Fatal USCG SAR Training Flight: Inadvertent IMC
Fatal USCG SAR Training Flight: Inadvertent IMC (Airbus MH-65D CG-6535, 28 Feb 2012) On 28 February 2012 a US Coast Guard (USCG) Airbus MH-65D Dolphin (AS365) CG-6535 impacted the sea in Mobile Bay, Alabama with the loss of all four crew members. This followed an unintended flight into a Degraded Visual Environment (DVE) during a night Search and Rescue (SAR) training flight. The Accident Flight The helicopter was assigned to USCG Aviation Training Center (ATC) at Mobile, Alabama. It was conducting a night training flight that include approaches to the hover, basket hoists with the 41-foot Motor Vessel (MV) Solomon and rescue swimmer hoists. The crew consisted of an ATC instructor as Pilot-in-Command (PIC), a pilot under instruction as Copilot (CP), a flight mechanic hoist operator (FM) and a rescue swimmer (RS). According to the USCG accident report the PIC had 3,972 hours of total, 3,629 on type. The CP had just 263 hours, 39 on type. The CP was nearing the completion of his course, having reported to the ATC on 16 January 2012 for the 7-week MH-65D Transition Course. The weather at the time of departure and forecast for the evening was VMC. The crew completed planned training but the weather had deteriorated during the RS exercises with a ceiling lowered to 400 feet and reduced visibility (4.4 nm at the nearest met station). According to the USCG accident report the crew had some difficulty maintaining position during some of the RS hoists according to witnesses on the MV Solomon. Its not clear if that was related to the weather or not. After the completion of RS hoisting, the PIC transferred the controls to the CP for over-water hover training. The CP spent two minutes practicing over-water hover position keeping using the Hover Augmentation (HOV-AUG) flight director mode. Following the over-water practice hovering, the PIC directed the aircraft to be reconfigured for forward flight and disengaged the HOV-AUG mode. Forty-four seconds prior to the mishap, the CP began a manual instrument takeoff/departure (ITO) from the over-water hover. A manual ITO is conducted without the assistance of the aircraft’s flight director modes. Based on cockpit recorded dialog, it appears that [ANVIS-9] Night Vision Goggles (NVGs) were in use by the PIC. Investigators say both PIC and CP were using NVGs when the aircraft departed. During the ITO, the PIC acknowledged that a positive rate of climb was established and discussed hoisting performance with the RS. Shortly after CG-6535 ascended above 200 feet, but below the maximum achieved altitude of 362 feet, the PIC recognized the aircraft had encountered IMC and verbalized a transfer of control of the aircraft. The PIC assumed control of the aircraft approximately 23 seconds prior to impact. Sixteen seconds prior to impact… ….the PIC stated his intention to slowly come down to try and regain visual conditions and requested that the CP provide the Radar Map page on the PIC’s multi-function display flight instrument. The PIC did not verbalize the minimum altitude he intended to descend to or alter the pilots radar altimeter warning setting. While maneuvering the aircraft without the assistance of the aircraft’s flight director, CG-6535 entered an attitude indicating a right hand turn greater than 43 degrees angle of bank, 5.5 degrees per second yaw rate to the right, and 22 degrees...
read morePilot Induced B407 HEC Power Loss
Pilot Induced B407 HEC Power Loss (Guardian Helicopters N999GH at PG&E Training Site, Livermore, CA) On 11 May 2022 Bell 407 / Eagle 407HP conversion N999GH of Guardian Helicopters was involved in an accident near Livermore, California during a Part 133 rotorcraft external-load flight. The pilot was seriously injured. remarkably, the lineman, suspended on a long line below the helicopter, escaped with only minor injuries. The Accident Flight The US National Transportation Safety Board (NTSB) safety investigation report was issued on 14 May 2024. The NTSB explain that: The pilot was performing a HEC [Human External Cargo] long-line qualification exam flight at the Livermore Electric Safety Academy, a training operations facility owned by the Pacific Gas and Electric Company (PG&E). The pilot was flying the helicopter solo from the right seat with the door removed so that he could lean outside and observe below. According to the helicopter operator, this was the second time he had taken the check ride, having not passed on the first attempt. The maneuvers were observed and monitored on the ground by a group of examiners. The pilot had about 3,500 hours of total flight time, including about 1,000 hours as a flight instructor and agricultural pilot and almost 175 hours on type. He started working for the helicopter operator about 15 months earlier. The pilot had logged c 87 hours of FAR Part 133 external load time before the accident (most in the AS350) and c 10 in the B407. After performing the initial maneuvers, the pilot transitioned to the HEC phase of the exam by carrying a lineman on a 60-ft long line. While maneuvering the helicopter at an altitude of about 175 ft above ground level (agl), the helicopter lost engine power. Multiple witnesses recounted observations that matched the pilot’s statement. All stated that the helicopter appeared to be operating without issue throughout the maneuvers until they heard a change in engine tone, with some then observing the main rotor blades slowing as the helicopter began to rapidly descend In response, the pilot selected what he thought was the “emergency” throttle detent, but the engine did not respond. The pilot maneuvered the lineman away from the landing helicopter and performed an autorotation. The helicopter landed hard and sustained substantial damage. The Safety Investigation [E]xamination of the airframe, engine, and engine control systems did not reveal any evidence of preimpact mechanical malfunction or failures. The helicopter contained fuel, was loaded within its envelope, and weather was not a factor. Onboard video recorded a section of the annunciator panel that showed some, but not all, engine warning lights, none of which illuminated at any point during the flight. The recording did capture an audio tone as the descent began that was the same frequency as the engine out and low rotor warning indicators. The video recording appeared to show the pilot was anxious throughout the flight; however, considering the nature of the work he was performing and the stress he would have been experiencing, this is understandable. It could not be determined if this contributed to the accident. The engine was test run in a test cell and it performed nominally. Significantly: Review of data recorded by the engine control unit (ECU) revealed that at the time of the loss of engine power,...
read moreHEMS Downwash Injuries: Two More Case Studies
HEMS Downwash Injuries: Two More Case Studies We return again to a safety issue we have previously highlighted, namely helicopter downwash. Case Study 1: AW169, G-KSSC, UK, 11 October 2023 On 11 October 2023 a bystander was injured when Leonardo AW169 air ambulance G-KSSC landed at Bearsted Common, Maidstone, Kent. The UK Air Accident Investigations Branch (AAIB) explain in their safety investigation report, issued 13 June 2024, that the Gama Aviation (formerly Specialist Aviation Service) / Air Ambulance Kent Surrey Sussex Helicopter Emergency Medical Service (HEMS) aircraft was on final approach to a cricket pitch, c 80 m from an emergency incident. The crew assessed the field and established that its size, approximately 80 m by 120 m, was more than sufficient to use as a HEMS landing site. In daytime a ‘2D’ sized clear area is required, which AAIB note is 30 m by 30 m for an AW169, though there are other considerations for safe operations, as this occurrence highlights. The crew decided on an approach track that avoided the cricket pavilion and some residential properties to the north-east of the pitch. This also allowed the approach to be conducted largely into wind, which was from the south-west. The crew noted that there were pedestrians at the northern end of the field and some ground covers protecting the playing surface, but the main pitch area was clear. They elected to use a helipad profile approach with a committal height of 180 ft agl to provide sufficient clearance from surface obstructions. On the final approach to land, when passing abeam the pavilion, the crew noticed that two previously unseen members of the public had appeared at the north-eastern edge of the cricket square, near the pavilion. The pilot flying stopped the descent at a height of approximately 160 ft agl to minimise the effect of the rotor downwash and extended his aiming point further into the area. As the crew established the helicopter in a hover at about 40 ft agl, one of the medical crew in the cabin noticed that the ground covers had rolled from their original position. The pilot flying decided to continue with the landing as any additional manoeuvring would risk blowing the covers further. The helicopter was shut down and shortly after the crew were made aware a woman “had suffered a cut to her leg when one of the ground covers rolled towards her, striking her”. She was subsequently taken to hospital. The Safety Investigation It was found that… …the covers were mounted on wheels which were equipped with brakes. The brakes had not been applied and the covers were moved easily. AAIB comment that: HEMS operations are inherently reactive and time sensitive. Due to the urgency involved, it is often impractical to provide formal site security measures to control access to third parties at landing sites. The applicable regulatory guidance material, GM1 SPA.HEMS.100(a), sets out the “HEMS Philosophy” that includes the concept that “potential risk must only be to a level proportionate to the task”, with the following hierarchy of protection: (1) third parties (including property) – highest protection; (2) passengers (including patients); and (3) crew members (including technical crew members) – lowest. Oddly this puts third-party property above passengers and crew and equally with third party individuals. AAIB note that: The speed...
read moreHESLO R44 Snagged by its Own Longline
HESLO R44 Snagged by its Own Longline (Synergy Aviation C-CGEC Oil & Gas Accident Alberta) On 25 August 2023 Robinson R44 C-GNEC of Synergy Aviation crashed during a Helicopter External Sling Load Operation (HESLO) due to the longline being becoming entangled with gas production infrastructure. The Transportation Board of Canada (TSB) published their brief safety investigation report on 4 March 2024. The Accident Flight The helicopter had landed at ‘multi-gas well battery’ east of Grande Cache, Alberta to pick up an empty cargo net to retrieve pipeline integrity gauges from another site. The TSB reported that the pilot (4926 hours total, 4796 on type)… …landed near a work platform but did not shut down the helicopter. He then exited the helicopter and connected the 100-foot longline and cargo net, which was on the platform, to the cargo hook of the helicopter. The pilot got back in the running helicopter and lifted off into a hover. The pilot initiated a vertical climb, observing the longline and cargo net through the window in the pilot’s door. Once the helicopter had cleared the work platform, the pilot turned his attention from the load under the helicopter to the front of the helicopter and began forward flight toward the next site. During the transition to forward flight, the helicopter did not respond to the pilot’s flight control inputs. Unknown to the pilot, the longline had snagged a railing on the work platform. As the pilot attempted to maintain control of the helicopter, the main rotor rpm began to decay. Given the likelihood of a crash, the pilot steered the helicopter away from the piping and tanks, subsequently colliding with terrain at 0931. The pilot, who was not wearing a helmet because it was being repaired, suffered serious injuries. The Emergency Locator Transmitter (ELT) did not activate, not uncommon in helicopter accidents. Satellite flight following did alert the company to the accident. The TSB Safety Investigation When investigators arrived at the accident site, the lanyard that had snagged on the railing of the work platform was still attached. The longline was equipped with a locked latch hook. This type of hook has a locking mechanism that prevents the hook’s keeper from opening, which can mitigate the risk of snagging (top image). The end of the steel lanyard that was attached to the locked latch hook had a spring latch hook installed (bottom image). This type of hook does not have a mechanism to prevent the hook’s keeper from opening, and this is the hook that became snagged on the platform’s railing. Safety Actions After the accident, Synergy Aviation issued an internal memo with the following actions: All loads are to be set and removed from the ground adjacent but clear of the platforms. All lanyards with the spring latch systems are to be removed from service and replaced with a locked latch style hook with a manual release. All longline operations require the pilot to remove the aircraft door to ensure the best visibility of the external load and/or end of the longline. A review of all operations associated with the pilot operating contracts as well as site hazard identification. TSB do not discuss the procedures and risk assessments in place prior to the accident. TSB make no recommendations. Safety Resources The European Safety...
read moreDrift into Danger: AW109SP Night HLS Accident
Drift into Danger: AW109SP Night HLS Accident (G-RAYN, North Wales) On 1 November 2022, a Leonardo AW109SP, G-RAYN, struck trees and crashed during a nighttime departure from an unlit landing site, in a field at Nantclwyd Lodge, near Llanelidan, Denbighshire. The UK Air Accidents Investigation Branch (AAIB) issued their safety investigation report on 18 April 2024. History of the Day’s Operations The pilot (who had 3,815 hours in total, of which 1,565 were on type) flew G-RAYN from Biggin Hill, Kent on the morning of 1 November 2022, to transport passengers to North Wales for a day’s game shooting. The helicopter was owned by the lead passenger, but maintained and routinely operated commercially for third-parties by an approved air operator. When used privately by the owner, the flights were conducted as NCO flights (‘non-commercial air operations with other-than complex motor-powered aircraft’), using a pilot approved by the operator. This pilot had at that point worked for the operator for 5 years but was contracted directly by the owner for an NCO flight. The pilot arrived at Biggin Hill at approximately 0645 hrs. His scheduled duty check-in time was 0700 hrs, 30 minutes before takeoff. While he had arrived early, much of that extra time was taken up with an unanticipated supportive conversation with a very recently bereaved colleague. The pilot self-briefed the weather, refuelled G-RAYN to approximately 600 kg of fuel and completed the prescribed pre-flight walk round check of the helicopter before taking off at 0727 hrs. The helicopter landed at the owner’s private landing site at Lisvane, near Cardiff, at 0830 hrs to collect the passengers. Because the flight was in support of the helicopter owner, who was a frequent flyer, the pilot did not consider that a refresher pre-flight safety briefing was required. He was not aware that some of the passengers had not flown in that model of helicopter before. The flight to North Wales was uneventful and the helicopter landed near Llanelidan at 0920 hrs at a site listed in the operator’s Company Landing Site Directory (CLSD) as ‘LEA2’. The site was a flat area of grass adjacent to a row of trees and a shooting lodge. The ground sloped down and away toward several isolated trees to the north west, as indicated by the chevrons above. The pilot departed to Hawarden aerodrome to refuel. The return flight had originally been scheduled as a day departure at 1630 hrs. The takeoff became delayed until after just after nightfall (that occurred at 1718 hrs). The pilot’s recollection was of having approximately 340 kg of fuel on board the helicopter before the flight and that he “took his time” after engine start to burn off additional fuel because he knew the helicopter would be close to its maximum takeoff weight (MTOW). The landing site was unlit but the pilot was satisfied there were sufficient visual references available for him to safely conduct a vertical departure. The helicopter’s external lights were illuminating the area immediately around the helicopter and he could see what he described as a “vague horizon” ahead. The pilot judged that lights from the shooting lodge’s windows to his right would be an adequate lateral marker for the departure climb. During take off from the unlit ad hoc landing site, at a height of...
read moreFatal Fall after HESLO Helicopter Hooks Worker
Fatal Fall after HESLO Helicopter Hooks Worker (AS350BA C-FHAU) On 20 August 2023, the Expedition Helicopters Airbus AS350BA C-FHAU, was involved in a fatal accident in which a ground crew member died during Helicopter External Sling Load Operations (HESLO). The Transportation Safety Board of Canada (TSB) released its safety investigation report on 28 March 2024. The Accident The TSB explain the helicopter was being flown by a single pilot and moving drilling equipment with a 100 ft longline, in support of mining company Angus Gold‘s exploration activities being conducted by drilling contractor G4 Drilling Canada Ltd approximately 25 nm west of Wawa, Ontario. The pilot had over 4,580 hours total flight time, with 1,210 hours conducting longline operations. The pilot’s door was replaced by a vertical reference bubble window was installed. The conditions allowed day Visual Flight Rules (VFR) flight. The winds at Wawa were reported as being “from the north at 10 knots, variable from 320° to 050° true”. The pilot’s task consisted of transferring surface drilling equipment by longline from an old drill site on an island to a new drill site on a nearby peninsula, approximately 900 feet away. The G4 ground crew consisted of a foreman, an assistant foreman, a driller, and a helper. The pilot started his duty day at approximately 0615 [Local Time] and flew various short flights for about 2.5 hours. He was then off duty until the first drilling equipment transfer flight, which started at approximately 1520. The foreman and the assistant foreman were stationed at the old site, preparing and attaching the drilling equipment to the longline, while the driller and helper were at the new site receiving, positioning, and detaching the drilling equipment from the longline. TSB explain that: The foreman, driller, and helper had completed all required common core training modules including the speciality module on loading and unloading personnel and equipment from helicopters. However: The investigation did not reveal any documentation indicating that the assistant foreman was qualified as a driller or that he had received any of the required common core or specialty module training. The initial loads were successfully moved. By approximately 1630, only the drill shack cage remained to be moved. This cage was to be placed over the drill and equipment on the drilling platform at the new site. On arrival taglines would be used by ground personnel to rotate the cage to align it. However… When the helicopter reached the new site with the cage, the pilot, the driller, and the helper had difficulties positioning the cage. After several unsuccessful attempts, the pilot decided to bring the assistant foreman to the new site to help. The pilot flew back to the old site, released the cage, picked up the assistant foreman and took him to the new site. The pilot then returned to collect the cage and delivered it to the new site. At approximately 1700, the pilot positioned the helicopter into the wind and lowered the cage over the drill. The driller and helper each held 1 tag line and the assistant foreman held 2 tag lines. When the pilot looked down through the vertical reference window, he could see the driller and the helper only, because a piece of plywood on top of the cage was blocking his view of the assistant foreman....
read moreHEMS H145 Bird Strike
HEMS H145 Bird Strike (HB-ZQJ) On 24 March 2021 Airbus H145 air ambulance HB-ZQJ of Schweizerische Luft-Ambulanz was damaged by a bird strike in the cruise. The 1.3 kg bird penetrated the lower cockpit window at rudder pedal level. The Swiss Safety Investigation Board (SUST) issued their safety investigation report in French on 10 March 2024. The Flight The helicopter was undertaking a night patient transfer from Yverdon-les-Bains Hospital to Vaudois University Hospital in Lausanne (both hospitals have elevated helipads). On board were one pilot, two medical personnel and the patient. At 22:01 Local Time, 5 minutes into the flight, the helicopter was in the cruise at c 1000 ft AGL on autopilot when the bird strike occurred over Bretigny-sur-Morrens. The pilot felt a pain in his right leg having been impacted by remains of the bird… [The pilot] took manual control of the helicopter, reduced speed and ensured that the power and airworthiness of the helicopter were not affected by the impact. Despite entry at foot height the pilot was also hit in the head by debris. The pilot’s helmet “had numerous stains from the bird.” The helicopter diverted to their base at Lausanne. SUST Analysis and Conclusions SUST do not report the bird species but explain: The impact of the bird surprised the crew while the helicopter was cruising at night. It was therefore not possible to detect the presence of birds and attempt an avoidance maneuver. The shattering of the canopy with the penetration of the bird and the projection of the remains into the dark cabin must have caused a stressful situation which was well managed by the pilot. …the decision to divert to home base was appropriate. Of note is: The pilot’s equipment including helmet, robust suit and mountain boots contributed to the pilot’s physical integrity. Aerossurance customers who operate the H145 fly HEMS, helicopter hoist and military missions with the helicopter and operate with a similar ‘aircrew equipment assembly’ standard. Design & Certification Standards The current H145 lower cockpit windows are 2mm acrylic, reinforced round the edges. The current windshields are 6mm acrylic. The H145 is a derivative of the original BK117 (the four main rotor blade H145 is the BK117D2 and the five bladed H145 the BK117D3). While, as per the Changed Product Rule (Part-21.A.101), the certification basis for some changed H145 elements are recent amendments of CS-29, the EASA H145 Type Certificate Data Sheet (TCDS) states that otherwise FAR 29 Amdt. 40 from 1996 applies for all the other applicable requirements, except for three reversion to FAR 29 Amdt. 16 from 1978, significantly including “FAR 29.631 (for cockpit windscreens only)“. FAR 29 only introduced a bird strike requirement at FAR 29 Amdt. 40 in 1996: The rotorcraft must be designed to ensure capability of continued safe flight and landing (for Category A) or safe landing (for Category B) after impact with a 2.2-lb (1.0 kg) bird when the velocity of the rotorcraft (relative to the bird along the flight path of the rotorcraft) is equal to VNE or VH (whichever is the lesser) at altitudes up to 8,000 feet. Compliance must be shown by tests or by analysis based on tests carried out on sufficiently representative structures of similar design. So the H145 cockpit windscreen was not required to meet the 1996...
read moreNight Offshore Helicopter Approach Water Impact
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...
read moreNight Offshore Take-Off Loss of Control Incident Norway
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,...
read moreAir Ambulance Night Wirestrike at Poorly Chosen Landing Site
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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