NTSB Probable Causes and Bad Apples
NTSB Probable Causes and Bad Apples (and the Bad Apple Index) During an on-line discussion about an Aerossurance post to mark the 20th anniversary of a CFIT accident in Guam, there was criticism that the NTSB ‘Probable Cause‘ was: The captain’s failure to adequately brief and execute the nonprecision approach and the first officer’s and flight engineer’s failure to effectively monitor and cross-check the captain’s execution of the approach. Some contributors rightly felt this simplistically blamed the crew (i.e. taking a ‘bad apple’ ‘old view’ of human error) rather than explained the accident. Others pointed out the accident was 20 years ago and investigators take a more sophisticated approach today. So we decided to look at the full NTSB air accident reports issued since the start of 2016: AAR1601: The Probable Cause was: “the pilot’s conduct…” (see Aircraft accident Embraer EMB-500 Phenom 100 N100EQ) AAR1602: The Probable Cause was: “the captain’s inability” (see Delta MD-88 Accident at La Guardia 5 March 2015) AAR1603: The Probable Cause was: “the flight crew’s mismanagement…” (see Execuflight Hawker 700 N237WR Akron Accident: Casual Compliance) AAR1701‘s Probable Cause, after a lot of debate in the public hearing, was “(1) preflight hydraulic check, which depleted hydraulic pressure… and (2) lack of salient alerting…” but the pilot’s actions were determined to be contributory (see Crashworthiness and a Fiery Frisco US HEMS Accident) AAR1702: The Probable Cause was: “(1) the pilot’s decision to…and (2) the company culture…” (see All Aboard CFIT: Alaskan Sightseeing Fatal Flight) AAR1703: The Probable Cause was: “the pilot’s pattern of poor decision-making…” (see Balloon accident Kubicek BB85Z N2469L) AAR1801: The Probable Cause was: “the failure of the high-pressure turbine (HPT) stage 2 disk…” (see Uncontained CF6-80 Failure: American B767-300 28 Oct 2016) AAR1802: The Probable Cause was: “the flight crew’s decision to continue the VFR flight into deteriorating visibility and their failure to perform an immediate escape maneuver after entry into IMC…” (see Operator & FAA Shortcomings in Alaskan Accident) That’s a 5.5 out of 8 bad apple index (69%) as far as we are concerned! In the NTSB Board debate over the one case (AAR1701) where the Probable Cause was not crew actions (or inactions), Board member Robert Sumwalt, who has recently been sworn in as NTSB Chairman, objected to the original draft Probable Cause saying: This pilot did not do what he was supposed to do. But if we dig deeper — and that’s what really bothers me about the original probable cause is that it is saying that the pilot screwed up… To put the pilot as the primary factor of the probable cause is just wrong, because it points to the last person who made the last mistake. I think we need to dig deeper to get to the root cause of this. So while the concept of Probable Cause is enshrined in US law, perhaps we will see a change of interpretation in future. Certainly the Contributory Factors identified by the NTSB are often better indications of what caused an accident than the official Probable Causes. Note: This is an update of an article originally published on LinkedIn by Aerossurance’s Andy Evans. Tracking the Bad Apple Index UPDATE 7 March 2019: AAR1901: The Probable Cause was: “the jammed condition of the airplane’s right elevator…” However “Contributing to the survivability of the accident was the captain’s timely and appropriate decision to reject the takeoff, the check airman’s disciplined adherence to standard operating procedures….”. If we score this as...
read moreA330 Starts to Taxi Before Tug is Clear
A330 Starts to Taxi Before Tug is Clear In the early hours of 9 September 2016 AirAsia X Airbus A330-343X 9M-XXK pushed back from gate D12 at Melbourne Airport, Victoria. The Australian Transport Safety Bureau (ATSB) say in their safety investigation report that: The aircraft maintenance engineer (AME) conducting the pushback was provided by a contracted company, the tug and tug driver were provided by a third company. At 0008, after both engines were started, the AME disconnected the headset and tow bar from both the aircraft and the tug, the AME also removed the bypass pin. The tug driver turned the tug around to allow the AME to attach the tow bar to the rear of the tug. The tug driver then moved the tug and tow bar to a position forward of the aircraft’s right engine and visible to the first officer. The AME then walked to a position in front of the tug, and displayed the bypass pin to the first officer. Sighting the bypass pin was the final item on the flight crew’s after start checklist. The flight crew then contacted ATC and obtained a taxi clearance. At 0009, the first officer confirmed to the captain that the AME and tug were clear, the captain then began to taxi. At this time, the AME was walking towards the left side of the tug, which remained parked forward of the aircraft’s right engine and wing. As the AME walked, they detected the aircraft’s taxi light illuminate and the aircraft begin to move. The AME then ran toward the tug door and alerted the tug driver to the aircraft movement. Video footage of the incident shows the tug driver taking action to avoid a collision with the taxiing aircraft. The ATSB explain that the flight crew procedures included the following steps: After the pushback and engine start sequence is complete, the bypass pin must be sighted. Once taxi clearance is obtained, the flight crew shall ensure both sides of the aircraft are clear prior to taxi The ground handling procedures include the following steps: Once the tow bar is connected to the tow vehicle (after being disconnected from the aircraft), the tow vehicle must move away to an area that is visible to the flight crew. At a suitable and safe distance from the aircraft, (the AME must) hold up the bypass pin to provide visual confirmation that it has been removed to the flight crew and give a ‘thumbs up’ signal indicating ‘clearance to proceed’. Once acknowledged by the flight crew, move away from the aircraft to a safe distance for the aircraft to taxi. The ATSB report that: The tug driver and AME both commented that they expected the aircraft to remain stationary until they had moved clear of the S7 disconnect point boundary. The flight crew commented to the ATSB: Both flight crew interpreted the AME displaying the bypass pin as meaning the tug and AME were clear, and it was safe to commence taxi. The flight crew assumed that ATC providing the taxi clearance meant that ATC had confirmed the tug was clear of the aircraft. The first officer observed the tug and AME to the right of the aircraft and assessed that they were clear of the right engine. The ATSB say that before this incident: In 2015, ATC provider, Airservices...
read moreC208B Force Landing After Inadequate Maintenance Fault Finding
C208B Force Landing After Inadequate Maintenance Fault Finding On 12 May 2016 Cessna 208B Caravan N1114A of the Parachute Center was substantially damaged during a forced landing near Acampo, California, 1 minute into a skydiving flight. The aircraft ended inverted in a vineyard, the pilot suffered minor injuries, but the 17 passengers were all uninjured. According to the US National Transportation Safety Board (NTSB) in their safety investigation report: The pilot reported that…as the airplane passed 1,000 ft above ground level (agl), the engine lost power. The rear door had been opened for ventilation and “one of the jumpers called out there was fuel streaming past the door“. The pilot initiated a turn toward the airport, however, realized he was unable to make it, and landed in an open field. During the landing roll, the airplane exited the field, crossed a road [at about 30 knots], impacted a truck [with two occupants], continued into a vineyard, and nosed over. The accident was filmed from inside by one passenger. Safety Investigation Examination of the wreckage revealed: The fuel pressure line that connects the fuel control unit to the airframe fuel pressure transducer, Pratt & Whitney Canada (PWC) part number 3033981, was fractured below the fuel control unit fitting swaged seat. The supporting clamp, PWC part number 3006614, was fractured and was separated from its mating fuel pressure fuel line, PWC part number 3032010. In addition, the airframe P3 air line that provides air to the vacuum system exhibited a hole within the tube. The operator reported that they had replaced the fuel line, PWC part number 3033981, the night before the accident due to the original fuel line being fractured. They stated that the new fuel line had about 4 hours of operational time since the installation. Review of the maintenance logbooks revealed that an entry regarding the replacement of the fuel line was dated April 11, 2016 [sic], with no airframe, engine, or HOBBS meter times listed. The operator…stated that the clamp was attached at the time of the fuel line replacement. Both the new and old fuel lines and separated clamp were sent to the NTSB Materials Laboratory for further examination. Lab analysis showed that both fractured tubes “were found to exhibit features consistent with crack initiation due to reverse bending fatigue”. The orientation of the reverse bending fatigue cracks and the spacing of the fatigue striations on the tube fracture surfaces were consistent with high-cycle bending fatigue due to a vibration of the tube. The cushioned support clamp is designed to prevent such vibrations from occurring. However, if the clamp tab is fractured, it cannot properly clamp the tube and will be unable to prevent the vibration. The NTSB concluded that “the clamp most likely failed first, resulting in the subsequent failure of the tubes”: Since the clamp was likely fractured when the first fractured fuel pressure line was replaced, the clamp was either not inspected or inadequately inspected at the time of the maintenance. Other Safety Information It is reported that since 1999, 15 people have died jumping “from planes that took off from the parachute center”. The Parachute Centre was involved in a fatal parachute accident later in 2016. In September 2016, following that accident, 20 instructors at the centre were suspended and 120 others were told they needed to undergo more training after an investigation...
read moreThe “Hold My Beer” Helicopter Accident
The “Hold My Beer” Helicopter Accident “Hold My Beer” is label applied on-line to video footage of many dangerous and/or ill-advised stunts, where the impending embarrassing and often painful failure is usually glaringly obvious before the end of the video. The US National Transportation Safety Board (NTSB) has reported on a helicopter accident that had a fatal alcohol fuelled ending. The Accident Flight On 12 June 2016 Robinson Helicopter Company (RHC) R44 II Raven N789MR impacted the ground during takeoff from the Classic Airstrip, near Jonesboro, Arkansas on a personal flight. The sole occupant, a 73 year old commercial licensed pilot, was fatally injured. The helicopter was destroyed by the impact and post-crash fire. A witness…reported that before noon, he saw the accident pilot drinking from a red cup that smelled like alcohol. The pilot refilled the cup 2 or 3 times during the next 2 or 3 hours. When the witness finished working on a task, he heard the pilot say that he was going to put on an airshow. The witness did say that ” I thought he was kidding “. However subsequently from a distance: The witness observed the helicopter lift off at a 45° angle backward and upward. The helicopter rose to about 125 ft and then descended out of sight behind hangars… The witness reported that he thought he “heard it hit”… The helicopter began to rise upwards above the hangars and it began to spin around. It appeared that the tail rotor was not working and the skids were bent as if it had hit the ground. The helicopter continued to rise to about the same height as when it lifted off. The helicopter then descended again, impacted terrain, and burst into flames in the middle of the west airstrip. The witness stated that another witness nearby called 911 and they waited for first responders to arrive. Medical And Pathological Information The autopsy indicated that the pilot’s cause of death was multiple blunt force injuries. A toxicology report indicated that the samples sustained putrefaction and listed the following findings: 418 (mg/dL, mg/hg) Ethanol detected in Blood 336 (mg/dL, mg/hg) Ethanol detected in Heart 309 (mg/dL, mg/hg) Ethanol detected in Lung 182 (mg/dL, mg/hg) Ethanol detected in Kidney 152 (mg/dL, mg/hg) Ethanol detected in Urine It should be no surprise to readers that: Ethanol is the intoxicant commonly found in beer, wine, and liquor. It acts as a central nervous system (CNS) depressant. After ingestion, at low doses, it impairs judgment, psychomotor functioning, and vigilance… The effects of ethanol on aviators are generally well understood; it significantly impairs pilots’ performance, even at very low levels. The NTSB note that: Federal Aviation Regulations prohibit any person from acting or attempting to act as a crewmember of a civil aircraft while having 0.040 gm/dl (40 mg/dl) or more ethanol in the blood. While ethanol can be produced in the body after death by microbial activity, the results indicate the pilot is likely to have been well over the regulatory limit. Diphenhydramine, a sedating antihistamine used to treat allergy symptoms and as a sleep aid, was also detected plus two other drugs that are considered ‘non-imparing’. NTSB Probable Cause The pilot’s failure to maintain helicopter control during takeoff. Contributing to the accident was the pilot’s impairment due to his combined use of alcohol and diphenhydramine,...
read moreInvestigators Criticise Cargo Carrier’s Culture & FAA Regulation After Fatal Somatogravic LOC-I
Investigators Criticise Cargo Carrier’s Culture & FAA Regulation After Fatal Somatogravic Loss of Control – Inflight (LOC-I) On 29 October 2014, Shorts 360 N380MQ, operated by SkyWay Enterprises as a Part 135 flight on contract to FedEx, crashed into the sea, shortly after a night time take-off from Sint Maarten in the Caribbean. The aircraft, which was was on a regular cargo flight to San Juan, Puerto Rico, was found on the sea bed 0.8 miles from the Princess Juliana International Airport, Sint Maarten (SXM). The two pilots, the only occupants, were both killed. The Sint Maarten Civil Aviation Authority (SMCAA) conducted an investigation into the accident. They raised safety issues that include: loss of situational awareness pilot monitoring duties loss of control / upset recovery crew resource management company safety culture FAA oversight and regulation of Part 135 operations and maintenance The Accident Flight The crew had reported for duty at 0845 in San Juan for the inbound flight to Sint Marteen, arriving at about 1130. The crew then had the day free, arriving back at the airport at about 1700. The SMCAA say that : The Captain observed the cargo loading and provided a cargo manifest to the ramp agent. A repetitive company flight plan was on file. The flight was approved for engine start by the Juliana Tower at 1817L. Area sunset was at 1742L and end of civil twilight at 1804L; night conditions and rain prevailed at the time… The flight commenced taxi to runway 28 at 1828L [and] was cleared for take-off at 1838L. At 1840L Tower personnel observed a normal take-off and initial climb. Then Tower personnel reported, [that upon] passing the departure end of the runway, the aircraft began descending both visually and on radar. There was no response to calls from the Tower…and the ATC data block for the flight no longer appeared on the airport radar screen. The first Coast Guard vessel was dispatched at 1900L. The sea and air search in the immediate hours of the crash confirmed aircraft debris in the area but there was no evidence of any flotation devices or survival equipment on the sea surface. The submerged wreckage was later located by divers. The operator had obtained the aircraft from American Eagle in 2000 and converted the aircraft to a cargo only configuration. In 2001 the GPWS, Rad Alt, CVR, FDR, attitude gyro, and TCAS were all removed. Part 135 only required these for passenger operations. However: A handheld GPS device was later recovered from submerged wreckage. …recorded data indicated the aircraft past the departure runway threshold on take-off and attained a maximum GPS altitude of 433 feet at 119 knots groundspeed at 18:39:30L. The two remaining GPS data points were over the sea and recorded decreasing altitude and increasing airspeed. A modification had been approved in 2005 that added an external antenna for this carry on GPS device. The Operator, its Safety Management and Safety Culture SkyWay Enterprises (SWE) was originally issued an FAA Air Carrier Certificate in 1979. They primarily operated cargo services within the Caribbean. When queried during the investigation both the DO [Director of Operations, who was also the company President] and the CP [Chief Pilot] stated that they had not been informed of any specific safety concerns nor had they seen the need to conduct safety meetings or distribute further information dedicated...
read moreHoist Assembly Errors: SAR Personnel Dropped Into Sea
Hoist Assembly Errors: SAR Personnel Dropped Into Sea (NASC UH-60M NA-703) On 30 June 2017 Sikorsky UH-60M Black Hawk helicopter NA-703 of the Taiwanese Ministry of the Interior National Airborne Service Corps (NASC) was conducted a Search and Rescue (SAR) training mission off Taichung Harbour, Taiwan. During the third hosting operation the hook assembly separated from the hoist cable, causing two rescuers to fall into the sea. The two were recovered by a surface craft. One sustained minor injuries but the other was seriously injured. The Aviation Safety Council (ASC) of Taiwan has released its final report on their investigation in Chinese only. The helicopter was fitted with a Breeze-Eastern BL29900-30-1 hoist. On 28 June 2017, ‘bird caging‘ had been detected on the hoist cable (a phenomenon where several outer strands become loose). The cable was replaced by NASC maintenance personnel. The ASC determined that the hoist hook had been inappropriately assembled doing that maintenance. ASC Findings Related to Cause During hoist cable replacement maintenance, an unknown external force may led the bearing [to be] moved and stuck in the bearing housing when the hook assembly was disassembled When assembling the hook assembly, the mechanic could not properly bottom the bushing nut to the bearing housing due to the bearing stuck in the bearing housing. A 1.5 mm gap was created between the lower flange bottom surface of the bushing nut and top surface of the bearing housing. The above gap caused the locking screws [to] not properly engage into the castled slots on the bearing housing. The inspector did not properly check whether the two locking screws were engaged into the castled slots on the bearing housing prior to the completion of the hoist cable replacement. Due to the two locking screws were not properly engaged into the castled slots on the bearing housing, therefore the bearing housing did not lock with the bushing nut. Without lock mechanism, the bearing housing was loosening from the screw threads of bushing nut and separated from the hoist assembly when hook assembly swivelled during hoist retrieving process. ASC Findings Related to Risk The mechanics and the inspectors neither understood and followed the procedures correctly during assembling nor visually inspected the locking screws were properly engaged into the castled slots on the bearing housing. They misunderstood that the locking screws were properly seated in the castled slots once the cotter pin holes could be seen. The NASC did not assign a proper quality inspector to perform the hoist maintenance for the occurrence helicopter. The inspector who performed the inspection of the hoist maintenance did not complete the type hoist maintenance training, had limited understanding of the hoist manufacture maintenance manual, and failed to conduct the vital point inspection correctly. Most maintenance manuals adopted by the NASC are in English. The NASC did not establish the English ability requirement and evaluation system of their mechanic[s]. The NASC did not have proper process to integrate/control both technical information from hoist manufacturer and technical manual from aircraft manufacturer regarding the hoist maintenance. The different understanding of how to use the manual existed in NASC different department that disadvantaged the NASC mechanic to use the manual correctly and conduct the training properly. The NASC did not record inspection results of vital point onto rescue hoist maintenance log as required by the hoist manufacturer maintenance manual. There are neither...
read moreMan Hit By Aircraft During Arctic Nuclear Sub Exercise
Man Hit By Aircraft During Arctic Nuclear Sub Exercise (UPDATED 19 Dec 2019) Often headlines disappoint. Well this story is exactly what the headline says. On 20 March 2018, de Havilland Canada (now Viking Air) DHC-6 Twin Otter N716JP struck an individual during take-off from a remote sea ice airstrip (‘Ice Camp Skate’), about 140 miles north of Deadhorse, Alaska (the flight’s destination). The US National Transportation Safety Board (NTSB) report that the casualty suffered serious head and neck injuries and the aircraft received substantial damage to the left wing and left aileron. The Part 135 VFR flight was operated by Bald Mountain Air Service as part of a contract for logistical support of ICEX 2018, a 5 week exercise with three US Navy and Royal Navy nuclear submarines (USS Connecticut, USS Hartford and HMS Trenchant) operating beneath the frozen Arctic Ocean. The Accident Flight The aircraft commander reported clear skies with ice pack haze. The airstrip was lined with snow berms on both sides. The take-off was to the North at 19:45 LT and he noted that: …the sun was low on the horizon, resulting in shadows on the airstrip, and that flat light conditions made it difficult to discern topographical features. The injured person, an employee of the Arctic Submarine Laboratory, who operated the site, made a statement that he had informed the aircraft commander that he would position himself alongside the runway to photograph the departure, behind the 3-4 ft tall snow berm. The aircraft commander reported that… …just before the takeoff roll, he and the first officer saw a pedestrian standing near the left side of the departure end of the airstrip. The aircraft commander stated that… As the takeoff roll continued, the airplane became airborne, so the captain lowered the nose to remain within ground effect and gain airspeed before initiating a climb. The captain added that, as the airspeed increased, he started to climb the airplane and then initiated a left turn. Both pilots reported that, during the turn, they heard a loud thump, which was immediately followed by an aileron control anomaly. The captain initiated a left turn back toward the airstrip and subsequently made an emergency landing. After landing, both pilots saw the pedestrian lying near a snow berm on the left side of the airstrip. The captain reported that he did not remember if it had been prearranged to have the pedestrian stand near the departure end of the airstrip during the departure. The pedestrian reported that…as the airplane’s takeoff progressed, it did not climb as quickly as it had during previous departures and that the last thing he remembered before the collision was seeing the left wing getting lower to the ground as the airplane began a left turn and flew toward him while continuing to accelerate. A security video camera recorded the accident sequence, and the recording supported the pedestrian’s account of the sequence of events. Although the captain reported that he climbed the airplane before initiating a left turn, the review of the video revealed that the flight crew operated the airplane at a low altitude and along a flightpath that placed it in dangerous proximity to the pedestrian (which was inconsistent with federal regulations) and left no margin to avoid the collision with him. The next thing the injured person remembered was waking up in the medevac helicopter. The aircraft was equipped with a...
read moreKing Air 200 Smoke and Fumes From Windshield Electrical Fault
King Air 200 Smoke and Fumes From Windshield Electrical Fault Privately owned Beechcraft King Air B200 JA01EP was climbing from FL150 to FL200 en route from Gifu to Takamatsu in Japan on 6 April 2017 when smoke and a burning smell appeared in the cockpit. The whole right windshield inner pane cracked “like a spider’s web”. The crew declared an emergency and diverted back to Gifu, making a safe landing. The Japan Transport Safety Board (JTSB) say in their safety investigation report that burn marks were subsequently found at and around the terminal block of the right windshield. The JTSB say: [The] right windshield terminal lug was loose and there was gap of 0.05mm between the screws and the terminal lugs. …it is probable that the smoke was generated by overheating the terminal block and the surrounding parts and components were burned out, because the electrical resistance at the contact points of the terminal block junction was increased, due to the loosened screws of the terminal block. Due to a previous partial delamination, the windshields had been replaced by a 3rd party maintenance organisation in January 2012. The JSTB note that: The description concerning the replacement of windshield in the maintenance manual do not include any reference to tightening torque for screws of terminal block, therefore, the screws were tightened using standard torque value (20 to 25 in-lbs). While inspections of the windshield are required every 200 flight hours for cracks and sealant deterioration, there is no requirement to check the power connection. As no subsequent problems were reported, no further maintenance had been conducted in this area in the subsequent 5 years The JTSB concluded that loosening of the screws likely occurred due to the vibration “because the tightening torque of the screws was not sufficient when replacing the windshield”. Safety Resources UPDATE 1 October 2020: JTSB have issued their report into a serious incident that occurred on 30 October 2019 to Bombardier CL-600-2C10 (CRJ100) JA11RJ of IBEX Airlines which suffered arcing and a cracked windshield. Professor James Reason’s 12 Principles of Error Management Back to the Future: Error Management Safety Performance Listening and Learning – AEROSPACE March 2017 Maintenance Human Factors: The Next Generation Airworthiness Matters: Next Generation Maintenance Human Factors Aerossurance worked with the Flight Safety Foundation (FSF) to create a Maintenance Observation Program (MOP) requirement for their contractible BARSOHO offshore helicopter Safety Performance Requirements to help learning about routine maintenance and then to initiate safety improvements: Aerossurance can provide practice guidance and specialist support to successfully implement a MOP. Aerossurance is pleased to sponsor the 9th European Society of Air Safety Investigators (ESASI) Regional Seminar in Riga, Latvia 23 and 24 May 2018 Aerossurance has extensive air safety, operations, airworthiness, human factors, aviation regulation and safety analysis experience. For practical aviation advice you can trust, contact us at: enquiries@aerossurance.com Follow us on LinkedIn and on Twitter @Aerossurance for our latest...
read moreIndian King Air Take Off Accident: Organisational & Training Weaknesses
Indian King Air Take Off Accident: Organisational & Training Weaknesses Beechcraft King Air 200 VT-BSA of the Indian Border Security Force (BSF) Air Wing crashed on 22 December 2015 after a Loss of Control – Inflight (LOC-I) shortly after take off on a flight from New Delhi to Ranchi. There were ten persons on board, all of whom were fatally injured. The Accident Flight In their report the DGCA India say: Shortly after take-off and attaining a height of approximately 400 feet AGL, the aircraft progressively turned left with simultaneous loss of height. It had taken a turn of approximately 180º and impacted some trees before hitting the outside perimeter road of the airport in a left bank attitude. Thereafter, it impacted ‘head on’ with the outside boundary wall of the airport. After breaking the outside boundary wall, the wings impacted two trees and the aircraft hit the holding tank of the water treatment plant. The tail portion and part of the fuselage overturned and went into the water tank. There was post impact fire and the portion of the aircraft outside the water tank was destroyed by fire. The weather at the time of accident at Delhi was foggy with visibility reported as 800 meters and winds of 3 knots. The previous METAR which was available with the flight crew mentioned visibility of 600 meters. The visibility was marginal and it is inferred that the marginal visibility was a contributory factor to the accident. The safety investigators explain that: As per the Pilot Operating Handbook procedure…the autopilot should be engaged only after attaining the height of 500 feet AGL… …however conversation recorded on the CVR indicates that… …the Autopilot was engaged just after the aircraft had lifted off (even the landing gear had not been retracted). This hurried and non-standard action by the flight crew…reveals their eagerness to let the aircraft be flown by the autopilot… Engagement of the autopilot without engaging the Heading Mode resulted in the aircraft turning left probably due to the existing left bank or inadvertent manual input by the flight crew at the time of engagement of the autopilot. The bank angle increased progressively and beyond 45º , a situation the flight crew could not decipher because of their disorientation. Organisational Factors and Culture The safety investigators make the point that: An Organisation may look compliant vis-a-vis the mandatory requirements but may still be seriously deficient in discharging its duties safely and efficiently. We would add, that they may even be compliant but effectiveness may be weak. The investigators elaborate: Therefore deeper analysis of the Organizational Structure & Procedures (if existing), and those practised is required to find out the answer to the circumstances leading to the accident. The safety investigators then note that: Civil Aviation Requirement Section 3 – Air Transport Series C Part X Issue I, gives the minimum procedural requirements for the issue of permission to undertake aircraft operations by State Governments or Public Sector Undertakings of the Central/ State Governments. Unlike in some other nations, this requires a Safety Management System (SMS) for such operations. However they determined that the Safety Department and SMS “was practically non-existent” (similar to a prior 2015 Indian offshore helicopter accident): From the discussions with the Officers who were designated as the Chief of Flight Safety in the present and past, it was noted that as and when any...
read moreSignificant Twin Otter NLG Crack
Significant DHC-6 Twin Otter NLG Crack A significant crack was found in the Nose Landing Gear (NLG) of a Viking DHC-6 Twin Otter according to a Service Difficult Report (SDR) submitted to the Civil Aviation Safety Authority (CASA) in Australia. The SDR states: During maintenance inspections, a crack was detected at the upper end of the nose landing gear outer cylinder. It was found that other operators had also experienced similar failures and…previous investigations had found that the crack originated from a corrosion pit found under the upper bearing installed on the outer cylinder. This is because the upper bearing migrates up and allows the moisture to penetrate. As a result a pit forms and thus results in the propagation point for a crack. Safety Resources Eclipse 500 Landing Gear Production Defect “Shoulda gone around”: B727 Landing with NLG Retracted Poor Painting Prevents Proper Performance: Shorts Sherpa NLG Collapse B1900D Emergency Landing: Maintenance Standards & Practices A Lufthansa MD-11F Nose Wheel Detached after Maintenance Error ATR72 VH-FVR Missed Damage: Maintenance Lessons B747 Landing Gear Failure Due to Omission of Rig Pin During Maintenance When Down Is Up: 747 Actuator Installation Incident Lost in Translation: Misrigged Main Landing Gear Maintenance Human Factors in Finnish F406 Landing Gear Collapse S-92A Nose Landing Gear Incidents UPDATE 28 April 2020: Beech 99A MLG Collapse Aerossurance has extensive air safety, operations, airworthiness, human factors, aviation regulation and safety analysis experience. For practical aviation advice you can trust, contact us at: enquiries@aerossurance.com Follow us on LinkedIn and on Twitter @Aerossurance for our latest...
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