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.
Stop Bar Lights Recommended
Boeing 737, Airbus A319. No damage. No injuries.
A Boeing 737-800 with 99 passengers and six crewmembers inadvertently was taxied beyond the assigned runway-holding position and into the path of an Airbus A319 that was on short final approach to Dublin (Ireland) International Airport with 125 passengers and five crewmembers the morning of Oct. 16, 2010.
The A319 flight crew had spotted the encroaching 737 and had initiated a go-around less than 200 ft above the ground and 0.4 nm (0.7 km) from the A319’s projected runway-touchdown point, said the report on the serious incident by Ireland’s Air Accident Investigation Unit (AAIU).
The AAIU concluded that the incursion was caused by the 737 crew’s noncompliance with the taxi clearance limit issued by the airport ground movements controller and their entrance onto the active runway without permission.
Factors contributing to the serious incident were the crew’s misinterpretation of published airport information, their distraction by “head-down cockpit tasks” while taxiing and the absence of a company standard operating procedure (SOP) requiring the crew to conduct a verbal cross-check before entering a runway, the report said.
The incursion occurred in an area designated on the airport chart as an “incursion hot spot, a location which requires heightened attention by crews,” the report said. In what was described as an unusual and complex configuration, Dublin International’s southernmost taxiway, E1, provides access from the aprons on the east side of the airport to the departure thresholds of both Runway 28 and Runway 34, which branch out from a common paved area on the south side of the airport.
Weather conditions were described as good when the incident occurred, and Runway 28 was being used for both arrivals and departures. In a written report filed after the incident, the commander told investigators that while preparing the aircraft for a flight to Istanbul, Turkey, he and his copilot had discussed information published in a Jeppesen Airport Briefing, which stated that holding positions are established on all taxiways that intersect runways at Dublin International.
The briefing also said, “A further holding position is established on Runway 16/34.” This statement referred to a holding position that is applicable to aircraft taxiing south on Runway 16 for departure from Runway 28; the holding position is north of the intersection of Taxiway E1 and Runway 16/34.
However, the commander said that they interpreted the word “further” to mean “ahead,” the report said. As a result, the pilots expected to see one set of holding-position markings on Taxiway E1 that were applicable to Runway 34 and then to see another set of markings ahead on Runway 34 that were applicable to Runway 28.
When the 737 crew reported ready to taxi from the apron, the surface movements controller told them to taxi to E1 and “hold short runway two eight.” As the aircraft neared the taxiway, the controller again instructed the crew to hold short of Runway 28 and told them to monitor the tower radio frequency. The crew acknowledged both “hold short” instructions.
The commander said that he was “doing mandatory head-down tasks” when the aircraft entered E1 and “had quick sight” of the holding-position markings on the taxiway. He said that, based on the misinterpretation of the airport-briefing information, he believed that the markings were applicable only to Runway 34 and “continued for the holding point [for] Runway 28, which was supposed to be on Runway 34.”
The 737 was on the runway centerline at the approach threshold when “all of a sudden, we recognized that when we penetrated into Runway 34, we also penetrated Runway 28,” the commander said.
Meanwhile, the air movements controller had issued a landing clearance to the Airbus crew, who were inbound from Cologne, Germany. The A319 was 1.7 nm (3.1 km) from the projected touchdown point when the crew acknowledged the clearance. The crew then radioed, “We’re going around. There’s [an aircraft] entering the runway.” This radio transmission coincided with a go-around instruction by the controller, who also had detected the conflict.
The 737 crew heard the A319 crew’s call and began taxiing the 737 toward Taxiway E2, to vacate the runway. The A319 passed about 300 ft above the 737 during the go-around. While climbing straight ahead to 3,000 ft in compliance with the missed approach procedure, the crew received a traffic-alert and collision avoidance system (TCAS) advisory applicable to an aircraft that had previously departed from Runway 28.
The report said that there was no conflict; the A319 was at 2,100 ft, and the other aircraft was at 2,600 ft and 3 nm (6 km) ahead. The A319 subsequently was landed without further incident on Runway 28. The 737 meanwhile had departed uneventfully for its flight to Istanbul.
Following the incident, airport and government authorities took action in response to AAIU recommendations to include additional information in the Aeronautical Information Publication Ireland to clarify the holding position locations for Dublin’s Runway 28 and Runway 34. In response to another recommendation for stop bar lights at the holding position on Taxiway E1, the authorities said that installation of stop bar lights already was in progress when the incident occurred and that the lights were expected to be in operation in October 2011.
The AAIU also issued a recommendation to the operator of the 737 to establish procedures requiring the handling pilot to maintain an “external look-out at all times while taxiing” and requiring both pilots to “verbally cross-check with each other that they have received the appropriate clearance to cross or enter a runway, whether active or non-active,” before entering a runway.
Drenched on Short Final
Airbus A320-232. Minor damage. No injuries.
Inbound from Toronto with 179 passengers and seven crewmembers, the flight crew was cleared to conduct the VOR ILS (VHF omnidirectional radio, instrument landing system) approach to Runway 06 at Varadero, Cuba, the night of Jan. 31, 2010. The airport was reporting winds variable from 350 degrees to 070 degrees at 8 kt, 1,000 m (5/8 mi) visibility in heavy rain and a broken ceiling at 1,600 ft.
“The flight was following a Boeing 737 that was approximately 20 nm [37 km] ahead on the same approach,” said the report by the Transportation Safety Board of Canada. “Except for a few rain showers to the left of its track, there was no significant weather showing on the aircraft’s weather radar.”
The A320 was turning onto final approach when the 737 crew conducted a missed approach. “When the flight crew of the 737 called the ACC [Havana area control center] to advise them of the go-around, they did not provide a reason or offer a pilot report,” the report said. “In addition, no information was requested by or issued to the crew of [the A320] regarding the reason for the go-around of the preceding aircraft.”
The approach was stabilized when the A320 descended below 1,000 ft. The crew established visual contact with the runway environment shortly thereafter and was cleared to land. The airport traffic controller also advised that the winds were from 060 degrees at 12 kt.
“Throughout the last 400 ft of the approach, the flight data recorder (FDR) indicated the wind was at 045 degrees at 15 kt and decreased in speed to 10 kt at touchdown,” the report said.
Rainfall intensity increased as the aircraft descended. The FDR data indicated that the approach remained stable as the A320 descended below the decision height. However, the aircraft began to deviate below the glideslope and drift right after the captain, the pilot flying, disengaged the autopilot. The aircraft crossed the runway threshold at 20 ft and in a nearly 11-degree right bank.
“Just prior to touchdown, the precipitation intensified and the visibility decreased to the point where the crew lost most visual references,” the report said. “Given the aircraft configuration, its low-energy state and position relative to the runway, a go-around was rejected as an option, and the captain committed to landing the aircraft.”
The runway was covered with standing water when the aircraft touched down left of the centerline, about 640 ft (195 m) from the threshold, and banked 7 degrees right. The spoilers deployed automatically, the crew engaged the thrust reversers, and the captain applied left rudder as the aircraft began to veer right. “White streaks left by the tires are indicative of scouring action caused by some form of hydroplaning,” the report said.
The A320 veered off the right side of the runway at 130 kt and tracked parallel to the runway on hard-packed grass and gravel for about 1,745 ft (532 m) before re-entering the runway at 40 kt. “The crew ascertained that the aircraft was fit to taxi to the gate and did so,” the report said.
The crew reported the excursion to the controller and later to the airline. The aircraft was found to have sustained minor damage to its tires, fan blades in the right engine, the right air conditioning pack and a flap-track fairing.
The report noted that the crew had not used the windshield rain-repellent system when the rainfall intensified during the approach. “The system delivers a calibrated quantity of rain-repellent fluid which is dispersed evenly onto the windshield [and] restores visibility in seconds,” the report said. However, the original fluid used by the system had been banned for environmental reasons in 1996. A replacement fluid that became available in 1998 required minor modification of the system.
The airline had reactivated the rain-repellent systems on its Airbus fleet in 2008. “The crew of [the incident aircraft] was unaware that the capability had been put back into service,” the report said. “No official memorandum or other formal means of communication from the company informing flight crews of the reactivation of the rain-repellent systems could be found.”
Thrust Setting Error Cuts Margins
Boeing 737-700. No damage. No injuries.
Two qualified captains were assigned to ferry the 737 back to its home base in Nigeria after maintenance was completed at Southend Airport in Essex, England, the morning of Nov. 21, 2010. The designated commander, who was to serve as the pilot monitoring, encountered problems with transportation to the airport and arrived 90 minutes late. Meanwhile, the designated copilot had begun preparations for the flight.
The copilot conducted performance calculations for a maximum-thrust takeoff from Runway 24 and entered the data in the 737’s flight management computer (FMC). When the commander finally joined the copilot on the flight deck, the flight was about two hours late.
“The two captains reviewed the FMC programmed data in accordance with the operator’s SOPs and confirmed that it was correct,” said the report by the U.K. Air Accidents Investigation Branch (AAIB). “The aircraft engines were then started, and the crew received clearance to taxi.”
Weather conditions were clear, with surface winds from 360 degrees at 5 kt and a temperature of 7 degrees C (45 degrees F).
As the crew taxied toward Runway 24, they were advised by air traffic control (ATC) that the runway in use had been changed to Runway 06.
While the commander continued to taxi the aircraft, the copilot reprogrammed the FMC “with some urgency,” the report said. “Reprogramming the FMC with the new runway deleted the previously entered performance data, thus allowing an ‘assumed’ temperature to be entered for a reduced-thrust takeoff, should it be required.”
According to the report, the copilot entered an assumed temperature of about 50 degrees C, which was suitable for the longer runways typically used by the crew in Africa but 21 degrees higher than the maximum assumed temperature appropriate for the conditions at Essex. The result was a takeoff thrust setting of 86 percent N1, which was insufficient for the runway length.
Moreover, the crew did not back-taxi on the runway to use the full available takeoff distance of 4,785 ft (1,458 m) but began the takeoff from the displaced threshold, leaving 600 ft (183 m) of runway behind.
As the 737 reached 100 kt, the commander perceived that the acceleration was too slow and called for maximum thrust. However, recorded flight data indicated that the thrust settings remained about 86 percent. The aircraft lifted off the runway and crossed the departure threshold at 150 ft.
The report said that although the aircraft was able to become airborne with both engines operating, calculations performed by Boeing indicated that the crew would not have been able to stop the aircraft on the runway after rejecting the takeoff just before reaching V1 — the aircraft would have overrun the runway at 60 kt. The manufacturer also determined that if the crew had continued the takeoff after an engine failed one second before V1, the 737 would not have become airborne before reaching the end of the runway.
Excess Speed, Short Runway
Eclipse 500. Substantial damage. No injuries.
The pilot had conducted several long, private flights with various passengers before landing the very light jet at Wings Field in Philadelphia to refuel before returning with one passenger to Brandywine Airport in West Chester, Pennsylvania, U.S., the evening of July 30, 2008.
Clear skies and calm winds prevailed when the airplane took off about 1830 local time for the five-minute flight to West Chester. The pilot told investigators that he was “a little high” on the visual approach to Brandywine’s 3,097-ft (944-m) Runway 27 and “dipped down.”
“As he passed the runway threshold, his speed was ‘a little high,’ but he thought it was manageable,” said a report issued by the U.S. National Transportation Safety Board (NTSB) in September 2011.
The Eclipse touched down about 14 kt above the appropriate landing speed. “Skid marks from the accident airplane began approximately 868 ft [265 m] beyond the displaced threshold and continued for about 2,229 ft [679 m] until they left the paved portion of the runway,” the report said.
The landing gear separated, the wings were bent and sections of the airframe were fractured and crushed when the airplane traveled down a 40-ft (12-m) embankment, crossed a service road and came to a stop against trees and a chain-link fence. A fuel tank was breached, but there was no fire. “Neither of the two occupants received any injuries during the impact sequence or subsequent egress,” the report said.
Snow Triggers Control Loss
Pilatus PC-12/45. Destroyed. Two fatalities.
Snow was falling heavily when the single turboprop was pulled out of its heated hangar at Yampa Valley Airport in Hayden, Colorado, U.S., the morning of Jan. 11, 2009. The pilot conducted a preflight inspection before boarding the airplane with his passenger. They remained inside the PC-12 while it was refueled for the intended business flight to Chino, California.
The manager of the airport’s fixed base operation said that the pilot declined his recommendation to have the airplane deiced before departure. The PC-12 then was towed to the taxiway to prevent it from becoming stuck in the snow on the ramp.
“Line crewmembers reported seeing an accumulation of wet snow on the airplane’s wings,” the NTSB report said. “One of the crewmembers described the accumulation as ‘probably a good inch of slushy, wet snow.’”
The airplane had been outside in the heavy snow about 22 minutes when the pilot began the takeoff from the 9,998-ft (3,047-m) runway with a 4-kt tail wind and 3/4 mi (1,200-m) visibility. Two line crewmembers said that the PC-12 appeared to accelerate slowly and rolled about 4,000 ft (1,219 m) before lifting off and entering a shallow right turn. The airplane then was lost from sight.
A search was initiated after the pilot did not establish radio communication with ATC. The wreckage was found about 1 mi (2 km) from the airport. Recorded ATC radar data indicated that the airplane had entered “an ever-tightening right turn until it impacted the ground,” the report said.
NTSB concluded that the probable cause of the accident was “the pilot’s loss of control due to snow/ice contamination on the airplane’s lifting surfaces as a result of his decision not to deice the airplane before departure.”
Passengers Jump After Engine Fails
Cessna 208. Substantial damage. No injuries.
The engine lost power as the Caravan was climbing through 12,500 ft to drop 15 parachutists near Cairns (Queensland, Australia) Airport the morning of Dec. 31, 2009. “The pilot reported that there were no cockpit warnings, vibrations or other indications of the impending engine failure,” said the report by the Australian Transport Safety Bureau (ATSB). “The parachutists exited the aircraft, and the pilot completed a glide approach and uneventful landing at Cairns Airport.”
Investigators determined that the failure of the Pratt & Whitney PT6A-114 engine likely was precipitated by the fracture of unapproved compressor blades that had been installed during an overhaul about four years earlier. The engine had accumulated 1,926 hours and 3,002 cycles since the overhaul. The manufacturer recommends overhauls every 3,600 hours.
The report said that the failed blades were approved for several PT6A model engines but not for the -114 and others with higher operating temperatures that would cause them to be “more susceptible to thermally induced microstructural decay.”
Unlocked Door Separates
Beech King Air 300. Substantial damage. No injuries.
The King Air was climbing through 7,000 ft after departing from Minneapolis–St. Paul (Minnesota, U.S.) International Airport the evening of Dec. 10, 2010, when the pilot advised ATC of a pressurization problem and his intention to return to the airport. “He did not report that the cabin entry door had separated from the airplane,” the NTSB report said.
The pilot landed the airplane without further incident. Examination of the King Air revealed a 4-in (10-cm) hole in the rear fuselage. The cabin door was found several weeks later about 6 mi (10 km) from the airport. “The door handle was in the latch position and not in the lock position,” the report said. “No mechanical anomalies were noted with the door. … The door-open annunciator light was functional.”
Slowdown Leads to Stall
Mitsubishi MU-2B-60. Destroyed. Four fatalities.
Weather conditions at Lorain County Regional Airport in Elyria, Ohio, U.S., the afternoon of Jan. 18, 2010, included surface winds from 240 degrees at 9 kt, 2 mi (3,200 m) visibility in mist and a 500-ft overcast. Inbound from Florida, the pilot conducted a go-around on his first ILS approach to Runway 07 because the airplane was too high.
While receiving ATC radar vectors for a second ILS approach, “the pilot requested that the controller extend the outbound leg to provide more time to get established on the inbound course,” said the NTSB report. “The radar track data indicated that the airplane was about 11 mi [18 km] from the airport before it turned inbound to intercept the localizer course.”
The controller cleared the pilot for the approach and told him to change to the airport’s advisory frequency. Analysis of recorded ATC radar data indicated that the MU-2 crossed the final approach fix 60 ft too low and continued to descend, with airspeed decreasing from about 130 kt to below 100 kt. “The ILS approach flight profile indicates that 20 degrees of flaps should be used at the glideslope intercept while maintaining 120 kt minimum airspeed,” the report said.
A witness waiting for the airplane to arrive saw it descend out of the clouds in a nose-low attitude and then roll into a steep turn, banked almost 90 degrees right. He said the airplane was “definitely out of control” when it descended rapidly to the ground about a half mile from the runway threshold.
NTSB concluded that the probable cause of the accident was an aerodynamic stall that resulted from “the pilot’s failure to maintain adequate airspeed.”
Suitable Airport Bypassed
Beech B60 Duke. Destroyed. Two fatalities.
Shortly after the pilot leveled the airplane at 6,000 ft, about 15 minutes after departing from Huntsville (Alabama, U.S.) International Airport the afternoon of Jan. 18, 2010, the right engine failed catastrophically. The pilot reported the engine failure to ATC and said, “We’ve got control, but we’re going to need to land.”
The pilot also told the controller that he had feathered the right propeller but was “having a hard time holding altitude.” The controller advised the pilot that there was an airport with a 5,000-ft (1,524-m) runway about 10 nm (19 km) away, but the pilot requested clearance to return to Huntsville, which was 30 nm (56 km) away, the NTSB report said.
ATC radar data indicated that the Duke gradually descended until radar contact was lost at 800 ft. The pilot had been cleared for a straight-in landing at Huntsville. As the airplane neared the airport, one witness observed that the right engine cowling was “propped up.” Another witness saw the airplane strike treetops and “nose-dive straight into the ground” about 3 mi (5 km) from the airport.
Examination of the right engine showed that the no. 2 cylinder had separated due to the propagation of fatigue cracks.
Britten-Norman Trislander. Minor damage. No injuries.
While holding for takeoff from Guernsey, Channel Islands, for a commercial flight with five passengers to Alderney the morning of Jan. 17, 2011, the pilot was advised by ATC that Alderney was reporting 3 km (2 mi) visibility and a broken ceiling at 300 ft. The reported visibility exceeded the 1,200 m (3/4 mi) required for the nondirectional beacon (NDB) approach, but the ceiling was below the published minimum descent height of 390 ft.
“Because the weather at both Guernsey and Jersey was above applicable minimums and the pilot had plenty of fuel, he decided he would attempt an approach to assess the conditions himself,” said the AAIB report.
During the NDB approach, the Trislander was descending through 1,000 ft about 3 nm (6 km) from the runway when the Alderney airport traffic controller cleared the pilot to land and advised that there were broken clouds at 200 ft and a few clouds at less than 100 ft. Shortly thereafter, the controller said that the visibility had decreased to about 1,200 m in fog. The pilot replied, “I haven’t got anything yet.”
Several seconds later, the aircraft was about 230 ft above ground level and 680 m (2,231 ft) from the runway threshold when the pilot radioed, “Got the lights.” He then made a left turn and a steep right turn to align the airplane with the runway. The aircraft touched down on the right main landing gear, and the wing tip scraped the runway.
“With a surface wind from the left, the pilot felt uncomfortable and decided to go around,” the report said. The aircraft veered off the right edge of the runway before becoming airborne.
The pilot was positioning the Trislander for another NDB approach when the controller advised that runway visual range had decreased to 325 m (1,100 ft). The pilot then asked to fly a holding pattern, but the controller replied that the company had just requested that the aircraft return to Guernsey. “The return flight was uneventful, and the aircraft landed safely,” the report said.
Fuel Stop Bypassed
Beech 58P Baron. Substantial damage. One fatality.
The Baron was en route from Morristown, New Jersey, U.S., to a planned fuel stop in West Virginia the night of Jan. 5, 2011, when the pilot decided not to stop for fuel but to continue to the destination, Alabaster, Alabama. Visual meteorological conditions had been forecast for Alabaster’s Shelby County Airport, but nearing the destination after more than five hours in flight, the pilot found that the airport had 2 mi (3,200 m) visibility in drizzle and an overcast at 300 ft.
The pilot received clearance to divert to his planned alternate, Birmingham, Alabama, and was cleared to conduct the ILS approach to Runway 24. “The airplane initially intercepted the localizer for the approach but did not intercept the glideslope,” the NTSB report said. The Baron then deviated left of the localizer and descended below the glideslope.
The pilot confirmed that he was not established on the ILS, and the approach controller provided instructions for a missed approach. The report said that the pilot likely had become spatially disoriented; he acknowledged the controller’s instructions but did not turn to the assigned heading or climb to the assigned altitude.
The Baron crashed on a street in a residential area about 0.5 mi (0.8 km) from the runway. Examination of the airplane revealed no pre-impact malfunctions.
Eurocopter AS 350-B. Substantial damage. Two minor injuries.
The AS 350 was among four helicopters chartered to transport passengers from Parramatta, New South Wales, Australia, to attend an automobile race in Bathurst the morning of Oct. 10, 2010. During a preflight briefing, some of the pilots expressed concern about the weather conditions, but no formal risk assessment was performed for the visual flight rules operation, the ATSB report said.
“Once under way, two of the line pilots continued to voice their concerns [about] the weather over the company’s radio frequency,” the report said. “However, the chief pilot requested that the flight continue.”
The chief pilot, who was flying the lead helicopter, attempted to climb “toward a patch of blue sky” but, about 10 minutes after departure, “decided that they would not be able to find a way through the cloud and instructed all pilots to return” to the Parramatta heliport, the report said.
The AS 350 pilot was completing the turn back to the heliport when the helicopter entered clouds. The pilot became spatially disoriented, and the helicopter descended and struck trees. Two of the five passengers sustained minor injuries.
Too Heavy to Hover
Robinson R44. Substantial damage. Four minor injuries.
The pilot told investigators that the helicopter encountered a downdraft during takeoff from a hilltop helipad in Aguadilla, Puerto Rico, on Aug. 8, 2010. “He stated that he attempted to compensate for the wind with a collective [control] input, but the helicopter descended and struck the downsloping hillside,” the NTSB report said.
The report said that analysis of the existing environmental conditions and the performance data in the R44’s operating handbook indicated that the helicopter was 94 lb (43 kg) over maximum gross weight and 120 lb (54 kg) over the maximum allowable weight for hovering out of ground effect.