OGP is now IOGP
OGP is now IOGP The International Association of Oil & Gas Producers (known across the industry as OGP) has rebranded as IOGP to coincide with their 40th anniversary. They say: Over the past year we have been developing an updated brand for the International Association of Oil & Gas Producers. Our aim from the start: to have an identity that better reflects our global role and the industry we serve. While the organization’s formal name remains unchanged, the look is very different. Moreover our new abbreviation – which features an ‘I’ for ‘international’ – provides a fresh emphasis on our global remit as a trusted source of fact-based information and a credible advocate of the industry we serve. While the colour scheme is more garish this clearly isn’t one of the most fundamental rebranding exercises. Perhaps a little bizarrely the launch involved projecting the old and new logos on to the Tower of London (home of the crown jewels and historically a site of execution for traitors). Aerossurance is an Aberdeen based aviation consultancy with an international customer base. For independent advice you can trust on aviation safety & contracting for the oil and gas industry and first-hand knowledge of IOGP Aviation Management Guidelines (Report 590), IOGP Offshore Helicopter Recommended Practices (OHRP – Report 690) and the FSF BARSOHO Standard contact: enquiries@aerossurance.com Follow us on LinkedIn and on Twitter @Aerossurance for our latest updates. ...
read moreUK CAA Release CRM Videos
UK CAA Release Crew Resource Management Videos In an initiative to improve Crew Resource Management (CRM) in the industry the UK Civil Aviation Authority (CAA) has released a series of open-access training videos. The CAA comment that: The three case-study videos have been developed to highlight some of the main human factors concerns currently facing the aviation industry, such as ‘automation complacency’ and ineffective monitoring – both phenomena being the result of an over reliance on technology to the detriment of ‘hand flying’ skills. The momentum behind the production of the videos, and the need for a new approach to CRM training in the commercial air transport sector in general, came from research carried out by a panel of senior CAA and airline flight instructors and examiners. Analysis of 250 accidents involving large public transport aircraft, for example, shows that 28% of fatal accidents worldwide include flight handling issues and 24% include inappropriate action by crew (see CAP1036, Global Fatal Accident Review). An airline’s CRM training is now therefore a vital part of its overall safety strategy. The CRM panel’s full recommendations can be found at www.caa.co.uk/cap737 The Videos 1) Getting Out of Trouble: Multi Pilot CRM A reconstruction of an actual incident where a malfunction forced the crew of a large helicopter to divert to an unfamiliar airfield. Autopilot mode confusion during the glidescope capture results in loss of control a breakdown in collective situation awareness. 2) Getting Behind the Aircraft: Single Pilot CRM In a fictional incident poor pre flight planning results in missing a NOTAM regarding unserviceable glideslope. Distracted the business jet pilot then misses cues from ATIS, other aircraft and ATC and finds himself getting behind the aircraft. Committed to make a meeting a rushed steep descent almost ends in catastrophe. 3) Getting Down to Root Causes: Assessment of CRM Based on the reconstruction of an actual Line Orientated Evaulation (LOE) this video shows how human behaviour can be identified. The first briefing reveals knowledge differences between the FO and Captain while poor monitoring by the crew almost causes a stall. Bristow Group, FlightSafety International and Thomas Cook Airlines supported the production of these videos. Versions without captions or interviews (suitable for use in training discussions) can be found on the CAA YouTube channel. 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. Aerossurance has extensive air safety, design, human factors 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 moreNTSB Update on SpaceShip Two Accident
NTSB Update on SpaceShip Two Accident Today the National Transportation Safety Board (NTSB) issued a press release on progress with the investigation into the Virgin Galactic Scaled Composites Model 339 SpaceShip Two N339SS accident on 31 Oct 2014: November 12, 2014 WASHINGTON — The National Transportation Safety Board issued an investigative update today into the crash of SpaceShip Two on Oct. 31, 2014, in Mojave, Calif. • The on-scene portion of the investigation into the crash of Virgin Galactic/Scaled Composites SpaceShipTwo, a test flight conducted by Scaled Composites, has concluded and all NTSB investigators have returned to Washington, DC. • The SpaceShipTwo wreckage has been recovered and is being stored in a secure location for follow-on examination. • The NTSB operations and human performance investigators interviewed the surviving pilot on Friday. According to the pilot, he was unaware that the feather system had been unlocked early by the copilot. His description of the vehicle motion was consistent with other data sources in the investigation. He stated that he was extracted from the vehicle as a result of the break-up sequence and unbuckled from his seat at some point before the parachute deployed automatically. • Recorded information from telemetry, non-volatile memory, and videos are being processed and validated to assist the investigative groups. • An investigative group to further evaluate the vehicle and ground-based videos will convene next week at the NTSB Recorders Laboratory in Washington, D.C. • The systems group continues to review available data for the vehicle’s systems (flight controls, displays, environmental control, etc.) The group is also reviewing design data for the feather system components and the systems safety documentation. • The vehicle performance group continues to examine the aerodynamic and inertial forces that acted on the vehicle during the launch. The press release will again raise questions about the manner in which data about on-going investigations, particularly over the attributions of apparent actions of individual crew, is released early in the investigation. Professor Graham Braithwaite of Cranfield University recently presented to the International Society of Air Safety Investigators (ISASI) on the perils of working with the media in the aftermath of an accident, Previous briefings are available online: Additionally footage at the accident site is available: UPDATE 28 July 2015: Board Meeting : Commercial Space Launch Accident – SpaceShipTwo NTSB Final Report Executive Summary: On October 31, 2014, at 1007:32 Pacific daylight time, the SpaceShipTwo (SS2) reusable suborbital rocket, N339SS, operated by Scaled Composites LLC (Scaled), broke up into multiple pieces during a rocket-powered test flight and impacted terrain over a 5-mile area near Koehn Dry Lake, California. The pilot received serious injuries, and the copilot received fatal injuries. SS2 was destroyed, and no one on the ground was injured as a result of the falling debris. SS2 had been released from its launch vehicle, WhiteKnightTwo (WK2), N348MS, about 13 seconds before the structural breakup. Scaled was operating SS2 under an experimental permit issued by the Federal Aviation Administration’s (FAA) Office of Commercial Space Transportation (AST) according to the provisions of 14 Code of Federal Regulations (CFR) Part 437. Scaled had developed WK2 and was developing SS2 for Virgin Galactic, which planned to use the vehicles to conduct future commercial space suborbital operations. SS2 was equipped with a feather system that rotated a feather flap assembly with twin tailbooms upward from the...
read moreDash 8 Runway Excursion after Unstable Crosswind Approach – Danish AIB Report
Dash 8 Runway Excursion after Unstable Crosswind Approach – Danish AIB Report The Danish Accident Investigation Board (DAIB), the Havarikommissionen, has recently issued their report into an accident to Bombardier Dash 8-200 OY-GRI, operated by Air Greenland, at Greenland’s third largest town, Ilulissat (BGJN), on 29 January 2014. The DAIB summary states: Adverse crosswind conditions at BGJN led to flight crew target fixation, a flight crew divergence from the operator’s stabilized approach parameters and a mental blocking of an appropriate decision on going around. The flight crew divergence from the operator’s stabilized approach parameters induced a non-stabilized approach, which in combination with power levers retarded below flight idle in flight resulted in an accelerated rate of descent leading to a hard landing, with side load on the left main landing gear at touchdown. The left main landing gear structural fuse pin sheared as a result of lateral and vertical overload stress. Cycling the power levers between ground and flight range prevented an appropriate deceleration of the aircraft and prolonged the landing roll. The prolonged landing roll combined with the application of full left rudder and no decisive use of reverse thrust on the side with the unaffected main landing gear made it impossible for the flight crew to maintain directional control. The lack of directional control resulted in the aircraft running off the side of the runway and the safety zone, respectively. The aircraft was destroyed as it skidded off the and down an embankment. Fortunately only two minor injuries were sustained among the 15 occupants. The DAIB found the crew had agreed to a visual steep approach of 5.1° and a reference airspeed of 99kt. They also agreed a crosswind limitation of 31kt, above the operator’s limit of 25kt. The wind conditions given to the crew during short final approach warned of speeds up to 39kt. Though the DAIB comment about a possible confirmation bias: The combination of the ATS phraseology (“maximum to…… three niner knots) and at that time an increasing flight crew work load might have triggered the first officer’s perception of an ATS wind speed reporting of “maximum two niner knots”, which was below the flight crew agreed cross wind limitation of 31 knots. As the aircraft passed below 1,000ft airspeed was still 144kt, exceeding the operator’s stable-approach maximum of 119kt for that aircraft’s configuration. The airspeed was still 138kt shortly after descending below 500ft. The crosswind and a low flap setting of 15°, affected the crew’s ability to handle the aircraft. While still airborne, the crew retarded the throttle below the flight-idle setting – into the ‘beta range’ normally used on the ground. Use of this setting in flight presents risks propeller overspeed and engine damage, but a warning horn to alert the crew does not activate if the aircraft is below 20ft. The European Aviation Safety Agency (EASA) published a Safety Information Bulletin on crosswind landings earlier in the year. UPDATE 19 May 2016: The Japanese Transport Safety Board (JTSB) release their report into a heavy landing incident during training in crosswinds on Bombardier Dash 8-200 JA801B of Oriental Air Bridge in Nagasaki in February 2014. UPDATE 10 March 2017: Unstable Approach Dash 8 Touches Down 450ft Before Threshold UPDATE 24 April 2017: Unstabilised CL-600 Approach Accident at Aspen UPDATE 13 July 2020: ATR72 Survives Water Impact During Unstabilised Approach UPDATE 4 October 2020: Investigators Suggest Cultural Indifference to Checklist Use...
read moreBooming Airline Interior Sector Consolidates
Booming Airline Interior Sector Consolidates Recently in Aircraft Interiors International‘s 2015 Showcase Edition, Jon Lundberg and Ben Bettell of Counterpoint Market Intelligence recently reviewed the state of the airline cabin interiors industry, a $10.5bn market sector, that they forecast will expand faster than others sectors. They note that the civil airliner industry is seeing a period of strong growth with build rates reaching record levels. Consequently the supply chain is benefiting, with many sectors achieving impressive growth. The airline interiors sector is also benefiting from cabin upgrades due to strong competition between airlines to compete on the quality of their passenger experience. https://www.youtube.com/watch?v=tvnVRoGcJ1w Even in the short haul sector airlines are investing. In June 2014 Keith Williams, British Airways’ executive chairman, said: The short-haul landscape has changed enormously in recent years. To stay competitive and keep offering customers choice, great fares and great service, we are giving our cabins a radical makeover. There will be a new look, but the traditional British Airways’ comfort, elegance and value will remain. The need to provide passengers with restricted mobility more equitable facilities is also important: Another reason for this is simply to reduce weight. Meanwhile, Aerossurance previously looked at top end helicopter VVIP interiors in September. Airbus Helicopters has been developing a new cabin fit for the EC225 using a more comfortable Fischer seat with open headrests, which we had the chance to view a few months ago at the Airbus facility in Aberdeen. Counterpoint forecast that the compound annual growth rate for the interior sector will be 5.5% over the next 10 years (compared to 3.7% for engine parts and 2.7% for aerostructures). There has also been a lot of consolidation in the sector too, with Counterpoint highlighting two rapidly growing companies:: B/E Aerospace has acquired 23 other interior companies since 1987 (three this year alone: Emteq, Wasp and Fischer) Zodiac Aerospace had acquired 17 companies since 1992 (including Greenpoint Technologies this summer) Counterpoint argue there is still a role to play for smaller companies, but they will have to convince their customers of their financial stability and long term prospects. UPDATE December 2014: As a further illustration of the growth in this sector: Zodiac seat delays underscore broader constraint in supply chain, affecting Boeing 787 deliveries. Airbus deliveries have also been affected: A380 delays come as galley engineering constraint is apparent. One reason for the slight delay in the delivery of the first A350XWB is said to have been to similar Buyer Furnished Equipment (BFE) issues. One way to shorten time to market is collaboration and slicker certification: Airframers, suppliers collaborate to shorten lead times for seats: Consumer technology changes every six to 12 months, but the lead times required for bringing new aircraft seats with inflight entertainment systems to market can actually take years due to a variety of factors, including the lengthy and convoluted process for clearing Head Injury Criterion (HIC) certification. The result is that, by the time an aircraft enters revenue service, its integrated IFE/seats can look and feel somewhat outdated to passengers. Now the seat makers, IFE vendors and airframers including Airbus and Boeing are working together as part of a new Society of Automotive Engineers (SAE) aircraft seat committee to streamline testing and make certification easier. This in turn will help the industry keep pace with the rapidly changing consumer environment, and better support airframers’ ramp-up...
read moreGo Around Flap Overspeed and Altitude Exceedance – ATSB Report
Go Around Flap Overspeed and Altitude Exceedance – ATSB Report The Australian Transport Safety Bureau (ATSB) has issued a report on an occurrence during a go around: On 3 September 2012, an Airbus A321, registered VH-VWY and being operated by Jetstar Airways, was being flown on a scheduled passenger flight from Melbourne, Victoria to Cairns, Queensland. During a visual approach to runway 15 at Cairns, the aircraft drifted slightly high on profile and the captain instructed the first officer, who was the pilot flying, to go around. During the go-around, to 2,700 ft, exceeding the 2,000 ft limit assigned by air traffic control. The ATSB found that the first officer had a low level of expectancy of, and was not mentally prepared for, a go-around. Although the initial steps in the go-around procedure were implemented effectively, the first officer’s attention focussed on airspeed management and they did not retard the thrust levers from the take-off go-around detent to the climb detent at an appropriate point during the go-around. Consequently, the aircraft’s auto-thrust system was not activated to reduce the amount of thrust. After the initial breakdown in applying the go-around procedure, the crew experienced a high workload, which significantly limited their capacity to resolve the situation. The ATSB found that this occurrence had similar features to many previous go-around occurrences. In summary, all-engine go-arounds in modern air transport aircraft are often a challenging task when there is a requirement to level-off at a low altitude, and many pilots have had limited preparation for such tasks. Following this and a number of related occurrences, Jetstar Airways included ‘unscripted’ go‑arounds in its recurrent training sessions. One of these sessions also emphasised the importance of moving the thrust levers to the climb detent without delay. In August 2013, as a result of a detailed review of similar go-around occurrences, the French Bureau d’Enquêtes et d’Analyses pour la sécurité de l’aviation civile (BEA) issued a series of recommendations about go-around issues to the European Aviation Safety Agency. ATSB Analysis The ATSB identified these contributory factors: The first officer had a low level of expectancy that a go-around would be required and they were not mentally prepared to conduct the go-around manoeuvre. After conducting the initial steps of the go-around procedure, the first officer’s attention focussed on airspeed management and they did not retard the thrust levers to the climb detent in order to reduce thrust. After the initial breakdown in applying the go-around procedure, the crew was experiencing a high workload, which significantly limited their capacity to resolve the situation. When moving the flap selector to position 1, the captain paused at position 2 for a significant time period while they completed other tasks. Other factors that increased risk were: All-engine go-arounds in modern air transport aircraft are often a challenging task when there is a requirement to level-off at a low altitude, and many pilots have had limited preparation for this task. (Safety issue) Due to a limited amount of sleep in the previous 24 hours, the captain was probably experiencing a level of fatigue that has been demonstrated to have an influence on performance. ATSB Safety Message A go-around with all aircraft systems available to the crew is a normal but infrequently flown, dynamic manoeuvre, requiring a very methodical series of actions on...
read moreUK MAA NPA for RPAS
UK Military Aviation Authority Notice of Proposed Amendment on Remotely Piloted Air Systems The UK MAA has issued an NPA as part of the consultation on a change to the MAA Regulatory Publications (MRPs) to cover the better integration of RPAS. The MAA introduce the NPA as follows: The aim of the review of RPAS regulations is to ‘normalise’ the regulation of RPAS in the MAA Regulatory Publications (MRP) in order to create a more proportionate regulatory regime. The scope of the review is to address the accuracy, relevancy and coherency of extant regulation. Particular attention has been paid to the utility of implementing a classification framework for the regulation of RPAS and of determining the regulations which would be appropriate/applicable to each classification based on a determination of the likely Risk to Life (RtL) posed. Where duplication, omission, incoherence, ambiguity or unnecessary regulatory requirements were identified in the MRP, the relevant RAs [Regulatory Articles] have been amended, consolidated or new regulation introduced. The classification framework, which is considers both weight and both aggravating and mitigating factors is of particular note: The NPA can be found here: npa_14_14_combined. It is open for comment until 26 November 2014. UPDATE: The final results went live on 19 January 2015: https://www.gov.uk/government/news/new-regulations-for-remotely-piloted-air-systems-rpas-go-live Aerossurance has experience in UAS/RPAS going back to the mid 1990s. If you want to discuss their safety, technical, operational and regulatory issues, contact Aerossurance at: enquiries@aerossurance.com Follow us on LinkedIn for our latest updates. ...
read moreCrises – Failure of Conventional Responses
Crises – Failure of Conventional Responses After a major accident, as well as the emergency response to deal with the immediate casualties (a subject Aerossurance examined in May 2014), there is usually a need to deal with the resulting crisis. This is typically either a crisis of confidence in, or an adverse affect on, the organisation or organisations involved. Dr Ian Mitroff, Professor Emeritus at the USC Marshall School of Business at the University of Southern California, has identified 16 patterns that are common in crises. A poor performance or response in relation to any of these elements can deepen the crisis. 1) Uncertainty At the beginning of a crisis there is often a lot of uncertainty both on what has happened and what needs to be done. This is frequently evident after air accidents and similar events where evidence is either unavailable, quarantined or in the hands of accident investigators. Poor organisations hide from public view at this stage, awaiting clarity and certainty but actually creating a vacuum that is filled by the speculation of others. A recent poor example was the loss of MH370 which was widely regarded as a classic of poor response (PR week and MediaFirst). It contrast after the recent loss of the Virgin Galactic SpaceShipTwo, Sir Richard Branson was on site, engaging publically the next day and setting a dignified and concerned tone. His performance after the 2007 Greyrigg train derailment (an accident that was caused by rail deficiencies not by his companies train) is often regarded as a classic. Branson cut short a holiday to attend the site in Cumbria immediately and makes clear that Virgin care about ‘people’ and ‘safety’ above ‘profit’. He was able to show human empathy and avoided getting into a ‘blame game’ (see below). Notice his control during the interview. Another example held up as an impressive handling of a crisis was British Midland’s Sir Michael Bishop after the 1989 Kegworth accident. MediaFirst have published an insightful analysis of his actions here. It is noticeable that Bishop was on duty for the night of the 1967 Stockport Argonaut disaster, an accident that had a major influence on airliner survivability and on the exchange of safety data, and his experiences influenced his widely praised actions after Kegworth. 2) Trial By Image The footage of flames, smokes, wreckage or victims is repeatedly used by the media. Images of the disintegration of Space Shuttles Challenger and Columbia ironically represented those disasters as did the wreckage of MV Herald of Free Enterprise. In the later case, within 8 months of the 1987 accident, the operator Townsend Thoersen, whose origins went back to 1929, was rebranded by recent new owners P&O and her sister ships renamed. However, if an organisation issues images, they should be aware that they will be critically viewed, as this image below, purporting to show the scale of an emergency response was examined: 3) Objectivity is a Turnoff While it is logical to use data to refute speculation and to put a crisis in context, often when organisations attempt to counter speculation they are seen as uncaring or overly calculating when they use statistics (such as 5 year rolling accident rates – no matter how good). This is particularly when contrasted with highly personal accounts of tragedy. 4) The Court of Public Opinion Mitroff suggests that whereas in court you are innocent until...
read moreRoselawn Accident: ATR72 N401AM 31 October 1994
Roselawn Accident: ATR72 N401AM 31 October 1994 On 31 October 1994, 68 people died when an American Eagle ATR72, operated by Simmons Airlines, flying from Indianapolis to Chicago O’Hare, crashed near Roselawn, Indiana due to a loss of control after icing while holding. The aircraft was in a holding pattern and descending to a newly assigned altitude of 8,000 feet when the initial roll excursion occurred. https://youtu.be/0UdE8_PP_ik The National Transportation Safety Board (NTSB) investigation was published in two volumes: Volume I of this report explains the crash of American Eagle flight 4184, an ATR 72 airplane during a rapid descent after an uncommanded roll excursion. The safety issues discussed in the report focused on communicating hazardous weather information to flightcrews, Federal regulations on aircraft icing and icing certification requirements, the monitoring of aircraft airworthiness, and flightcrew training for unusual events/attitudes. Safety recommendations concerning these issues were addressed to the Federal Aviation Administration, the National Oceanic and Atmospheric Administration, and AMR Eagle. Volume II contains the comments of the Bureau Enquetes-Accidents on the Safety Board’s draft of the accident report. For those keen to analyse past accidents this accident is interesting because of prior incidents after icing with the ATR-42 and ATR-72. See the Federal Aviation Administration (FAA) Lessons Learnt discussion on this accident: There was disagreement between the NTSB and the FAA regarding whether Roselawn should have been foreseeable based on these previous incidents of roll instability in severe icing conditions. The five incidents involving the ATR-42 were: Mosinee, Wisconsin, December 22, 1988 Indian Ocean, April 17, 1991 Brecon, South Wales, United Kingdom, August 11, 1991 Newark, New Jersey, March 4, 1993 Burlington, Massachusetts, January 28, 1994 The FAA contended that the Roselawn accident was not foreseeable because: a) The roll anomalies in all of the pre-Roselawn ATR-42 incidents were induced by a stall, not by an aileron hinge moment anomaly as occurred during the Roselawn ATR-42 accident b) Unlike the Roselawn accident there was no evidence of higher than normal control wheel forces in the pre-Roselawn incidents One other source is Stephen Fredrick’s 1996 account, Unheeded Warning (Amazon.com / Amazon.co.uk). Fredrick was at the time an American Eagle ATR-72 pilot. In part it is the story of a whistle-blower and a couple of chapters suffer from the author’s closeness to the accident, but well worth a read. The accident anniversary is being marked today. UPDATE Just a few days later the FAA issued a final rule that addresses freezing rain and Roselawn recommendations! Other Safety Resources We have published other articles on icing including: De-Iced Drama: a Norwegian Air Shuttle Boeing 737-800 came close to stalling as a result of a blocked elevator. Canadian Mining Air Accident (Cessna 208B Caravan): where a cold soaked aircraft took off over gross weight due to accumulated ice from a previous flight. Cessna Citation Excel Controls Freeze due to leaking water. Breaking the Chain: X-31 Lessons Learned: where an experimental NASA aircraft was lost after pitot tube icing. ATP Serious Incident – Temporary LOC In Icing Conditions in Norway. ATR72 Control Problems in Severe Icing, Norway, 14 November 2016 The NTSB gave a presentation on icing in 2011. Icing conditions (ground and in flight) was the topic for a European Aviation Safety Agency (EASA) conference in 2013. For expert advice you can trust on aviation certification and safety matters, contact Aerossurance at enquiries@aerossurance.com Follow us on LinkedIn and on Twitter @Aerossurance for our latest updates....
read moreBoeing 737 Automation Related Descent Below Cleared Altitude – ATSB Report
Boeing 737 Automation Related Descent Below Cleared Altitude – ATSB Report The Australian Transport Safety Bureau (ATSB) has issued a report on an automation related occurrence: On 17 October 2012, a Boeing 737-838 aircraft, registered VH-VXB and operated by Qantas Airways Limited (Qantas), was conducting a flight from Adelaide, South Australia to Canberra, Australian Capital Territory… As the aircraft approached 8,000 ft, ATC provided a descent clearance to 7,000 ft and also cleared the aircraft for the approach. As the aircraft approached [approach fix] HONEY it descended below the 7,000 ft altitude clearance limit. After being alerted to this by ATC, the flight crew climbed the aircraft back to 7,000 ft and continued the approach to land. The ATSB found that, as the aircraft approached 8,000 ft, the auto-flight system vertical mode changed from a flight management computer-derived and managed vertical navigation mode into the vertical speed mode. This was followed by a number of automated, but unnoticed, and crew-initiated changes in the aircraft’s auto-flight system vertical mode. The combination of auto-flight system mode changes and the management of the airspeed during the descent resulted in a high workload environment where the 7,000 ft altitude clearance limit was overlooked by the flight crew. The ATSB also found that, on receipt of the approach clearance, the Qantas RNAV (RNP) approach procedures allowed the flight crew to remove the current limiting altitude from the auto-flight system’s Mode Control Panel (MCP) and set the decision altitude. Application of this procedure by the flight crew removed the last automated safety system available to them to prevent descent through the current altitude limitation, well before the aircraft was established on the approach. ATSB identified these contributing factors: The crew’s focus on managing the increase in the aircraft’s speed due to the high-speed descent and a reducing tailwind, combined with unintended mode changes in the aircraft’s automatic flight system, resulted in a high workload environment. Due to the workload associated with managing the high airspeed, the flight crew did not identify that the flight management computer-derived VNAV PTH mode had disengaged, which permitted the aircraft to descend below the calculated profile. The company’s Required Navigation Performance approach procedure allowed the flight crew to set the approach minimum altitude in the auto-flight system prior to commencing the approach. This did not ensure the altitude alerting system reflected the assigned altitude limit of 7,000 ft and removed the defence of that alert when the flight crew did not identify the disengagement of the flight management computer-derived VNAV PTH mode. [Safety issue] The high workload and removal of the assigned 7,000 ft limit from the altitude alerting system led to the flight crew’s loss of awareness of the descent clearance limitation. This loss of awareness, when combined with the high rate of descent, resulted in the aircraft descending below the descent clearance limit. Following this occurrence ATSB report that: Qantas changed their RNAV (RNP) approach procedures to only allow the altitude on the MCP to be changed from the current limiting altitude once the aircraft was within 2 NM (4 km) of commencing the approach. The ATSB has highlighted these safety lessons: The importance of paying continuous attention to active and armed auto-flight modes The need to continually monitor descent profiles and airspace limitations, irrespective of the expectation...
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