News & Comment

Night Offshore Helicopter Approach Water Impact

Posted by on 7:26 pm in Accidents & Incidents, Crises / Emergency Response / SAR, Design & Certification, Helicopters, Human Factors / Performance, Offshore, Oil & Gas / IOGP / Energy, Regulation, Safety Culture, Safety Management, Special Mission Aircraft, Survivability / Ditching

Night Offshore Helicopter Approach Water Impact (Bond Offshore Helicopters EC225 G-REDU, BP ETAP CNS) On 18 February 2009 Airbus EC225 G-REDU of Bond Offshore Helicopters impacted the sea during a night visual approach to BP‘s Eastern Trough Area Project (ETAP) Central Production Facility.  The crew’s perception of the position and orientation of the helicopter relative to the installation proved erroneous.  After entering the water the helicopter floated and everyone on board was rescued.  The aircraft capsized subsequently. This article primarily summarises the extensive 171 page UK Air Accidents Investigation Branch (AAIB) safety investigation report published 14 September 2011. Background Bond Offshore Helicopters had been formed in August 2001 and commenced operations in August 2004 with a long term contract for BP for commercial air transport and for Search and Rescue (SAR) operations, known as ‘Jigsaw’.  They subsequently gained work with some smaller oil & gas customers and in February 2009 added another large oil and gas customer in Aberdeen.  They had also won contracts, commencing in 2010 in Blackpool and Norwich with the AS365N3. Their operations department was structured as follows: On 27 December 2006, at night, in poor weather CHC AS365N G-BLUN, operating from Blackpool, impacted the Irish Sea near the North Morecambe gas platform with 7 fatalities On 12 February 2007, the UK CAA Head of Flight Operations Inspectorate (Helicopters) wrote to all UK offshore helicopter operators to ask they review the following topics and inform their CAA inspector: Consequently the Bond Director of Flight Operations tasked their Flight Safety Officer with “carrying out an audit and Flight Operations Risk Assessment (FORA)” against these issues. AAIB found that the Bond Operations Manual at the time of the G-REDU accident summarised crew approach and landing duties as follows: However: There were no specific vertical or horizontal profiles set out in the Operations Manual for an offshore visual approach. More comprehensive duties, challenges and responses were set out for precision and non-precision instrument approaches. These included altitude calls and instrument crosschecks as well as any deviation from the horizontal or vertical profile of the approach. Also: There was no specific company lesson plan for teaching offshore approach and landing techniques. However, the training staff had detailed lesson plans which identified the need to use the flight instruments to monitor the approach and the Oculogravic illusions which may be experienced when pitching up. However: Neither crew member could recall receiving this information during their company training. G-REDU, registered in May 2008, was the first EC225 in their fleet, that until that point had consisted of AS332L2s. A Honeywell MkXXII Enhanced Ground Proximity Warning System (EGPWS) Terrain Awareness Warning System (TAWS) had been retrofitted to G-REDU in November 2008. This modification was not required by regulation but was “recommended” for “long term” contracts in the Aircraft Management Guidelines (AMG Report 390) of the International Association of Oil and Gas Producers (IOGP, then OGP), of which BP was a member.  This recommendation was subject to the caveat that “when an approved modification exists for the aircraft type and it is recommended by Company Aviation Advisory personnel”.  The TAWS replaced the original Automatic Voice Alerting Device (AVAD), also an OGP recommendation for long term contracts. Although recommended by OGP, AAIB note that because helicopters can “land close to or on nominally hazardous terrain or...

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Night Offshore Take-Off Loss of Control Incident

Posted by on 4:03 pm in Accidents & Incidents, Helicopters, Human Factors / Performance, Offshore, Oil & Gas / IOGP / Energy, Safety Management

Night Offshore Take-Off Loss of Control Incident (Bristow Norway Sikorsky S-92A LN-ONT) On 24 February 2020 Sikorsky S-92A LN-ONT of Bristow Norway suffered a 40 second loss of control during a night time offshore take off from the Maersk Invincible (now Nobel Invincible) jack-up drilling rig in AkerBP Valhall field the North Sea.  Control was regained and the flight continued safely to its destination. The Norwegian Safety Investigation Authority (NSIA) issued their safety investigation report on this Serious Incident on 15 February 2024. The Incident Flight The helicopter had been turned round on the rig’s helideck, ready for a return flight to Stavanger with 11 persons on board. The aircraft commander had 6,750 flying hours of experience, 2,191 on type.  He had performed 8 night deck landings in the last 90 days. The co-pilot had 5,800 flying hours of experience, 605 on type.  He had completed 11 night deck landings in the last 90 days and 211 night hours, 84 on type in the last 12 months. The operator’s pilots regularly received simulator training. This included take off and landing on offshore helidecks in various simulated weather conditions, day and night. Based on the wind direction the Pilot Flying (PF) would be the co-pilot and the commander would be the Pilot Monitoring (PM). The crew told the NSIA that, with the rain beating against the front windows, it was impossible to see any form of horizon in the dark. The entirety of the oil rig with its lights and lit structures, which could have provided visual references, was behind the helicopter. At 19:56 hrs [UTC], the first officer [the PF] brought the helicopter into a 5-ft hover above the helideck and prepared to take off into the wind. When the commander had completed the hover check, the first officer moved the collective to 80% torque to start a vertical climb to the take-off decision point (TDP). When the commander [the PM] called ‘TDP’ at 19:56:18 hrs, the first officer moved the cyclic gradually forward to a 5° nose down pitch to initiate horizontal acceleration. A 5° nose-down pitch is in accordance with the helicopter manufacturer’s recommendations and the helicopter operator’s procedures for take-off from a helideck in night-time conditions or poor weather with reduced horizontal visibility. The torque was 74% on both engines. As the helicopter transitioned forward they entered darkness, what is known as a ‘black hole’.   Such conditions typically occur over water or over dark, featureless terrain. Initially the helicopter exhibited “a low” sink rate and the commander “focused his attention on the vertical speed indicator”. When it showed a sink rate of 100 ft/min, he called out ‘We are descending’ two times. Just after that, the voice alert ‘Altitude, altitude – altitude, altitude’ indicated that the helicopter was about to drop below the minimum altitude selected on the radar altimeter [set at deck height, 260 ft]…  The commander has explained that, after the voice alert, he got the feeling that the instrument readings did not match with what he expected, and he felt that he became disoriented. A few seconds afterwards, when the helicopter had accelerated to approximately 35 kts at an altitude of 306 ft, the [pitch] angle increased by 6.4° per second to more than 25° nose up pitch up. At the same time,...

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Air Ambulance Night Wirestrike at Poorly Chosen Landing Site

Posted by on 6:47 pm in Accidents & Incidents, Helicopters, Human Factors / Performance, Safety Management, Special Mission Aircraft

Air Ambulance Night Wirestrike at Poorly Chosen Landing Site (AMC AS365N3 N520CF) On 26 July 2022 Airbus AS365N3 air ambulance helicopter N520CF operated by Air Methods Corp (AMC) for Dayton‘s Miami Valley Hospital Careflight, was involved in an wirestrike accident near Hamilton, Ohio.  The three occupants sustained minor injuries.  The US National Transportation Safety Board (NTSB) issued their safety investigation report on 7 February 2024. The Accident Flight The helicopter took off at 04:28 Local Time from Warren County Airport, Ohio, heading to an ad hoc landing site near a motor vehicle accident.  The Pilot (4336 hours total, 620 on type) and one Flight Nurse occupied the front seats and one Flight Nurse was in the cabin.  The Pilot was using a Night Vision Imaging System (NVIS) and flying in night Visual Meteorological Conditions (VMC). When about 9 miles away, the Pilot contacted on-scene fire department personnel for site information. They reported that there were high voltage power lines on the south side of the landing site.  The site was marked by four illuminated orange cones. As the pilot continued to the scene, he knew the winds were calm and, therefore, he orbited the scene from the south to the north. The pilot made an approach from the south and was looking out for the powerlines… He could see the towers but not the wires.  The pilot used the landing light to try illuminate the wires without success. The pilot stated that he did not think the wires would be in and around the landing zone.  He thought the wires were farther out from the landing zone and not below the helicopter. However, as the helicopter descended for landing, the main rotor blades contacted the wires and the helicopter fell about 30 to 50 ft. The nose and left main landing gear struck the ground first at 04:55. The helicopter sustained substantial damage to the main rotor blades, main rotor gearbox, and motor mounts [sic]; additionally, the left engine was hanging off the side of the helicopter. All three occupants egressed the helicopter after the engines were shut down. A 69 year old woman, who had been involved in the road traffic collision, died at the scene. NTSB Safety Investigation Post accident examination by a Federal Aviation Administration (FAA) inspector revealed that the helicopter struck the high voltage wires, severing one wire, and then landed hard. We note that the Flight Nurses do not appear to have been interviewed nor is their presence discussed in the NTSB report or public docket other than in relation to their post accident egress.  Furthermore the fire fighters were not apparently interviewed either and their NTSB report is silent on their training and procedures for establishing an ad hoc landing site. Some free guidance on training material for first responders is provided in links below, though reliance purely on generic guidance documents, PowerPoints or videos is highly unlikely to be sufficient. There also are no details on what mapping and obstacle data was available to the pilot or what Helicopter Terrain Awareness and Warning System (HTAWS) was fitted.  According to 135.605: After April 24, 2017, no person may operate a helicopter in helicopter air ambulance operations unless that helicopter is equipped with a helicopter terrain awareness and warning system (HTAWS) that meets the requirements in TSO–C194 and...

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HEMS Air Ambulance Landing Site Slide

Posted by on 11:06 am in Accidents & Incidents, Helicopters, Human Factors / Performance, Safety Management, Special Mission Aircraft

HEMS Air Ambulance Landing Site Slide (BSAA H145 SE-JSS) On 12 February 2022 Airbus Helicopters H145 air ambulance helicopter SE-JSS, based at Mariehamn Airport, Åland island, Finland was deployed to the nearby island of Fiskö after a person fell on ice.  After landing at a confined site near the casualty, power was reduced to idle, the helicopter slid backwards and struck adjacent obstacles. The Safety Investigation Authority Finland (SIAF) issued their safety investigation report on 28 January 2024. The Accident Flight A 112 emergency call was received at 15:33.   Two roads with almost identical names are located in the municipality of Brändö, which caused confusion at first. At 15:50 it was decided to task the helicopter to attend.  The helicopter had three occupants, pilot (1,725 total hours, 1,330 on type), Technical Crew Member (TCM) and nurse.  Babcock Scandinavian Air Ambulance had provided ambulance helicopter services in Åland under a contract with Åland Health Care District from 2019 (but Babcock has since sold this business to Avincis). Shortly after becoming airborne the helicopter was passed coordinates for helipad on Korsö island, approximately 15 min flying time away.  Only when halfway into the flight, were the helicopter crew informed that the casualty was on Fiskö and they were asked to proceed direct to the accident site (about 5 km northwest of the helipad). SIAF say: At 8 km from the accident site, the pilot descended to 500 ft (150 m) above ground level.  During the approach, he reduced speed so he could identify the correct house among the buildings of the small community. They had been told that “someone would be outside waving a white cloth to help in identification”. The crew did not obtain visual contact with this person or the house during the first overflight, but during the second they spotted the house and agreed on the conduct of an off-airfield landing. Even though buildings, trees and a power line were observed in the area, the vicinity of the intended landing site and the approach path were clear of obstructions that could have jeopardized the landing. SIAF only mention this ’17 m danger zone’ in the caption of image above and don’t elaborate on landing site size requirements otherwise.  AMC1.SPA.HEMS.125(b)(4) (performance requirements for HEMS operations) states a 2 D site is required by day (which for a H145 is 27.3 m). An approach was made… After the pilot had brought the helicopter to hover, the {technical] crew member [TCM] opened the door and scanned the area below and to the left for any obstructions that would be a factor during landing. He notified the pilot of a bush to the left of the helicopter’s tail about 6 m away but paid no particular attention to the fact that the ground was partially covered with ice. SIAF also comment on their being loose articles at the site.  The pilot elected to land. Even though landing was uneventful, and the helicopter appeared stable…the pilot felt it was slightly tilted to the right. With the flight controls neutralized, the attitude indicator showed 2° to 3° right bank, well below the maximum permitted value of 8°. The pilot set the engines to idle. The crew’s attention was diverted to a person approaching the helicopter who was signalled by hand to wait.  However, seconds after the engines were...

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Undetected Cross Connection Maintenance Error Resulted in a DA42 Hard Landing During a Maintenance Check Flight

Posted by on 2:30 pm in Accidents & Incidents, Business Aviation, Design & Certification, Fixed Wing, Human Factors / Performance, Maintenance / Continuing Airworthiness / CAMOs, Safety Management

Undetected Cross Connection Maintenance Error Resulted in Diamond DA42NG N591ER’s Hard Landing During a Maintenance Check Flight On 25 May 2022, Diamond DA42NG N591ER departed London International Airport, Ontario, on a maintenance check flight but suffered control difficulties and was forced to make a hard landing on the grass alongside the runway.  The Transportation Safety Board of Canada (TSB) issued their safety investigation report on 5 January 2024.  We examine the maintenance human factors involved. The Accident Flight The maintenance check flight followed a 2000-hour inspection (“including a mechanical and structural inspection, and general refurbishing”) that had been completed at the Diamond Aircraft Industries facilities at London International Airport. During the take-off, when the aircraft became airborne, the aircraft yawed abruptly to the left. The pilot attempted to correct for the unexpected yaw but had difficulty maintaining directional control of the aircraft. The pilot attempted to make an emergency landing on Runway 27; however, during the approach, the pilot continued to have difficulty controlling the aircraft and instead attempted to land on Taxiway A before ultimately landing on the grass between the runway and the taxiway. When the aircraft touched down hard on the grass, the rudder and the left-wing aileron mass balance weight broke off. The landing gear collapsed, and the aircraft slid to a stop approximately 265 feet from the initial impact point. The aircraft was substantially damaged but the pilot was uninjured. The Safety Investigation & Our Comments Upon initial examination it was discovered that the rudder moved in the opposite direction to the pilot input.  Significantly, during the preceding maintenance the rudder guide tubes had been replaced. [The Aircraft] Maintenance Manual (AMM) explains that the “two fuselage cables go through Teflon tubes in the rear fuselage. The cables attach to the rudder lower mounting bracket. The cables cross over each other in the rear fuselage” Significantly: The rudder cable guide tubes are not normally replaced…during the course of regular maintenance because they are rarely found to be defective, and there is no specific requirement to change or inspect them at regular intervals. The AMM also provides some troubleshooting guidance, which suggests that rudder stiffness or catching may be caused by the rudder cables chaffing in the guide tubes. The AMM suggests to replace the rudder cables and guide tubes; however, there is no method or procedure in the AMM specific to replacing the guide tubes. The AMM system description does explain and illustrate that the cables cross over, but that is not referenced from AMM section for the task.  The AMM contains instructions for the replacement of a single cable but makes no mention that it crosses from one side to the other (i.e. assumes the other cable is in place). TSB note that the only other information was in production drawings.  These apparently could be requested, but wasn’t requested for this task.  Clearly a maintenance organisation owned by the Type Certificate (TC) Holder has an advantage accessing production data, though if it is needed its a sign of an inadequacy in the AMM. Investigators determined the tube were therefore installed… …without the aid of specific procedures, guidance, or supervision. We discuss the supervision aspect further below.  As noted above, the lack of procedures and guidance was not a ‘Failure to Follow (F2F) procedures’ by maintenance personnel (a...

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Air Ambulance EC135 Loss of Control & Main Rotor / Engine Overspeeds

Posted by on 4:54 pm in Accidents & Incidents, Helicopters, Human Factors / Performance, Safety Management, Special Mission Aircraft, Survivability / Ditching

Air Ambulance EC135P2+ Loss of Control & Main Rotor / Engine Overspeeds (Air Methods, N531LN) On 22 January 2022, an Airbus EC135P2+ air ambulance, N531LN (LifeNet 81), of Air Methods Corporation (AMC) was destroyed in an accident in Drexel Hill, Pennsylvania.  The pilot was seriously injured but the two medical personnel and the patient (a child under the age of 5) aboard escaped injury. The US National Transportation Safety Board (NTSB) issued their safety investigation report on 4 January 2024. The Accident Flight The helicopter departed Chambersburg Hospital about 12:05 Local Time, destined for Children’s Hospital of Philadelphia. The helicopter established itself in cruise at an altitude of c 3,500 ft before descending as they approached Philadelphia. At 12:53:11, Automatic Dependent Surveillance – Broadcast (ADS-B) data revealed “a series of heading and altitude excursions” before the data was lost 6 seconds later. Doorbell cam recordings on the ground captured a “high-pitched whine…volume and pitch”. The NTSB report that: Surveillance video showed the helicopter in a near-vertical, nose-down, spiralling descent. The medical crew reported that the helicopter rolled inverted.  No other evidence supported that. They however did manage to secure the patient and brace for impact. The injured pilot, who had 4,123 total hours, 185 on type) had no memory of the initiating event and limited recollection of the final seconds of the flight.  However the NTSB established that the pilot…. …arrested the rotation and recovered the helicopter from the dive but was unable to climb or hover due to insufficient engine power, thereby resulting in a hard landing… The helicopter impacted the ground upright and came to rest on its left side adjacent to a church building. All wreckage was found in a compact area with no substantial debris trail. The main fuselage was whole but… the airframe was partially separated on the upper side of the frame between the cockpit and cabin. All occupant seats remained installed within the cockpit and cabin. The aft-left seat was partially bent in a downward direction near the front edge of the seat. Although not remarked upon by NTSB, it came to rest partly on a low wall. The pilot was extracted from underneath.  The medical personnel egressed through the right cabin door, carrying the patient. NTSB Analysis The accident helicopter, manufactured in 2006, was not equipped with, nor perhaps surprisingly “was it required to be equipped with, a flight data recorder (FDR), a cockpit voice recorder (CVR), or any flight recorder system that records cockpit audio and image”. The FAA had changed Part 135 in 2017 so that helicopter air ambulance operators had to comply with a Flight Data Monitoring (FDM) System requirement, FAR 135.607: After April 23, 2018, no person may operate a helicopter in air ambulance operations unless it is equipped with an approved flight data monitoring system capable of recording flight performance data. Its not clear in the NTSB report how AMC were achieving that regulatory requirement. The NTSB investigators concluded that: Examination of the helicopter revealed no evidence of malfunction that would result in an abrupt departure from cruise flight. The investigators also note that: The accident helicopter was equipped an AFCS [Automatic Flight Control System] composed of a SAS [Stability Augmentation System] and autopilot systems that can control helicopter pitch, roll, and yaw through various actuators. The AFCS does not...

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Police Helicopter Unanticipated Yaw & Fatal Water Impact

Posted by on 2:42 pm in Accidents & Incidents, Helicopters, Human Factors / Performance, Safety Management, Special Mission Aircraft, Survivability / Ditching

Police Helicopter Unanticipated Yaw & Fatal Water Impact (Huntington Beach Police Department MD520N N521HB) On 19 February 2022 at 18:34 Local Time MD Helicopters 500N (MD520N) N521HB of Huntington Beach Police Department (HBPD) was destroyed when it impacted the water off Newport Beach, California in a Loss of Control – Inflight (LOC-I) accident.  The police pilot escaped with minor injuries but the police Tactical Flight Officer (TFO) was fatally injured. The Huntington Beach Police Air Support Unit was formed in 1968, only the fifth in the US.  In 1992 they introduced their first MD520N and became an all MD520N fleet in 2002. Instead of having a conventional tail rotor for anti-torque control the MD520N has a NOTAR (NO TAil Rotor) design with a variable thruster and ducted fan system.  In 2023, the unit changed over to the tail rotor-equipped MD530F]. The Accident Flight The US National Transportation Safety Board (NTSB) issued their safety investigation report on 14 December 2023 into the Newport Beach accident. The law-enforcement helicopter was performing right turns at night over an waterfront peninsula supporting officers attending a street fight involving up to 10 people. The pilot estimated “that they were flying about 500-600 agl, which is standard practice” when the helicopter yawed aggressively to the right and he… …immediately applied full left foot pedal and forward cyclic to arrest the rotation, but there was no response. He then applied right pedal to see if the pedals had malfunctioned, and observing no change, he reverted to full left pedal. He continued to apply corrective control inputs, but the helicopter did not respond and began to progress into a spinning descent. The pilot stated that the rotation became more aggressive, and he began to modulate the throttle, collective, and cyclic controls to try to arrest the rotation rate. He stated that his efforts appeared to be partially effective, as the helicopter appeared to respond; however, because it was dark, he had no horizon or accurate external visual reference as the ground approached. The engine continued to operate, and he chose not to perform an autorotation because the area was heavily populated. He then had a sense that impact was imminent, so he pulled the collective control in an effort to bleed off airspeed. The helicopter impacted the water… …on the TFO’s side in a downward right rotation. The pilot recalled a sudden smash and saw water and glass coming toward him as the canopy shattered. He felt the rotor blades hitting the water, everything then stopped, and within a few seconds he was submerged. The Pilot’s Underwater Escape & the Attempted Rescue of the TFO The police department’s personnel… …fly with a full tactical vest, an inflatable “horse collar”, Submersible Systems “Spare Air” [Compressed Air – Emergency Breathing System] tank, gun, radio, magazines, and handcuffs, all carried on their chest. The pilot held on to the collective as a reference point.  He recalled that: He waited for the helicopter to stop moving, grabbed the Spare Air mouthpiece, cleared it, and started to breath. Holding the collective with one hand he reached down and released his seat harness. His eyes were closed, and he was able to move by feel. He did not recall opening the door.. He exited the helicopter and was upside down. He tried to relax and...

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Multi-Tasking Managers & Deficient Operational Control: Low Viz AS350B3 Take-Off Accident

Posted by on 11:05 am in Accidents & Incidents, Helicopters, Human Factors / Performance, Maintenance / Continuing Airworthiness / CAMOs, Regulation, Safety Culture, Safety Management, Survivability / Ditching

Multi-Tasking Managers & Deficient Operational Control: Low Viz Take-Off Accident (Midtnorsk Helikopterservice AS350B3 LN-OBP, Norway) On 1 November 2022 Airbus AS350B3 LN-OBP of Midtnorsk Helikopterservice crashed shortly after take-off at Slottelid (ENVS), Verdal, Trøndelag County, central Norway.  The two passengers on board died.  The pilot was seriously injured.  A pet dog aboard also survived. The Norwegian Safety Investigation Authority (NSIA) published their safety investigation report on 5 December 2023. The Air Operator ad Pilot The operator was founded in 2002 and at the time of the accident operated one AS350BA, the AS350B3 and an EC120.  They employed 8 people. The pilot had 6,115 hours total experience, 3,800 on type.  He held 4 positions within the operator; Accountable Manager, Compliance Monitoring Manager, Safety Manager and Deputy Manager of Flight Operations.  The later potion was necessary because the Manager of Flight Operations was a retired fixed wing pilot, with no flight experience on rotorcraft.  The Manager of Flight Operations and Technical Manager were part time employees, the former running a human factors & CRM business. The Accident Flight The plan was to transport two passengers, a dog and cargo from the operator’s base Verdal to a mountain farm in Snåsa. Two days before the accident, the pilot had tried to fly the passengers to the farm, but had to abort due to fog in the mountains. The day before the accident there was fog in Verdal that prevented a flight. On the day of the accident the morning fog lay low in the terrain in Verdal, and followed the valley and river. The fog varied in density and two other company pilots had departed about 08:15 after a delay. The passengers due to travel on LN-OBP arrived at around 09:00. The pilot loaded their baggage / cargo and waited for the visibility to improve. The pilot told investigators “there was a calm atmosphere and that he did not feel any stress”. The pilot told investigators the fog had started to lift to the north east. He intended to take off in that direction, flying around a small cluster of trees near the landing site. The pilot to a photograph looking north east though the cabin at c 10:30.  Also evident is a large amount of unrestrained cargo. CCTV evidence shows the helicopter lifted off at c 10:35 but crashed less than 20 seconds later, 450 m away, bouncing several times and coming to rest 540 m from the landing site. The pilot, who suffered several back fractures, regained consciousness, egressed the helicopter and raised the alarm.  The Emergency Locator Transmitter [ELT] antenna had factored during the crash and the helicopter tracking system had not registered the short flight. Dense fog contributed to the problem of locating the aircraft. After 10–15 minutes, a doctor and rescue personnel arrived at the accident site. Both a rescue helicopter and an air ambulance helicopter were unable to land near the accident site due to fog. After a little while, the air ambulance helicopter was able to land in a field slightly higher up in the terrain about 2 km from the accident site. NSIA Safety Investigation & Analysis There are no indications of any pre-impact technical failures.  NSIA concluded the helicopter was most likely overloaded by c 60-80 kg. A key issue for the NSIA...

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Fire-fighting Bell 204B Underwater Escape

Posted by on 10:49 am in Accidents & Incidents, Helicopters, Special Mission Aircraft, Survivability / Ditching

Fire-fighting B204B Underwater Escape (Forest Air Helicopters VH-EQW, Queensland) On 20 September 2023, Bell 204B VH‑EQW of Forest Air Helicopters crashed into a reservoir during fire-fighting operations for the Queensland Fire and Emergency Services (QFES) at the Southern Downs fire, near Cunninghams Gap.  The pilot escaped from underwater and sustained minor injuries.  The helicopter was destroyed. The Australian Transport Safety Bureau (ATSB) released a preliminary report on 7 December 2023. The Accident Flight The aircraft was tasked with fire-fighting operations near Tarome, Queensland, using a 1,200 l bucket and a short line.  The single pilot (2,599 hours of total experience, 221 on type) was operating the helicopter from the left seat “for visibility” say ATSB.  During their first water uplift, the pilot… …heard an unusual noise and that the helicopter ‘kicked’. Remaining in the hover, the pilot checked that all engine indications were normal and that the bucket and line were in the appropriate place. However, the pilot reported that something still did not feel right. As a result, they elected to dump the water from the bucket and initiate a climb out. Within about 10-15 seconds, as engine power was being applied, and the water was being released from the bucket, the pilot heard what they described as a ‘loud roaring’ sound and the helicopter pitched up, yawed, and subsequently had a reduction in power. The helicopter rolled left and impacted the water at low [forward] speed.  The Pilot’s Escape Almost immediately after the impact, the helicopter inverted, started to fill with water, and sink rapidly. The pilot had previously undertaken practical HUET (helicopter underwater escape training) but does not appear to have been equipped with a Compressed Air – Emergency Breathing System (CA-EBS) or similar survival aid.  However, he was able to take a breath before the cabin filled with water.  The pilot removed their seatbelt and helmet, and attempted to open the front left door but could not open it with either the normal or emergency release handles. When the helicopter was almost fully submerged, the pilot swam to the rear of the cabin and tried to open the rear right door but could not open it either, making further attempts to get out by kicking the helicopter windows. Unlike a modern offshore helicopter, the cabin windows had not been modified into push out exits.  The pilot then moved to the rear left door and, utilising considerable force, was able to successfully open it. The pilot noted in interview, that when they initially attempted to open the doors, they may have been trying to move the door handles in the incorrect (opposite) direction due to the helicopter being inverted. The pilot escaped and swam a few metres to the surface and then to the side of the dam.  The ATSB Safety Investigation The helicopter was salvaged.  To date, the ATSB has interviewed the pilot and witnesses, and conducted preliminary examination of the helicopter wreckage. The…rotor systems, flight controls, exits, and engine were visually examined. No pre‑accident damage was identified. The pilot’s left front door emergency jettison system was tested serviceable. ATSB say they intend to examine the pilot’s training and records, maintenance documentation, and certain key components of the helicopter. We will update this article as further information emerges. Safety Resources The European Safety Promotion Network Rotorcraft...

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In-Flight Break-up of King Air C90 After Wing Spar Repaired Against Manufacturer’s Advice

Posted by on 10:26 am in Accidents & Incidents, Design & Certification, Fixed Wing, Human Factors / Performance, Maintenance / Continuing Airworthiness / CAMOs, Regulation, Safety Management, Special Mission Aircraft

In-Flight Break-up of King Air C90 After Wing Spar Repaired Against Manufacturer’s Advice (N3688P, Falcon Executive Aviation) On 10 July 2021 Beech King Air C90 N3688P broke-up in flight and crashed near Wikieup, Arizona. The aircraft was operated Falcon Executive Aviation in support of firefighting for the Federal Bureau of Land Management (BLM), The pilot and the US Forest Service (USFS) Air Tactical Group Supervisor onboard were fatally injured. The US National Transportation Safety Board (NTSB) issued their safety investigation report on 23 August 2023. The Accident Flight The aircraft was on station for about 45 minutes, completing multiple orbits over the Cedar Basin wildfire.  One witness saw the aircraft the descend in a steep dive.  No distress call was heard and it impacted mountainous desert terrain.  Another witness, a firefighter, observed the outboard left wing falling to the ground shortly after the aircraft had impacted the ground. The Safety Investigation Investigators found that: The main wreckage was mostly consumed by a post-crash fire. Debris was scattered over an area of several acres. The outboard left wing was found about 1250 m from the main wreckage.  It had separated outboard of the engine nacelle. The C90 was manufactured in 1980.  It had been flown as a aerial supervision / reconnaissance aircraft for firefighting since 2007.  This involved operating in orbits at c 1000-3500 ft AGL.   It was not used in the more demanding lead aircraft role (low level operation to lead in a larger firefighting aircraft for its drop). The aircraft had flown 17,262.6 hours and 15,475 cycles at the time of the accident.  Since 2007, it had accumulated 3,507 hours and 1,877 cycles. The NTSB examined the maintenance history of the aircraft.  Since 1990, FAA Airworthiness Directive (AD) 89-25-10, Wing Main Spar Inspection had been applicable. This required inspection of “the wing lower forward spar attach fittings, center section, and outboard wing spar caps adjacent to the attach fitting”.  It stated: If any crack is found in a main spar lower cap or fitting, prior to further flight repair or replace the defective part using the instructions and limitations specified in the Beech SIRM or other FAA approved instructions provided by Beech Aircraft Corporation. On this aircraft… A total of 16 wing spar inspections were accomplished since the AD became effective and 6 times since the airplane went on contract to the USFS in 2007. Further, the annual spar cap visual inspection for cracks and corrosion [as specified in the Beech Structural Inspection and Repair Manual (SIRM) 57-13-01] was accomplished 16 times since 2007. However, in March 2021… During a scheduled [AD 89-25-10 and SIRM 57-13-01] maintenance inspection…eddy current (EC) non-destructive testing (NDT) of a left wing’s lower forward spar cap detected a crack in a fastener hole. The hole was then oversized/reamed to a larger size, but the EC reinspection still produced a crack indication. The operator then submitted a structural damage report and service request detailing the crack indication to the aircraft manufacturer. The manufacturer responded in April 2021 that this necessitated the replacement of “the center section forward spar cap, center section forward lower fittings and both outboard main spar assemblies.” The email response…to FAS also included the warning below from their published instructions for wing structure inspections in the SIRM 57-13-01, (in part [emphasis in...

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