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.
Pilots Flared High, Landed Long
Learjet 25D. Substantial damage. No injuries.
“Mission pressure to land” was cited by the U.S. National Transportation Safety Board (NTSB) as a contributing factor in a runway-overrun accident that substantially damaged a Learjet 25D of Mexican registry that was completing an emergency medical services flight in low instrument meteorological conditions (IMC) at Houston. None of the six occupants of the airplane was injured in the March 4, 2011, accident.
The Learjet had departed from Tuxtla Gutiérrez in southern Mexico at 0140 local time with two passengers, two medical crewmembers and two flight crewmembers. As the airplane neared the destination — Houston’s William P. Hobby Airport — about four hours later, the automated weather observing system was reporting 3/4 mi (1,200 m) visibility in mist, an indefinite ceiling at 200 ft and surface winds from 200 degrees at 3 kt.
The flight crew apparently conducted the instrument landing system (ILS) approach to Runway 12R, which is 7,602 ft (2,317 m) long and 150 ft (46 m) wide. The report said that the runway was dry.
“The pilot and the copilot both reported that, due to the fog and low visibility, they could not see the far end of the runway, and the pilot flared the airplane too high,” the report said. “After landing long on the runway, the pilot said he applied maximum braking and reverse thrust but could not stop the airplane before exiting the runway.”
The Learjet struck ILS localizer antennas and came to a stop in a flat, grassy area about 1,000 ft (305 m) from the departure end of the runway. The operator of the airplane told investigators that there was no pre-existing mechanical malfunction or failure that would have precluded normal operation of the airplane.
“The operator [also] stated that the decision not to delay the flight and to land in marginal conditions was influenced by medical considerations for the passenger, who needed immediate specialized medical treatment,” the report said.
Crew Forgot About Shortened Runway
Airbus A319-111. No damage. No injuries.
While preparing for a four-sector trip beginning at Stansted Airport, London, the morning of July 4, 2012, the flight crew reviewed a notice to airmen (NOTAM) about runway construction in progress at the third stop of the trip: Prague Airport in the Czech Republic. The NOTAM said that, due to the construction on Runway 24, the runway length temporarily would be reduced from 3,715 m (12,188 ft) to 2,500 m (8,203 ft).
Late that afternoon, “the aircraft landed at Prague on Runway 30 after the third sector of the duty, and the flight crew started preparation for their final flight to Stansted” with 149 passengers and six crewmembers, said the report by the U.K. Air Accidents Investigation Branch. “The runway in use for takeoff was Runway 24. The pilots listened to the ATIS [automatic terminal information service] broadcast, but it was reportedly in heavily accented English. They did not glean from it that the runway length was reduced and had forgotten the content of the associated NOTAM seen at the preflight stage.”
As a result, the pilots used the normal length of the runway when they calculated the A319’s takeoff performance. The report noted that the pilots had not seen the construction activity on Runway 24 when they landed on Runway 30. Moreover, “the work in progress on Runway 24 was at the departure end, not easily visible to the crew at the start of the takeoff roll,” the report said. “The commander noted later that there were no warnings from ATC [air traffic control] or ground signage indicating that the runway length was reduced.”
The takeoff initially appeared normal to the flight crew, but then they saw that the A319 was rapidly nearing the runway-construction area. “The aircraft rotated and became airborne at the planned speeds but approached much closer to the works than would have been intended,” the report said. “The event posed a considerable distraction for the crew which, combined with a frequency change immediately after takeoff, led to [their failure] to select the landing gear up or check that it was retracted prior to reaching the landing gear limit speed.” The flight proceeded to London without further incident.
The commander told investigators that the oversight regarding the shortened runway could be attributed to “reduced crew awareness at the end of a lengthy duty period.” He also said that a contributing factor was the presence in their route manuals of charts showing both the normal (full) length of Runway 24 and the reduced length of the runway. “As the crew were not aware during planning that the available length was reduced, they referred only to the normal charts,” the report said.
“[The commander] also noted that the crew’s preflight activities had been interrupted by a visit to the flight deck by an acquaintance and thought that this distraction may also have been a factor.”
Engine Separates on Takeoff
Boeing 707-300. Destroyed. Three minor injuries.
The failure of a midspar engine-mount fitting that was known to be susceptible to fatigue cracking and that should have been replaced with a more fatigue-resistant version was the probable cause of an accident during an attempted takeoff at Point Mugu Naval Air Station near Los Angeles the afternoon of May 18, 2011, the NTSB report said.
The report also said that an erroneous maintenance entry made when the 707 was in the hands of a previous owner, incorrectly indicating that the engine-mount fitting had been replaced in accordance with an existing airworthiness bulletin, was a contributing factor in the accident, which destroyed the airplane and resulted in minor injuries to the three flight crewmembers.
The airplane was operated by a company that provided aerial-refueling services on contract to the U.S. Navy. Manufactured in 1969 and converted to a tanker in 1996, the airplane had accumulated 47,856 flight hours and 15,186 cycles.
The 707 was within weight-and-balance limits when it departed from Runway 21 at Point Mugu to refuel McDonnell Douglas F/A-18s offshore. Surface winds were from 280 degrees at 24 kt, gusting to 34 kt, creating a crosswind for the takeoff on the 11,102-ft (3,384-m) runway.
“According to the crew, the takeoff roll was normal,” the report said. “At rotation speed [152 kt], the captain rotated the airplane to an initial target pitch attitude of 11 degrees airplane nose-up.”
Shortly after the airplane lifted off about 7,000 ft (2,134 m) down the runway, the crew heard a loud noise as the left inboard engine separated and propelled itself above and over the left wing. The nacelle and pylon also separated and then struck and broke off the inlet cowling on the left outboard engine.
The captain applied full right rudder and nearly full right aileron in an attempt to maintain directional control, but the airplane continued to drift left. Both of the right engines were producing maximum power, but the power produced by the damaged left outboard engine was negated by the drag created by the absence of the inlet cowling, the report said. The airplane descended, and the captain leveled the wings just as it touched down on the runway. The 707 then veered off the left side of the runway and came to a stop in a marsh near the departure end.
“All three crewmembers successfully evacuated through the left forward entrance via the escape slide” before the airplane’s fuselage was nearly consumed by fire, the report said.
The midspar fitting that had failed was among several that attached the engine to the wing and had a history of fatigue cracking that had caused at least three previous accidents. “To address the midspar cracking issue, a series of Boeing service bulletins (SBs) and FAA [U.S. Federal Aviation Administration] airworthiness directives (ADs) were published between 1975 and 1993,” the report said. Among them was an AD requiring compliance with SBs recommending repetitive inspections of the original fittings until they were replaced by a redesigned, stronger fitting.
The aerial-refueling company had acquired the 707 in 1994 and had inspected the midspar fittings after converting the airplane to a tanker. However, the company deleted the inspection requirement from its maintenance program after finding a maintenance record indicating (erroneously) that redesigned fittings had been installed in 1983. The report noted that U.S. “federal regulations do not require an owner/operator acquiring an aircraft to physically verify the compliance of every AD for which compliance has been recorded.”
Bleed Air Overheat
Airbus A320-214. No damage. No injuries.
Before departing from Helsinki, Finland, for a scheduled flight to London with 140 passengers and six crewmembers the morning of March 5, 2011, the flight crew found that the no. 1 (left engine) bleed air system was inoperative and that repair had been deferred per provisions of the minimum equipment list (MEL).
“According to [the MEL], it was permissible to fly the aircraft for 10 days with one engine bleed air system out of service,” said the report by the Safety Investigation Authority of Finland. “The aircraft had already flown for seven days with this technical limitation. The previous flights had been uneventful.”
The flight to London was initiated with the cross-bleed valve open to supply bleed air from the no. 2 engine to both air-conditioning packs. However, about 10 minutes after reaching cruise altitude, Flight Level (FL) 360 (approximately 36,000 ft), the pilots noticed fluctuations in the no. 2 bleed air pressure and the cabin altitude indications. The A320 was over the Baltic Sea, north of Öland Island, Sweden, at the time.
A few minutes later, the electronic centralized aircraft monitor (ECAM) generated a fault warning for the no. 2 bleed air system. “The bleed air temperature of the right engine had exceeded its maximum permissible value (247 degrees C [477 degrees F]),” the report said. “As a result of this, the system shut down and the cabin pressure altitude slowly began to climb. The bleed air needed for cabin pressurisation was no longer available, and therefore the flight crew had to immediately initiate a descent to a safe altitude.”
The crew requested and received clearance from ATC to descend to FL 100, “the maximum recommended altitude for unpressurised cabins,” the report said. During the descent, the ECAM generated a warning about the cabin altitude, which had reached 9,450 ft. The pilots donned oxygen masks, and the captain, the pilot flying, extended the speed brakes to increase the descent rate. At no time did the crew declare an emergency.
“The aircraft momentarily, and slightly, exceeded its maximum airspeed during the descent,” the report said. “There was no high terrain or, in this case, any other flight activity below the planned route. … At no stage of the occurrence were the passengers at risk, nor did the automatic pressure control deploy the passenger oxygen masks in the cabin.”
The report noted that the crew did not start the auxiliary power unit, which can supply sufficient bleed air for pressurized flight below 20,000 ft. However, during the descent, the crew was able to reset the no. 2 bleed air system. Investigators later determined that the system had overheated due to a malfunction of the fan air valve or the thermostat. “The pre-cooled air was too hot; therefore, the temperature sensor of the system worked as per its design and shut off the overheated system,” the report said.
The no. 2 bleed air system had cooled sufficiently during the descent to resume normal operation, and the crew leveled the aircraft at FL 140. “Seeing that the engine bleed air system continued to function normally and there was sufficient fuel to take them all the way to London, the flight crew decided to continue the flight to their destination at a lower flight level [than originally planned], FL 250,” the report said.
Although bleed air temperature neared the limit during the last 20 minutes of cruise flight, the A320 was landed without further incident in London.
Elevator Trim Cable Snaps
Cessna Citation 560XL. Minor damage. No injuries.
The flight crew was conducting a positioning flight from New Orleans to Houston the afternoon of April 8, 2011. The flight was uneventful until the Citation reached about 22,000 ft during the climb to cruise altitude. “The captain noticed an abnormal feel in the flight controls, followed by the pitch trim annunciator light coming on,” said the NTSB report.
He disengaged the autopilot, and the airplane abruptly pitched nose up. He moved the control column forward to correct the pitch attitude and attempted unsuccessfully to relieve the control forces with the electric and the manual pitch trim systems. “The pitch trim wheel spun without effect or friction,” the report said. “The captain slowed the airplane to the speed at which it was trimmed and ran the checklist for jammed elevator trim.” Completion of the checklist actions did not rectify the problem.
The crew declared an emergency and diverted the flight to San Antonio, Texas. “The captain did a controllability check to [ensure] no other control issues existed,” the report said. “He then flew a long final approach to an uneventful landing at San Antonio.”
Examination of the airplane revealed that the elevator trim cable had failed due to fatigue. “The fracture occurred 11 inches [28 cm] from the roller chain that tracked through the elevator trim actuator,” the report said. The cable had been installed during manufacture of the Citation, which had accumulated 5,445 hours before the incident occurred.
In April 2012, a year after the incident, Cessna Aircraft issued a service bulletin recommending replacement of the elevator trim cables in 560XLs with cables made of “improved rope wire material,” the report said.
Dual Engine Failure
CASA 212. Destroyed. One fatality, one serious injury, one minor injury.
About three hours after departing from Saskatoon, Saskatchewan, Canada, to conduct a local geophysical survey flight the afternoon of April 1, 2011, the right engine lost power. “No annunciators or warning lights were illuminated, and there were no abnormal engine instrument indications,” said the report by the Transportation Safety Board of Canada.
The flight crew had felt the right engine shudder before it smoothly spooled down, the report said. The aircraft was at 400 ft above ground level (AGL) at the time. The crew applied full power to the left engine, feathered the right propeller and secured the right engine. They declared an emergency and turned back to the airport.
“The crew did not attempt to restart the right engine,” the report said. “Their priorities were aircraft controllability, climbing to a higher altitude, recovering the birds [two externally deployed sensors] and returning to Saskatoon.”
Neither pilot noticed that the master caution light had re-illuminated after it was reset following completion of the checklists for the right-engine failure. In addition, the left fuel quantity and fuel pressure lights had illuminated.
The C-212 was at about 1,300 ft AGL and 3.5 nm (6.5 km) out on final approach to Runway 27 when the left engine “smoothly lost power with no surging,” the report said. “The captain [the pilot monitoring] was looking at the engine instruments at the time, and all indications had been normal.”
Realizing that they could not reach the runway, the crew turned toward a road. However, they saw traffic on the road and decided to land the aircraft on a grassy area next to the road. Nearing the grassy area, the pilots saw a concrete noise-abatement wall too late to avoid it. “The aircraft landed astride the wall at 90 kt,” the report said.
The C-212 was destroyed by the impact. The survey equipment operator was killed, the first officer was seriously injured, and the captain sustained minor injuries.
Investigators determined that the shudder felt by the pilots before the right engine spooled down was caused by failure of a gear on the torque sensor shaft, which in turn caused loss of drive to the engine-driven fuel pump. “The immediate result would have been fuel starvation of the engine, flameout and the loss of power,” the report said.
Fuel starvation also was the likely cause of the loss of power from the left engine. The first officer had placed the aircraft in a slight left bank, per procedure, following the failure of the right engine. This caused fuel to flow from the center collector tank into the wing tanks and one of the two ejector pumps, which pump fuel from the wing tanks into the collector tank, to unport. The nozzle in the other ejector pump was found to be partially blocked by unidentified debris; the pump therefore was unable to deliver a sufficient quantity of fuel to the collector tank.
Smoke Prompts Emergency Descent
Beech King Air B200GT. Minor damage. No injuries.
The airplane was cruising at FL 230 during a ferry flight from Melun, France, to Toulouse the night of April 15, 2010, when the flight crew noticed that the cabin heating system was not providing sufficient heat. They reset the system from the automatic mode to the manual mode.
“A few moments later, acrid smoke penetrated the cabin,” said the report by the French Bureau d’Enquêtes et d’Analyses. “The captain and copilot put on their oxygen masks, switched off the heating, declared an emergency … and began an emergency descent to Flight Level 100.”
While conducting the corresponding checklist, the crew noticed that the smoke abated soon after they closed the left bleed air valve. They continued the flight without further incident to Toulouse.
Investigators determined that a fault in the automatic temperature controller had caused the heating system to shut down. Moreover, they found that a warm air duct previously had been split by a sharp instrument during a maintenance inspection of the air conditioning system and then repaired improperly with a sheet of aluminum and gray adhesive tape. Heat transferred to the adhesive subsequently had caused it to deteriorate, and the rapid increase in heat when the crew selected the manual mode caused it to melt.
Gear Extension Falls Short
Bombardier Q300. Minor damage. No injuries.
A faulty “inhibit switch” caused the nosewheel steering system to malfunction as the flight crew prepared to depart from Hamilton, New Zealand, for a scheduled flight with 41 passengers and a flight attendant to Wellington on Feb. 9, 2011.
“The faulty switch caused a loss of hydraulic pressure to the nosewheel steering,” said the report by the New Zealand Transport Accident Investigation Commission. “The nosewheel steering system was considered nonessential, so, in accordance with the approved minimum equipment list, the aeroplane departed Hamilton with the system inoperative.”
The faulty switch also prevented normal extension of the landing gear on final approach to Hamilton. The crew conducted a go-around and completed the “Alternate Gear Extension” checklist, which resulted in extension of the main landing gear but not the nose gear. The crew diverted the flight to Woodbourne Aerodrome and landed the Q300 with the nose gear retracted.
“There was nothing mechanically wrong with the alternate landing gear extension system,” the report said. “The nose landing gear did not extend because the pilots did not pull hard enough on the handle that should have released the uplock. If the uplock had released, the nose landing gear would have lowered under gravity and locked down.”
The report noted that the force required to release the uplock during flight simulator training was much less than the force required in the aircraft itself.
‘Minimal Experience in IMC’
Beech 58C Baron. Destroyed. Four fatalities.
The Baron was en route under instrument flight rules from Scott City to Topeka, both in Kansas, U.S., the afternoon of April 22, 2011, when the pilot found that the back-course localizer approach to Runway 31 was in use at the destination, and the airport was reporting a 500-ft overcast and 10 mi (16 km) visibility.
The NTSB report noted that the private pilot had 438 flight hours, including 29 hours in multiengine airplanes, 50 hours of simulated instrument time and 11 hours in actual instrument conditions. He had earned a multiengine rating two months earlier and had logged 0.7 flight hours in IMC since earning an instrument rating five months earlier.
Nearing the airport from the south, the pilot received vectors from ATC to establish the airplane on the localizer back course. After the Baron flew through the inbound course, the controller issued a heading to re-intercept it, terminated radar service and told the pilot to contact Topeka Tower.
The airplane again flew through the inbound course. The pilot declared a missed approach but then asked the tower controller if he could circle to land. The controller told him to conduct the published missed approach procedure, climb to 4,000 ft and re-establish radio communication with the center controller. During the climb, the pilot requested clearance to conduct the global positioning system (GPS) approach to Runway 36.
“The pilot was maneuvering in IMC to set up for the GPS approach when the airplane departed controlled flight and impacted terrain,” the report said. “The airplane struck the ground in a left descending turn at high speed.”
NTSB concluded that the pilot’s failure to maintain control of the airplane was the probable cause of the accident and that his “minimal experience flying in actual instrument conditions” was a contributing factor.
Caught in a Crosswind
Piper Aerostar 602P. Substantial damage. No injuries.
Inbound from Lock Haven, Pennsylvania, U.S., the pilot was cleared to land on Runway 26 at Philadelphia International Airport, which was reporting surface winds from 330 to 340 degrees at 14 to 18 kt, gusting to 25 kt, the afternoon of April 2, 2012. The runway was 5,000 ft (1,524 m) long and 150 ft (46 m) wide.
“The pilot said that he landed on the left main gear, with the right main intermittently touching the ground, and tried to lower the right wing to improve wheel-to-runway contact but was unsuccessful because of a wind gust,” the NTSB report said. “He felt the left main gear become ‘mushy’ as he was braking to avoid an overrun.”
The Aerostar then veered off the left side of the runway onto a soft, grassy area. The main landing gear collapsed, and both wings were substantially damaged before the airplane came to a stop.
Set Up for a Stall
Beech 76 Duchess. Substantial damage. One serious injury, one minor injury.
The pilot said that he thought the Duchess was near its maximum gross weight for the departure from Perris Valley (California, U.S.) Airport the morning of July 30, 2011. Nevertheless, he began the takeoff from the midpoint of the 5,100-ft (1,554-m) runway, applying full power before releasing the wheel brakes, the NTSB report said.
“The pilot [had] selected Runway 15, which had a 6-kt tailwind component at the time of the attempted takeoff,” the report said. Before reaching the normal airspeed for rotation, the Duchess pitched nose-up and became airborne. Shortly thereafter, the left cockpit door opened. The pilot was closing the door when the airplane stalled, struck an embankment and crashed in an open field about 1,000 ft (305 m) off the end of
The pilot was seriously injured, one passenger sustained minor injuries and two passengers escaped injury.
Investigators calculated that the airplane was more than 273 lb (124 kg) above maximum gross weight and that the center of gravity was 0.4 in (1.0 cm) aft of the limit. In addition, “the elevator trim tab was found in the full nose-up position,” the report said.
Thin Air, Overweight Takeoff
Bell 206B. Substantial damage. Two serious injuries.
The pilot did not perform weight-and-balance calculations before attempting to take off from Midrand, South Africa, with a full load of fuel and two passengers and their baggage the afternoon of May 27, 2012, according to the report by the South African Civil Aviation Authority.
Aural and visual low rpm warnings were generated soon after the pilot lifted the helicopter into a hover. He set the helicopter back on the ground, offloaded one passenger and some baggage, and attempted another takeoff. Investigators determined that the JetRanger was 140 lb (64 kg) over maximum gross weight for the conditions, which included a density altitude of 7,000 ft.
“The pilot was able to become airborne due to the fact that he was able to gain airspeed by remaining within ground effect for a considerable distance,” the report said. “Once he started to climb, conditions changed and power required to sustain flight exceeded the power available, and the rpm started to decay.”
The pilot told the airport traffic controller that he was having an engine problem and was going to fly one circuit of the pattern to evaluate the problem. The helicopter was on a left downwind leg when he reported that the engine was losing power and that he was going to land. Shortly thereafter, the JetRanger struck a tree and a concrete fence next to a road. Both occupants sustained serious
Pilot Loses Consciousness
Robinson R44. Substantial damage. One fatality, one serious injury.
The pilot and a crewman were conducting a geophysical survey that required landings at waypoints about 2.5 km (1.4 nm) apart. After completing about 80 takeoffs and landings south of Newman, Western Australia, the morning of Sept. 3, 2011, the crewman saw that the pilot, who was seated in front of him, had slumped forward.
“The crewman attempted to rouse the pilot, but all attempts failed, and the helicopter’s descent rate was not arrested,” said the report by the Australian Transport Safety Bureau. The crewman was seriously injured when the R44 struck terrain. The pilot regained consciousness momentarily but succumbed to chest injuries sustained during the impact.
Investigators found that the pilot had sought help from medical practitioners several times after losing consciousness, once because of a “vasovagal episode” involving lowered heart rate and blood pressure, and once because of a blow to the head. None of the prior episodes of loss of consciousness occurred during flight. “The information contained in the pilot’s aviation medical records did not accurately reflect the pilot’s medical history, elements of which may have, if known, led to further medical testing and influenced the subsequent renewal of the pilot’s Class 1 aviation medical certificate,” the report said.