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.
Jets
Unfamiliar With Airport
Boeing 737-900. No damage. No injuries.
Inbound from Incheon, Korea, with 106 passengers and eight other crewmembers the evening of Aug. 5, 2013, the captain decided to allow the 737, which was carrying extra fuel and was near its maximum landing weight, to roll to the end of the runway after landing at Japan’s Niigata Airport.
Night visual meteorological conditions (VMC) prevailed, with surface winds from 050 degrees at 5 kt, as the flight crew conducted a nonprecision instrument approach to Niigata’s Runway 10, which was 2,500 m (8,202 ft) long and 45 m (148 ft) wide, according to the report by the Japan Transport Safety Board (JTSB). The report said that the pilots were not familiar with Niigata Airport.
While briefing the first officer on the landing, the captain mentioned a notice to airmen indicating that the centerline lights on Runway 10 were partially out of service.
The 737 touched down slightly below the reference landing speed of 146 kt and about 600 m (1,969 ft) from the approach end of Runway 10. The aircraft was decelerating through 80 kt and the crew was retracting the spoilers and disengaging the thrust reversers when the airport tower controller told them to “turn right end of runway … and taxi to spot … cross runway zero four two two.” Runway 04/22 intersects Runway 10 about 400 m (1,312 ft) from the departure threshold.
Neither pilot understood the intent of the controller’s instruction and presumed that it was a clearance to cross the intersecting runway during their landing roll, the report said. The first officer read back the clearance as “cross runway four two two, end of runway right turn.” His confusion was evident when he commented to the captain, “Cross runway?”
However, the pilots did not request clarification, and the first officer’s out-of-sequence readback did not alert the controller to the crew’s confusion over the combined runway-exit and taxi instructions, the report said. It noted that controllers should “refrain from issuing more than one clearance at a time.”
Although the aircraft already had passed Runway 04/22 when the controller issued the instructions, the pilots believed that they had not yet reached the intersection. The captain saw the red lights marking the end of Runway 10 but momentarily mistook them for the stop bar lights for Runway 04/22.
The aircraft was rolling at about 56 kt when the captain realized there was no more runway beyond the red lights and applied maximum wheel braking. The 737 came to a stop with the nose landing gear on the grass off the departure end of the runway. The incident resulted in no injuries or aircraft damage, but it was classified as a serious incident by the JTSB.
‘Violent’ Evacuation
Airbus A330-343. Minor damage. Two serious injuries.
About 20 minutes after departing from London for a flight to the United States the morning of April 16, 2012, the flight crew received two brief master warnings for smoke in the aft cargo compartment.
Another warning was generated while the commander was communicating by radio with company engineers. The commander then told the copilot to declare an urgency and to inform air traffic control (ATC) that they were returning to London Gatwick Airport.
“The crew carried out the actions displayed on the ECAM [electronic centralized aircraft monitor] display … which involved discharging fire extinguishing agent into the aft cargo hold,” said the U.K. Air Accidents Investigation Branch (AAIB) report. “Eighteen seconds after discharge, the smoke warning activated again.”
The commander briefed the flight service manager that he would order an evacuation if airport traffic controllers saw signs of smoke after landing. During approach, he told the tower controller that he would stop the aircraft on the runway to allow rescue and fire fighting service (RFFS) personnel to examine it.
The A330 had no means to jettison fuel, and the crew conducted the landing according to the “Overweight Landing” checklist. No damage resulted from the overweight landing, but the tires and brakes later were replaced as a precaution.
After the aircraft came to a stop, the tower controller told the crew that “there may just be a little bit of smoke at the bottom of the left-hand engine.” RFFS personnel said that they did not see any smoke but noted that smoke might be dissipating in the engine exhaust.
During this time, a smoke warning again was generated on the flight deck. The commander declared an emergency and ordered an evacuation. The report noted that several fuselage skin panels were dented or punctured when the evacuation slides were deployed.
All 304 passengers exited on slides within 90 seconds. However, two passengers sustained serious injuries during the evacuation. One cabin crewmember told investigators that “the slide experience was very fast and painful”; another described the evacuation as “more violent than in training.”
“Many passengers were seen to land awkwardly at the bottom of the slide, and one lady was observed to fall onto the tarmac, after which passengers following behind collided into her,” the report said.
Examination of the A330 revealed no signs of smoke or fire in the aft cargo compartment. Investigators determined that the spurious smoke warnings had been caused by a latent fault in a smoke detector’s thermistor channel and a fault in a “controller area network” electrical bus combined with “high levels of humidity in the cargo compartment due to the carriage of perishable goods,” the report said.
Anti-Skid System Fails
Embraer Phenom. Minor damage. No injuries.
The pilot told investigators that he had experienced no problems during the positioning flight until after touching down at the airport in Meridian, Mississippi, U.S., the afternoon of April 5, 2013.
“Immediately upon brake application, the airplane began sliding in a manner that the pilot said was similar to hydroplaning even though … the runway was dry,” said the report by the U.S. National Transportation Safety Board (NTSB). The Phenom slid about 2,800 ft (853 m) before coming to a stop with both tires on the main landing gear deflated.
Examination of the airplane revealed that the anti-skid braking system had failed, resulting in the main wheels locking on landing. The report noted that an “ANTI-SKID FAIL” message had been displayed in the cockpit just before touchdown.
GPU Still Connected
Learjet 35A. Minor damage. One serious injury.
A ground power unit (GPU) was used to start the Learjet’s engines in preparation for a medical transport flight from Fort Lauderdale, Florida, U.S., the night of Feb. 2, 2014. “After completing the engine start, the copilot gave the ‘disconnect ground power’ hand signal to the lineman,” the NTSB report said. “The lineman responded with the ‘hold’ signal and then moved to the left and rear of the airplane to disconnect the GPU.”
The pilot observed a drop in voltage — one sign that the GPU had been disconnected — but asked the two medical crewmembers in the cabin if they saw the lineman. One crewmember said that the lineman was standing next to the GPU.
The pilot began to taxi the Learjet, pulling the GPU, which was still connected, onto its side, striking the lineman’s right leg.
“The pilot should have ensured that the GPU was disconnected from the airplane via hand signals from the lineman … before taxiing the airplane,” the report said. “His failure to do so resulted in the lineman’s injury.”
Turboprops
Stall on Circling Approach
Rockwell 690B. Destroyed. Four fatalities.
Inbound from Teterboro, New Jersey, U.S., the morning of Aug. 9, 2013, the pilot acknowledged an ATC advisory to expect the instrument landing system (ILS) approach to Runway 02 at Tweed-New Haven (Connecticut) Airport and to circle to land on Runway 20.
The surface winds at the airport were reported from 170 degrees at 12 kt, gusting to 19 kt, visibility was 9 mi (14 km) in light rain, and the ceiling was overcast at 900 ft, variable between 600 ft and 1,100 ft.
The controller later told investigators that the Commander was “skimming” the cloud bases on downwind, and he asked the pilot if he would be able to maintain visual contact with the airport. The pilot replied “affirmative,” and the controller cleared him to land.
“The controller then lost visual contact with the airplane, and about two to three seconds later it reappeared nose-down, rotating counter-clockwise and descending from the clouds to the ground,” the report said. The Commander struck two houses in East Haven, killing two people on the ground as well as the pilot and his passenger.
Recorded ATC radar data indicated that the airplane had been flown at 100 kt, at or below the minimum descent altitude of 720 ft and close to the runway on downwind. Investigators concluded that the Commander likely stalled and entered an uncontrolled descent when the pilot initiated a steep turn toward the runway.
Wrong Frequency
Bombardier Q400, Robinson R22. No damage. No injuries.
Inbound from the south with 36 passengers and four crewmembers the afternoon of April 18, 2013, the Q400 pilot decided to conduct a straight-in landing on Runway 30 at the airport in Cloncurry, Queensland, Australia, due to the prevailing winds.
Operations usually were conducted on Runway 12 at Cloncurry, but the airport was reporting winds from 210 degrees, resulting in a direct crosswind for either runway, said the report by the Australian Transport Safety Bureau.
The pilot told investigators that the crew made several broadcasts on the airport’s common traffic advisory frequency (CTAF) on approach and that neither he nor the copilot heard any transmissions on the very-high frequency (VHF) CTAF from other pilots.
The R22 pilot said that he attempted to broadcast his intention to depart from a hangar south of the runway for a northbound departure but did not realize that his radio was set to receive VHF transmissions and to transmit on ultra-high frequencies (UHF). Thus, the Q400 crew did not hear his UHF transmission; and, due to the helicopter’s proximity to the hangar, the R22 pilot did not hear the VHF transmissions from the airplane.
As the R22 crossed the runway at 100 ft, the pilot heard a transmission from the Q400 crew, advising that they were about to touch down on Runway 30 and that the helicopter should “get off the runway.”
The Q400 pilot told investigators that he had seen the helicopter nearing the runway about 1,000 m (3,281 ft) ahead but decided that it would be safer to continue the landing than to go around. The Q400 passed about 200 m (656 ft) from the helicopter during the landing roll.
Excursion on a Slippery Runway
De Havilland Twin Otter. Substantial damage. No injuries.
The pilot was conducting his first flight in two years to Apalapsili Aerodrome in the Papua province of Indonesia the afternoon of Feb. 5, 2013. The Twin Otter had been chartered to deliver cargo from Jayapura to Apalapsili.
The weather at the airport was clear, but rain the previous night had left the turf runway soft and slippery, said the report by the Indonesian National Transportation Safety Committee.
The flight crew conducted a visual approach to Runway 15, apparently with a right crosswind. During final approach, the pilot perceived that the Twin Otter was aligned with the runway centerline, but the copilot told him that he thought the aircraft was slightly left of the centerline.
The report said that the Twin Otter was in a right crab (i.e., the nose was pointed right of the runway centerline) when it touched down. The aircraft then began to skid and veer toward the left side of the slippery runway.
“The pilot pushed the right rudder pedal [and] brake, and engaged the right engine reverse [thrust] followed by nose wheel steering to the right in order to recover the aircraft to the centre of the runway,” the report said. It noted that these actions only worsened the skid.
The Twin Otter departed the left side of the runway and struck a drainage ditch. Aircraft damage was substantial, but the pilot, copilot and engineer were not injured.
Piston Airplanes
Engines Fail on Ferry Flight
Piper Chieftain. Destroyed. No injuries.
A flight crew was hired to ferry the Chieftain from the United States to Thailand, but they abandoned the aircraft in Sondrstrom, Greenland, late in December 2013 because of low oil pressure indications for both engines. “This may have been due to the use of an incorrect grade of oil [W100] for cold weather operations,” the AAIB report said.
The aircraft remained in Sondrstrom until late February 2014, when another pilot was engaged to complete the ferry flight. Although a supply of multigrade oil more suitable to extremely cold temperatures had been shipped in, the pilot told investigators that he did not have the oil changed because of the lack of maintenance facilities in Sondrstrom.
The pilot flew the Chieftain to Narsarsuaq, Greenland, without incident. However, on the next leg — to Wick, Scotland, on March 3 — the right engine began running roughly. A technician found low compression in the no. 4 cylinder and replaced the cylinder and related components (seals, gaskets, etc.).
The work was completed in late March, and the pilot resumed the ferry flight on April 9. However, 25 minutes after departing from Wick for a flight to France, the right engine lost power. Restart procedures were unsuccessful, and the pilot diverted toward Aberdeen.
However, the left engine also lost power, and the pilot made an emergency landing on a plowed field. The Chieftain was destroyed, but the pilot escaped injury.
Investigators found that pistons in both engines had been damaged from “blow-by” gases that had escaped from the combustion chambers. “Ultimately, it was not possible to establish why pistons in both engines had suffered virtually identical types of damage, although it is likely to have been a ‘common mode’ failure, which could include wrong fuel, incorrect mixture settings (running too lean) and existing damage arising from the use of incorrect oil in cold temperatures,” the report said.
Incapacitation Suspected
Cessna 421C. Destroyed. One fatality.
The 421 was cruising in VMC at Flight Level 270 (approximately 27,000 ft) during a flight from Slidell, Louisiana, U.S., to Sarasota, Florida, the morning of April 29, 2012, when it began to deviate from its assigned altitude and route.
ATC was unable to hail the pilot, and the North American Aerospace Defense Command launched fighters to intercept the 421.
“The military pilots reported that the airplane was circling in a left turn at a high altitude and a low airspeed, and that its windows were partially frosted over,” the NTSB report said. “They also reported that the pilot was slumped over in the cockpit and not moving. They fired flares, and the pilot continued to be unresponsive.”
The 421 circled for about 3 hours before it descended into the Gulf of Mexico and sank. The airplane and the pilot have not been recovered.
Although the 65-year-old pilot’s medical records revealed no conditions that would have rendered him unfit to fly, the NTSB concluded that pilot incapacitation was the probable cause of the accident.
Helicopters
Pitch Link Separates
Robinson R44. Destroyed. Two fatalities.
The pilot, who also owned a commercial helicopter operation, departed with a mechanic from Kendall–Tamiami (Florida, U.S.) Executive Airport the afternoon of April 3, 2013, to conduct a post-maintenance test flight following replacement of the main rotor blades and adjustment of the pitch change rods.
“Multiple witnesses reported hearing a loud ‘pop’ noise and seeing parts separate from the helicopter,” the NTSB report said. “Witness statements and wreckage documentation were consistent with a main rotor blade rotating upward during the accident, which was followed by a tail strike and the helicopter rolling inverted.” The R44 then crashed in a parking lot.
The NTSB concluded that the probable cause of the accident was “the mechanic’s failure to properly secure the pitch link hardware of one main rotor blade to the rotating swash plate, which resulted in the pitch link separating in flight and the pilot’s subsequent loss of control.”
“Contributing to the accident was the pilot’s/owner’s pressure on the mechanic to return the helicopter to revenue service,” the report said. Witnesses told investigators that the pilot had been upset and had expressed frustration that the manufacturer had installed refurbished spindles on the new rotor blades.
“The owner’s frustration likely distracted the mechanic and/or applied pressure for the mechanic to return the helicopter to service and revenue operations as soon as possible,” the report said.
Tossed by a Thunderstorm
Bell 206B. Substantial damage. Two minor injuries.
VMC prevailed for the aerial surveillance flight, but the pilot was aware of thunderstorm activity close to the airport while returning to Amarillo, Texas, U.S., the afternoon of April 26, 2012.
The pilot told investigators that he conducted a “straight in” approach to the JetRanger’s hangar. “The helicopter was about level with the hangar roof when, according to the pilot, a strong gust of wind forced the helicopter’s nose up, and the helicopter briefly entered into a climbing right turn,” the report said.
The JetRanger then began to spin right. “The pilot reported that left pedal had no effect and that he had only partial control as the helicopter made a full 360-degree turn, descended and impacted the ground,” the report said. “During the impact, the lower fuselage sustained crushing damage and the main rotor separated from the main rotor mast.”
The report said that the probable cause of the accident was “the pilot’s failure to maintain helicopter control during landing in gusty wind conditions associated with a thunderstorm, which resulted in a loss of tail rotor effectiveness.”