Leonardo Strives For Greater Gearbox Loss of Lube Capability
Finmeccanica Strives For Greater Gearbox Loss of Lube Capability Finmeccanica Helicopters (the recently rebranded AgustaWestland (UPDATE: and now Leonardo) is working to enhance the durability of helicopter Main Gear Boxes (MGBs) after a loss of lubrication. The company’s Marco Tamborini presented their approach at the European Aviation Safety Agency (EASA) 9th Rotorcraft Symposium held in Cologne in December 2015. His presentation can be downloaded as part of a large zip file from the EASA website or here. Background – Certification & Controversy Often erroneously referred to as a ‘run-dry test’, an ‘Additional Test’, defined in 29.927(c), is required for Category A rotorcraft to demonstrate at least 30 minutes of operation after a loss of MGB lubrication (at least 29 minutes 35 seconds at the minimum torque necessary for sustained flight and then 25 second period to simulate the landing). In a certification memo issued in 2013, EASA say (emphasis added): The intent of the rule change for Category A rotorcraft was to assure that these rotorcraft have significant continued flight capability after the loss of lubricant to any single transmission in order to optimize eventual landing opportunities. Extending the bench testing beyond 30 minutes, although not required, is considered highly desirable. Accomplishing this would further improve the capability of the rotorcraft to reach a suitable landing location in order to improve occupant safety when operating in remote geographic areas that include harsh environmental conditions. The earlier certification of the Sikorsky S-92A MGB was controversial. As we have reported, the Norwegian Accident Investigation Board (AIBN) has recently commented: In 2002, Sikorsky carried out a test of the main gear box, where the oil was drained… A catastrophic failure occurred after 11 minutes. Accordingly, the requirement for 30 minutes’ safe operation was not met. With reference to AC 29-2C, Sikorsky decided to install a bypass valve in the external oil cooler circuit. By closing the valve, any external oil leaks could be stopped. It was considered extremely remote that other leaks in the oil system could prevent a safe landing within 30 minutes. This was accepted by the certification authority, the Federal Aviation Administration (FAA). Sikorsky was the only manufacturer to seek such an alleviation. In service two leaks occurred outside of the S-92A oil cooler, destroying the myth that such failures were extremely remote. Tragically the second resulted in the S-92A fatal accident offshore Canada in 2009 in which 17 people died, although miraculously one passenger survived. This has triggered both further work on helicopter ditching and on transmission loss of lubrication rule making. See also: Helicopter MGB oil system failure analysis using influence diagrams and random failure probabilities The Finmeccanica MGB Loss of Lubrication Strategy Finmeccanica has a 5 stage design strategy: Minimising the probability of a major oil loss (e.g replacing external pipe work with cast internal passages, having redundant pumps, fail-safe fittings, not sharing lubrication with external accessories and enhanced pre-delivery checks) Minimising power losses to reduce heat build up (e.g minimising the number of reduction stages, using fine pitch gears to reduce sliding velocity and super-finishing, adding shrouds to reduce windage drag, preferring roller bearings, ceramic elements and low friction coatings). At minimum cruise power the AW189 MGB efficiency is 96.5%. Maximising heat rejection (e.g improving MGB bay ventilation to help if flow through the oil cooler stops) Increasing high temperature running capability (e.g. maintaining clearances, plays and backlashes even at the highest expected temperatures, using High Hot Hardness (H3) steel for gears and bearings and heat tolerant silver-plated bearing cages)...
read moreSafety Lessons from TransAsia ATR-72 Flight GE222 CFIT
Safety Lessons from TransAsia ATR-72 Flight GE222 CFIT The Aviation Safety Council (ASC) of Taiwan has issued their investigation report into the loss of TransAsia Airways (TNA) ATR 72-500 B-22810 on 23 July 2014 during an attempted landing in poor weather. It highlights a number of important safety lessons. The Accident During a non-precision approach, after around 34 minutes of holding, the aircraft impacted terrain in a residential area 800m NE of the threshold of runway 20 at Magong Airport, Penghu Islands, Taiwan during a heavy thunderstorm associated with Typhoon Matmo. Ten of the 58 on board survived. The Commander was Pilot Flying (age 60, ex-military, joined airline in 1992, ATPL, 22,994 hours total, 19,070 hours on ATR42/72) and the First Officer (FO) was Pilot Monitoring (age 39, direct recruit by the airline in 2011, CPL, 2,393 hours total, 2,084 hours on ATR42/72). There was no approach briefing before commencing descent and the FO “proposed that he conducted the before landing check by himself without a cross-check”, which the Commander approved. The ASC say the Controlled Flight Into Terrain (CFIT) occurred because: The crew continued the approach below the [330ft] minimum descent altitude (MDA) when they were not visual with the runway environment contrary to standard operating procedures. When the aircraft had descended to 249 feet, the first officer illustrated the position of the [Missed Approach Point] MAPt by saying “we will get to zero point two miles”. At 1905:44, altitude 219 feet, the captain disengaged the autopilot. Four seconds later, the captain announced “maintain two hundred”. The captain maintained the aircraft’s altitude between approximately 168 and 192 feet in the following 10 seconds… The flight crew intentionally operated the aircraft below the MDA…while attempting to visually sight the runway so they could land the aircraft. Neither flight crew member recognised the need for a missed approach until the aircraft was at just 72ft, 0.5 nm beyond the MAPt, where impact with the terrain was “unavoidable”. Further accident site photos can be found here and here. During the investigation the ASC used an unmanned air vehicle (UAV aka RPAS aka drone) to assist with the site survey. Having discussed the effect of a cockpit gradient, the ASC note that in interviews with other TransAsia crews the consensus was that “the occurrence first officer would accommodate the captains’ flying habits, and tended not to challenge captains’ landing decisions”. We have previously discussed whether it is better for the Commander to be the Pilot Flying or the Pilot Monitoring and this accident re-emphasises that question. However, we do note below that the FO did intervene after several course, mode and communication errors by the Commander. Should We Just Blame the Pilots or Look Deeper? As is perhaps inevitable, the press simplistically ‘blamed’ ‘pilot error’. Reminiscent of two business jet accidents we have previously discussed in the US and France), the ASC say: According to the flight recorders data, non-compliance with standard operating procedures (SOPs) was a repeated practice during the occurrence flight. The ASC also say the Commander was “likely overconfident in his flying skills”, potential the reason for pressing on below MDA. We do note however a Uni Air ATR72-600 aircraft had successfully landed on Runway 20 just 8 minutes earlier which may have influenced the Commander’s behaviour. However, it would be no surprise to any aviation safety professional that the ASC report revealed a range of systemic factors. Systemic Factors – Fatigue The ASC used QinetiQ’s System for Aircrew Fatigue Evaluation (SAFE) biomathematical fatigue model in...
read moreNASA Challenger Launch Decision
NASA Challenger Launch Decision On the evening of Monday 27 January 1986 34 people in three locations were preparing for what we now know as one of the most infamous telephone conferences in history. The call had been prompted by a weather forecast that predicted the temperature would drop to 22°F (-5.5ºC) overnight. This group was just one of a number that night who had to decide if this would affect an event planned for 09:38 the next day. For at that time NASA planned to launch the Space Shuttle Challenger on flight STS-51L, with seven people aboard, from Kennedy Space Centre (the 25th Shuttle launch). Seventy three seconds after launch, travelling at over Mach 3 at an altitude of 10.4 miles the vehicle exploded. We will look at this telecon and in particular the conclusions of a study by sociologist Prof Diane Vaughan, from her book: The Challenger Launch Decision, published on the 10th anniversary of the disaster, and other selected viewpoints on the disaster. The Circumstances The presidentially appointed Rogers Commission was tasked with investigating the accident. Over time the technical cause emerged. In their report the Commission identified that the low temperatures had compromised the reaction of rubber ‘O’ rings that needed to move to seal the segments of the vehicle’s Solid Rocket Boosters (SRBs sometimes called SRMs: Solid Rocket Motors) as the casing swelled under pressure of the rocket gases. The slow reaction of the stiffened ‘O’ rings has allowed hot combustion gases to erode the ‘O’ rings and ultimately, these gases escaped, causing a catastrophic explosion of the large external fuel tank. Commission member and maverick physicist Richard Feynman’s demonstration of the stiffening of an ‘O’ ring at low temperatures with a cup of ice water, an ‘O’ ring and a C-clamp has entered popular folklore. The affect of cold had been recognised before. NASA and engineers at Morton Thiokol, the SRB contractor, had been examining anomalies in ‘O’ ring performance from previous launches. Concerned that the launch was outside past launch experience and suspecting cold was a factor, when the forecast came through Morton Thiokol made a “no launch” recommendation. This was something they had never done before. The infamous telephone conference was to discuss that recommendation with the NASA SRB specialists and managers. The data they faxed to NASA to make their case was the same data they had previously used to support earlier launch recommendations, even though they now proposed a new temperature limitation. Not only did that inconsistency draw NASA challenge, but blow-by on a 75ºF launch seemed to undermine the claimed correlation. In the face of questions from NASA, the Morton Thiokol team in Utah asked for a brief off-line caucus to gather their thoughts. Unbeknown to participants at the Kennedy Space Centre and elsewhere, senior managers at Morton Thiokol decided to reverse that recommendation (one famously having been told to “take off your engineering hat and put on your management one”) without seeking a consensus with their engineers. Statistician Edward Tufte has highlighted that if all ‘O’ ring performance had been presented, a different decision would likely have been made. However, it is unclear how much of this data had been collated in one place at that time. Ironically the telecon was 19 years to the day since three astronauts of Apollo 204 (aka Apollo 1) died in a launch pad ground test fire. Many media commentators have speculated on overt or perceived NASA HQ...
read moreHEMS S-76C+ Night Approach LOC-I Incident
HEMS S-76C Night Approach Loss of Control – In-flight (LOC-I) Incident A Helicopter Emergency Medical Service (HEMS) Sikorsky S-76C+ C-GHHJ operated by Helijet on behalf of the BC Ambulance Service was on a VFR approach to the coastal Tofino/Long Beach Airport (CYAZ), British Columbia, Canada at 02:39 Local Time on the dark, moonless night of 15 November 2015. It suffered a Loss of Control and cleared the ground by just 3ft. An occurrence report update, dated 27 November 2015, posted by Transport Canada stated: …after flying an autopilot coupled approach (RNAV29) to an altitude of 600 feet MSL in the vicinity of the threshold to Runway 29, the crew uncoupled the autopilot and continued to maneuver visually for the planned landing area. While on final approach, a high rate of descent (1100 [feet per minute] fpm) and low airspeed developed, accompanied by a violent left and right movement. The crew applied collective and forward cyclic input and the aircraft recovered at low level and airspeed. Subsequent engine and airframe indications appeared to be normal and the crew completed a second approach for an uneventful landing. A post landing inspection revealed the presence of oil on the rotor blades and airframe. A maintenance inspection confirmed that the rotor hub spindles and a damper were damaged. A press report in December suggested the main rotor speed (NR) dropped so low that the AC generator dropped off line. They also state the patient the helicopter was due to collect, a stroke victim, was collected by a fixed wing air ambulance later in daylight. Bill Yearwood of the Transportation Safety Board of Canada (TSB) said in a TV interview: Below 600 feet there were some excursions in heading and evidence of a high rate of descent, as much as 2,500 feet a minute for a very short time. After examination of the Flight Data Recorder we were able to determine the main rotor transmission was most likely over-torqued. That concern was raised and the company grounded the aircraft and changed all the drive train components. This is significantly greater than the initial maintenance action reported (changing the main rotor spindles). Its not clear from the interview if the aircraft had continued flying before the FDR was analysed. However an occurrence update dated 21 December 2015 on a subsequent, 25 November 2015, occurrence involving C-GHHJ states the helicopter was: …preparing to depart Vancouver, BC (CYVR) on a MEDEVAC flight to Chemanius, BC. Upon raising the collective to lift off from the helipad, the flight crew detected a high frequency vibration in the flight controls and an abnormal noise. When the collective was lowered the vibration and noise ceased. Another attempt to takeoff was conducted with a similar vibration and noise observed. The aircraft was taxied back to the hangar and maintenance personnel were consulted. Drivetrain components, including the aircraft’s transmission, were replaced and helicopter was returned to service. The local press also claim that both pilots were dismissed after the Tofino incident. This has not been independently confirmed but the TSB comment: It would be uncomfortable or disturbing to find out that actions were taken based on our investigation or the data that’s provided for our investigation. In their Safety Policy the operator states: Helijet supports and will exercise a non-punitive environment for individuals who are intending to prevent an injury or accident or are reporting any...
read moreCAP1145 Helicopter Water Impact Survivability Statistics – A Critique
CAP1145 Helicopter Water Impact Survivability Statistics – A Critique Eurocopter AS332L2 G-WNSB impacted the sea 1.5 nm west of Sumburgh Airport, Shetland Islands on 23 August 2013 (see the last AAIB Special Bulletin) with the loss of 4 lives. https://youtu.be/C_3xlunGUk0 Within weeks the UK Civil Aviation Authority (CAA) ordered a hurried safety review. This resulted in the CAP1145 report (‘Safety review of offshore public transport helicopter operations in support of the exploitation of oil and gas’), issued in 20 February 2014. CAP1145 states that between 1976 and 2012 there were 12 fatal accidents involving offshore oil and gas helicopters. These involved 115 fatalities (although 45 were in a single accident, Boeing BV234LR G-BWFC in 1986 [AAIB Report] due to a gear box failure and two related to helideck officer fatalities). Therefore in the 40 years from 1976 to 2015 there were 13 fatal accidents and 119 fatalities. Note: The first UK offshore oil and gas helicopter flight was in February 1965, using a Bristow Westland Whirlwind to the Mr Cap jack-up rig off Sunderland. In CAP 1145, and one year later in the first paragraph of Chapter 1 of CAP 1243, the Offshore Helicopter Review Progress Report, the CAA specifically emphasised that: Evidence showed that just over half of the accidents in which offshore helicopters impacted the sea between 1976 and 2012 were potentially survivable, but led to 38 fatalities. This relates to crashes into the sea surface, rather than deliberate and controlled ditchings. They also say that 31 of the 38 failed to escape the crashed helicopter. They then go on to justify a Safety Directive on enhanced Emergency Breathing Systems (EBS) and more restrictive seating arrangements depending on passenger and push-out window size. However, readers who closely studied the list of offshore oil and gas helicopters accidents between 1976 and 2012 in CAP1145 Appendix 1 to Annex C ‘Review of Accidents’ would have been unable to identify these 38 fatalities. Checking the Facts Behind the UK CAA Statement We asked the CAA to identify which accidents they included. They identified 9 accidents with 39 (not 38) fatalities in that time period. One third of those accidents and 20 of the 39 fatalities do not relate to offshore oil and gas flights and so aren’t detailed in the CAP1145 Annex C ‘Review of Accidents’. Mixing datasets can lead to the suspicion of searching for data to support your chosen course of action. The CAA say that these non-oil and gas accidents have lessons that are relevant to oil and gas survivability, though of course so would non-UK accidents. However, an accident 20, 30 or 40 years ago will feature non-crashworthy seating and potentially primitive safety equipment that may render any supposed lessons void. Below we look to see how relevant these accidents are for improvements to water egress, just one element of surviving an offshore accident, but the element that received most attention in CAP1145. We have marked then RELEVANT or IRRELEVANT in relation to the benefit of having an EBS that can be deployed underwater ( a ‘Cat A’ EBS, something we discussed in an earlier article) and of having a window exits compatible with the size of the passengers who would have to use it. We have also considered, based on information in the AAIB reports, if the occupants who died inside the aircraft were in a fit state after the impact to egress with such enhancements. This is clearly subjective, but vital to understand when...
read moreMaintenance Personnel Fatigue and Alertness
Maintenance Personnel Fatigue and Alertness Maintenance personnel fatigue and a consequential lack of alertness is regularly being identified as contributory, or potentially contributory, to maintenance related air accidents and serious incidents. We have covered three examples previously: Some involve poor shift patterns: Missing Igniters: Fatigue & Management of Change Shortcomings: The UAE GCAA investigation report explains most of the maintenance personnel were working a 56 days on / 28 days off shift pattern with no intermediate rest days. Some involve shortages of personnel and overtime: e.g. A319 Double Cowling Loss and Fire: The UK AAIB investigation report highlighted that due to long-term staff shortages both the personnel directly involved were working overtime (one had worked 70.2 hours in total in 7 days, the other 55.8 hours). And involve last minute changes of rosters, sleep patterns and working on until a job is complete: e.g. Fatal $16 Million Maintenance Errors: In this fatal accident the US NTSB the two personnel, were asked to come in early the next day during their rest period. The mechanic managed just 5 hours sleep that night, the inspector 7 hours. The critical inspection was completed near the end of a 13 hour 24 minute shift. In 2010 the Royal Aeronautical Society (RAeS) Human Factors Group: Engineering (HFG:E) published a Guidance Paper Military Maintainer & Groundcrew Working Hours and Fatigue Risk Management by Major Chris Evans and an associated risk assessment diagram: This model was designed to be a quick but useful way to predict fatigue in combat deployments. There other techniques such as the HSE fatigue and risk index tool used by the AAIB during the A319 investigation. UK CAA Paper 2002/06 – The Folkard Report is also a useful resource. Dossier – Fatigue Awareness If you found this helpful you might like these other Aerossurance articles: Maintenance Human Factors: The Next Generation Aircraft Maintenance: Going for Gold? Professor James Reason’s 12 Principles of Error Management Back to the Future: Error Management How To Develop Your Organisation’s Safety Culture Critical Maintenance Tasks: EASA Part-M & -145 Change Does Continuation Training Change Behaviours? Coaching and the 70:20:10 Learning Model UPDATE 4 April 2016: Fatigued Flight Test Crew Crosswind Accident UPDATE 14 June 2017: Perception and Fatigue: CH124 Sea King Engine Failure This article was originally published on LinkedIn. UPDATE 10 July 2018: Delighted to have co-presented at a World Food Program (WFP) webinar on alertness and maintenance fatigue today. Other research, from healthcare, highlights that compliance with routine ‘secondary’ requirements, such as hand washing, drops the longer a shift is, but do improve the longer the intermediate rest period is: NTSB Most Wanted 2014: UPDATE 23 March 2016: The Federal Aviation Administration (FAA) has launched a consultation on AC120-MFRM Maintainer Fatigue Risk Management: This advisory circular (AC) describes the basic concepts of human fatigue and how it relates to safety for aviation maintenance organizations and individual maintainers; provides information on Fatigue Risk Management (FRM) in terms of fatigue hazards and mitigation strategies specific to aviation maintainers; describes the benefits of implementing FRM methods within aviation maintenance organizations; and identifies methods for integrating FRM within a Safety Management System (SMS) (if applicable). Personnel fatigue was first identified as a critical issue in aviation maintenance by the National Transportation Safety Board (NTSB) in 1996, stemming from the ValuJet accident in Florida. Since then, it continued to gain attention as a maintenance safety risk: 1) In 2000, an FAA field study that collected...
read moreHUMS Vibration Health Monitoring Success
HUMS Vibration Health Monitoring Success Australia’s Civil Aviation Safety Authority (CASA) has published a Service Difficulty Report (SDR), dated 1 November 2015, that highlights a Health & Usage Monitoring System (HUMS) Vibration Health Monitoring (VHM) success. During investigation of a HUMS vibration alert, the main rotor head of an Airbus Helicopters EC225/H225 offshore helicopter was examined and wear was identified beyond the limits specified in the maintenance manual. The damper assembly (Time Since New [TSN]: 1047 hours) was replaced. The offshore helicopter safety organisation, HeliOffshore, has launched a Health & Usage Monitoring System (HUMS) Best Practice Guide to standardise and improve HUMS use worldwide. Among our past articles on HUMS/VHM are: Aerossurance Wins MAA HUMS Maintenance Credit Contract EASA HUMS Research Developments EASA & FAA HUMS / VHM Developments HeliOffshore Launch HUMS Best Practice Guide Helicopter HUMS Maintenance Credit: New Initiatives UPDATE 14 June 2020: Freewheel Jerk on an SA330J Puma at Sea: Oil Analysis Opportunity Aerossurance is an Aberdeen based aviation consultancy with extensive HUMS and VHM experience. For practical advice and support you can trust on HUMS/VHM and all aspects of helicopter design and continuing airworthiness contact us at: enquiries@aerossurance.com Follow us on LinkedIn and on Twitter @Aerossurance for our latest...
read moreCSB: ‘Multiple Safety Deficiencies’ Led to ExxonMobil Refinery Explosion
CSB: ‘Multiple Safety Deficiencies’ Led to ExxonMobil Refinery Explosion The US Chemical Safety Board (CSB) report that they have “uncovered multiple process safety management deficiencies” that led to the 18 February 2015, explosion at the ExxonMobil Torrance refinery, California and an associated serious near miss. The CSB explain: …two workers were injured when an explosion occurred in the refinery’s electrostatic precipitator, or ESP, which is a piece equipment used to control air pollution. Due to a series of events that unfolded over several days, hydrocarbons accumulated inside the ESP. The result was a blast that dispersed large quantities of catalyst dust up to a mile away from the facility. The sequence of events that eventually led to the explosion at the refinery began on February 12, 2015, when problems with a piece of equipment called an expander caused the refinery’s fluid catalytic cracking, or FCC, unit to be put into a idled condition referred to as safe park. With the FCC unit shut down, steam was forced into a reactor to prevent hydrocarbons from flowing back from the main distillation column. On the morning of the accident, this steam was escaping through an open flange on the expander, preventing operators from continuing their maintenance work. It had travelled through a leaking slide valve connected to the reactor. An outside supervisor then reduced the amount of steam being forced into the reactor so that work could continue. However, at the time, workers were unaware that hydrocarbons were leaking into the main distillation column from interconnected equipment. As the pressure of the steam dropped, the hydrocarbons flowed back into the reactor, out through the leaking slide valve and eventually into the ESP. There the hydrocarbons found an ignition source – and exploded. The explosion scattered debris around the site: One of these pieces of debris hit scaffolding in the refinery’s alkylation unit, narrowly missing a tank containing tens of thousands of pounds of modified hydrofluoric acid, or HF. HF is used by some refineries in a step for the manufacture of unleaded fuel. That debris is reported to have been equipment weighing 36 tonnes (80,000 lb): That neighbouring community includes 333,000 residents, 71 schools, and 8 hospitals within 3 miles of the ExxonMobil Torrance facility. CSB Chairperson Vanessa Allen Sutherland says: Hydrofluoric acid can pose a severe hazard to the population and environment if a release occurs. After HF acid vaporizes it condenses into small droplets that form a dense low-lying cloud that will travel along the ground for several miles and can cause severe damage to the respiratory system, skin, and bones of those who are exposed, potentially resulting in death. Consequently: The CSB determined that had the debris struck the [HF] tank, a rupture could have been possible, resulting in a potentially catastrophic release of extremely toxic modified HF into the neighbouring community. It is reported by the local media that ExxonMobil disagree on the threat to the community amd says it had taken “unspecified” “corrective actions” to prevent a re-occurrence. It is also reported by the press that ExxonMobil claim to have 136,000 pages of documentation and 67 interviews to the CSB. Yet the CSB say: …investigators have faced a lack of cooperation from ExxonMobil to comply with their requests for information about the near miss incident involving the alkylation unit and modified HF even after repeated voluntary requests and subpoenas. To date, the...
read moreThe Passengers Who ‘Caused’ a 737 Tail Strike: Ground Handling Lessons
The Passengers Who ‘Caused’ a 737 Tail Strike On 12 January 2003 a serious incident occurred involving Transavia Boeing 737-800 PH-HZB at Rotterdam. The Dutch Safety Board (DSB) report says the aircraft: …pitched nose-up just after take -off thrust had been selected. The pitch up movement stopped when the aft fuselage and the tailskid assembly contacted the runway. The crew rejected the take -off, after which the aircraft’s nose came down again to the ground. The aircraft sustained damage to the lower fuselage area in front of the tailskid, to the tailskid and to the nose gear. There were no injuries to persons. The Investigation So what did the passengers have to do with this? Well, nothing in relation to any action they took but everything to do with it in relation to the body weight of the 113 passengers and where they had been allocated seats! The aircraft was scheduled for flight from Rotterdam, via Maastricht-Aachen to Arrecive, Lanzarote. The DSB found that: …nearly all passengers at Rotterdam Airport were checked in at the rear of the cabin and seated themselves there. To facilitate boarding at the next airport (Maastricht-Aachen Airport) the ground handling company Aviapartner had assigned these rear seats to the passengers at Rotterdam Airport. After all, this allowed passengers at MaastrichtAachen Airport to seat themselves in front of the cabin. Because of the uneven passenger distribution, the aircraft’s centre of gravity was situated far behind the applicable aft limit. As a result the nose of the aircraft pitched up and its tail touched the ground. The DSB used Tripod-Beta as an accident analysis tool. Tripod-Beta is derived from classic bow-tie theory. The DSB identified four main groups of contributing factors: The flight crew’s centre of gravity awareness (and so failed to “respond adequately” when the cabin crew reported the uneven passenger distribution) The loading procedures (a “process of producing the load and trim sheets is separated in time and place from the process of actual loading”) The airline’s supervision of its ground handling company, who had come on contract the previous year, and the airline’s quality system (both inconsistent reporting and “an internal audit, identified several deficiencies…[but] the subsequent corrective actions…were insufficient” say the DSB, and while crew had reported loading problems in the past, various methods had been used, limiting the ability to detect a trend) The effectiveness of the ground handling company’s quality system (as the DSB say the company “did not instruct and train its staff sufficiently”) The DSB also state: Search in databases of other Safety Boards and international organizations revealed that similar occurrences of uncommanded pitch up movements on the ground had occurred. In three cases the aft limit of the CG for take-off was exceeded. The cause was that the distribution of the passengers in the cabin deviated from the load and trim sheet used by the cockpit crew. In another case a significant error in the CG calculation itself was made. Safety Recommendations Consequently recommendations were raised. To the airline: Enhance its pilot’s awareness about the effect of passenger distribution on the centre of gravity of Boeing 737-800 aircraft, and Evaluate its quality system, in particular regarding the: supervision on contracted ground handling companies; results of audits, and the effectiveness of associated corrective actions; procedures about reporting safety-related occurrences. To the ground handler: Improve its quality system as such that shortcomings regarding the dispatch of passengers become visible. To Minister of...
read moreAerossurance Marks RAeS 150th Anniversary by Sponsoring Rotorcraft Automation Conference
Aerossurance Marks RAeS 150th Anniversary by Sponsoring Rotorcraft Automation Conference The Royal Aeronautical Society (RAeS) was founded on 12 January 1866, so is today celebrating its 150th anniversary (or sesquicentennial). To mark this significant milestone Aerossurance is pleased to be sponsoring the Society’s 2016 Rotorcraft Conference. This conference, to be held 6-7 July 2016 at the Society HQ at 4 Hamilton Place, London, will be the second in the series of ‘Automation & Offshore Operations’ conferences held by the RAeS Rotorcraft Group. Aerossurance was delighted to attend and report on the 2014 conference: Technology Friend or Foe – Automation in Offshore Helicopter Operations. The 2014 Technology Friend or Foe conference was triggered by: A CFIT accident on approach to Sumburgh airport in August 2013 (AS332L2 G-WNSB), for which the UK Air Accidents Investigation Branch (AAIB) final report is expected soon (UPDATE 15 March 2016: AAIB Report on 2013 Sumburgh Helicopter Accident), The issue, a few weeks later in 2013, of a Transportation Safety Board of Canada (TSB) report into a serious incident where S-92A C-GQCH where the helicopter descended to within 38ft of the sea, and The realisation that automation issues were not addressed in detail in the UK Civil Aviation Authority (CAA) North Sea Review, which resulted in the CAP1145 report (the ‘Safety review of offshore public transport helicopter operations in support of the exploitation of oil and gas’) issued 20 February 2014. The RAeS will publish further details of the 2016 Rotorcraft Conference in due course. Confirmed Speakers include: Dr Hazel Courteney, Head of Research Management, Civil Aviation Authority Capt Ian Scott FRAeS, Head of Aircraft Services UPX, Shell International Simon Sparkes, Head of Rotary Wing, Nova Systems Rick Newman, Flight Operations Manager – Helicopter, Civil Aviation Authority UK Alex Stobo, Director of Operations, Babcock Mission Critical Services Onshore Lt Steve Baldie, Training Officer 846 Naval Air Squadron, Royal Navy Adam Poole, WW Customer Support & Service, AgustaWestland / Leonardo Helicopters UPDATE: HeliOffshore Conference Summary RAeS Conference Report: what good might look like The Royal Aeronautical Society Originally formed as the Aeronautical Society of Great Britain, the Society gained its Royal Charter in 1918. The Society now has over 20,000 members and is an international, multidisciplinary professional institution dedicated to the global aerospace community. Extra Helicopter Automation Resources: The European Helicopter Safety Team (EHEST) has published: Safety Leaflet HE9 Automation and Flight Path Management At the EHEST Safety Worksop at Helitech in London in October 2015: The UK CAA gave this presentation: Training – Overview of Automation Issues Airbus Helicopters presented: Training – For Automation UPDATE 18 September 2016: AAIB: Human Factors and the Identification of Flight Control Malfunctions UPDATE 9 January 2017: HeliOffshore have released a HeliOffshore Automation Guidance document and six videos to demonstrate the offshore helicopter industry’s recommended practice for the use of automation. UPDATE 13 August 2018: Isn’t it ironic, don’t you think Thirty-five years ago a paper was presented entitled Ironies of Automation, by Lisanne Bainbridge. It included many insightful ideas: The designer’s view…may be that the operator is unreliable and inefficient… so should be eliminated from the system. There are two ironies of this attitude. One is that designer errors can be a major source of operating problems… The second irony is that the designer who tries to eliminate the operator still leaves the operator to do the tasks which the designer cannot think how to automate…it means that the...
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