BK117 Offshore Medevac CFIT & Survivability Issues
BK117 Offshore Medevac CFIT & Survivability Issues (Southern Lakes BK117C1 ZK-IMX, Southern Ocean off Auckland Islands) On 22 April 2019 Southern Lakes Helicopters Airbus / Kawasaki BK117C1 ZK-IMX suffered a Controlled Flight into Terrain / Water (CFIT/W) while positioning for an offshore medical evacuation (medevac) flight. The Accident The New Zealand Transport Accident Investigation Commission (TAIC) issued their safety investigation report on 22 April 2023. TAIC explain the helicopter, based at Te Anau, was tasked for a medevac from a fishing vessel in the Southern Ocean off Auckland Islands. The casualty “required urgent hospital treatment” (though their medical condition is not elaborated upon) and “the first aid stocks on the vessel needed replenishment”. The operator had 8 helicopters (a mix of BK117s, AS350s, EC120s and R44s). They held a New Zealand CAA Part 135 approval. TAIC give very little other information about them, although while they… …had substantial procedure manuals for major operations, such as flying in the Antarctic or when working with the local search and rescue organisation, the guidance procedures for this high-risk type of operation was spread across several sections of the exposition. Ominously: Much of the operator’s experience had yet to be documented. In the early 2000’s Ambulance New Zealand and the NZ Helicopter Association had developed a joint standard called the ‘New Zealand Aeromedical and Air Rescue Standard’ (NZAARS). This standard reportedly did not apply because “this flight was a privately-funded medical evacuation”. There is no clarity on how the flight was tasked or by who. TAIC comment that: The operator had found from experience that standard aviation weather forecast information was not reliable for the Southern Ocean. They obtained their own weather information from several different but well-known sources, including the automatic weather station (AWS) on Enderby Island, then made their own assessment. As they were aware of the cold front approaching they planned to position to Enderby Island (the ‘positioning flight’) before it arrived and stay overnight at a hut where the operator had a fuel store. The next day the helicopter would rendezvous with the fishing vessel, hoist aboard the casualty and after refuelling again at Enderby Island, return to New Zealand on 23 April 2019 in the clearer air behind the cold front. On board for the visual flight rules (VFR) positioning flight were a single pilot, a paramedic in the front left hand seat, and a hoist operator in the cabin. The pilot had 6673 hours in total (all VFR). They had trained on night vision goggles (NVGs) in 2013 and had 73 hours on NVG experience, but had done less than 1 hour in the last 90 days. The pilot did not hold an instrument rating and and had only flown to Auckland Islands once before. The paramedic had a logged time 198 hours on NVGs but worked for another company and was only called in when medevacs occurred. The pilot had completed Helicopter Underwater Escape Training (HUET) in July 2013. The paramedic’s last HUET was in May 2018 and the hoist operator, who was a casual part-time employee, had completed HUET in September 2013. Our observation: two of the crew had therefore not done HUET in over 5½ years and two were casual staff who were only called in when their specialist skills was required. TAIC explain...
read moreEC135 Air Ambulance CFIT when Pilot Distracted Correcting Tech Log Errors
Airbus EC135P2+ Air Ambulance CFIT when Pilot Distracted Correcting Tech Log Errors (Med-Trans / LifeForce 6 N558MT, North Carolina) On 9 March 2023 LifeForce Airbus EC135P2+ air ambulance N558MT, operated by Med-Trans Corporation (part of Global Medical Response), suffered a Controlled Fight into Terrain (CFIT) during a night time patient transfer near Franklin, North Carolina. The helicopter stuck trees atop high ground an force landed on to a road. Three of the occupants received minor injuries and the fourth escaped uninjured. The US National Transportation Safety Board (NTSB) safety investigation report was published 6 June 2023. The Accident Flight The helicopter was based as Western Carolina Airport, Andrews, North Carolina. The pilot was working a 06:30 to 18:30 shift. The 51 year old pilot had 4723 flying hours of experience, 1867 on type according to the accident report form. We suspect this may be just civil time as the pilot is a former USMC squadron commander. At c17:50 a request was received for a patient transfer between two hospitals. This would have been the pilots fourth tasking of the day, but the pilot stated to the NTSB “we felt confident we could complete the flight within the 14-hr window” (presumably the applicable duty time limit). At 18:13 they arrived at Erlanger Western Carolina Hospital, Murphy, North Carolina to collect the patient. The pilot stated that while the patient was prepared for flight there was one distraction for the pilot, a call with the Regional Area Manager (RAM): I was instructed to double check maintenance due times to ensure we would not overfly any inspections due to a temporary glitch between RAMCO (company maintenance program) and FlightLog that was being rectified. Subsequently: I computed and recorded the weight & balance information in the flight log for the upcoming leg and attached the NVG [Night Vision Goggles] battery pack and mount to my helmet in anticipation of donning the goggles during the next leg… There is no indication that the NVGs were tested. The flight was forecast as 38 minutes and twilight was at c19:19. Weather was workable: reporting and forecasting VFR along the route. The majority of the reports…indicated 10SM, -RA, BKN 060 30.14. The pilot commented to NTSB that the highest obstacle en route was 6,100 ft with several 5,000 to 5,500 ft peaks too. The helicopter departed shortly after 18:45. Upon reaching Vy (65kts) I selected IAS (indicated airspeed) mode on the autopilot and HDG (heading) mode to take us just north of the Tusquitte Spine (an east west running ridge..). At c18:50: I dialled in 5500’ and shifted to V/S (vertical speed) mode with AltA (Altitude Acquire). Upon reaching that altitude airspeed increased to ~110 KIAS (~132 Kts ground speed.) Although, the pilot was intending to don NVGs they were not mounted on the pilot’s helmet ready to flip down. They were in fact “resting on the logbook” (i.e. Technical Log) on the empty front seat. I was just about to remove the caps and don them when I chose instead to relocate the logbook to the pilot door compartment where we typically stow it during flight. With logbook in hand, I decided to double check the printed-out RAMCO due values against the logbook values since we had already flown over four hours that day with an...
read moreOil & Gas Aerial Survey Aircraft Collided with Communications Tower
Oil & Gas Aerial Survey Aircraft Collided with Communications Tower (Airborne Energy Solutions Cessna 172N C‑GZLU) On 18 September 2022 Airborne Energy Solutions aerial survey Cessna 172N C‑GZLU, surveying oil and gas pipeline infrastructure, collided with a communications tower near Shaunavon, Saskatchewan (a Controlled Flight Into Terrain [CFIT]). Both pilots onboard died. The Accident Flight The Transportation Safety Board of Canada (TSB) issued their safety investigation report on 16 May 2023. The TSB explain that the aircraft had departed Swift Current Airport (CYYN), Saskatchewan at 08:27 Local Time and was conducting a visual flight rules (VFR) flight to gather electronic data for a unnamed client along a route that extended southeast of Shaunavon, then eastward to Estevan. The contract… …required that there be two pilots on board: one to fly the aircraft, the other to monitor the captured electronic data and assist with navigation duties. The pilots switched seats and duties on alternating flight legs. The customer’s “job form” for the survey specified a height of 550 feet AGL (±50 feet). The aircraft was equipped with an altimeter, which indicated altitude in feet ASL; however, it was not equipped with, for example, a radio altimeter, to indicate height in feet AGL. The Pilot Flying, sat in the left seat, held a Commercial Pilot Licence and had 355 hours total flight time, 77 of which were on the C172 for Airborne Energy Solution. The other pilot also held CPL and had 536 hours of total flight time, 529 on type. However: At approximately 1003, the aircraft struck a communications tower approximately 6 an SSW of Shaunavon. The height of the communications tower was 3840 feet ASL, or 440 feet AGL. It was marked and lit in accordance with the Canadian Aviation Regulations. The tower was also depicted on the Regina VFR Navigation Chart. The aircraft’s last recorded position on its flight tracker (at 1001:30) was 1.2 nm WNW of the communications tower at an altitude of 3741 feet above sea level (ASL), which was 572 feet above ground level (AGL). The occurrence aircraft was travelling on a track of 88° true (T) when it struck the communications tower approximately 25 feet below the tower’s highest point. A 4-foot section of the aircraft’s right wing was shorn off and was discovered at the base of the tower. The fuselage then travelled approximately 240 m on a track of 174°T, before impacting the ground. A post-impact fire ensued, which consumed most of the remaining fuselage. TSB note that the… …area forecast for the occurrence area, valid from 0600, indicated clear sky conditions with visibilities greater than 6 statute miles. Weather was not considered to be a factor in this occurrence. However: The sun’s position at the time of the occurrence would have been rising in the east. Solar position calculations indicate that the solar azimuth was 125°T (37° right of the aircraft’s track of 88°T) and the solar elevation was 28° at the time of the collision. It is possible that glare from the sun obscured the pilot’s view of the communications tower. TSB Safety Message Interestingly the treat of glare was not the subject of TSB’s safety message, instead they give the self-evident reminder of… …the importance of consulting available navigational charts when flight planning and in flight so as to avoid colliding with obstacles identified on those charts. Our Observations...
read moreHH-60L Hoist Cable Damage Highlights Need for Cable Guards
Sikorsky HH-60L Hoist Cable Damage Highlights Need for Cable Guards (N964SB, Santa Barbara County Fire Department) On 3 December 2022 Sikorsky HH-60L N964SB of the Santa Barbara County Fire Department suffered hoist cable damage while conducting hoist training from Santa Ynez Airport/Kunkle Field, California. The Incident The helicopter was also equipped with a belly-mounted Kawak Aerial Liquid Delivery System (ALDS) firefighting tank system and elongated landing gear. The Department of the Interior (DOI) & US Forest Service (USFS) SAFECOM aviation safety reporting system report states: …the helicopter slowly approached the deployment location with the Crew Chief seated at the rear door [i.e. the right hand cabin door]. As the rescuer neared the ground, a cable swing developed in which the crew chief determined to be excessive. The Crew Chief decided to bring the rescuer back up to the helicopter… As the cable length reduced the swing amplitude consequently increased and… …the cable swung forward of the aircraft sidestep and wrapped around the backside of the cable guard where two bolt heads were protruding. These screws are reported to have had “sharp edges” and “about 1/4″ of threads showing”. This contact resulted in extensive damage to the hoist cable with 7 of the outer cable strands becoming sheared. The rescuer made it into the aircraft safely, but the cable was not able to be reeled all the way into the drum. The cable hook was secured to the aircraft’s upper strut tiedown and the aircraft was flown back to base, where the cable was changed, and the aircraft was placed back into service. Safety Action Kawak is developing a user-installed kit “that will prevent the deployed cable from coming in contact with any structure on the tank or step.” It will add a “simple but robust bar guard, and will have rub strips along the whole length” and kits and a Service Letter will be distributed to operators free of charge. Our Safety Observations This occurrence highlights the importance of cable guards and considering the credible cable swing arc. The Flight Safety Foundation (FSF) BARSOHO offshore helicopter operations Safety Performance Requirements contains Control 12.4: Hoist Cable Protection: Hoist cables must be protected from damaging contact with aircraft structure. UPDATE 30 May 2024: IOGP has issued version 1 of their Recommended Practice 699 Emergency Response Services. 699/5-1 does require hoist cable protection in a table of equipment, which is good. It is however accompanied by footnote 8. Readers will notice there are only 7 footnotes listed below the table and that footnote 5 (not assigned to an item in the table) actually says: If hoist cable protection is not available due to the aircraft type in use this is to be discussed, agreed and documented with the Company Aviation Advisor. This was the only equipment listed in the table that IOGP recommend can be waived by Company Aviation Advisor (something that was unsuccessfully challenged in two rounds of industry comment). In contrast we contend that if an aircraft is proposed to be used for hoisting and it lacks such protection it is both unsuitable and unsafe. Furthermore, any aviation advisor who waived hoist cable protection would be demonstrating gross negligence. Safety Resources The European Safety Promotion Network Rotorcraft (ESPN-R) has a helicopter safety discussion group on LinkedIn. You may also find these Aerossurance articles of...
read moreSwinging Snorkel Sikorsky Smash: Structural Stress Slip-up
Swinging Snorkel Sikorsky Smash: Structural Stress Slip-up (Brainerd Helicopters Sikorsky UH-60A Black Hawk N9FH Firefighting STC MCF) On 25 May 2021 Sikorsky UH-60A Black Hawk N9FH of Brainerd Helicopters Inc (parent company to Firehawk Helicopters) crashed near Leesburg International Airport (LEE), Florida. This was during the post-maintenance check flight after installation of a snorkel equipped aerial firefighting system. The restricted category helicopter was destroyed and all 4 occupants died. The US National Transportation Safety Board (NTSB) issued their safety investigation report on 19 April 2023. The Modification Eight days earlier the snorkel/tank system had been installed on this ex-military restricted category helicopter in accordance with a Blackhawk Mission Equipment LLC (BME), Federal Aviation Administration (FAA) Supplemental Type Certificate (STC), number SR00933DE, approved by the by the FAA Denver ACO. BME is a subsidiary of Brainerd Helicopters. Several days of ground testing and calibration were performed before the accident flight, which was the first flight after the 925 gallon carbon composite cabin tank and the external snorkel were installed. The snorkel has non-retractable 15 foot long, 6 inch diameter, flexible hose which hangs from the left side of the tank to allow water uplift in a low hover. The snorkel is outboard of a water chute, that extends out of the left cabin door, as the means to empty the tank. The snorkel is attached to the tank at metal nozzle port which is secured to the tank via a by 8 AN4 bolts fastened to a backing nut plate at carbon fibre flange. The snorkel connects is attached to the nozzle port by a two lever cam-lock (the ‘coupler’). A 7.5 hp pump is mounted at the lower end of the hose. A power cable for the pump and a lightning protection cable run down the length of the snorkel and are secured using nylon zip ties. The snorkel hose and pump assembly [mounted at the bottom] weighs 137.5 pounds. The Fatal Accident Flight The purpose of the local flight was to check the operation of the newly installed fire-fighting system. The helicopter made six uneventful passes in front of the operator’s hangar at LEE and dropped water that was picked up from a lake adjacent to the airport. On the seventh pass, an employee of the operator noticed that the snorkel was swinging. He called the LEE air traffic control [ATC] tower and told the controller to ask the pilot to slow down and land immediately. Before the controller could contact the pilot, the helicopter transitioned to forward flight, gaining altitude and airspeed. During the helicopter’s last pass another witness saw the snorkel swinging in a large circle that came “very close” to the main rotor blades. The employee who contacted ATC said the snorkel was “violently” swinging, then heard a loud bang and… …saw pieces of the helicopter, including the tail section, separate from the helicopter. Afterward, the helicopter started to spin and descended below the tree line. The employee then heard an explosion and saw smoke rise above the tree line. The wreckage was contained in a 31-foot diameter vertical impact crater…in a localized swamp approximately 1,000 feet southeast from the approach end of Runway 3…and had been consumed by fire. The vertical tail, tail rotor, stabilator, and aft portion of the empennage was located about...
read morePoor Contracting Practices and a Canadian Helicopter HESLO Accident
Poor Contracting Practices and a Canadian Helicopter HESLO Accident (Heli-Express Airbus AS350B2 C-GHEX at Hydro-Quebec Powerline Worksite) On 11 May 2021, Héli-Express Airbus AS350B2 C-GHEX was conducting Helicopter External Sling Load operations (HESLO) flights from a staging area to a 315 kV powerline maintenance site, northeast of Les Escoumins, Quebec. During one HESLO flight the loadmaster notified the pilot by radio from the ground that the load was oscillating. The pilot expected the load would stabilise as the helicopter accelerated. At an airspeed of c65 knots, the load struck the tail boom however. The pilot pitched up to slow the helicopter and jettisoned the load which then struck the tail rotor. The pilot subsequently lost control of the helicopter and made a forced landing in sparsely wooded rugged terrain. The pilot suffered serious injuries. The helicopter was contracted to GLR a specialised powerline construction and maintenance company, who were contracted by power utility Hydro-Québec. The Transportation Safety Board of Canada (TSB) discuss important contracting issues and commercial pressures in their safety investigation report (issued 10 January 2023). The Safety Investigation We start by considering the last portion of the flight, after the load impacted the helicopter. But to understand why the load behaved as it did we then step right back to understand the organisational factors that were influencing the operation. Safety Investigation: The Flight After the Load Instability Examination of the load confirmed that it was struck in its understated by a tail rotor blade as the blade rotated backwards. The TSB explain that after the load was jettisoned: The pilot immediately realized that the anti-torque pedals were no longer allowing him to control the yaw, and he quickly experienced difficulty maintaining control of the aircraft. As part of their recurrent training the pilot had practised a technique described in the Rotorcraft Flight Manual that assumed a loss of tail rotor control (but not a loss of tail rotor thrust). In such a case, it is still possible to land with the engine running. The absence of tail rotor thrust cannot be reproduced in flight for training purposes (Héli-Express do not appear to use simulators). With a loss of tail rotor thrust… To land, the pilot must conduct an autorotation while shutting down the engine. As the pilot did not think he had lost the tail rotor… After regaining speed, the pilot headed to a landing strip near the staging area to land with the engine running, like he had learned to do in training. However, after losing and regaining control of the aircraft’s yawing motion twice while heading to the landing strip, his speed and altitude were too low to take back full control of the aircraft when he lost control of the yawing motion a 3rd time. When power was cut, the helicopter was likely at a height that could not sufficiently dampen the autorotational descent… TSB note (our emphasis added) Héli-Express’ training program also includes ground and flight training on the transport of Class B external loads [i.e. suspended loads that can be jettisoned] and operations near high-voltage transmission lines, including flying under the lines. However, the exercises for practising flying near or under high-voltage transmission lines do not include practising transporting a sling load in this particular environment. The pilot had been employed by...
read moreDouble Trouble: Offshore Surveillance P68 Forced to Glide
Double Trouble: Offshore Surveillance P68 Forced to Glide After Power Loss 11 nm Offshore (Réunion Fly Services Vulcanair P68C F-ORET, Mayotte) On 12 December 2021 Vulcanair P68C F-ORET of Réunion Fly Services suffered a double engine power loss event off the French Indian Ocean island of Mayotte. As the aircraft was conducting a border patrol mission for the Prefecture of Mayotte the investigation was conducted by Le bureau s’appelle désormais Bureau Enquêtes Accidents pour la sécurité de l’aéronautique d’État, the French state aircraft accident investigators, the BEA-É. The Serious Incident Flight In their safety investigation report (issued in French only) they explain that the aircraft took off from Dzaoudzi Pamandzi airport, Mayotte at 07:26 Local Time operating under EASA Part-SPO regulations. Mayotte is midway between Madagascar and the Comoros islands. On board were a pilot and an observer and the aim was to conduct a maritime surveillance mission at 500-1,200 feet. Shortly after, c12 nm to the southeast, at an altitude of 800 ft, the pilot heard an abnormal noise from the left (no 1) engine and observed an “oscillatory movement of the propeller spinner”. Concerned at the possible release of debris the pilot initiated an in flight shutdown of that engine and a return to base. Shortly after, 11 nm from the airport at 450 ft, the right (no 2) engine suffered a loss of power and cut out. Four attempts to restart that engine failed to achieve more than a brief period of running and an attempt to re-start the left engine also failed. The pilot ultimately successfully glided to Dzaoudzi Pamandzi airport and made a safe landing. Safety Investigation The BEA-É comment that the pilot was experienced on twin-engine aircraft, also an instructor and was used to demonstrating and carrying out engine failure exercises. The investigators note that this experience may have paradoxically encouraged early shut down of the no 1 engine before gaining more height. In contrast, the failure to restart the left engine was, in the opinion of the investigators, most likely due to an surprisingly hurried attempt but crucially without use of the checklist that may have resulted in omission of one of the series of steps necessary. The report gives no detail on what sea survival measures were in place for this operation. No 1 Engine Failure Upon disassembly damage was found to the propeller spinner support. Investigators concluded that the origin of the damage was misalignment of the low pitch thrust bearing tightening nut, in turn causing longitudinal misalignment of the spinner resulting in the damage found. This failure is not further elaborated upon. No 2 Engine Failure The aircraft had been parked outside for the 12 days since it arrived on the island. On the first 11 evenings it had been refuelled from 195-litre AVGAS 100 LL drum stock. Only on the evening prior to the accident was the fuel not topped up. That evening the aircraft was parked overnight facing east on an apron with a slight slope to the south, with c300 litres of fuel evenly distributed in the two wing tanks (the maximum capacity is 538 litres). Each engine is usually connected to the corresponding wing tank. It is possible to modify this configuration flight by connecting an engine to the opposite tank by means of the fuel selector...
read moreTwisted Firestarters
Twisted Firestarters in this article we look at wo occasions a helicopter has triggered a bush fire. In the first the helicopter succumbed to the flames. In the other case the helicopter fled the scene and the environment suffered. Robinson R44 Northern Territory, 22 June 2022 This R44 was conducting a geophysical survey north of Alice Springs. The survey involved landing every 1 km to collect data. On board were the pilot and a survey field technician. According to the Australian Transport Safety Bureau (ATSB) occurrence brief: At about 1000 local time, the pilot landed in an area of spinifex grass and the field technician disembarked the helicopter to carry out their survey tasks. The technician reported that, after setting up the equipment, they looked up and noticed flames under the helicopter. It was reported that the helicopter’s engine bay was positioned close to an area of dry spinifex and the heat from the engine’s exhaust ignited the grass. The ensuing fire spread very quickly, engulfing the helicopter. The pilot vacated the aircraft and sustained minor burns to their leg while attempting to retrieve a satellite phone on board. The helicopter was destroyed. The ATSB noted they were aware 5 occurrences in the preceding 10 years where a Robinson helicopter has been destroyed by grass fire. The R22 and R44 Pilot Operating Handbooks contain a warning: Do not land in tall dry grass. The exhaust is low to the ground and very hot; a grass fire may be ignited. Australian Army NH Industries NH90 (MRH-90 Taipan), Namadgi National Park, Australian Capital Territory, 27 January 2020 The military NH90 was supporting local civil authorities when it landed in the Orroral Valley within teh national park so crew members could ‘disembark for a short break‘. However a landing light caused a grass fire. The aircraft suffered significant damage but took off and flew back to Canberra. It landed safely and in “little over an hour…Defence public affairs was directed to start developing a holding statement and talking points.” The grass fire had however developed into what was capital city Canberra’s “most serious” bushfire threat since 2003 that consumed more than 7,900 hectares. Critical to the fire’s rapid development was the failure of the helicopter crew to raise the alarm for c45 minutes (i.e. until they landed). A lack of precise information sowed confusion as fire crews were dispatched to different parts of the national park in attempt to locate and extinguish the blaze. The title of the article is a reminder of your nan’s favourite 1990s bad boy, The Prodigy‘s Keith Flint. We will remain alert to any opportunity to reference Skin or PJ Harvey in future titles. Safety Resources The European Safety Promotion Network Rotorcraft (ESPN-R) has a helicopter safety discussion group on LinkedIn. You may also find these Aerossurance articles of interest: South Korean Fire-Fighting Helicopter Tail Rotor Strike on Fuel Bowser S-76A++ Rotor Brake Fire USAF RC-135V Rivet Joint Oxygen Fire C-130 Fireball Due to Modification Error Competitive Behaviour’ and a Fire-Fighting Aircraft Stall Short Sling Stings Speedy Squirrel: Tail Rotor Strike Fire-Fighting in Réunion Wayward Window: Fatal Loss of a Fire-Fighting Helicopter in NZ Helicopter Tail Rotor Strike from Firefighting Bucket Maintenance Issues in Fire-Fighting S-61A Accident Korean Kamov Ka-32T Fire-Fighting Water Impact and Underwater Egress Fatal Accident Firefighting AW139 Loss...
read moreManaging Interruptions: HEMS Call-Out During Engine Rinse
Managing Interruptions: HEMS Call-Out During Engine Rinse – Panel Lost (ANWB Airbus EC135T2+ PH-MAA) On 7 February 2022 air ambulance Airbus Helicopters EC135T2+ PH-MAA of ANWB Medical Air Assistance suffered the in flight loss of an engine inspection panel shortly after departure from Groningen Airport. According to the Dutch Safety Board (DSB) safety investigation (issued in March 2023), the operator conducts an engine rinse “every 5 flying hours / 3 days, or after flights over sea and/or a polluted environment”. This involves the aircraft commander in the cockpit and a second person operating the necessary ground support equipment. The investigators explain that: The procedure required the engine cowlings of the EC135T2+ to be opened in order to access the compressor rinse connection and to be closed after the rinsing procedure was completed. The…procedure also stipulated a plan in case of a Helicopter Emergency Medical Service (HEMS) scramble during the rinsing procedure. In this case a call-out did indeed interrupted the task. Shortly after take off… …the pilot heard a noise and suspected the helicopter had struck a bird. Another ANWB EC135T2+ had indeed suffered a bird strike on 14 January 2021. Investigators note that: There were no indications or warnings in the cockpit of a helicopter system malfunction and the commander decided to continue the flight. However shortly after the call out was cancelled anyway and the helicopter proceeded to return to base. Only after landing was an engine inspection panel found to be missing. The investigators conclude It is likely that the right engine cowling was not properly closed after the engine compressor rinsing procedure was interrupted by a HEMS scramble. Consequently, as a result of aerodynamic overload, it departed the helicopter during the flight. Our Observations It is good that the operator’s engine rinse procedure reportedly considered the task could be interrupted by a call-out. A lazy analysis would be to simply conclude there was a ‘failure to follow procedures’. That is lazy because: the DSB don’t actually describe what was expected in the event of an interruption it fails to recognise that by their very nature interruptions and distractions break and disrupt procedural flow. For this specific task one advantage is that it needs two people, so there are two people who can be used to cross-check key steps to return the aircraft for flight (e.g. disconnecting GSE, securing panels etc). Safety Resources The European Safety Promotion Network Rotorcraft (ESPN-R) has a helicopter safety discussion group on LinkedIn. You may also find these Aerossurance articles of interest: After Landing this HEMS Helicopter Suddenly Started to Slide Towards it’s Hangar… Human Factors of Dash 8 Panel Loss EC120 Forgotten Walkaround Distracted Dynamic Rollover US HEMS EC135P1 Dual Engine Failure: 7 July 2018 Dusk Duck: Birdstrike During Air Ambulance Flight Limitations of See and Avoid: Four Die in HEMS Helicopter / PA-28 Mid Air Collision EC135P2 Spatial Disorientation Accident HESLO EC135 LOC-I & Water Impact: Hook Confusion after Personnel Change Air Ambulance Helicopter Fell From Kathmandu Hospital Helipad (Video) Air Ambulance B407 Hospital Helipad Deck Edge Tail Strike During Shallow Approach US Air Ambulance Helicopter Hospital Heliport Tail Strike Air Methods AS350B3 Air Ambulance Tucson Tail Strike NTSB on LA A109S Rooftop Hospital Helipad Landing Accident Helicopter Destroyed in Hover Taxi Accident Air Ambulance Helicopter Downed by Fencing FOD Ambulance / Air...
read moreHESLO AS350 Fatal Accident Positioning with an Unloaded Long Line
HESLO H125 / AS350B3e N755AE Fatal Accident Positioning with an Unloaded Long Line On 29 July 2020, Airbus Helicopters H125 / AS350B3e N755AE of St Louis Helicopter was destroyed, and the two occupants killed, in an accident near Pioche, Nevada. According to the US National Transportation Safety Board (NTSB) safety investigation report (issued 16 March 2023) the helicopter had landed on a mountain ridge (at an elevation of c 6,741 ft AMSL) during a survey prior to Helicopter External Sling Load Operations (HESLO) schedule for that day to move equipment to a mobile phone cell tower site. The accident flight was to be a c3 minute flight down from the ridge to a fuel truck to refuel (the fuel truck had been unable to drive any closer to the work site). On board were the pilot (owner of the company and who had 12,500 hours of total flight time) and a passenger. A witness reported that…a cable that was laid out on the ground in front of the helicopter. The pilot stated to him that the cable was 70 feet long. The witness left the pilot and passenger at the helicopter and drove away; shortly thereafter, he received a phone call about smoke in the vicinity and learned that the helicopter had crashed. The helicopter came to rest on its right side in heavily wooded terrain c 630 m from the fuel truck.. The aircraft was equipped with a Crash Resistant Fuel System (CRFS). This suffered some impact damage, but there was no evidence of any fuel loss. Examination…revealed that the long line was entangled with the tail rotor, which had separated from the helicopter. One tail rotor blade remained attached to the tail rotor; the other blade was not located. The tail boom was broken off and partially attached at the lower aft bulkhead by control cables. The tail cone/vertical fin assembly was found about 365 ft from the main wreckage and exhibited evidence of cable abrasion. The engine data recorder…indicated that the engine was placed in flight, then reduced to idle near the end of the recording. During this sequence, the main rotor speed decayed below that necessary to maintain lift. Examination of the flight controls and engine, as well as review of recorded engine data, revealed no evidence of mechanical anomalies that would have precluded normal operation. The helicopter was equipped with an Appareo Vision 1000 cockpit video recording device. The removable memory SD card was found to be blank. When the internal memory card was downloaded it contained data from 25 January 2020, 6 months earlier. Appareo identified several electrical system reasons this may not have occurred (including the circuit breaker being open). However: A return trip to the accident helicopter at the wreckage facility was attempted, however due to COVID-19 travel restrictions, and other factors, it was not conducted… So we are sadly none the wiser on this failure. NTSB conclude that… …it is likely that the pilot failed to achieve adequate clearance between the long line and terrain before descending downhill toward the fuel truck, which resulted in the helicopter’s long line, becoming entangled with the tail rotor, and a subsequent loss of helicopter control. Remarkably there is no comment on whether the longline was weighted or not. While an unweighted long line could...
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