AC-130J Prototype Written-Off After Flight Test LOC-I Overstress
AC-130J Prototype Written-Off After Flight Test LOC-I Overstress The prototype US Air Force (USAF) AC-130J Ghostrider, 09-5710, has been declared a total loss after the airframe was “severely overstressed” after a Loss of Control – Inflight (LOC-I) during a flight test from Eglin AFB, Florida on 21 April 2015. Loss of the aircraft is estimated at $115.6 million. The Occurrence The aircraft “exceeded its design limit load to an extent that rendered it unsafe for flight and is considered a total loss to the Air Force” during a “medium risk” test sortie according to Air Force Materiel Command‘s Accident Investigation Board report: The incident occurred while the crew from the 413 Flight Test Squadron at Eglin was performing steady heading sideslips at an altitude of approximately 15,000 feet. The aircraft exceeded the targeted angle of sideslip until it departed controlled flight and momentarily inverted before being recovered after losing approximately 5,000 feet of altitude. The aircraft returned to base and landed safely without further incident. The aircraft pulled 3.19 G and oversped the maximum flap airspeed by 100 knots during the event. The Investigation The report notes that: The Threat Hazard Analysis Worksheet (THAW) and the test cards emphasis for recovery from departures was weighted toward stalls as opposed to sideslip, based on the cautions, warnings, and recovery procedures mentioned. This might be explained by a previous LOC-I during stall testing (see below). Furthermore, data from Lockheed Martin sideslip trials with the unmodified C-130J were not available to the team as the USAF had failed to put a contract in place. It was also not clearly stated in manuals that the Head Up Display (HUD) indication of sideslip freezes and does not increase once a warning level is reached. The President of the Accident Investigation Board concluded: I find, by a preponderance of the evidence, the cause of this mishap was the [Mishap Pilot’s] MP’s excessive rudder input during the test point followed by inadequate rudder input to initiate a timely recovery from high angle of sideslip due to Overcontrolled/Undercontrolled Aircraft and Wrong Choice of Action During an Operation. Additionally, I find, by a preponderance of the evidence, Instrumentation and Warning System Issues, Spatial Disorientation, Confusion and the fact the test team was Provided Inadequate Procedural Guidance or Publications were factors that substantially contributed to the mishap. The report also states: Due to the nature of the acquisition process and the parties involved, there appeared to be poorly defined and/or confusing lines of communication and organizational priorities. Although the President of the Board did not consider it causal or contributory he does comment on the fact that: The squadron’s technical director first removed himself from reviewing any test cards in the unit and then rescinded his signature from the [method of test] MOT. The report goes on: We wondered if the technical director’s actions were symptomatic of safety concerns that were not being respected by other unit leadership. Why would anyone remove their signature from the MOT if he/she felt the procedures were sound. We found no substantial evidence to suggest he was concerned for the safety of the flying qualities test activities. He stated “No changes need to be made to the existing documentation.” The board debated the significance of the situation, and was left with the impression it was a personality issue for the unit and possibly...
read moreCHIRP Critical of an Oil Company’s Commercial Practices
CHIRP Critical of an Oil Company’s Commercial Practices The CHIRP Charitable Trust, who run the UK’s Confidential Human Factors Incident Reporting Programme (CHIRP), has highlighted two “of the many” reports received relating to an oil company changing its North Sea helicopter operator for the second time in three years. CHIRP do not name the oil company. This particular case, which involved an AOC holder, who had set up bases in other EU countries to support that specific oil company, is well known in the industry and has also been covered extensively by the local press. In particular concerns were raised to CHIRP over the effect of psychological stress on flight safety amongst pilots faced with redundancy when the impending termination of the contract became known. Similar concerns were raised by the Commander of a Boeing 757 involved in a serious incident in 2013 were possible distraction due to ‘company turmoil’ was noted. In one of the two reports published, it is also alleged that both in 2012 when the non-UK AOC holder was awarded the contract, and again in 2015 when they were replaced, very short notice mobilisation occurred with a high degree of secrecy. In the Editorial of Feedback 116 CHIRP Chief Executive Ian Dugmore comments: There has to be a better way. He goes on to say: The operator’s creditable efforts to mitigate the risks by encouraging pilots to stand themselves down if they felt unduly stressed were partially offset by pilots’ concerns that demonstrating weakness, particularly mental weakness, could jeopardise future employment prospects. It is not enough to tell pilots that they should not report to work if they are not mentally focussed or stressed. A way must be found to generate the conditions in which pilots can do what they know to be correct without fear of long term disadvantage. CHIRP then goes on to draw parallels with the attention on mental health since the loss of Germanwings Airbus A320 D-AIPX in the French Alps on 24 March 2015. After that accident we discussed the challenges of psychological screening of flight crew and the low rate of self-reporting of mental health issues. UPDATE 13 March 2016: The Bureau d’Enquêtes et d’Analyses (BEA) report, issued to day into the Germanwings accident, does examine the difficulties in self declaring issues that could affect employment. See: Germanwings: Psychiatry, Suicide and Safety Having received these confidential reports CHIRP raised the matter with the UK Civil Aviation Authority (CAA), who in turn contacted the National Aviation Authority of the AOC Holder in question. CHIRP report on one piece of reassuring evidence, that there had been no increase in ‘Level 1’ Flight Data Monitoring (FDM) alerts during the period. It is not stated if CHIRP or the UK CAA made contact with the oil company in question. CHIRP go on to say that: Nonetheless, recognising the conflict between normal commercial pressures that affect almost all elements of industry and safety concerns associated with changes of contract, the CAA decided that this is an issue that will be taken up for discussion with industry in the CAA-led Offshore Helicopter Safety Action Group (OHSAG). Aerossurance has previously summarised the minutes of the last OHSAG to be published (minutes of the most recent October 2015 meeting have not yet been made public). UPDATE 13 December 2015: UK OHSAG Oct 2015 Minutes (though no discussion on the CHIRP report is minuted). CHIRP conclude: …it is noteworthy that the...
read moreMicro FOD: Cessna 208B Grand Caravan Engine Failure & Forced Landing
Micro FOD: Cessna 208B Grand Caravan Engine Failure & Forced Landing We often think of FOD, Foreign Object Damage, as something caused by a carelessly discarded piece of waste or forgotten nut or bolt. The recently issued US National Transportation Safety Board (NTSB) report on a Cessna 208B Grand Caravan accident in Hawaii however describes a ‘micro FOD’ accident from 160 to 195 µm particles that got within an engine during off-wing maintenance. As N861MA, operated by Mokulele Airlines, climbed through 8,000ft over open ocean water on 21 October 2013 with 2 crew and 8 passengers, there was a loud bang and a grinding sound. This was followed by a loss of engine power and sparks from the engine’s right exhaust. The crew initiated a turn back towards Kahului Airport, which was about 13 miles north. The crew performed the emergency checklists and elected to make an emergency landing on Maui’s State Route 31. The aircraft suffered substantial damage to the right wing when it hit two road signs during the emergency landing. The Safety Investigation The NTSB explain that: … all of the compressor turbine (CT) blades [of the single Pratt & Whitney Canada PT6-114A turboprop engine] had separated near the blade platforms, and the remaining stubs were gouged and battered. The fracture surface of one of the blades displayed smooth features characteristic of fatigue fracture; all other blade fracture surfaces displayed course features characteristic of overload fracture. The CT hub displayed a frosted appearance over the entire front and aft surfaces, and glass beads and bead fragments were observed between the fir-tree joints of the blade platforms and the CT disc, consistent with the disc assembly having been cleaned by aggressive glass media blasting in the assembled condition. A dimensional and chemical analysis of a sample of the glass-like beads was accomplished by the manufacturer’s materials laboratory. The beads were revealed to be approximately 195 to 160 µm in size and were composed predominantly of silica with small quantities of sodium, calcium, magnesium and sulfur, which were consistent with the chemical components of glass. The engine manufacturer specifies that all media blast cleaning be performed with the CT disc and blades disassembled. The glass bead contamination of the fir-tree joints caused the CT blades to be unevenly restrained, and it altered the blades’ designed vibration frequency, making them susceptible to the aerodynamic vibrations from the combustor gas flow. Therefore, the fatigue fracture of the blade was most likely due to the glass bead contamination. The CT disc assembly had been removed from the engine for repair about two months before the accident, and this was likely when the glass bead media cleaning occurred and the beads became embedded in the exposed fir tree joints. When the CT disc assembly is installed in the engine, the fir tree joints are protected from exposure; therefore, the glass bead contamination could not have occurred when the engine was installed on the airplane. More detail can be found in the NTSB Powerplant Group factual report. The NTSB determined the probable cause to be: Improper maintenance that resulted in contamination of the engine’s compressor turbine disc and blade assembly by glass bead remnants, which resulted in a blade failure. We have previously written about Foreign Object Debris (FOD) Damages 737 Flying Controls, where a cleaning cloth got trapped on-board a New Zealand aircraft. UPDATE 12 November 2015: European Aviation...
read moreCoaching and the 70:20:10 Learning Model – Beyond Training
Coaching and the 70:20:10 Learning Model – Beyond Training In a recent Harvard Business Review interview Andre Agassi was asked: What distinguishes the best coaches from the rest? His answer: Coaching is not what you know. It’s what your student learns. And for your student to learn, you have to ‘learn’ him. I think the great [coaches] spend a lot of time understanding where the player is. The day they stop learning is the day they should stop teaching. We doubt Agassi would ever have achieved much if the only ‘coaching’ he got was day long PowerPoint sessions delivered by strangers unaware of his current performance and development needs. Yet remarkably some organisations are still hooked on pre-fabricated classroom training as the primary path to perceived competence and performance. 70:20:10: The 3Es – Experience, Exposure & Education Charles Jennings’ 70:20:10 Learning Model was based on the conclusion that 70% of actual learning is through Experience (i.e. actual practice, including On The Job Training [OJT]), 20% is through Exposure to informal, social learning & coaching and only 10% through formal classroom courses and other Education. Scrap Learning Furthermore, one study published in May 2015 suggests nearly 50% of formally delivered learning is ‘scrap’, i.e. never used in practice. Some say its even higher! There can also be an initial ‘illusion of learning‘, but as “lessons communicated in a lecture don’t stick”, initial positivity about a course then evaporates back in the real world. Progressive Learning Organisations Deloitte’s April 2015 study Building Competitive Advantage with Talent, concluded only about 10-15 percent of companies have well-developed learning and development programmes. These progressive organisations are taking more innovative and effective approaches to get higher performance (rather than simply picking from a training catalogue). They are: Considering the specifics of what individuals need to learn to excel in their job, and Applying a variety of techniques (including courses, workshops, on-the-job training and coaching) to satisfy those needs in more focused and effective ways. Critically they are ensuring that learning is actually applied in the workplace and, as research shows, thereby delivering winning performance. We recently also looked at some of the improvement lessons from the turn-around of British Cycling that are also highly relevant to to organisations striving for peak performance. Note: this article was originally published on LinkedIn Pulse under the title: Andre Agassi on Coaching – The Antithesis of Training. You may also enjoy our article: Aircraft Maintenance: Going for Gold? It asks: Should we start treating our people more like athletes who need to achieve peak performance every day? Other Learning Resources Peter Senge’s book The Fifth Discipline is also work a read: Matthew Syed‘s book Bounce discusses the myth of talent and the importance of focused practice. It also discusses how a culture that emphasises the invincibility of talent over learning a can go badly and self-delusionarily wrong, citing Enron. A 2014 report published by the Royal Academy of Engineering identified six engineering habits of mind (EHoM) which fall within 7 wider learning habits of mind (LHoM): Amy Edmonson discusses psychological safety and openness, another function of good leadership that builds trust and aids learning: https://youtu.be/LhoLuui9gX8 Sir John Whitmore has recently written that: Coaching is one of the most effective skills for human growth. It is different way of viewing people, a far more optimistic way than most of us are accustomed to, it results in a different way of treating them. It requires us to suspend limiting beliefs about people, including ourselves, abandon old habits &...
read moreATP Serious Incident – Temporary LOC In Icing Conditions
ATP Serious Incident – Temporary LOC In Icing Conditions The Accident Investigation Board Norway (AIBN) has issued their report into a serious incident where West Air Sweden BAE Systems ATP cargo aircraft SE-MAF suffered control problems while en route on 25 September 2014. Coincidentally, their report was issued on the eve of the 21st Anniversary of the Roselawn ATR 72 accident (we covered the 20th Anniversary of that 1984 accident last October). The AIBN say: A cargo aircraft flying from Oslo to Trondheim gradually lost speed after reaching cruising altitude. The crew observed ice forming on the aircraft and activated the de-icing system. However, the speed continued to drop. The commander decided to descend to a lower altitude. Before the descent could be initiated, severe buffeting occurred. The nose pitched up and the aircraft banked in an uncontrolled manner. The first officer, who was at the controls, stated that he had to push the nose down by force. The ailerons did not respond properly, and the buffeting was so violent that he could hardly read the instruments. He was able to disconnect the autopilot, and the speed increased as the nose was lowered. Control was regained after about 30 seconds. The loss of altitude was not critical in relation to the terrain. The aircraft continued to its destination and landed safely. The AIBN go on to say: Findings made during the investigation indicate that the loss of speed was a result of a combination of icing and mountain waves. A simultaneously occurring technical malfunction in the de-icing system had a minor impact only. The investigation has also shown that the vibrations and the loss of control most likely were caused by a stall or incipient stall. When control was lost, the speed had dropped to 22 kt below the manufacturer’s recommended minimum speed for flying in icing conditions. The crew was not aware that minimum speed in icing conditions existed other than for the approach phase, and believed they had sufficient margin in relation to a stall. The senior operational personnel with the operator seem to have suffered from the same lack of knowledge. The investigation also revealed that the operator’s training program did not touch upon minimum speed in relation to icing during the cruising phase. A potential for improvement in documentation from the type certificate holder was also identified. The AIBN comment that the BAE Systems’ subsequent communications and clarifications in the AFM are significant improvements. However they make two recommendations regarding making minimum speeds in icing conditions easily available for reference in the cockpit. Other Resources Icing conditions (ground and in flight) was the topic for a European Aviation Safety Agency (EASA) conference in 2013. Aerossurance has also published other icing articles: 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. Breaking the Chain: X-31 Lessons Learned: where an experimental NASA aircraft was lost after pitot tube icing. Cessna Citation Excel Controls Freeze UPDATE 3 December 2016: ATR72 Control Problems in Severe Icing, Norway, 14 November 2016 UPDATE 29 December 2016: CRJ-200 LOC-I Sweden 6 Jan 2016: SHK Investigation Results, another West Air accident. UPDATE 29 November 2018: Iced C208 Loses Airspeed During Circling Approach and Strikes Ground...
read moreHeliOffshore Progress One Year On
HeliOffshore Progress One Year On We first reported on the plan to create HeliOffshore in June 2014. HeliOffshore was formally launched on 21 October 2014 in London and held its first AGM and conference in Lisbon in May 2015. When membership was opened up beyond helicopter operators in January 2015, Aerossurance is pleased to have been one of the first Alliance Members to join. The organisation has recently issued a news bulletin on progress. Articles include an update from CEO Gretchen Haskins, updates on HeliOffshore’s six priority workstreams, a welcome message for newly appointed Operations Director Francois Lassale and a report from Capt. John Black on Helitech 2015, which included supporting European Helicopter Association (EHA) and European Helicopter Safety Team (EHEST) events. In a spirit if transparency, the audio from two all members conference calls held of 28 October 2015 has also been made publically available. This session included briefings on three of the six current workstreams underway: Automation Health & Usage Monitoring with a HUMS Best Practice Guide, which Aerossurance has had the privilege of being invited to contribute to, due to be launched in November 2015 Information Exchange HeliOffshore CEO Gretchen Haskins has also recently been elected as a Board Member of the Flight Safety Foundation (FSF). Haskins was recently interviewed by Energy Voice commenting: The blame culture doesn’t work as well as the lesson learning culture. HeliOffshore will do everything it can to ensure the lessons do get learned. People are willing to talk about the difficult stuff, act on it and improve safety. What becomes crucial is the adoption of best practice so that we can standardise and improve the safety of global offshore operations. The interest has been great from all sectors, operators big and small from all over the world, manufacturers, oil companies. Everyone is getting together, I’m very excited about how it is progressing. UPDATE 22 May 2016: Offshore Helicopter Safety Performance: 2016 HeliOffshore Conference Report UPDATE 21 May 2017: Deepening Delivery: HeliOffshore 2017 Conference Report UPDATE 13 May 2018: Delivering Our Priorities: HeliOffshore 2018 Conference Report UPDATE 8 May 2022: HeliOffshore 2022 Conference Review Aerossurance is an Aberdeen based aviation consultancy with extensive helicopter safety, operations and contracting experience. For helicopter advice you can trust, contact us at: enquiries@aerossurance.com Follow us on LinkedIn and on Twitter @Aerossurance for our latest updates....
read moreUK CAA PBR Stakeholder Engagement (CAP1345)
UK CAA Performance Based Regulation (PBR) Stakeholder Engagement (CAP1345) We have previously written about the emerging concept of performance based regulation (PBR) and discussed some of the challenges to overcome. This week the UK Civil Aviation Authority (CAA) have issued a consultation document on PBR: CAP1345: Performance Based Regulation: Business Engagement Assessment In the document the CAA illustrate their PBR process: The CAA identify 5 areas of change: Consistently gathering and analysing safety risk information about all parts of an organisation’s operations. Assessing the performance of each regulated entity to manage its safety risks effectively and agreeing with the entity’s Accountable Manager the actions that are needed to uphold standards and further enhance safety. Grouping safety risk information about entities into sectors of the industry with similar types of operation to create a better understanding of the top risks posed by the total aviation system and good practice approaches to managing them. Making more informed decisions about the safety outcomes to better manage the top risks and setting out the actions required. Directing regulatory resources proportionately to entities and sectors where standards are not being upheld or there is the significant potential to enhance safety. The CAA say they expect that the benefits of PBR to be in three main areas: 1. Improvements in the performance of industry and the CAA to manage and oversee safety risks, and the ability to demonstrate on-going improvements in safety. 2. Improvements in the CAA’s ability to allocate resources to areas with the greatest potential to enhance safety (i.e. better management of resource capacity, competencies and workload against a prioritised set of safety risks). 3. Increased efficiency and effectiveness of the CAA’s core oversight processes, generating the potential for the reallocation of capacity to higher priority areas of safety risk or reducing the amount of people needed to carry out tasks associated with traditional compliance activity. CAP1345 reveals CAA have previously committed to external change management / programme management support and software costs estimated at £740,000 between April 2014 and March 2016 for PBR. The consultation is open until the end of the year (see CAP1345 for full details). For more on the general topic of PBR see this 2002 paper from the Harvard John F Kennedy School of Government: Performance-Based Regulation Prospects and Limitations in Health, Safety and Environmental Protection UPDATE 21 December 2015: The UK CAA have published a report (CAP1365) on a conference held in London in October 2015 on PBR. It also described the CAA’s new Regulatory Safety Management System (RSMS) that sits above its Performance Based Oversight (PBO) process. UPDATE 17 January 2017: We discuss new UK CAA guidance: Performance Based Oversight: Accountable Manager Meetings (CAP1508) UPDATE 19 March 2017: The Rule Illusion: Organisations should beware of a ‘rules bias’, a tendency to give in to risk aversion by establishing ever more rules: Just like in the real world, stricter rules in an organization are rarely effective in stopping the most egregious transgressions. In practice, those who make the rules are often insulated from the true consequences. The lack of a good feedback mechanism to adjust the rules would be bad enough if the rules were based on evidence and logic. But it’s often even worse, because rules often originate from received (but dubious) wisdom, unproven ‘common sense’, or reactions to one-off events. Rules that are based on beliefs rather than evidence, and never tested, are unlikely to produce net benefits. Yet...
read moreFatal G-IV Runway Excursion Accident in France – Lessons
Fatal G-IV Runway Excursion Accident in France – Lessons The French accident investigation agency, the Bureau d’Enquêtes et d’Analyses (BEA), has issued their report (warning 12Mb) on the 13 July 2012 accident to Gulfstream G-IV business jet N823GA. The US registered aircraft was operated by Universal Jet Aviation (UJT) under 14 CFR Part 135. It suffered a runway excursion while landing during a short ferry flight from Nice, France to Le Castellet Airport. All three occupants were killed. The Accident The BEA comment (emphasis added): Between Nice airport and Le Castellet aerodrome which was not familiar to the crew, the flight was short. The cruise, which lasted only five minutes, left the crew little time to prepare for their arrival. The flight was the last of the day and it was made without any passengers, with the co-pilot in the right seat as PF. This context may have been conducive to lax pre-flight planning and management of the flight by the crew with a heavy workload during the cruise and the approach. Despite having been warned the day before of the need to park the aeroplane at Le Castellet, the copilot learnt the characteristics of the aerodrome during the flight. Few checklists and briefings were heard throughout the flight. During the flight, the crew referred to the proximity of the terrain, the need to reduce speed and anticipate the configuration, and the short runway length. The crew nevertheless understated the impact of a short flight on the preparation of the arrival. The BEA say that: During a visual approach to land on runway 13 at Le Castellet aerodrome, the crew omitted to arm the ground spoilers. During touchdown, the latter did not deploy. The crew applied a nose-down input which resulted, for a short period of less than one second, in unusually heavy loading of the nose gear. The aeroplane exited the runway to the left, hit some trees and caught fire. The Investigator’s Conclusions The BEA concluded: The runway excursion was the result of an orientation to the left of the nose gear and the inability of the crew to recover from a situation for which it had not been trained. The investigation revealed inadequate pre-flight preparation, checklists that were not carried out fully and in an appropriate manner. A possible link between the high load on the nose gear and its orientation to the left was not demonstrated. In particular they explain: Forgetting to arm the ground spoilers delayed the deployment of the thrust reversers despite their selection. Several MASTER WARNING alarms were triggered and the deceleration was low. The crew then responded by applying a strong nose-down input in order to make sure that the aeroplane stayed in contact with the ground, resulting in unusually high load for a brief moment on the nose gear. After that, the nose gear wheels deviated to the left as a result of a left input on the tiller or a failure in the steering system. It was not possible to establish a formal link between the high load on the nose gear and this possible failure. The crew was then unable to avoid the runway excursion at high speed and the collision with trees. The aerodrome fire-fighter, alone at the time of the intervention, was unable to bring the fire under control after the impact. Although...
read moreAAIB Report on Glasgow Police EC135T2+ Clutha Helicopter Accident
AAIB Report on Glasgow Police Scotland Airbus EC135T2+ Helicopter Clutha Accident (Bond [now Babcock] G-SPAO) The UK Air Accidents Investigation Branch (AAIB) has published their report (which has since been subject to minor corrections) into the fatal accident involving a Airbus Helicopters (formerly Eurocopter) EC135T2+ G-SPAO. It crashed onto the Clutha Vaults Bar in Glasgow, Scotland on the night of Saturday 29 November 2013. The helicopter was operated under a UK CAA issued Police Air Operator’s Certificate by Bond Air Services for Police Scotland. In addition to the pilot and two police observers, seven people in the packed bar died. The Flight The AAIB report: The helicopter departed Glasgow City Heliport (GCH [then located at Stobcross Quay alongside the River Clyde]) at 2044 hrs on 29 November 2013, in support of Police Scotland operations. On board were the pilot and two Police Observers. After their initial task, south of Glasgow City Centre [at Oatlands, 2 nm from GCH], they completed four more tasks; one in Dalkeith, Midlothian [south of Edinburgh], and three others to the east of Glasgow, before routing back towards the heliport. When the helicopter was about 2.7 nm from GCH, the right engine flamed out [at around 22:21:40]. They note that the single engine emergency shutdown checklist was not completed. Shortly [~32s] afterwards, the left engine also flamed out. An autorotation, flare recovery and landing were not achieved and the helicopter descended at a high rate onto the roof of the Clutha Vaults Bar, which collapsed. The three occupants in the helicopter and seven people in the bar were fatally injured. Eleven others in the bar were seriously injured. Organisational Matters, Police Observers & Operational Tasking Police Scotland is the UK’s second largest police service. It was formed in 1 April 2013, from the merger of 8 regional forces and several specialist agencies, but has not been without controversy and the Chief Constable has recently resigned. Originally the Glasgow based helicopter had been a Strathclyde Police asset, Strathclyde being the region of Scotland around Glasgow. The helicopter is tasked by the Police Scotland control room with, typically short-notice, ‘non-routine’ tasks. An inventory of ‘routine’ tasks is contained in a folder available to the crew. The AAIB report that: The primary duties of the front seat observer [FSO] are the operation of the FLIR Television/IR camera, to assist the pilot and rear seat observer [RSO] with navigation, using visual references and maps, and to assist the pilot as and when directed. The primary duties of the rear seat observer are the navigation to and from each task, utilising police role equipment and navigational aids, and Police radio communications. The front seat observer normally assumes ‘operational command’ of the tasking of the aircraft. However, when two experienced observers fly together, the more experienced observer will normally assume operational command in relation to the tasking of the helicopter. Given that both observers were experienced it is likely that they would alternate operational command. However, it is not known who had operational command on the accident flight. In addition to their other training, police observers undergo recurrent Crew Resource Management (CRM) training. The specific CRM training is not identified but BAS do market such training. While part of the crew, as they have specific in-flight tasks, the UK CAA treat police observers as passengers. Police tactical communication is by the emergency services Airwave secure radio, which is recorded. The...
read moreMisloading Caused Fatal 2013 DHC-3 Otter Accident
Misloading Caused Fatal 2013 DHC-3 Otter Accident The US National Transportation Safety Board (NTSB) investigation into a fatal accident to Rediske Air de Havilland DHC-3T Otter N93PC in Soldotna, Alaska on 7 July 2013, has determined it was caused by misloading. A passenger iPhone video of the aircraft’s take-off was recovered from the wreckage and analysed. The full report can be found here. Shortly after take-off: …the airplane’s angle of attack continually increased as the airplane’s airspeed decreased from about 68 mph to about 44 mph over a period of about 8.5 seconds. About 11 seconds after takeoff, airspeed and angle of attack reached values consistent with an aerodynamic stall. The airplane rolled right-wing-down and impacted the ground several seconds later. (a) Camera Orientation Estimation – A/c Reference Points Aligned with Image (b) A/c Location and Orientation Estimation – Ground Reference Points Aligned with Image (Credit: NTSB) Estimated Speed, Altitude and Pitch Angle (Credit: NTSB) The cabin was destroyed by the impact and a post-crash fire. The pilot and nine passengers aboard the 16 seat aircraft were fatally injured. The NTSB say (emphasis added): Before picking up the nine passengers, the pilot loaded the accident airplane at the operator’s base in Nikiski with cargo (food and supplies for the lodge). The operator of the lodge where the passengers were headed estimated the cargo weighed about 300 pounds (lbs) and that the passengers’ baggage weighed about 80 lbs. Estimates of the passengers’ weights were provided to the lodge operator in preparation for the trip, which totalled 1,350 lbs. The load manifest listed each of these weight estimates for a total weight of 1,730 lbs and did not contain any balance data. The cargo was not weighed, and the pilot did not document any weight and balance calculations nor was he required to do so. The weight of the cargo recovered from the crash site, and determination of the weight of cargo destroyed in the impact and post-crash fire, showed the cargo weight was about 418 pounds higher than the cargo weight stated on the load manifest, resulting in a center of gravity aft of the limits for the airplane. Neither 14 CFR Part 135 (as 14 CFR 135.63(c) does not apply to single engined aircraft) nor the operator’s operations specifications required that aircraft weight and balance actually be documented. The NTSB determined the probable cause to be: The operator’s failure to determine the actual cargo weight, leading to the loading and operation of the airplane outside of the weight and center of gravity limits contained in the airplane flight manual, which resulted in an aerodynamic stall. Contributing to the accident was the Federal Aviation Administration’s failure to require weight and balance documentation for each flight in 14 Code of Federal Regulations Part 135 single-engine operations. This accident again demonstrated the investigative value of video footage and that small consumer devices can survive impacts and fires. Comment It also demonstrates the vital importance of correct loading and weight & balance. Aerossurance has previously written about a misloaded Pilatus PC-12 were pitch control lost on take off resulting in a series of pitch oscillations and stall warnings, but fortuitously only damage to one wheel: Wait to Weight & Balance – Lessons from a Loss of Control. Loading issues also featured in this Canadian accident: Culture + Non Compliance +...
read more
Recent Comments