Schiebel Camcopter S-100 Engine Failure Results in Baltic Crash
Schiebel Camcopter S-100 Engine Failure Results in Baltic Crash On the 4 May 2022 a Norwegian registered Schiebel Camcopter S-100 rotorcraft Unmanned Air Vehicle (UAV) crashed into the Baltic near Staberhuk in Germany after an engine failures. The German Federal Bureau of Aircraft Accident Investigation (BFU) explain in their interim safety investigation report that the 200 kg Unmanned Air System (UAS) has been conducted ship environmental emissions sampling for the European Maritime Safety Agency (EMSA) and the Bundesamt für Seeschifffahrt und Hydrografie (BSH). At 1300:56 hrs , the UAV took off in manual flight mode (MANU VTOL Mode)… At 1302 hrs, the pilot activated the automatic flight mode (AUTO FLIGHT). During the flight, the UAV was up to 30 NM away from the take-off site. The pilot activated the manual flight mode (MANU FLIGHT) a total of seven times in order to approach a vessel manually in low altitude and measure emissions. Flight altitudes were between 71 ft and 267 ft AMSL. Between 1508:51 hrs and 1512:15 hrs, while the UAV was in manual flight mode, loss of link occurred… The recorded engine parameters (cooling water temperature, rotor cooling and exhaust gas temperature) prior to the loss of link and afterwards were within the normal range. At 1514:55 hrs, the pilot activated the automatic flight mode and the UAV commenced a return to base cruising at c 85 kt . At 1531 hrs, the UAV began to reduce speed. …after waypoint 11 was reached at an altitude of about 220 ft, the last programmed waypoint 12 was approached at 1534:20 hrs with a ground speed of about 15 kt and a rate of descent of about 315 ft/min. At 1534:56 hrs, the recorded rotation speed of the engine of previously 7,100 rpm and that of the main rotor of 1,187 rpm plunged within one second. …the UAV was about 50 m east of the Fehmarn beach in horizontal flight at about 90 ft above the water with a ground speed of 1 kt. At 1535 hrs, the UAV crashed into the Baltic Sea. The flotation system fitted to the left side of the fuselage deployed automatically and kept the UAV close to the surface. This was shortly before the Pilot Control Operator (PCO) would have taken over from the Pilot in Command for a manual landing. Safety Investigation The engine was disassembled by investigators. It was determined that parts of the coating inside the Wankel rotary engine had separated and the rotor had been blocked by coating debris. We will update this article as more details emerge. 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: Drone Goes Walkabout: Hemispherical Human Factors Hiccup Software Bug and High Winds Down Drone Facebook Aquila Drone Accident: Gust Induced Structural Failure Drone Operation Injury USAF MQ-9A Reaper Lever Confusion: Human Factors Drone Pilot Injured in US Prison Geo-fence Incident Inspection UAS Collides with PNG LNG Export Jetty UPDATE 7 August 2022: Fuel Tube Installation Trouble Aerossurance has extensive air safety, operations, SAR, UAS/RPAS/Drone, engine design & certification, airworthiness, human factors, aviation regulation and safety analysis experience. For practical aviation advice you can trust, contact us at: enquiries@aerossurance.com Follow us on LinkedIn and on Twitter @Aerossurance for our latest updates. TRANSLATE with x English Arabic Hebrew Polish Bulgarian Hindi Portuguese Catalan Hmong Daw Romanian Chinese Simplified...
read moreB212 LOC-I: Windshear Encounter in the Lee of Mountain Ridge
Bell 212 Loss of Control – Inflight: After Windshear Encounter in the Lee of Mountain Ridge (Airspan Helicopters C-GNYI) On 5 March 2021, Bell 212 C-GNYI of Airspan Helicopters, on contract to electrical power utility BC Hydro, crashed on Bowen Island, British Columbia. The two pilots both received serious injuries. History of the Accident Flight The Transportation Safety Board of Canada (TSB) explain in their safety investigation report, issued 28 July 2022, that according to weather forecasts consulted during flight planning… …moderate, with localized severe, mechanical turbulence and low-level wind shear were expected in the area… Though the strong winds were a concern, the flight was dispatched with the knowledge that it would be a turbulent flight. The PIC [the operator’s President and Operations Manager, who had 9126 hours of experience, 1247 on type] made the decision to depart based on an improving forecast later in the day, the desire to complete the operational flight, and the observation that other aircraft were operating in and out of Sechelt Aerodrome. The second pilot [who had 5757 hours of experience, 480 on type] then began to prepare the helicopter for the flight. …while in the cruise… the helicopter entered wind shear and experienced a sudden, dramatic right roll with nose-down pitch. Unrestrained items in the cabin struck the pilots, and an impact on the second pilot’s helmet made their visor cover to move temporarily blocking their vision as a critical moment. After regaining control, the number 2 engine experienced an uncommanded in-flight shutdown and the flight controls became very hard to manipulate. A location on nearby Bowen Island, BC, was selected for an emergency landing; however, the helicopter was still difficult to control and the pilots were unable to manoeuvre it to the desired location. During the descent, the helicopter began a rapid rotation to the right, which the pilots were unable to arrest. After several rotations, the helicopter collided with trees and came to rest on a rocky ridge approximately 270 feet above sea level on the northwest corner of Bowen Island. Fortunately there was no post-crash fire as… …fuel lines under the cabin floor panel were compromised during the impact and began leaking fuel onto the pilots, who were still seated in the inverted fuselage, restrained by their safety harnesses. The PIC assisted the second pilot, whose foot was pinned in the footwell, and they both egressed successfully. The TSB Safety Investigation & Analysis The TSB explain that: On the morning of the occurrence, strong south easterly winds were blowing in the vicinity of the accident site. The west side of Bowen Island is dominated by a long ridge which is anchored at the south end by Mount Gardner with an elevation of 2388 feet ASL. The flight’s intended destination, Cypress Provincial Park, is approximately 6 NM east of Bowen Island. Within the park are Mount Strachan with an elevation of 4714 feet ASL and Black Mountain with an elevation of 4016 feet ASL. The final minutes…would have been flown on the downwind, or lee side, of this terrain. Lee effects are described in The Weather of British Columbia as follows: When the winds blow against a steep cliff or over rugged terrain, gusty turbulent winds result. Eddies often form downwind of the hills, which create stationary zones of stronger and lighter winds. These zones of strong winds are fairly...
read moreWhat Lies Beneath: The Scope of Safety Investigations
What Lies Beneath: The Scope of Safety Investigations Oilfield service company Baker-Hughes released a pair of safety videos in 2016 that tell the story of a safety incident. Together they illustrate an important point about safety investigations and how safety investigations ae interpreted (or sometimes misinterpreted). These short videos are meant to be watched in turn with reflection after each in order to get the full learning benefit. The docudrama narrative approach allows viewers to be a fly-on the wall of an incident to see and hear what happened. That gives an insight that safety investigators almost never have. However, in this exercise the downside is that you can’t ask questions and follow-up leads as you might in a normal investigation. That however, is immaterial to the learning the videos provide. Those not familiar with the working on a drilling floor might feel intimidated by the jargon and unfamiliar environment, but don’t let that put you off. Safety investigators not only need to be prepared to use their investigation expertise in unfamiliar circumstances but they need to avoid the hubris of thinking they are more expert at doing work than the workers involved. What Lies Beneath: Video 1 (5:24 mins) Watch the story unfold and think about what happened in the run-up to the incident and what the various people involved did or didn’t do. Feel free to replay again to crystallise your thoughts. You probably have many questions your burning to ask some or all of the players in this story. Note down which of the characters you most want to talk to and why. Only when you have done that, should you play the second video. What Lies Beneath: Video 2 (10:07 mins) A public inquiry chaired by Anthony Hidden QC investigated 1988 Clapham Junction rail accident. In the report of the investigation, known as the Hidden Report, he commented: There is almost no human action or decision that cannot be made to look flawed and less sensible in the misleading light of hindsight. It is essential that the critic should keep himself constantly aware of that fact. The Baker-Hughes videos show that narrowly focusing on the proximal means missing the full context. Aerossurance’s Andy Evans was recently interviewed about safety investigations, the perils of WYLFIWYF (What-You-Look-For-Is-What-You-Find) and some other ‘stuff’ by with Sam Lee of Integra Aerospace: Safety Resources You may also find these Aerossurance articles of interest: How To Develop Your Organisation’s Safety Culture James Reason’s 12 Principles of Error Management Psychology of Blame Airworthiness Matters: Next Generation Maintenance Human Factors Aircraft Maintenance: Going for Gold? B1900D Emergency Landing: Maintenance Standards & Practices Meeting Your Waterloo: Competence Assessment and Remembering the Lessons of Past Accidents Also: Safety Performance Listening and Learning – AEROSPACE March 2017 Learning from Adverse Events: Includes nine principles for incorporating human factors into learning investigations. UPDATE 24 October 2022: The Royal Aeronautical Society (RAeS) has launched the Development of a Strategy to Enhance Human-Centred Design for Maintenance. Aerossurance‘s Andy Evans is pleased to have had the chance to participate in this initiative. Aerossurance has extensive safety management, culture & leadership, flight operations, SAR, airworthiness / maintenance, human factors, aviation regulation and safety analysis experience. For practical aviation advice you can trust, contact us at: enquiries@aerossurance.com Follow us on LinkedIn and on Twitter @Aerossurance for our latest updates. tt Detected language :...
read moreDistracted Dynamic Rollover
Distracted Dynamic Rollover (R22 N19VH) On 6 April 2022 Robinson R22 Beta II N19VH of Quantum Helicopters was damaged at Phoenix-Mesa Gateway Airport, AZ during a night solo training flight. According to the US National Transportation Safety Board (NTSB) safety investigation report (released on 13 July 2022), the helicopter had landed and was rotors running reportedly with “full collective friction applied”. The pilot (who had 177 hours total time, all on the R22) used a torch to view the Hobbs meter. This was due to it being their last solo flight and they wanted to confirm if the flight was going to accumulate sufficient time. Unfortunately “the collective crept up, the helicopter rolled to the right and dynamically rolled over”. The canopy, horizontal stabilizer and main rotor were damaged, although the pilot was uninjured. NTSB Probable Cause The pilot’s failure to maintain helicopter control while on the ground when his attention was diverted, which resulted in a dynamic rollover. Safety Observations and Distraction & Dynamic Rollover Safety Resources The pilot stated in the accident report form that in relation to preventing the accident: I could have prevented the accident by trusting the timer that I had set in the aircraft instead of needed a visual confirmation of the hobbs meter. I could have also rolled down the throttle to lower the RPM’s of the rotor head prior to checking the timer. EHEST Leaflet HE 1 Safety Considerations discuses static and dynamic rollovers. The UK CAA has issued this infographic on distraction: Other 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: Be Careful If You Step Outside!: Unoccupied Rotors Running AS350 Takes Off AS350B3 Rolls Over: Pilot Caught Out By Engine Control Differences AS350B3 Dynamic Rollover When Headset Cord Snags Unguarded Collective Fatal B206L3 Cell Phone Discount Distracted CFIT Cessna 208B Collides with C172 after Distraction HEMS Pilot Seizure While Rotor-Running Taxiing AW139 Blade Strike on Maintenance Stand R44 Force Lands After Improper Repair UPDATE 25 March 2023: Managing Interruptions: HEMS Call-Out During Engine Rinse UPDATE 10 June 2023: EC135 Air Ambulance CFIT when Pilot Distracted Correcting Tech Log Error UPDATE 4 February 2024: HEMS Air Ambulance Landing Site Slide Also on human factors: Professor James Reason’s 12 Principles of Error Management Back to the Future: Error Management …and our review of The Field Guide to Understanding Human Error by Sidney Dekker presented to the Royal Aeronautical Society (RAeS): The Field Guide to Understanding Human Error – A Review Aerossurance has extensive air safety, operations, SAR, airworthiness, human factors, aviation regulation and safety analysis experience. For practical aviation advice you can trust, contact us at: enquiries@aerossurance.com Follow us on LinkedIn and on Twitter @Aerossurance for our latest updates. OO Detected language :...
read moreR44 Ditched After Loss of TGB & TR: Improper Maintenance
R44 Ditched After Loss of TGB & TR: Improper Maintenance (N1241W, Air Adventures Helicopters, Key West) On 17 June 2019 Robinson R44 N1241W of Air Adventures Helicopters was ditched off Key West, Florida following the in-flight loss of its Tail Gear Box (TGB) and tail rotor during a Part 91 revenue sightseeing flight. The three occupants were all uninjured. History of the Flight The US National Transportation Safety Board (NTSB) safety investigation report explains that: As the helicopter climbed through 300 ft AGL, the pilot [aged 29, 1430 flying hours total, 1274 on type] detected “rapid tail vibrations.” The pilot radioed tower and requested a return to the airport. He proceeded back to the airport when he heard a loud pop and felt a “hard” right yaw. Attempts to regain control of the helicopter with the anti-torque pedals were ineffective. He initiated an autorotation, and the helicopter began to yaw to the left. Again, attempts to regain control of the helicopter were ineffective. As the helicopter descended toward the water, the pilot deployed the floats, and landed the helicopter upright on the water without further incident. Safety Investigation Examination of the helicopter revealed that the tail rotor assembly had separated from the tail boom… As well as losing the means of yaw control this will have also resulted in a significant forward shift in centre of gravity, adding to the challenges the pilot faced. [E]xamination of the mounting hardware between the TGB input cartridge and the tail boom mating flange found that two of the four bolts were missing; both missing bolts came from the right side of the connection. The left side bolts remained secured in place. The missing bolts’ holes in the input cartridge were deformed and were out of round. All of the 4 bolt holes on the input cartridge displayed imprints from the bolt threads, with the deepest imprints on the right sides of the holes, consistent with movement between the lug holes and the bolt shanks. All tail boom flange bolt holes were examined and found that the threading was present, not stripped, and locking inserts present. The NTSB reveal that c60 flying hours and 5 weeks earlier the tail boom assembly had been removed and replaced. As part of this maintenance, the tail rotor input cartridge and gearbox would have been removed from the old tailboom and placed on the new tailboom. It is likely that, during this procedure, the right-side mounting bolts were not completely secured to the tail boom casting locking inserts and properly torqued [the the required 240 in-lbs], which resulted in the failure of the right side mounting bolts. The NTSB report unfortunately contains no further detail on the conduct of this maintenance. Following the replacement of the tail boom, the pilot reported rapid tail rotor vibrations which required multiple attempts to successfully balance the tail rotor as part of the post maintenance checks. NTSB Probable Cause The failure of maintenance personnel to properly secure the right-side tail boom mounting bolts which resulted in the failure of the bolts and an inflight separation of the tail rotor. 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: Compressive Creep and the Loss of a UH-1H’s Tail Rotor Prompt Emergency Landing Saves Powerline Survey Crew After MGB Pinion Failure Fatal $16 Million Maintenance Errors Dramatic Malaysian S-76C 2013 Ditching Video NTSB Report on...
read moreFatal EC130B4 Water Impact in the Tennessee River after “Entry to VRS” Say NTSB
Fatal EC130B4 Water Impact in the Tennessee River after “Entry to VRS” Say NTSB (N55GJ) On 3 August 2020 a privately owned Airbus EC130B4 N55GJ impacted the Tennessee River near Knoxville, Tennessee. One passenger, 84 year old local business man Joe Clayton, was fatally injured although the other three occupants escaped uninjured. History of the Flight The US National Transportation Safety Board (NTSB) safety investigation report, issued 28 June 2022, explains that the helicopter was making a local flight from McGhee Tyson Airport (TYS), Knoxville with the intention of landing at the pilot’s riverside property. The pilot, the deceased passenger’s 86 year old brother, had 12600 hours of flight experience, 300 on type. The pilot made a right circling approach at 1000-1200 ft AMSL. The landing site was at c840 ft AMSL according to one mapping site. The pilot stated… …he “was descending with low power and a 25° angle of descent, slowing to come to a hover at low speed over the water.” He…was planning to hover taxi to the landing site at a height about 75 feet above the water and that when he added power to arrest the descent, the helicopter “started to settle.” The pilot is said to have commented to another pilot the next morning that he made a “steep approach” with “little-to-no airspeed” and a rate of descent “greater than 300 feet per minute”. He stated he “pulled max power to stop the settling,” but it was as if the helicopter “didn’t have any power” and it continued to descend until it impacted the river. A passenger reported the helicopter to have been level when it descended and… …the left “skid hit and then rotor hit” and the helicopter was “torqued into the water on the left side.” The pilot and two passengers were able to egress before the helicopter sank. The helicopter came to rest on the bottom of the Tennessee River about 435 ft from the intended landing site. The body of the fourth occupant, seated in the front left seat, was recovered by divers later that evening. The autopsy report noted..[the deceased]…was free-floating in the fuselage and not restrained at the time of recovery. Safety Investigation Damage to the helicopter was “consistent with a low-energy impact”. No pre-impact malfunctions were identified. The…vehicle and engine monitoring display and a digital engine control unit…stored records of failure messages associated with engine operations. The data revealed no failures or limit exceedances prior to impact and indicated the engine was running at the time of impact. Weather reports and statements from the pilot and witnesses indicated that the helicopter descended steeply with little forward airspeed and a tailwind of about 5 knots… The NTSB highlight that the FAA’s Helicopter Flying Handbook (FAA-H-8083-21B) described the aerodynamic condition of Vortex Ring State (VRS) and states: Situations that are conducive to a VRS condition are attempting to hover out of ground effect (OGE) without maintaining precise altitude control, and approaches, especially steep approaches, with a tailwind component. According to ESPN-R / EHEST Leaflet HE 1 Safety Considerations, VRS… …is likely to occur when descending in powered flight at an airspeed below 30 Kts with a Rate of Descent (ROD) close to the main rotor “downwash velocity”. Downwash velocity (or induced velocity) is defined as the airspeed of the airflow drawn down through the rotor disc (Froude formula). The induced velocity is a function of the helicopter type and gross weight. For example, a...
read moreNYPD B429 Accident at Manhattan Heliport “Overapplication of Flight Controls”
NYPD Bell 429 Accident at Manhattan Heliport “Overapplication of Flight Controls” (N920PD) On 13 December 2021 New York City Police Department (NYPD) Bell 429 N920PD was damaged while landing at the Downtown Manhattan Wall Street Heliport, NY. The US National Transportation Safety Board (NTSB) explain in their safety investigation report (issued 14 June 2022) that: The pilot reported that during landing and once established directly over the helipad, he proceeded to hover taxi over to the assigned landing location, but during touchdown the helicopter unexpectedly shifted forward, rotating onto the front skids, then began to oscillate. The crew heard a loud “bang” and subsequently the helicopter became airborne briefly before settling down hard on the pavement and the helicopter started to go into ground resonance, becoming uncontrollable. The pilot reported that the helipad was congested with several other aircraft on the ground and two preparing to land, so when the helicopter became uncontrollable, he “dumped” the collective and rolled back the throttle. During the oscillations, the main rotor blades stuck the wire strike protection system, which resulted in substantial damage to the rotor blades. As well as damage to all four main rotor blades and the WSPS, the landing skids collapsed, the cockpit centre pedestal supports were bent, there was fuselage cracking, damage to the MX-10 turret and an antenna, and leaks of fuel and hydraulic fluid. NTSB Probable Cause The pilots overapplication of flight controls during landing, which resulted in the rotor blades contacting the wire strike protection system and subsequent hard landing. 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: Erratic Flight in Marginal Visibility over New York Ends in Tragedy Inadvertent PTT Pedal Input Causes Tail Rotor Tailboom Contact Loose Clothing Downs Marijuana Survey Helicopter HEMS A109S Night Loss of Control Inflight Air Ambulance A109S Spatial Disorientation in Night IMC A HEMS Helicopter Had a Lucky Escape During a NVIS Approach to its Home Base Air Ambulance Helicopter Struck Ground During Go-Around after NVIS Inadvertent IMC Entry CFIT Gangnam Style – Korean S-76C++ and Decision Making Fatal B206L3 Cell Phone Discount Distracted CFIT US Air Ambulance Helicopter Hospital Heliport Tail Strike Air Ambulance B407 Hospital Helipad Deck Edge Tail Strike During Shallow Approach Air Methods AS350B3 Air Ambulance Tucson Tail Strike NTSB on LA A109S Rooftop Hospital Helipad Landing Accident Air Ambulance Leaps into Air: Misrigged Flying Controls US Air Ambulance Near Miss with Zip Wire and High ROD Impact at High Density Altitude Hanging on the Telephone… HEMS Wirestrike Air Ambulance Helicopter Downed by Fencing FOD Ambulance / Air Ambulance Collision Beware Last Minute Changes in Plan Grand Canyon Air Tour Tragic Tailwind Landing Accident Pedestrian Seriously Injured by Air Ambulance Landing at Melbourne Hospital RLC B407 Reverses into Sister Ship at GOM Heliport Wire Strike on Unfamiliar Approach Direction to a Familiar Site Tool Bag Takes Out Tail Rotor: Fatal AS350B2 Accident, Tweed, ON When Habits Kill – Canadian MD500 Accident EC120 Forgotten Walkaround UPDATE 2 July 2022: Fatal EC130B4 Water Impact in the Tennessee River after “Entry to VRS” Say NTSB Aerossurance has extensive air safety, operations, SAR, airworthiness, human factors, aviation regulation and safety analysis experience. For practical aviation advice you can trust, contact us at: enquiries@aerossurance.com Follow us on LinkedIn and on Twitter @Aerossurance for our latest updates. TRANSLATE with x English Arabic...
read moreLimitations of See and Avoid: Four Die in HEMS Helicopter / PA-28 Mid Air Collision
Limitations of See and Avoid: Four Die in HEMS Helicopter / PA-28 Mid Air Collision (MAC) – EC135P2+ D-HDRV and PA-28 HB-PGF On 23 January 2018 DRF Luftrettung Airbus EC135P2+ HEMS helicopter D-HDRV and Flugschule Basel Piper PA-28RT-201T Turbo Arrow IV trainer HB-PGF crashed after a mid-air collision near Philippsburg, Baden-Wurttemberg, in south west Germany. The accident, which occurred while each was conducting training, resulted in four fatalities (two occupants aboard each aircraft). History of the Flights The BFU safety investigation report, issued 15 September 2021 (in German only), explains the helicopter departed Karlsruhe/Baden-Baden Airport at 12:04 Local Time. The intent was to carry out circuits and emergency procedure training at Speyer Airfield as part of a type training course. The first landing at Speyer took place at 12:29 before commencing further circuits to runway 16. The helicopter took off again at 12:56 and headed to the south-east. There it slowed to wait for a Cessna 172 that had taken off at about 13:06, before making an approach to runway 34. The approach in that direction as the aim was to train for a tail rotor failure and EC135 Flight Manual guidance is that a crosswind from the left was a more advantageous scenario. Meanwhile the PA-28 had also been conducting a training flight having taken off from Basel Mulhouse Freiburg Airport, France at c12:05. During the flight the aircraft twice changed its intended destination, ultimately to Speyer. At 13:02:49, the crew selected the Speyer radio frequency. The air traffic controller at Speyer informed the PA-28 crew both that the current landing direction was runway 16 and of the other traffic in the circuit. ATC subsequently informed the crew of the EC135 that an aeroplane would be landing shortly and told the PA-28 crew that a helicopter was hovering. The aeroplane’s crew reported “traffic not in sight”. ATC radar data shows the PA-28 was in a constant descent from about 130 knots at 3000 ft AMSL toward the downwind leg for runway 16. The helicopter was at 50-70 knots groundspeed at a nearly constant altitude, turning toward runway 34 at 13:07:01. At this point both aircraft were c 1.6 nm apart. At 13:07:12, about halfway through the EC135’s turn, separation was c1 nm. At 13:07:23, the helicopter was now flying towards runway 34 and separation was 0.6 nm. Witnesses had observed the conspicuous, slow-moving helicopter and then suddenly became aware of an aeroplane descending toward the helicopter. Despite a dramatic last moment evasive movement by the PA-28 a collision occurred at about 13:07:41. Witnesses stated that they saw a fireball and aircraft parts falling to the ground. The right wing of the PA-28 had made contact with the helicopter’s main rotor blades, severing the wing. The helicopter caught fire and its tail boom was also severed. Wreckage was scattered over an area of approximately 350 m by 170 m. VIDEO at the scene. At the time of the accident, the sun was c20° above the horizon at c190°. Visibility was c 15nm and the cloud base >4500 ft. The BFU Safety Investigation The BFU note that the EC135 was equipped with a…. …Bendix King MST 67A Mode S transponder, without ADS-B transmission, and a Garrecht TRX 1500A collision warning device… The TRX 1500A collision warning device was designed to be able to recognize possible collision traffic using FLARM and transponder transmissions, visually display this traffic on an external display and, if necessary, generate warning sounds via an audio channel....
read moreInadvertent PTT Pedal Input Causes Tail Rotor Tailboom Contact
Inadvertent PTT Pedal Input Causes Tail Rotor Tailboom Contact (Intermountain Healthcare AW109S N271HC) On 12 November 2019, at c20:08 Local Time, Leonardo AW109SP Grand helicopter air ambulance N271HC of IHC Health Services, was substantially damaged in an nightime event during cruise near Spanish Fork, Utah. The pilot and two flight nurses onboard were uninjured. History of the Flight The US National Transportation Safety Board (NTSB) note in their safety investigation report, issued on 3 June 2022, that it was usual for one of the flight nurses to be in the front left seat during flights without a patient aboard. The flight nurse had been in that role for 11 years, 5 with IHC, but “normally rode in the rear cabin of the helicopter”. About 16 minutes into the flight and 5 minutes from their destination (the scene of a motor vehicle accident on Highway 6)… …the flight nurse, seated in the left front seat, attempted to contact personnel on the ground to coordinate their landing. Rather than step on the push-to-talk (PTT) button located on the cabin floor to activate the radio microphone, he inadvertently stepped on the left anti-torque pedal, which resulted in a rapid yaw to the left. The pilot described this yaw as “severe and violent”. The flight nurse said it “felt like they got hit with strong turbulence over a mountain”. No abnormal noise or vibration was detected. The pilot re-established straight and level flight and landed the helicopter uneventfully. The pilot was 72 years old and had 11173 hours of flying experience, 985 on type. The pilot did not observe any unusual signatures on the exterior of the helicopter during a walkaround inspection after they landed…however, he did not inspect the tail rotor blades or tailboom. The rest of the flight was uneventful, and the pilot did not report any anomalies with the tail rotor blades or tailboom during the subsequent flights that took place during his shift. Next day the oncoming pilot… …conducted a walkaround inspection in daylight conditions and discovered damage to the tailboom as he approached the helicopter. The helicopter was immediately taken out of service and ferried to the company’s maintenance facility for repair. NTSB Safety Investigation The damage to the blades and empennage was consistent with their making contact, and the flight data suggest this occurred during the first leg of the shift flight as the crew did not experience any other events that would have caused the degree of damage observed. When the flight nurse stepped on the left pedal, the pitch of the tail rotor blades would have increased, increasing tail rotor thrust, and yawing the aircraft counter-clockwise. The helicopter was equipped with an Appareo flight data monitoring (FDM) system, which indicated that the yaw was about 11°. An NTSB performance study using data retrieved from the FDM corroborated the pilot’s statement and showed that the helicopter rapidly turned left from a heading of 153° to 142° in 1.25 seconds. When the pilot countered the movement with right tail rotor pedal, the helicopter returned to 151° in 2 seconds. During this time, the helicopter rapidly rolled from level flight to -15° to 15° and pitched up 2° before returning to its original altitude. When the pilot countered with right pedal, the tail boom would have swung back towards the rapidly unloaded the tail rotor. It is likely that this is when the tail rotor blades impacted the tail boom. Further: The helicopter manufacturer provided flight...
read moreNorth Sea Helicopter Struck Sea After LOC-I on Approach During Night Shuttling
North Sea Helicopter Struck Sea After Loss of Control on Approach During Night Shuttling (S-76A G-BHYB 1987) On 9 December 1987 Sikorsky S-76A G-BHYB of Robert Maxwell owned British International Helicopters, formerly British Airways Helicopters and later bought by CHC, contacted the sea during a night approach to the Shell Fulmar Alpha offshore installation in the Central North Sea. The UK Air Accidents Investigation Branch (AAIB) safety investigation report explains that the helicopter, temporarily based on Fulmar Alpha, was shuttling maintenance workers between Fulmar Alpha and the Auk Alpha. Six 6 round trips (12 sectors) were planned that evening between the installations that are 6.4 nm apart. On the fourth sector, whilst descending on an approach from a height of about 500 feet to the Fulmar platform and at about a quarter of a mile from the helideck, the aircraft lost all forward speed and entered a steep descent towards the sea. At a very late stage, the co-pilot managed to arrest the descent just as the aircraft touched the water. The flight was continued to a normal landing on the Fulmar helideck. While this accident is many years in the past and much has changed, the AAIB report does highlight a series of threats that are still relevant to offshore helicopter operations. History of the Flight The flight crew had been detached to Fulmar Alpha and were working a split shift: The duty day began at 0600 hrs and ended at approximately 2000 hrs, and included a “split-duty” rest period between 0745 hrs and 1745 hrs. Both pilot’s had the rank of Captain and so “and it was decided between them who was to be commander”. Because the prevailing wind dictated that all the approaches would be made from the left side of the helidecks, it was also decided that the commander, [seated] on the right side of the aircraft would be the handling pilot [to use the terminology of the time] throughout. The pilots remained in these respective roles throughout the evening’s flying. The Aircraft Commander was 47 and had 6540 hours of flight time, 870 on type. He was… …very enthusiastic about physical fitness and had taken part, with notable success, in both physically and mentally demanding television and social competitions. During the day on which the incident occurred, he had, most unusually, lost several recreational games. The Co-Pilot was 39 and had flown 5662 hours, 518 on type. The fourth sector, with 8 passengers, commenced at 18:43. The weather that evening was well within the requirements for a visual flight and approach to the platforms, the wind was 3500/11 kt, the visibility unlimited and the cloud 4 octas at 2500 feet. Although the sky was nominally less than half obscured by the cloud, it was totally dark, and this darkness was emphasised by contrast to the platform illuminations. On the approach from the south, no other platform or rig was visible to the crew and the sole source of visual reference was the brightly illuminated platform, with its attendant brilliant and pulsating flare. AAIB observe that: …the flare…together with the platform’s working lights, combine to produce a significant contrast to the otherwise dark environment. The short cruise was conducted at about 140 kt, at an altitude of 500 feet. Deceleration commenced about 1 nm from the destination and abeam a Fuel Storage Unit (FSU) vessel moored in the field. Up to this point, the...
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