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.
Boeing 757-200. No damage. No injuries.
The departure for the nearly five-hour flight from Christchurch, New Zealand, to Pegasus Field, Antarctica, the morning of Oct. 7, 2013, was delayed while the Royal New Zealand Air Force flight crew gathered more information about the forecast weather conditions at the destination.
After receiving an updated report confirming that current and forecast weather conditions met their launch criteria, the flight crew departed from Christchurch at 0957 local time with 117 passengers and 11 other crewmembers.
A “point of safe return” had been calculated along the route beyond which the crew would be committed to land at Pegasus Field. The aircraft would not have enough fuel beyond that point to return to Christchurch or to divert to any alternate on Antarctica sufficient for a 757 to land, according to the report by the New Zealand Transport Accident Investigation Commission (TAIC).
While en route, the crew received periodic reports from weather specialists in Antarctica and at the U.S. Navy’s Office of Polar Programs. Observers at the field advised that there was a fog bank about 5 km (3 nm) nearby but said that it was not expected to affect flight operations.
Visual meteorological conditions (VMC) were still being forecast when the 757 neared the point of safe return at 1257 Christchurch time. “The crew received assurances from the forecasters that the weather was forecast to improve,” the report said. “Based on these assurances and using the crewmembers’ collective experience, both recent and from previous [flights to Antarctica], the crew made the decision to continue past the point of safe return.”
About 20 minutes later, the crew received the first of several reports of deteriorating weather conditions at Pegasus Field. Contrary to the forecasts, fog had developed over the field and its approach areas. The base of the broken ceiling was at 300 ft.
“The crew discussed their options and decided to fly the RNAV [area navigation] approach to Runway 33,” the report said. “That approach had a minimum descent altitude (MDA) of 360 feet. However, because the first 1,000 feet [305 m] of runway were not available for landing, the crew agreed to raise the MDA to 410 feet to try to provide a constant glide path angle to touchdown.”
The field had one runway suitable for heavy, wheel-equipped airplanes. “The runway was constructed on permanent ice … and was normally 10,000 feet long and 150 feet wide (approximately 3,050 m by 45 m),” the report said.
The crew conducted a go-around on the first approach because they were not able to see the runway environment through the fog. They decided to hold and wait for visibility to improve as forecast.
“After holding for nearly two hours with no improvement in the conditions, the crew decided to make a second approach using a lower ‘minimum descent altitude’ than the published minima in an attempt to increase the chance of becoming visual with the runway,” the report said.
This approach also terminated in a go-around, but one of the pilots glimpsed the runway markings just as the missed approach was initiated.
“With dwindling fuel reserves and conditions deteriorating, the crew elected to make a third attempt at landing [using the] lower ‘minimum descent altitude’ [i.e., 100 ft],” the report said. “When the aeroplane reached about 110 feet above the runway, the crew saw the runway approach lights and markings, and was able to make a successful landing in near-whiteout conditions.”
Based on the findings of the incident investigation, the TAIC concluded that “the observed and forecast weather conditions as reported to the crew met the criteria for the crew to continue past the point of safe return.”
The commission also said it found that “given no safe alternative, the actions of the crew in proceeding below the allowable minima for the aerodrome were appropriate and that the crew had taken all reasonable precautions to mitigate the risks involved in doing so.”
Because of the frequent lack of suitable landing sites for the aircraft type, the TAIC recommended that the air force review its risk assessment for using 757s for Antarctic flight operations.
High-Pressure Fuel Leak
British Aerospace 146. Minor damage. No injuries.
The flight crew received a warning of a fire in the no. 4 engine shortly after departing with 44 passengers and two flight attendants from O.R. Tambo International Airport in Kempton Park, South Africa, the evening of June 25, 2013.
“The flight crew completed the emergency memory items and shut down the engine,” said the report by the South African Civil Aviation Authority. “The crew decided to return to [Tambo] and declared an emergency.”
The 146 was landed without further incident. Maintenance personnel found that fuel had leaked at high pressure from a loose fuel nozzle and gasket. They also found “minor scorch marks” on the no. 4 engine, the report said.
The engine manufacturer had issued several service bulletins in reaction to previous fuel leaks, requiring periodic inspections and increased bolt torque, and introducing an improved fuel nozzle design, the report said. Investigators found that the operator had complied with the bulletins that specifically affected the incident aircraft.
Cleaning Fluid ‘Haze’
Cessna Citation CJ2. No damage. No injuries.
The flight crew detected an unusual odor at 80 kt but continued the takeoff from Rotterdam (Netherlands) The Hague Airport the afternoon of June 8, 2012. Shortly after the aircraft became airborne, the crew saw a “haze” forming in the cockpit.
“The crew performed the memory items, donned their oxygen masks and switched their microphones to the ‘OXY-MASK’ position,” said the report by the Dutch Safety Board. They informed air traffic control (ATC) of the problem and requested, and received, clearance to return to the airport.
Although the crew did not declare an emergency, “ATC handled the incident as an emergency situation and placed fire services on standby,” the report said. After the Citation was landed without further incident, fire service personnel inspected the aircraft and found no sign of fire.
Further examination of the aircraft revealed a substantial amount of white soap residue in the bleed air and air conditioning systems. “It was concluded that this residue caused the unusual smell and the haze in the cockpit,” the report said, noting that two days before the incident, the Citation had undergone scheduled maintenance that included engine compressor desalination and washing.
Touch-and-Go Control Loss
IAI Westwind. Substantial damage. No injuries.
The pilot was receiving training for a type certificate the morning of June 18, 2013. As the airplane touched down on the first landing at Cincinnati (Ohio, U.S.) Municipal Airport (Lunken Field), the flight instructor called for a go-around.
The pilot initiated the go-around, but the Westwind settled back onto the runway soon after becoming airborne, said the report by the U.S. National Transportation Safety Board (NTSB). The right wing tip struck the pavement, the airplane yawed left, and the left main landing gear separated. The airplane then skidded to a stop on the runway.
The NTSB concluded that the probable cause of the accident was “loss of control due to insufficient airspeed on takeoff and premature landing gear retraction.”
Pilatus PC-12/47. Destroyed. Six fatalities.
The private pilot conducted a flight from Fort Pierce, Florida, U.S., to Junction City, Kansas, the morning of June 7, 2012. The PC-12 was in instrument meteorological conditions (IMC) at 24,700 ft, climbing to the assigned flight level (FL 260, approximately 26,000 ft), when ATC advised the pilot of a large area of heavy precipitation ahead and suggested a deviation right of course.
Recorded flight data indicated that the airplane was in a 25-degree-banked right turn at about 109 kt when the autopilot disconnected. “The pilot allowed the bank angle to increase, and about 13 seconds after the autopilot disconnected and with the airplane descending in a right bank of about 50 degrees, the pilot began a test of the autopilot system,” the NTSB report said.
ATC radar data indicated that the bank angle increased to about 100 degrees and that indicated airspeed increased to 338 kt, or about 175 kt above maneuvering speed, as the rapid descent continued.
The PC-12 was descending through 15,000 ft when the pilot abruptly pulled the control wheel aft, resulting in the overstress and separation of both wings. “The separated section of right wing impacted and breached the fuselage, causing one passenger to be ejected from the airplane,” the report said. “Following the in-flight break-up, the airplane descended uncontrolled into an open field [in Lake Wales, Florida].”
The NTSB determined that the probable cause of the accident was “the failure of the pilot to maintain control of the airplane while climbing to cruise altitude in IMC following disconnection of the autopilot.” A contributing factor was “the pilot’s lack of experience in high-performance, turbopropeller airplanes and in IMC.”
The report indicated that the 755-hour pilot had flown piston singles before receiving 7.5 hours of dual instruction in a Piper Mirage in 2009. Since then, he had not flown until a month before the accident. He subsequently logged about 4.1 flight hours in the PC-12. His logbook showed 35 hours flight time in actual IMC.
‘Engine Out’ on Base
Cessna 441. Substantial damage. One fatality.
The pilot departed from Long Beach, California, U.S., early in the morning of Dec. 22, 2011, for a flight to York Airport in Thomasville, Pennsylvania. The en route portion of the flight was conducted at FL 350.
The pilot canceled his instrument flight rules flight plan about six hours after departing from Long Beach and continued toward Thomasville in night VMC, said the NTSB report.
An airport employee told investigators that the pilot requested an airport advisory and then entered a left traffic pattern for Runway 35. He saw the airplane turn onto a base leg and heard the pilot radio that he had an “engine out.” He then heard the pilot call “base to final” and saw the airplane enter a left turn.
“The angle of bank was then observed to increase to where the airplane’s wings became vertical, then inverted, and the airplane rolled into a near-vertical descent, hitting the ground upright in a right spin,” the report said.
Examination of the wreckage showed that the right engine was not producing power on impact and the propeller had not been feathered. Investigators were unable to determine why the engine failed.
“No mechanical anomalies could be found with the engine that could have resulted in its failure,” the report said. “The right fuel tank was breached; however, fuel calculations, confirmed by some fuel found in the right fuel tank as well as fuel found in the engine fuel filter housing, indicated that fuel exhaustion did not occur.”
The NTSB concluded that the probable cause of the accident was “the pilot’s failure to maintain minimum control airspeed after a loss of power to the right engine, which resulted in an uncontrollable roll into an inadvertent stall/spin.”
Stall on Departure
Beech King Air B200GT. Destroyed. One fatality.
The pilot conducted a ferry flight with two passengers in the newly purchased airplane from Georgetown, Texas, U.S., to Baton Rouge, Louisiana, the morning of June 7, 2013. “A review of the airplane’s cockpit voice recorder audio information revealed that, during the ferry flight, one of the passengers, who was also a pilot, was pointing out features of the new airplane, including the avionics suite, to the accident pilot,” the NTSB report said.
“The pilot had previously flown another, similar model airplane, but it was slightly older and had a different avionics package. The new airplane’s avionics and flight management system were new to the pilot.”
After deplaning the passengers in Baton Rouge, the pilot departed for a short flight to McComb, Mississippi. Shortly after takeoff, the pilot acknowledged a controller’s assignment of a heading and altitude.
“The radio transmission sounded routine, and no concern was noted in the pilot’s voice,” the report said. “However, an audio tone consistent with the airplane’s stall warning horn was heard in the background. Shortly thereafter, the pilot made a radio transmission stating that he was going to crash. The same audio tone was heard in the background, along with distress noted in the pilot’s voice.”
The King Air was descending through 400 ft at 102 kt when ATC radar contact was lost. The airplane struck the roof of a house and trees before crashing into two more houses. The pilot was killed, but no one on the ground was hurt.
The NTSB concluded that the probable cause of the accident was “the pilot’s failure
to maintain adequate airspeed during departure, which resulted in an aerodynamic stall.” A contributing factor was “the pilot’s lack of specific knowledge of the airplane’s avionics.”
Water in the Fuel System
Piper Twin Comanche. Substantial damage. Two fatalities, one serious injury.
Density altitude was about 6,100 ft, and the airplane was 177 lb (80 kg) over gross weight when it departed from Idaho Falls, Idaho, U.S., the afternoon of June 22, 2013. The rear-seat passenger later told investigators that the right engine surged at about 100 to 200 ft above the ground.
Witnesses on the ground heard several “pops” before the Twin Comanche entered a steep right bank and descended to the ground. “The confined distribution of the wreckage was consistent with a low-altitude aerodynamic stall,” the NTSB report said.
A witness who had refueled the airplane said that the pilot did not sump the fuel tanks during his preflight check. “Fuel samples obtained after the accident from the fuel strainer assemblies tested positive for water contamination,” the report said. “Visible sediment and rust were observed in several system components on both engines.”
Flight Path Divergence
Lockheed P2V-7. Destroyed. Two fatalities.
The Neptune tanker was engaged in firefighting operations over mountainous terrain near Modena, Utah, U.S., the afternoon of June 3, 2012. On their second drop, the flight crew again followed a lead airplane to the drop zone located in a shallow valley.
“The lead airplane flew a shallow right turn onto final and then dropped to an altitude of 150 feet above the valley floor,” the NTSB report said. “While making the right turn onto final behind the lead airplane, [the tanker’s] right wing tip collided with terrain, which resulted in a rapid right yaw and subsequent impact with terrain.”
Examination of photographs taken by two witnesses indicated that the Neptune did not precisely follow the lead airplane’s path. “Rather, it was about 700 feet left of the lead airplane’s path and made a wider right turn as it attempted to align with the final drop course,” the report said.
Data retrieved from the tanker’s global positioning system (GPS) receiver showed that the tanker crew had made their first drop above the ridge line but descended below the ridge line during the second approach. The report said that the wider turn into the drop zone during the second approach likely resulted from the crew’s inadequate compensation for a tail wind.
Loose Engine Idler Pin
Aero Commander 685. Substantial damage. Three serious injuries.
The pilot landed the Commander in a field after the left engine failed catastrophically on takeoff from Victoria, Texas, U.S., the morning of June 15, 2013.
“Disassembly of the left engine revealed that the idler pin was unsecured and that no nuts were present on either of the two bolt studs,” the NTSB report said. “The bolt studs were worn and stripped of threads near the base, consistent with being worn by the free movement of the idler pin.
“The engine casting where the idler pin was installed was fractured. The crankshaft, camshaft, starter drive and starter adapter gear teeth were stripped, and metal fragments were noted in the oil screen and sump.”
Investigators determined that the idler pin likely had not been secured properly during a major overhaul conducted in March 2009. The engine had been operated 114 hours since then.
Fog Forms at Helipad
Bell 206L-1. Destroyed. Three fatalities.
The pilot and two medical technicians had transported a patient to London, Kentucky, U.S., and were returning to their home base near Manchester, Kentucky, the night of June 6, 2013. VMC had been forecast for the air ambulance’s route of flight, but witnesses said that patchy fog had developed over the base helipad, reducing visibility to 1/4 mi (1,200 m).
A witness near the helipad told investigators that the LongRanger appeared to be flying lower than normal before it spun to the ground. “The wreckage was located in a school parking lot, which was about 750 feet [229 m] from the landing pad,” the NTSB report said. “The wreckage distribution was consistent with an in-flight separation of the main rotor and tailboom.”
The NTSB concluded that the pilot likely lost control of the helicopter after experiencing spatial disorientation while maneuvering to avoid IMC. “Although the pilot was instrument-rated, he had not logged recent instrument time,” the report said. “Further, although the pilot had recent training in night vision goggle [NVG] use and had [NVGs] available during the flight, it could not be determined if he was using them at the time of the accident.”
Engine Ingests Shop Rags
McDonnell Douglas 369E. Substantial damage. Three minor injuries.
Two pilots and a maintenance technician employed by a sheriff’s department departed from Casa Grande, Arizona, U.S. the morning of June 25, 2013, for a post-maintenance test flight.
Shortly after conducting a power check, the pilot heard a loud pop that preceded a total loss of engine power. The pilot initiated an autorotation, but the 369 landed hard and rolled over.
Examination of the helicopter revealed that cloth material had been ingested into the engine air intake. “During further examinations, more cloth material was found in the engine in a sufficient quantity and location to block the airflow through the engine and cause it to flame out,” the NTSB report said. “The cloth material found in the engine was consistent with maintenance rags found in a box at the operator’s hangar facility.”
Noting that a new air inlet barrier filter system had been installed in the engine, the report said that the probable cause of the accident was “maintenance personnel’s failure to remove shop rags before completing the installation of the system.”