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.
Late Go-Around Cited
Airbus A320, Bombardier Learjet 60. No damage. No injuries.
The absence of air traffic control (ATC) procedures ensuring separation between aircraft going around from one runway and entering the flight path of aircraft departing from a different runway contributed to an incident that placed the A320 and the Learjet in “hazardous proximity” at Las Vegas McCarran International Airport in Nevada, said the U.S. National Transportation Safety Board (NTSB).
“The closest proximity of the two aircraft was approximately 0.3 nm [0.6 km] laterally and 100 ft [30 m] vertically,” said the NTSB’s final report on the near midair collision, which occurred at 1225 local time on April 26, 2012.
The A320 was inbound to Las Vegas on a scheduled passenger flight from Boston, Massachusetts, and the Learjet, of Mexican registration, was departing from McCarran. The report did not specify the Learjet’s destination or how many people were aboard either of the two aircraft.
Day visual meteorological conditions (VMC) prevailed, with winds from the south at 19 kt, gusting to 26 kt. McCarran has two sets of parallel runways. Aircraft operations on Runways 25L and 25R, located on the south side of the airport, were being coordinated by a controller at the “local control 1” (LC1) position; operations on Runways 19L and 19R, on the west side of the field, were being coordinated by a different controller at the “local control 2” (LC2) position.
The A320 crew was conducting a visual approach to Runway 25L and had been cleared to land by the LC1 controller. Shortly thereafter, the Learjet crew was cleared for takeoff from Runway 19L by the LC2 controller.
The departure thresholds of the runways are about 1,600 ft (488 m) apart. “The two runways do not physically intersect,” the report said. “However, the flight paths of the runways intersect approximately 0.32 nautical miles [0.59 km] past the departure end of Runway 19L.” Runway 25L is 10,526 ft (3,208 m) long, and Runway 19L is 9,775 ft (2,979 m) long.
The A320 was about one-third of the way down Runway 25L when the crew reported that they were going around. The LC1 controller acknowledged, saying in part: “Roger, on the go, and traffic will be at your two o’clock and one mile, a Learjet.” The controller also shouted “go around,” a normal practice to alert the other controllers on duty in the tower cab that a go-around was in progress.
The Learjet was on initial climb about halfway down Runway 19L when the LC2 controller, alerted by the LC1 controller’s announcement of the go-around, advised the crew that there was “traffic, an Airbus, ahead and to your left.” The LC2 controller also said, “You have him in sight? Go low.”
The Learjet crew replied that they had the Airbus in sight but did not acknowledge the instruction to “go low.” This radio transmission included the background sound of the airplane’s stick shaker (stall-warning system), indicating that the airplane was at a high angle-of-attack. Recorded radar data confirmed that the airplane was in a rapid climb. The LC2 controller again told the Learjet crew to “go low” and to “maintain visual separation.” The crew did not acknowledge the instructions.
The LC1 controller then advised the A320 crew that the Learjet was “immediately off your right. He is climbing as rapidly as he … actually, I don’t know what he’s going to do for the climb, but it looks like he’s coming right at, turning to your right.” At this time, the Airbus was still over Runway 25L, heading west, and the Learjet was nearing the departure threshold of Runway 19L, heading south.
The A320 was nearing the departure threshold of Runway 25L when the crew asked the LC1 controller if she wanted them to turn left. The controller replied, “Turn left now. Turn left.” She then assigned a heading of 180 degrees. The Airbus was in the turn a few seconds later when the controller asked the crew if they had the Learjet in sight. The crew replied that they had the Learjet in sight and were told to maintain visual separation with the airplane.
As the A320 completed the turn to 180 degrees, it briefly flew parallel to the Learjet, which was on a heading of about 190 degrees. The airplanes came to their closest proximity at this time. “There was no damage reported to either aircraft, or any injuries to passengers or crew,” the report said.
The LC1 controller issued vectors to the A320 crew for another approach, and she asked them why they had initiated the go-around: “Was that for, ah, wake turbulence or for, ah, wind shear?” The crew replied “affirmative” and said that they had encountered “a good gust.”
During post-incident interviews by investigators, several controllers said that there had been similar conflicts in the hot spot between the runways but that the conflict between the A320 and the Learjet was the closest they could recall. They said that it likely was due in part to the “late” go-around by the Airbus crew; most pilots, they said, initiate a go-around before reaching a runway’s approach threshold.
The controllers said that they had resolved previous conflicts by alerting the pilots, issuing headings when necessary and instructing the pilots to maintain visual separation after they had confirmed that the traffic was in sight. One controller said that “after a go-around, controllers really don’t have any form of separation and that the important thing was to just get the aircraft to see each other.”
“Another ‘out’ [separation tool used by the controllers] was to instruct aircraft to ‘go low’ or ‘go high,’ but this was only done during a ‘t-bone’ (crossing conflict) situation,” the report said. One controller told investigators that the Learjet crew apparently had not understood their instruction to “go low” and had initiated a maximum-performance climb after seeing the Airbus.
The controllers described the incident as a “fluke” and as the result of a “perfect storm” of contributing factors. Several said they believed that awareness, discussion and training had prepared them to handle similar situations.
Nevertheless, NTSB concluded that the probable cause of the incident was “Federal Aviation Administration procedures that do not ensure separation in the event of a go-around during simultaneous independent runway operations on runways that do not physically intersect but whose flight paths intersect.”
Boeing 737-700. No damage. One serious injury, one minor injury.
The 737 was about 20 nm (37 km) northwest of Bob Hope Airport in Burbank, California, U.S., and was descending in VMC to land at the airport the afternoon of Feb. 13, 2010. The approach controller told the flight crew to fly a heading of 190 degrees and to descend to 6,000 ft.
“The captain [the pilot flying] stated that he set a 190-degree heading in the heading window and selected 6,000 feet in the altitude window of the airplane’s mode control panel (MCP), used to set autopilot functions,” the NTSB report said. The captain said that these actions were confirmed by the first officer.
The approach controller then advised the crew of traffic at their 11 o’clock position and about 4 nm (7 km) away. “The captain said that the flight crew began scanning for the traffic and received a traffic [alert and] collision avoidance system (TCAS) traffic advisory (TA), which identified that the traffic was about 500 feet below their airplane’s altitude,” the report said. “The captain stated that he began to shallow the airplane’s rate of descent … to avoid the traffic.”
The 737, meanwhile, had deviated about 27 degrees from the assigned heading. The controller told the crew to check their heading. “The captain said that he noticed that he had inadvertently allowed the airplane to turn to a 163-degree heading and immediately initiated a turn back to the assigned heading of 190 degrees,” the report said. “During the turn, the crew received a TCAS resolution advisory (RA) to descend at 1,500 to 2,000 feet per minute (fpm), followed by a command to climb at 2,000 fpm.”
The report said that the captain’s responses to the RAs, a 2,000-fpm descent followed by a 2,000-fpm climb, were abrupt. All 80 passengers were seated with their seat belts fastened, but the three flight attendants were standing in the aft galley, completing their preparations to land. One flight attendant suffered a broken scapula (shoulder blade). Another flight attendant sustained unspecified minor injuries, and the third flight attendant was not hurt.
The captain told investigators that while responding to the climb RA, the first officer and he saw an aircraft about 2 nm (4 km) ahead and slightly higher, and he made a shallow right turn to avoid the traffic.
Glide Path Distraction
Boeing 737-800. No damage. No injuries.
During the flight from Shannon, Ireland, with 125 passengers and six crewmembers the afternoon of Feb. 7, 2012, the flight crew briefed for the instrument landing system (ILS) approach to Runway 08R at London Gatwick Airport. Later, however, ATC told the crew that the ILS approach was not available and that they would receive radar vectors for a visual approach, according to the report by the U.K. Air Accidents Investigation Branch (AAIB).
VMC prevailed at Gatwick, with visibility limited by haze. The crew conducted the descent with the 737’s autopilot and autothrottle in the “LVL CHG” (level change) mode, in which engine thrust remains at idle while the pitch attitude is adjusted to maintain the selected airspeed. They also programmed the flight management system for a 3-degree final glide path to the runway.
ATC subsequently asked the crew if they could accept an early turn onto the final approach course, and the crew replied that they could. As a result, the aircraft was turned onto the final approach course at a higher altitude than the crew had anticipated. “The pilots used a combination of flap and speed brake to increase the rate of descent” to capture the 3-degree glide path from above,” the report said, noting that this distracted the pilots and added to their workload.
The 737 was descending at 1,500 fpm when it reached the programmed final glide path. Although the pilots noticed indications of this, they neglected to change from the “LVL CHG” mode to the “VNAV” (vertical navigation) mode, which would have caused the autopilot to capture the 3-degree glide path.
“The aircraft continued to descend through the glide path until, at approximately 1,000 ft, the EGPWS [enhanced ground-proximity warning system] generated a terrain caution and the pilots saw the PAPIs [precision approach path indicators],” the report said. The pilots later said that the haze prevented them from seeing the PAPI lights sooner.
“ATC informed them that the aircraft appeared slightly low and asked them if they were ‘visual,’” the report said. “The PF [pilot flying] disconnected the autothrottle and autopilot, reduced the rate of descent and, after re-establishing the correct approach angle, continued the approach. The aircraft landed without further incident.”
Unresolved Brake Warning
Embraer Phenom 100. Minor damage. No injuries.
After starting one engine in preparation to depart from Tucson, Arizona, U.S., the morning of Sept. 10, 2010, the pilots saw a crew alerting system (CAS) warning of a brake failure. They attempted unsuccessfully to reset the system and decided to continue with their planned flight to Brenham, Texas, the NTSB report said.
The CAS message stayed on throughout the flight. The pilot conducted the global positioning system (GPS) approach to Brenham’s Runway 16 and then transferred control to the copilot for the landing on the 6,003-ft (1,830-m) runway.
“After touchdown, the copilot … discovered that the brakes did not work, and the airplane began skidding when he pulled the emergency parking brake handle,” the report said. “The airplane was moving about 50 to 60 kt when both tires blew.”
The airplane veered about 120 degrees left, skidded off the left side of the runway and came to a stop after the right main landing gear collapsed in soft ground. The pilots, alone in the airplane, were not injured.
“A post-accident examination of the brake control unit (BCU) revealed a fault on the printed circuit board that led to an open circuit for a component installed on the board,” the report said. “The open circuit caused the failure of the BCU and the loss of normal braking.”
Collision With a Tug
Airbus A300-B4. Substantial damage. No injuries.
The scheduled cargo flight from East Midlands Airport in Derby, England, to Paris, the afternoon of April 14, 2012, also was to serve as a training flight. The captain-in-training was to fly the A300 from the left seat, under the supervision of the training captain/commander in the right seat, the AAIB report said.
After receiving ATC clearance to start the engines, the PF used the flight interphone to advise the ground crew headset operator that the aircraft was ready to be pushed back from the stand. During the pushback, the flight crew started the no. 2 engine.
When the headset operator advised the flight crew that the pushback was complete, the PF engaged the aircraft’s parking brake. “The headset operator then stood by while the no. 1 engine was started,” the report said. “When both engines were running, the PF told the headset operator to disconnect the tug and that he would look for his hand signals on the left side of the aircraft.”
The headset operator was unable to remove the pin securing the tow bar to the tug and asked the tug driver for assistance. “Between them, they withdrew the pin and disconnected the tow bar from the tug,” the report said. “The headset operator then disconnected the tow bar from the aircraft, turned his back on the aircraft and started to push the tow bar to an area forward of the aircraft, to reconnect it to the rear of the tug. At the same time, the tug driver reversed the tug away from the aircraft before driving forward to pick up the tow bar.”
Meanwhile, the flight crew completed the “After Start” checklist, and the PF asked the commander to request taxi clearance from ATC. After taxi clearance was received, the PF illuminated the taxi light and, without receiving the appropriate hand signal from the ground crew, increased thrust to begin taxiing. “It is likely that the tug and ground crew were not visible to the pilots when the aircraft started to taxi,” the report said.
The headset operator said that he felt the aircraft looming above him. He pushed the tow bar clear of the A300’s nosewheels and watched the aircraft pass in front of him. The tug driver saw the aircraft moving and attempted unsuccessfully to drive clear. The aircraft struck the left rear side of the tug and pushed it a short distance before coming to a stop.
The collision caused substantial damage to the A300’s nose landing gear and minor damage to the tug, but none of the flight crewmembers or ground crew was hurt.
Power Lever Jams
Piaggio P180 Avanti. Substantial damage. Four minor injuries.
The Avanti was climbing through 22,000 ft during a fractional ownership flight from Detroit, Michigan, U.S., to West Bend, Wisconsin, the morning of Nov. 16, 2011, when the flight crew noticed that the torque indication for the left engine had decreased to 94 percent. When the captain attempted to move the power lever forward, he felt mechanical resistance. The first officer commented, “That’s what it was doing the other day, too.”
The captain applied additional pressure to the power lever and heard a pop as the lever moved full forward, the NTSB report said. The lever jammed in this position, causing engine torque and temperature to exceed limits.
The pilots shut down the left engine, declared an emergency and diverted the flight to Bishop International Airport in Flint, Michigan. “After the engine shutdown, both primary flight displays went blank,” the report said. “The captain reset the right generator, and the flight displays regained power.” However, the displayed heading information was erroneous because the gyros had been reset. The report said that the crew did not check the headings against the magnetic compass.
VMC prevailed at the Flint airport, with surface winds from 290 degrees at 18 kt. The pilots were cleared by ATC to land on Runway 27 but became confused about their heading and location while circling to land. The airport traffic controller then cleared the crew to land on any runway. The first officer replied, “We’re taking this one here. We’re turning base to final.”
The Avanti touched down long on Runway 18, which is 7,848 ft (2,392 m) long. “At the point of touchdown, there was about 5,000 feet [1,524 m] of runway remaining for the landing roll,” the report said.
The captain applied reverse thrust from the right engine, and the airplane began turning right. He then reduced reverse thrust and applied full left rudder and left brake, but the airplane veered off the right side of the runway and flipped inverted. The pilots and the two passengers sustained minor injuries.
“Examination of the left engine revealed that the Beta clevis pin was installed in reverse [during maintenance], which caused an interference with a fuel control unit interconnect rod,” the report said. “Due to the interference, the power lever control linkage was jammed in the full-forward position.”
Control Lost During EMS Flight
Pilatus PC-12/45. Destroyed. Ten fatalities.
Two physicians and a nurse were aboard the PC-12 when the flight crew landed the emergency medical services aircraft in Patna, India, the night of May 25, 2011. After a critically ill patient and an attendant were boarded, the aircraft departed from Patna for the return trip to Delhi.
“Weather in Delhi started deteriorating as the flight came close to Delhi,” said the report by the Committee of Inquiry formed by the Indian Directorate General of Civil Aviation. “Widespread thunderstorm activity was seen north-northeast of the Delhi airport [and] moving south.”
The PC-12 was nearing the airport and descending through 12,500 ft when ATC radar showed abrupt and rapid altitude changes to 14,100 ft, 13,100 ft and 14,600 ft before groundspeed decreased substantially; the aircraft then entered a steep right turn and descended at rates nearing 11,600 fpm. During this time, ATC received two weak radio transmissions from the crew, both indicating that the aircraft was “into bad weather.” Radar contact was lost at 1,600 ft, and attempts to hail the crew by radio were unsuccessful.
The aircraft had struck a house in a residential area of Faridabad, about 15 nm (28 km) from the airport. All seven people aboard the aircraft were killed, as were three people in the house.
The PC-12 was destroyed by the impact and a subsequent fire. Examination of the wreckage revealed that the aircraft was intact before it struck the house, and there was no sign of mechanical failure.
“It is probable that a series of up- and downdrafts, turbulence (moderate to heavy) and the dark night conditions [had] caused the crew to become disoriented,” the report said. “The subsequent mishandling of [flight] controls caused the aircraft to [stall and] enter a spin.”
Gear Lubrication Neglected
Beech 99. Substantial damage. No injuries.
After dropping parachutists near Cedartown, Georgia, U.S., the morning of April 10, 2011, the pilot turned back toward the airport. He attempted to extend the landing gear, but the down-and-locked annunciator light for the left main landing gear did not illuminate.
“The pilot confirmed that he had an unsafe gear indication on the left main landing gear,” the NTSB report said. “He then actuated the test switch, and all three lamps illuminated, demonstrating that he did not have a burned-out indicating lamp.”
The pilot cycled the gear, but the problem persisted. He said that while subsequently using the backup manual gear-extension system, “the pressure required to pump the gear down became greater and greater until something gave way,” and the annunciator for light the left main gear did not illuminate.
“The pilot completed the landing on the nose and right main landing gear, which resulted in substantial damage to the left wing and fuselage,” the report said.
Examination of the left main landing gear revealed that the supports for the actuator bearings lacked adequate lubrication and were worn. Investigators were unable to determine whether the actuator had not been lubricated properly during installation 31 months earlier or subsequent inspections did not detect a loss of lubrication.
Engine Fails on Takeoff
Beech E18S. Destroyed. One fatality.
Shortly after taking off from Runway 09L at Opa-Locka (Florida, U.S.) Executive Airport for a cargo flight to the Bahamas the morning of May 2, 2011, the pilot told ATC that he was turning downwind, rather than departing to the east, as planned.
“According to witnesses, the airplane did not sound like it was developing full power,” the NTSB report said. “The airplane climbed about 100 feet, banked to the left, began losing altitude and impacted a tree, a fence and two vehicles before coming to rest in a residential area.” The pilot, alone in the airplane, was killed, but no one on the ground was hurt.
Investigators found that the pilot “had been having problems with the no. 2 [right] engine for months [but] continued to fly the airplane,” the report said, noting that the Twin Beech had been parked outside in a moist environment.
Examination of the right engine revealed several discrepancies that would have caused “erratic and unreliable operation,” including internal corrosion preventing both magnetos and the fuel pump from functioning properly, and low compression in four of the nine cylinders.
The report also said that the engine likely had lost power on takeoff and that “there was no evidence that the pilot attempted to perform the manufacturer’s published single-engine procedure, which would have allowed him to maintain altitude. Contrary to the procedure, the left and right throttle control levers were in the full-throttle position, the mixture control levers were in the full-rich position, neither propeller was feathered, and the landing gear was down.”
Parking Brake Overlooked
De Havilland DHC-2 Beaver. Substantial damage. No injuries.
After landing the single-engine airplane at a base camp on the Tahiltna Glacier in Alaska, U.S., on May 22, 2012, the pilot raised the landing skis, placing the Beaver on its wheels, and set the parking brake to prevent the airplane from sliding.
Later, while preparing to depart from the base camp, the pilot lowered the skis but forgot to release the parking brake, the NTSB report said.
The parking brake was still set when the pilot conducted a wheel landing on a hard-surfaced runway in Talkeetna. The Beaver came to an abrupt stop and pitched nose-down; the horizontal stabilizer was substantially damaged when it fell back onto the runway. The pilot and four passengers were not hurt.
Control Lost During Search
MD Helicopters MD902. Destroyed. Three serious injuries.
The pilot, flight engineer and forward-looking infrared radar (FLIR) operator aboard the state police helicopter were searching for a missing person near Engelsbrand, Germany, in night VMC on May 10, 2011. The helicopter was circling about 600 ft above a hill when the radar operator announced that the FLIR was showing an unidentified heat source.
The pilot and flight engineer donned night vision goggles (NVGs). The pilot then maneuvered the MD902 close to the displayed heat source and reduced speed to place the helicopter in a hover. “Suddenly, the helicopter yawed to the right,” said the report by the German Federal Bureau of Aircraft Accident Investigation. “He responded [by] actuating the left pedal up to the mechanical stop.”
However, the helicopter continued to yaw right and then descended out of control into the forest. All three occupants sustained serious injuries. The radar operator exited the wreckage unaided; the pilot and flight engineer were rescued by police ground crewmembers.
The report concluded that visual restrictions resulting from the use of the NVGs, distractions caused by the search for the missing person, and a “loss of spatial perception” were among factors that likely contributed to the accident.
“It is likely that while trying to position the helicopter as close as possible to the identified heat source, an unnoticed loss of altitude and backward movement of the helicopter occurred,” the report said. “It is highly likely that the restricted spatial perception of the pilot due to the NVGs contributed to the occurrence; the same is true for crewmembers whose attention was focused on the search.”
Distracted by Radio Call
Eurocopter AS350 B2. Substantial damage. Three minor injuries.
The pilot, who had recently purchased the helicopter, was receiving training by a certified flight instructor (CFI) at Alliance Airport in Fort Worth, Texas, U.S., the morning of May 29, 2011. “During practice traffic pattern work, the helicopter’s hydraulic system was turned off to simulate hydraulic failure on the flight control system,” the NTSB report said.
During the subsequent approach, the CFI and the pilot may have been distracted when an airport traffic controller advised that they were using an incorrect radio frequency, the report said. While the instructor was setting the correct frequency, the helicopter slowed and entered an uncommanded left yaw.
“The CFI tried to regain control by adding right pedal, trying to gain forward airspeed, and reducing power,” the report said. “The helicopter did not respond to the CFI’s control inputs, descended and impacted terrain.” The pilot, CFI and passenger sustained minor injuries.
Loose Nut Causes Power Loss
Bell 206B. Substantial damage. No injuries.
After the JetRanger’s engine lost power during an aerial-application flight near Burbank, Washington, U.S., on May 30, 2012, the pilot conducted an autorotative landing in an apple orchard. “During the landing, the rotor blades impacted the trees and the tail boom separated from the main fuselage,” the NTSB report said.
Maintenance records showed that the helicopter had been flown six hours since the engine bleed air valve was replaced. Investigators determined that maintenance personnel had not applied sufficient torque to secure a B-nut that attaches the compressor discharge pressure air tube to the engine. The B-nut had backed off the stud during the accident flight, causing the air tube to detach and the engine to lose power.