where the helicopter lost power and impacted the ground,” the report said.

Lost in the Clouds

Robinson R44. Destroyed. One fatality.

VMC prevailed when the pilot departed from Doylestown, Pennsylvania, U.S., for a visual flight rules flight to Greentown, Pennsylvania, about 60 mi (97 km) north, the morning of March 27, 2016. Instrument meteorological conditions existed along the route, but improvement was forecast by the time the R44 arrived at the destination.

The pilot “had flown the route multiple times in the past two years in the accident helicopter and in his airplane,” the NTSB report said. “Although he had an airplane instrument rating, he did not have a helicopter instrument rating, and the helicopter was not certificated for instrument flight.”

The helicopter was about 10 mi (16 km) south of the destination when it “climbed sharply as it approached a ridgeline and entered the clouds,” the report said. “It then completed a 330-degree left turn, slowed and climbed again before reversing course and entering an uncontrolled descent into terrain.”

NTSB concluded that the probable cause of the accident was “the pilot’s loss of control due to spatial disorientation, which occurred after ascending in order to clear rising terrain and inadvertently entering the clouds.”

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