Brake Malfunction Leads to Overrun

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

Brakes Failed on One Wheel

Bombardier Canadair Challenger. Substantial damage. One serious injury, one minor injury.

The brakes had functioned normally when the flight crew landed the Challenger on a 5,008-ft (1,526-m) runway at Florida Keys (U.S.) Marathon International Airport during a positioning flight the afternoon of March 1, 2015. After boarding six passengers, including the owner of the airplane, the crew departed from Marathon for a corporate flight to Marco Island, Florida, about 80 nm (148 km) northwest. The pilot-in-command (PIC) was the pilot flying.

Visual meteorological conditions prevailed at the destination. The automated weather observation system was reporting surface winds from 250 degrees at 5 kt, 10 mi (16 km) visibility and a few clouds at 9,000 ft.

Nearing Marco Island, the pilots saw an area of rain showers moving toward the airport from the east but observed that the runway appeared to be dry. They requested and received clearance from air traffic control (ATC) to conduct a visual approach to Runway 17, which was 5,000 ft (1,524 m) long.

“Before the approach, the pilots reviewed the speeds and [required] landing distance,” said the report by the U.S. National Transportation Safety Board (NTSB). “The calculated required landing distance, assuming a Vref [reference landing speed] of 133 knots, was 3,166 feet [965 m] for a dry runway and 4,166 feet [1,270 m] for a wet runway.”

The PIC flew the left downwind leg closer to the runway than normal to avoid the rain showers east of the airport and then made a continuous turn onto final approach. Airspeed was about 5 kt  higher than Vref when the Challenger crossed the runway threshold. The report said that the pilot likely did not flare the airplane properly, resulting in a touchdown more than 1,000 ft (305 m) beyond the approach threshold.

The crew attempted unsuccessfully to deploy the ground spoilers and thrust reversers after touchdown. The PIC applied manual wheel braking but perceived that the airplane was not decelerating. He released the brakes, disengaged the antiskid system and reapplied the brakes. “The SIC [second-in-command] reported that he, too, applied the brakes because he felt no deceleration,” the report said. The hard manual braking, with no antiskid protection, caused the tires on the left outboard wheel and both right wheels to burst.

The Challenger overran the runway at about 35 kt and came to stop in sand about 250 ft (76 m) past the departure threshold after the nose landing gear collapsed. The airplane owner had left his seat when he realized that the airplane was not going to stop on the runway; he was moving toward the cabin door when he was thrown against the side of the cabin and sustained serious injuries. Another passenger suffered a minor back injury. The other three passengers, the flight attendant and the two pilots escaped injury.

Examination of the airplane revealed that a spring in an upper brake control valve had failed, causing a loss of braking of the left inboard wheel. In addition, a coupling subassembly had fractured during the landing roll, causing a loss of braking of the left outboard wheel.

The NTSB concluded that the brake component failures and the “PIC’s deactivation of the antiskid system even though there were no antiskid failure annunciations” were the probable causes of the accident. Contributing factors were the “PIC’s improper landing flare” and his unsuccessful attempts to deploy ground spoilers and thrust reversers, which functioned normally during post-accident tests.

“The PIC’s unsuccessful attempts to deploy the ground spoilers and thrust reversers were likely due to errors made while multitasking when presented with an unexpected situation (inadequate deceleration) with little runway remaining,” the report said.

‘State of Panic’

Raytheon Premier I. Destroyed. No injuries.

While descending through 12,000 ft to land at Blackpool (England) Airport the morning of March 12, 2015, the flight crew observed cautionary annunciations of low hydraulic pressure. The hydraulic pressure gauge showed fluctuations but indicated that pressure was 2,800 psi (within the green arc) most of the time, said the report by the U.K. Air Accidents Investigation Branch (AAIB). The low-pressure annunciations illuminated intermittently.

“The copilot then actioned the ‘Hydraulic Pump Failure’ checklist,” the report said. “It stated that if the hydraulic pressure was a minimum of 2,800 psi, the flight could be continued.”

As the crew began the initial approach to Runway 10, which was 6,131 ft (1,869 m) long, they received cautionary messages that the hydraulic speedbrake system, the roll spoiler system and the wheel-braking system had failed. The copilot consulted the associated checklists, which advised in part that, with these systems not functioning, the required landing distance was 4,950 ft (1,509 m), compared with the normal landing distance of 3,000 ft (914 m). The pilots decided to continue the approach.

The report said that the crew did not realize that the aircraft had a total hydraulic system failure, which would require landing distance to be increased to 6,540 ft (1,993 m).

After attempting to extend the landing gear, the crew heard an aural warning indicating that the gear was not down and locked. They initiated a go-around, and the commander asked the copilot to conduct the ‘Alternate Gear Extension’ checklist. “However, a few seconds later, before the copilot could action the checklist, the main gear indicated down and locked,” the report said. “The commander disconnected the autopilot and continued the approach.”

The copilot advised ATC that they had a hydraulic system problem and asked that aircraft rescue and fire fighting services be placed on standby. The aircraft touched down at 132 kt and about 1,500 ft (457 m) from the approach end of the runway. “When the commander applied the toe brakes, he felt no significant retardation,” the report said. “The commander later commented that he was in a ‘state of panic’ during the landing roll and was unsure whether or not he had applied the emergency brake.” Investigators determined that the emergency brakes, which were not affected by the loss of hydraulic pressure, were not applied during the landing roll.

“When an overrun appeared likely, the commander shut down the engines, [and] the copilot transmitted a ‘mayday’ call to ATC,” the report said. “The aircraft subsequently overran the end of the runway at a groundspeed of about 80 kt.” The Premier was “damaged beyond economic repair” as it came to a stop on rough ground, the report said. The pilots and their two passengers were not injured.

Examination of the aircraft revealed that hydraulic fluid had leaked through a fatigue crack in the left hydraulic pump’s port cap (a cover plate on a casing over the suction and pressure ports).

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Turboprops

‘Inappropriate Handling Technique’

Bombardier Q400. Substantial damage. No injuries.

Visibility at the destination — Hubli, India — was 9 km (6 mi) when the Q400 departed from Bangalore with 78 passengers and four crewmembers the morning of March 8, 2015. However, as the aircraft neared Hubli, the flight crew was advised by ATC that visibility had decreased to 3,000 m (about 2 mi) in heavy rain. “Thereafter, the crew decided to hold over Hubli until the weather improved,” said the report by the Aircraft Accident Investigation Bureau of India.

About 20 minutes later, ATC advised the crew that visibility had improved to 4,000 m (2 1/2 mi). The crew requested clearance to descend for a landing on Runway 26. Although they were subsequently cleared to conduct the NDB (nondirectional beacon) approach to that runway, the PIC decided to conduct the VOR (VHF omnidirectional radio) approach, instead. The report noted that the crew was not authorized to conduct the VOR approach in instrument meteorological conditions (IMC).

“The PIC stated that he had established visual reference with the runway at about 6 nm [11 km] from the runway,” the report said. However, the crew experienced a loss of visual cues after the Q400 touched down on the runway. The PIC said that he applied reverse thrust and tried to keep the aircraft on the runway centerline, but investigators found that only the left thrust reverser activated briefly and that there were no rudder inputs.

The aircraft veered left, and the left main landing gear collapsed after striking a runway edge light. The blades on the left propeller separated when they struck the ground, and the nose landing gear collapsed before the aircraft came to stop. There were no injuries.

The report said that the probable cause of the accident was the “loss of visual cues after touchdown” and that a contributing factor was “inappropriate handling technique of the aircraft controls by the PIC.”

Out of Sight, Out of Mind

ATR 72-212A. No damage. No injuries.

After arriving at Manchester (England) Airport the morning of March 4, 2016, the aircraft remained on the ground in snow showers for more than an hour. “The flight crew decided no deicing or anti-icing treatment was needed, as they did not consider the snow was settling on the aircraft,” the AAIB report said.

The ATR subsequently rotated faster than expected on takeoff, and the commander had to apply maximum nose-down pitch trim to maintain the appropriate climb attitude. “The autopilot was engaged four times, but on each occasion it disengaged, as designed, and the commander had to apply continuous forward pressure on the control column to retain the desired pitch attitude,” the report said.

The need for forward control pressure continued after the aircraft entered cruise flight in IMC at 17,000 ft, and the commander decided to divert to East Midlands Airport. “While descending, the aircraft flew out of icing conditions, and the control difficulties dissipated,” the report said. “The crew assessed that ice contamination had caused the problem.” The pilots landed the ATR without further incident, and none of the 27 passengers and four crewmembers was hurt.

“The manufacturer analyzed the FDR [flight data recorder] data and concluded that the aircraft’s abnormal nose-up pitching tendency was consistent with the aerodynamic effects of upper surface icing on the horizontal tailplane,” the report said, noting that the pilots would not have been able to see the ice accumulation during a visual examination of the aircraft.

Deformed by Severe Turbulence

Beech 99A. Substantial damage. No injuries.

The pilot was conducting an instrument landing system approach to Rockland, Maine, U.S., during a charter cargo flight the morning of March 2, 2016, when the airplane encountered continuous light-to-moderate turbulence. “As the airplane descended through about 2,000 feet at an airspeed of 130 knots, it encountered severe turbulence,” the report said. “The pilot subsequently executed a missed approach and chose to divert to an alternate airport.”

The 99 continued to encounter light-to-moderate turbulence en route to the alternate airport in Bangor, Maine, but the pilot was able to land the airplane without further incident. Examination of the airplane revealed deformation of the skin on the wings and fuselage, and substantial damage to the right wing root.

“Although there were multiple AIRMETS [airman’s meteorological information] for widespread moderate turbulence and low-level wind shear, there were no pilot reports of, nor SIGMETS [significant meteorological information], forecasting severe turbulence at the time the pilot received her preflight weather briefing,” the report said.

Overheated Bearing Causes Power Loss

Saab 340. Substantial damage. No injuries.

The aircraft was climbing through 4,300 ft on departure from Dubbo, New South Wales, Australia, on a scheduled flight with 23 passengers and three crewmembers the morning of March 23, 2017, when the flight crew heard several bangs from the right engine and saw several indications of an engine failure. They shut down the right engine, performed the actions on the engine failure checklist and returned to Dubbo, where the Saab was landed without further incident.

Initial examination of the right engine revealed that the no. 4 bearing had failed. “The damage to the failed bearing was consistent with overheating due to a lack of lubrication,” said the report by the Australian Transport Safety Bureau (ATSB). “At the time of the release of this report, the reason for the lack of lubrication to the no. 4 bearing had not been determined.”

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Piston Airplanes

Truck Struck on Final

Piper Chieftain. Minor damage. No injuries.

The Chieftain descended below the intended glidepath on final approach to the airstrip in Barwon Heads, Victoria, Australia, the morning of March 29, 2017, and the pilot retracted the flaps by 10 degrees and then increased power to decrease the descent rate, the ATSB report said.

The pilot then noticed a truck approaching from the left on a road that runs very close to the runway threshold and applied full power to initiate a go-around. “As full power was applied, the aircraft passed over Barwon Heads Road and the left main landing gear impacted the truck,” the report said.

The pilot left the landing gear extended during the go-around and made two passes over the airstrip, during which another pilot on the ground radioed that the landing gear appeared to be intact. “The pilot subsequently landed the aircraft without incident,” the report said.

The truck driver told investigators that he did not see the aircraft before it passed overhead but felt what he thought was its downwash. The driver later realized that contact had been made when impact marks and damage were found on the roof of the truck.

Leaking Cabin Heater Causes Fire

Cessna 310Q. Substantial damage. No injuries.

The pilot said that the flight to Wapokoneta, Ohio, U.S., the morning of March 8, 2014, was uneventful. While parking the 310, he saw a puff of smoke emerge from below the instrument panel. “The pilot immediately shut down the electrical system, but the smoke continued to increase,” the NTSB report said. “He completed the airplane shutdown checklist, then he and the [two] passengers exited the airplane.”

The pilot heard the sound of fire in the nose compartment and saw the exterior paint beginning to discolor. He removed an access panel and doused the flames with a fire extinguisher.

Examination of the 310 revealed cracks in the cabin heater and signs of previous fuel leaks. “Airplane maintenance manuals and manufacturer service bulletins recommended recurring inspections of the heater system and fuel lines, but there was no documentation in the airplane’s maintenance records that the inspections had been completed,” the report said.

Loose Nut Prevents Gear Extension

Beech 58P Baron. Substantial damage. No injuries.

The landing gear warning horn sounded during approach to Rand (South Africa) Aerodrome the afternoon of March 21, 2016, and the pilot performed a go-around. An airport tower controller advised him that the nose landing gear appeared to be only partially extended.

“The pilot, with the help of a passenger, tried several times to extend the landing gear by means of the manual gear extension [system], but without success,” said the report by the South African Civil Aviation Authority. “He eventually ran out of options and proceeded to land the aircraft.”

The nose landing gear, as well as the main landing gear, collapsed on touchdown, and the Baron skidded about 80 m (262 ft) before stopping on the runway. Damage was substantial, but the pilot and his three passengers escaped injury.

Examination of the aircraft revealed that a nut was missing from the forward link retracting rod, resulting in the rod’s disconnection from the nose gear assembly. “The investigation concluded that the nut was not secured with a split pin [and] worked its way out of the joint due to in-flight vibration forces,” the report said.

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Helicopters

Tail Rotor Pitch Control Fails

Airbus AS365-N3 Dauphin. Destroyed. Two fatalities, three serious injuries.

The helicopter had departed from Taipei, Taiwan, with two pilots and a crew chief the afternoon of March 11, 2016, to transport two coast guard members to a cargo ship that had run aground at Shimen. After arriving at the ship, the helicopter started yawing left as the crew chief began to hoist one of the passengers to the deck, said the report by the Aviation Safety Council of Taiwan.

The pilot called out “mission abort, mission abort” shortly before the Dauphin entered a rapid left spin. The passenger in the hoist was killed on impact with the main rotor; the pilot was killed, and the other passenger, the crew chief and the copilot were seriously injured when the helicopter struck the sea.

Investigators found that a tail rotor control rod bearing had failed, causing a loss of tail rotor control.

Loose Cowling Strikes Rotor

Kaman K-1200. Substantial damage. No injuries.

After transporting a crew chief to Julian, California, U.S., the afternoon of March 12, 2017, the pilot opened the engine cowling to allow the engine to cool before restarting it. However, he did not perform a walk-around inspection of the helicopter before the subsequent departure.

“About 60 seconds after departure, he felt a large thump throughout the airframe and landed as soon as practicable,” the NTSB report said. “Upon shutdown and inspection, he noticed that the engine cowling had departed the helicopter and struck the right two main rotor blades and the vertical stabilizer.”

After the accident, the company issued a policy forbidding the opening of a cowling for the sole purpose of cooling the engine and requiring pre-takeoff inspections by qualified technicians.

Pilotless R22 Takes Flight

Robinson R22. Substantial damage. No injuries.

The helicopter had been parked outside with the doors fastened for 12 days in high heat and humidity at Richmond, Queensland, Australia. As the pilot prepared for a positioning flight the afternoon of March 21, 2016, he found that the adhesive holding the throttle twist grip to the collective had deteriorated. “The pilot then slid the cover forwards on the collective control to grip the steel column,” the ATSB report said.

After starting the engine, the pilot was told by the driver who had transported him to the airport that his drink bottle was still in the vehicle. They agreed to rendezvous at the airport perimeter fence.

The pilot flew to the appointed location, looped a bungee cord over the collective to keep it in place and exited the helicopter with the engine running. Soon after walking to the fence to retrieve the drink bottle, he heard engine speed increase. He “turned and ran back towards the helicopter,” the report said. “The pilot and driver then observed the helicopter rotate away from the direction of the pilot, lift up, [fly] into and over the fence, and land on its side on the other side of the fence.”

The pilot told investigators that the bungee cord apparently had slipped on the exposed steel, allowing the collective to rise and the R22 to lift off. “The pilot reported that they had not had any issues with the adhesive before, despite operating in temperatures over 40 degrees C [104 degrees F], but they did not usually have the doors on [while the helicopter was parked outside],” the report said.

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