Korean SAR S-76B Mountain Rescue Accident 2020
Korean SAR S-76B Mountain Rescue Accident 2020 (HL9646) On 1 May 2020 SAR Sikorsky S-76B HL9646 of Sejin Aviation crashed on Mount Jirisan, South Korea, while undertaking a mountain rescue tasking. One casualty being hoisted, a climber who had suffered a heart attack,, and another climber on the mountainside below were both killed. The five crew of the helicopter suffered minor injures. The helicopter was under contract to Gyeongsangnam-do Province Fire Department, from September 2019 to February 2022 as a stopgap awaiting the delivery of new helicopters. The Korean Aviation and Railway Accident Investigation Board (ARAIB) safety investigation report was published on 16 December 2024 (in Korean only). The Accident Flight The accident timeline is as follows: 11:28: HL9646 took off from the Gyeongsangnam-do Fire Aviation Rescue and Paramedic Unit. 11:42: The crew commenced a search of the mountains between Cheonwangbong and Beopgye Temple, at an altitude of approximately 5,900–6,200 feet, to locate the casualty. Mount Jirisan is the highest mountain in mainland South Korea. However, due numbers of hikers in the area, the casualty’s location could not be identified until the third orbit of the area. 11:50: HL9646 attempted it’s first approach to the casualty, but aborted due to strong crosswinds. 11:54: The crew arrived at the site for a second attempt from a different direction, and a two person rescue / paramedic team were successfully hosted to the casualty. Afterwards HL9646 moved away until requested to return. It moved into position, hovering approximately 5,935 feet above sea level and 30–35 feet above ground level. Outside Air Temperature was c15-16ºC (cISA+12). It appears one of the rescue / paramedic team was hoisted aboard first. 12:06: While hoisting the casualty, “the helicopter’s nose rotated to the right, and the aircraft shifted forward, descending unexpectedly”. The main rotor blades contacted the terrain below. Aircraft debris was scattered over a radius of about 15 m. The climber on the ground who was killed was struck by a rotor blade. Fir trees around the hiking trail, with a diameter of c 35 cm, prevented HL9646 from rolling down the steep slope. ARAIB Safety Investigation HL9646 did not have a flight data recorder (FDR), only a cockpit voice recorder (CVR). The wreckage was recovered using a Korea Forest Service S-64 Sky Crane. In interview, the Aircraft Commander (Pilot Flying) recalled that… …while the stretcher carrying the patient was being raised, [the helicopter] was hit by a vortex and sank. To prevent this, I increased the power, but the altitude did not recover, so I turned the aircraft nose to the right and made an emergency landing. The Co-pilot (Pilot Monitoring) recalled that: We approached the rescue site at about 5,700 feet, and the wind at that time was not strong at 5-6 knots. We hovered at an altitude of about 30-35 feet above the rescue site, and when the cardiac arrest patient rose to the middle, the aircraft lost power and felt like it was being pushed forward, and then it immediately started to sink. It rose slightly near the ground and then crashed. The hoist operator indicates that as the aircraft started to descend they tried to lower the patient to the ground. ARAIB highlight a range of factors that affect hover performance: In order to hover for mountain rescue or other missions, you...
read moreStartled Shutdown: Fatal USAF E-11A Global Express PSM+ICR Accident
Startled Shutdown: Fatal USAF E-11A Global Express PSM+ICR Accident On 27 January 2020 a USAF Bombardier E-11A (Global Express) 11-9358 crashed in the Deh Yak district in Afghanistan, killing both pilots. The accident featured what a 1998 AIA/AECMA study termed a Propulsion System Malfunction + Inappropriate Crew Response (PSM+ICR). A USAF Accident Investigation Board (AIB) issued its investigation report in November 2020. A USAF AIB does not conduct a safety investigation (a separate Safety Investigation Board [SIB] is convened but its report is not released), instead as it explains: In accordance with AFI 51-307, Aerospace and Ground Accident Investigations, this accident investigation board conducted a legal investigation to inquire into all the facts and circumstances surrounding this Air Force aerospace accident, prepare a publicly-releasable report, and obtain and preserve all available evidence for use in litigation, claims, disciplinary action, and adverse administrative action. The Accident The aircraft was operated by the 430th Expeditionary Electronic Communications Squadron (430EECS) from Kandahar Airport as part of Operation Freedom’s Sentinel. It was equipped as a Battlefield Airborne Communications Node (BACN) communications-relay platform. The accident flight was both an operational BACN mission and Mission Qualification Training for the co-pilot. The aircraft commander, a Lt Colonel, was a current and qualified instructor and evaluator pilot in the E-11A. He had 4736.9 flying hours of experience, which 1053.3 hours on type. He had also flown the KC-10, RQ-4, MC-12 and T-1. The co-pilot had completed Global Express ground and flight training at CAE on 10 November 2019, and received his basic qualification in E-11A on 17 January 2020. He had completed his first two MQT flights in theatre. The AIB was told “he demonstrated knowledge of the aircraft systems, high situational awareness, asked great questions and was a great student.” He had a total of 1343.5 flying hours, 27.6 hours on type. He had previously flown the T-6 as an instructor and 127.4 hours in the B-1. The aircraft took off at 11:05 local time and entered an orbit just west of Kabul at 42,000 feet altitude at c 11:36. The flight was conducted under Visual Flight Rules (VFR). At 12:50, the crew was cleared by ATC to climb to 43,000 feet. The engine throttles were advanced and the crew initiated the climb with the autopilot. At 12:50:52, a fan blade of the left hand Rolls-Royce BR710 engine was released. Post-accident photographs suggest the blade failure was contained in the nacelle. This failure was accompanied by a bang, recorded by the CVR, which then stopped due to the g switch being activated by the out of balance vibration. This Fan Blade Off (FBO) event resulted in an immediate shutdown of that engine by the engine control system and display of a L FADEC FAIL caution initially. The left engine N1 dropped to 7.6% within five seconds of the FBO before spiking to an unrealistic 255.9%. Within seconds the aircraft autothrottles also disengaged automatically. The autopilot remained engaged however. Bank angles remained essentially constant, consistent with a circular orbit, and the aircraft descended from 42,300 to 41,000 feet. Ten seconds after the catastrophic engine failure, the crew retarded both throttles to 14º (the throttle lever range is from 0-40º) for one second, then slightly advancing the left throttle separately to 26º for one second, then retarding it to align with the...
read more29 Seconds to Impact: A Fatal Night Offshore Approach in the Irish Sea
29 Seconds to Impact: A Fatal Night Offshore Approach in the Irish Sea (CHC Scotia AS365N G-BLUN) At 18:00 on 27 December 2006 CHC Scotia Airbus AS365N G-BLUN departed Blackpool to conduct 8 sectors within the Morecambe Bay gas field in the Irish Sea. The first two were completed without incident but, when preparing to land on the North Morecambe platform, in the dark, the helicopter flew past the platform and struck the surface of the sea. There were no survivors amongst the five passengers and two crew. The UK Air Accidents Investigation Branch (AAIB) issued their safety investigation report on 17 October 2008. The Accident Flight The flight crew had reported for duty at 12:00. The aircraft commander had 8,856 hours total time, 6,156 on type and had been “operating in the Morecambe Bay gas field…for 20 years”. At the time of the accident he was simultaneously Blackpool Chief Pilot, a Line Training Captain and a Crew Resource Management (CRM) Instructor. The co-pilot had 3,565 hours total time, 377 on type. This was his first offshore job, and had been employed by CHC Scotia for 13 months. He had recorded a total of 467 hrs of night flying, however, he had recorded only 3 hrs of night flying in the previous three months. Their recent experience included: They had already completed one multi-sector flight that day. Their second flight was scheduled to depart at 18:00, with eight night sectors all to be flown with the co-pilot as the handling pilot. G-BLUN was bult in 1985, had 20,469 hours and 130,038 cycles, indicating the nature of the operating environment with continual short sectors. AAIB explain that CHC Scotia’s AS365Ns were… …fitted with Trimble 2101 Navigator Plus Global Positioning System (GPS), cleared as a primary means of navigation in instrument conditions. The fleet [were] also fitted with an Automatic Direction Finder (ADF) and a Sperry Primus 500 colour radar system. The GPS is the primary means of off-shore navigation, with the radar being used as a back up and to cross-check the GPS data when required. After preparations…. The helicopter departed Blackpool at 1800 hrs and climbed to 1,000 ft on a westerly heading. At 1,000 ft, and at an initial IAS of 135 kt, the autopilot altitude mode was engaged; it was disengaged at 1807 hrs and the altitude and speed started to reduce. Given the average ground speed derived from the radar, and assuming that the GPS distances were accurate, the platform became visible at a range of approximately 4,400m: the windshield wipers were audible in the background. No Automatic Voice Alert Device (AVAD) annunciations were recorded but the transition through the radio height of 100 ft occurred rapidly as the helicopter transitioned from being over the sea to over the helideck. The helicopter landed on the AP1 platform at 18:11. The next sector, to the Millom West platform, was flown without any passengers, baggage or freight and with 360 kg of fuel. The helicopter took off at 1814 hrs, climbed to 500 ft on a north-westerly heading and accelerated to an initial IAS of 145 kt. The rig became visible 25 seconds after the 5 nm GPS call; this equates to a visual range of approximately 7,100 m. At 1820 hrs the helicopter initiated its descent whilst...
read moreLoss of Sikorsky S-76C+ 5N-BQG of Eastwind Off Nigeria 24 October 2024
Loss of Sikorsky S-76C+ 5N-BQG of Eastwind Off Nigeria 24 October 2024 On 24 October 2024 Sikorsky S-76C+ 5N-BQG of Eastwind cashed in the sea southeast of Eket, Nigeria at 11:25 in daylight. All 8 occupants perished. The Nigerian Safety Investigation Bureau (NSIB) published their preliminary report on 17 December 2024. The Aircraft Eastwind Aviation Logistics Services Limited is an operator based in Ikeja, Lagos. It has a Nigeria Civil Aviation Authority (NCAA) air operator certificate (AOC). It operated one helicopter, 5N-BQG. This S-76C+ had been imported from the US in 2012 where it had been an executive aircraft for a financial services firm. The NCAA describe its history in Nigeria as follows: At the time of the accident the aircraft had flown just 2783 hours and 5921 cycles since built in 1998. The aircraft had a Cockpit Voice Recorder (CVR) but not was not fitted with a Flight Data Recorder (FDR), despite that being a regulatory requirement. NSIB has consequently issued Safety Recommendation 2024-049: Nigeria Civil Aviation Authority should ensure strict compliance to the Nigerian Civil Aviation Regulations (Nig. CARs) 2023 part 7.8.2.2(q) which requires that all helicopters with a maximum takeoff mass over 3175 kg and up to 7000 kg to be fitted with a Flight Data Recorder (FDR). NSIB do not comment on what offshore modifications this former executive helicopter had. The Radalt was deferred six days earlier on 18 October 2024. The Flight Safety Foundation (FSF) Basic Aviation Risk Standard for Offshore Helicopter Operations (BARSOHO) states in Control 4.4: The radio altimeter must be serviceable for any flight at night or conducted under IFR (even if deferrable in the regulatory approved MEL). For reference the IOGP Report 690 Recommended Practices do not have a recommendation on radalt serviceability as its left to individual customers to agree a contracted Minimum Departure Standard (MDS) with the operator (690-5/1) ‘if applicable’. The Accident Flight The helicopter had departed the Port Harcourt NAF Base (DNPM) at 10:47 enroute to the Nuim Antan, a Floating Production Storage and Offloading (FPSO) vessel of Nigerian National Petroleum Company (NNPC). On board were two pilots and 6 passengers, one of whom was an Eastwind engineer. The Aircraft Commander had 4687 hours of experience, 3972 on type and was Pilot Flying (PF). The Co-pilot had 1719 hours, 1411 on type and Pilot Monitoring (PM). In 2014 Aerossurance published the article: Commanders: Flying or Monitoring? Their 90/28/7 day and 24 hour flight times were identical, suggesting they had been rostered to fly together repeatedly for 3 months (consistent with a small, single aircraft operator). The Meteorological conditions from FPSO Nuim Antan Helideck report were as follows: Based on their CVR analysis NSIB report that: At 11:07:46 h, Nuim Antan contacted 5N-BQG and asked them to repeat their Estimated Time of Arrival (ETA). The flight crew of 5N-BQG relayed their ETA to Nuim Antan at 11:30 h [sic]. Nuim Antan relayed up-take payload…of 1318 Lbs, which was acknowledged by 5N-BQG.At 11:08:27 h, 5N-BQG requested the current weather information at Nuim Antan and was asked to stand by. At 11:08:48 h, Weather information was relayed to 5N-BQG as Wind 180°/08 kts, visibility five miles, cloud one thousand two hundred, temperature 27° C and QNH 1015 hPa with an approaching cloud from the East bearing an easterly direction...
read moreAn Air Traffic Control Assisted H-60 Collision
An ATC Assisted Sikorsky H-60 Collision (HeliStream UH-60A N160AQ and US Navy MH-60R 166583, San Diego, CA) On 22 November 2022, civil firefighting Sikorsky UH-60A Black Hawk N160AQ (operated by HeliStream for San Diego Gas & Electric) and US Navy MH-60R Seahawk 166583 collided at Brown Field Municipal Airport (SDM), San Diego, California. There were no injuries to the 5 occupants of the two helicopters. The US National Transportation Safety Board (NTSB) released their safety investigation report on 5 December 2024. The Accident Flights The NSTB explain that: According to the pilot-in-command (PIC) of the UH-60A (callsign Copter 129), he and a second pilot were conducting night vision goggle training. ADS-B data showed that Copter 129 departed Gillespie Field Airport (SEE)…about 1741 and proceeded to Brown Field Municipal Airport (SDM)…. Copter 129’s initial contact with SDM’s tower and arrival was uneventful. SDM is in Class D airspace just one mile north of the Mexican border. About 1748, the controller asked Copter 129 if they could accept the underrun of runway 26L for landing at their own risk, and the pilot of Copter 129 accepted the underrun. Copter 129 crossed the airport midfield, at or above 2,000 ft mean sea level (msl), and entered the left traffic pattern for landing. At, 1753:50 the controller instructed Copter 129 to continue in the left closed pattern due to traffic, which the pilot read back. Copter 129 arrived at the underrun, then took off, flew one circuit, and landed again on the underrun of 26L. Meanwhile, the MH-60R (initially using the callsign Navy 410) made their initial contact with SDN tower at 1754 while they were about 5 miles west of the airport. The controller instructed Navy 410 to enter the downwind for underrun runway 26L. The pilot read back “left downwind for runway 26L.” The controller then asked if they could accept the underrun at their own risk. The pilot responded with “affirmative.” About 30 seconds later, the controller cleared Copter 129 for the option to land on the runway 26L underrun and the pilot acknowledged the instruction. About 1756, the controller informed Navy 410 that they were number 2 following a helicopter on short final for the runway 26L underrun, then cleared Navy 410 for the option to land on the runway 26L underrun, and instructed them to make left closed traffic. Navy 410 stated they had the traffic in sight. The controller further instructed Navy 410 to maintain visual separation from the helicopter on the underrun. The pilot responded that they “copied all.” Confusingly at about 1756, Navy 410 began to use the callsign Seahawk 410. About 1757, according to the controller, he saw that Seahawk 410 appeared to have turned to their base leg early. He then instructed Copter 129 that he needed them “on the go.” The pilot responded with, “Copter 129 on the go.” About 4 seconds later, the controller advised Seahawk 410 that, “the copter on the go was going to the left.” Seconds later, the pilot of Seahawk 410 asked the controller to repeat the instruction. The controller then stated, “Seahawk 410 verify you’re overflying…Navy.” About 3 seconds later, the controller instructed Seahawk 410 to, “go around the northside of runway 26L.” The pilot responded, “Seahawk 4.” According to the controller, he instructed Seahawk 410 to...
read moreDA62 Forced Landing After Double Engine Shutdown Due to Multiple Electrical Issues
DA62 Forced Landing After Double Engine Shutdown Due to Multiple Electrical Issues (N84LT, Dallas, TX) On 15 October 2022, private Diamond Aircraft DA62 N84LT made a forced landing near on West Kiest Boulevard near Dallas Executive Airport (RBD), Texas. The aircraft suffered substantial damage but the pilot and passenger were uninjured. The US National Transportation Safety Board (NTSB) released their safety investigation report on 26 November 2024. The Accident Flight The NTSB explain that the aircraft… …departed Winston Field Airport (SNK), Snyder, Texas, about 1448, and climbed to a cruise altitude of 11,500 ft mean sea level (msl). While descending in preparation to fly a visual approach [at RBD], the pilot lowered the landing gear and contacted the tower controller for landing clearance. During the controller’s response, the pilot reported hearing a “pop” and observed the avionics display screens lose power. A few seconds later, he observed that both engines had lost power. The pilot executed a forced landing on to a road, during which the airplane struck a power line in the descent, and after touchdown, two road signs, which resulted in substantial damage to the right wing. Safety Investigation The DA-62 was powered by two Austro Engine E4P-C liquid-cooled, in-line four-stroke four cylinder diesel engines. These each has two Electronic Control Unit (ECU) powered by an alternator when at least one engine is running. When both engines are off, the ECUs receive its their electrical power from either the main battery (a 24 V, 13.6 Ah lead-acid battery) or from back-up sealed-lead-acid ECU batteries. The back-up batteries give 30 minutes of electrical power. Investigators say a loss of main battery power… …most likely occurred during the landing gear extension when the hydraulic pump turned on, and simultaneous with the radio transmissions. Investigators also found that the electrical connector to the hydraulic pump pressure switch was damaged. NTSB do not comment on the possible source of damage or when it may have occured. Furthermore: At both alternator relays, the wiring was incorrect. As wired, the alternator relays would NOT disconnect the alternator power from the main electrical system. The relays would cut power to the glow plugs for the respective engines (…glow plugs are only used during engine start). In addition, the 80 Amp fuse was not between the alternator and the aircraft electrical distribution system. However, during the aircraft and component testing a definitive root cause of the initial power failure could not be determined. Testing could not duplicate the conditions of the flight when the electrical system anomaly occurred or the anomaly itself. Two battery system issued were identified: The main battery had been installed 23 days earlier. The aircraft had flown c 15 hours since. When its capacitance was tested by investigators it was found to be at 81.2% of rated capacity, below the >85% requirement. Four new ECU backup batteries had been installed during an annual inspection at a facility in Texas about 4 months earlier. Investigators found that these were incorrectly wired in parallel rather than in series. The in-line fuses for the backup ECU power system for both engines were found to be blown. In relation to the ECU backup batteries: The incorrect wiring would have resulted in only 12 volts instead of 24 volts being available which would have resulted in...
read moreCrew Confusion in Firefighting 737 Terrain Impact
Crew Confusion in Firefighting Boeing 737 Terrain Impact (Coulson, N619SW) On 6 February 2023 Coulson Aviation Boeing 737-3H4 N619SW, callsign Bomber 139, on an aerial firefighting task in Fitzgerald River National Park, Western Australia (WA), impacted a ridgeline during a retardant drop. The aircraft was destroyed but the two pilots miraculously only suffered minor injuries. The Australian Transport Safety Bureau (ATSB) issued their safety investigation report into on 6 November 2024. While undoubtedly a “controlled flight into terrain”, under the CAST/ICAO Common Taxonomy Team definition this was not a CFIT but a ‘LALT’ accident due to it being during low altitude operation. That Day’s Flying & the Accident Flight The aircraft was fitted with a Coulson Aerial Firefighter Tanker Modification (retardant aerial delivery system [RADS]). RADS incorporated two tanks on with a total capacity of 36,000 lbs of retardant. There were drop switches on both pilot’s controls: When the flight crew activates either switch, the primary user interface software will produce a door position command based on the predefined Coverage Level (CL) requirement, drop quantity, tank levels, ground speed and aircraft height above the ground. RADS also includes an emergency dump switch to dump the full load in less than 2 seconds. if a performance problem developed before all the retardant was released. To avoid nuisance audio alerts during a retardant drop, the RADS modification incorporated an audio inhibit switch, which inhibited the landing gear configuration, ground proximity warning system and traffic collision avoidance system for 5 minutes. The aircraft commander (8,233 hours of flying experience, with 1,399 hours on type and c 5,500 hours aerial firefighting) was the pilot flying (PF), The co-pilot (5,852 hours, with 128 hours on type and c 500 hours aerial firefighting experience) had been employed by the operator for less than a year and was the pilot monitoring (PM). Both had a a US Dept of Agriculture Forest Service (USFS) Air Tanker qualification. Their tour of duty had started on 20 January 2023. They had flown 7.3 hours and 13 drops on this tour prior to the day of the accident. Bomber 139 conducted 3 flights on that day, which was the last day of the flight crew’s tour of duty. The first 2 flights each comprised a single full load drop at the fire ground with a return to Busselton. The retardant drop is a manually flown contour flight manoeuvre in potentially rough air and over undulating terrain across a drop zone that has not been formally surveyed for obstacle clearance and gradient. Therefore, airspeed and height deviations could be expected. The second flight was intended to ‘tag and extend’ the retardant dropped during the first flight. ATSB note that: The aircraft captain completed the operator’s flight risk assessment tool (FRAT) at 1015. The FRAT score was 14, which was an acceptable level of risk with no mitigation or escalation required. If the FRAT had been reviewed between each flight, the SIGMET issued at 1400 would have added 8 points, resulting in a FRAT score of 22 for the accident flight that departed from Busselton at about 1530. A score >21 required mitigation or escalation for approval. The weather conditions, including the thunderstorm activity advised in the SIGMET, were not considered to be a factor in this accident. On the first two...
read moreCHC Scotia AS332L Rollover on West Navion Helideck After Loss of Dynamic Positioning
CHC Scotia Rollover on West Navion Helideck after Loss of DP (AS332L Super Puma G-BKZE) On 10 November 2001, CHC Scotia Airbus AS332L G-BKZE, chartered by BP, rolled over while being rotors running refueled on the helideck of the Norwegian drillship West Navion, 80 nm west of Shetland. The copilot, who was on the helideck, suffered serious leg injuries from flying main rotor debris. The UK Air Accidents Investigation Branch (AAIB) published their safety investigation report in May 2004. While their report was issued over 20 years ago this accident and the AAIB recommendations remains highly relevant for the safety of offshore helicopter operations. The Accident The helicopter departed on a routine crew change flight from Aberdeen, refuelling en route at Wick, before its approach to the Smedvig operated drillship. The helicopter touched down at 1242 hrs toward the forward edge of the deck on a heading of about 296°M (289°T). As used passenger disembarkation occurred while rotors running. The co-pilot left the aircraft to assist the ship’s helideck crew with the refuelling. The drillship’s position over the seabed well head was maintained by a simplex computer controlled Dynamic Positioning (DP) system. This determined position from navigation satellites and seabed transponders. Electrically powered thrusters were used to maintain station. The DP system was programmed to take account of the prevailing sea current and wind to maintain station. The DP system is normally operated in AUTOMATIC mode but has a manual reversion capability. MANUAL control is selected via a ‘one-touch’ switch. In AUTOMATIC mode, the DP system gives the operator a warning if the ship’s heading deviates more than ± 2°, and an alarm when it deviates by more than ± 3°. In MANUAL mode no warnings are given and the only indication to the DP operator that the system is operating in MANUAL mode is the absence of a heading window on one of his DP screens. AAIB explain that: At about 1245 hrs the commander became concerned about the ship’s movement and requested the pitch, roll and heave readings from the ship’s Radio Operator (RO). The RO was on the bridge below the helideck and only had a partial CCTV view of the helideck. After some confusion over exactly what the commander had requested the RO provided the readings, all of which were within the helicopter’s operating limits. Noticeably: The RO’s position on the bridge was between, and to the right of, two parallel consoles from where the ship is controlled when underway and when drilling. Weather, pitch, roll and heave information were normally available from a computer screen on the forward console. However, on the day of the accident, this screen was out of service and the RO had to use the information from the rear consoles, which were in use by the DP operator. Neither the forward computer screen nor the DP consoles were easily visible from the RO’s position and…much of the information on the DP screens is factored or averaged for use by the DP computers, [so] the basis of the data presented on the screen was not immediately evident. [Therefore]…the RO had to leave his station, walk to the DP operator’s position and ask for the requested data. The aircraft commander remarked that his instruments appeared to be showing greater movements. A little...
read moreFukushima Police AW139 Loss of Control Accident: JTSB Final Report
Fukushima Police Leonardo AW139 FTR LOC-I Accident: JTSB Final Report (JA139F) On 1 February 2020 Leonardo Helicopters AW139 JA139F of the Fukushima Prefectural Police Aviation Unit crashed near Mihota, Koriyama City, Fukushima Prefecture while transferring a human heart for a transplant operation. All seven occupants were injured, four seriously. This was an accident that Aerossurance first covered just 28 days later. when we translated the initial Japan Transport Safety Board (JTSB) release about the accident. The JTSB published its final safety investigation report into this accident earlier this year. The Accident Flight The captain had 1400 hours total experience, 450 on type. The co-pilot had 3800, 350 on type. Both had accumulated their AW139 experience relatively slowly over c 5 years. 07:09 JST: JA139F takes off from the Fukushima Prefectural Police Heliport destined for Aizu Chuo Hospital where it was to collect the organs for transplant in Fukushima. 07:24 JST: The helicopter passes over the vicinity of the accident site at c 3,000 ft and an indicated airspeed (IAS) of c 120 kt. 07:28 JST: The captain receives information about a 20 minutes delay at Aizu Chuo Hospital before they will be ready with the organs via police radio. 07:29 JST: The captain and co-pilot discuss flying at a higher altitude on the return trip due to strong winds (about 50 kt from the northwest) observed over Lake Inawashiro. 07:56 JST: The helicopter lands at the Aizu Chuo Hospital Temporary Operation Site. 08:00 JST: The helicopter takes off from Aizu Operation Site with the organs and medical passengers. 08:05 JST: After climbing up to an altitude of about 5,700 ft over Lake Inawashiro, the helicopter started descending gradually. The captain was conscious that they were flying with a strong tailwind. 08:07:31 JST: While flying over the Ou Mountain range at IAS 152 k, ground speed (GS) 198 kt and c 4,300 ft, the helicopter started rolling to the right at a rotational speed of 100 º/s or more after the IAS increased rapidly to 188 kt, and made right rolling motion exceeding 360º. The captain pressed the Force Trim Release (FTR) button on the cyclic stick (discussed more below and relevant to another AW139 accident we have discussed). Shortly after we see an aircraft upset evident in flight data: 08:07:38 JST: The main rotor blades contact the tail drive shaft. During the roll and sideslip manoeuvre that occurred the left hand cockpit window fell from the aircraft and the forward right cabin window fell into the cabin, resulting in a high cabin noise. This happened too in AW139 accidents in Spain and Nigeria which we have discussed previously. The captain also banged his head and lost his headset. Crew coordination was therefore difficult. The captain decided to attempt an autorotative landing. 08:07:49 JST: The captain operated the gear lever to extend the landing gears. 08:08:06 JST: The co-pilot reported by police radio that the helicopter would make a forced landing. 08:08:20 JST: The co-pilot set the AP switch to OFF in an attempt to reset the Autopilot (AP). 08:08:55 JST: The helicopter impacts a paddy field and rolls over. According to the Flight Data Recorder (FDR), touchdown was at 45 ft/s, a right yaw rate was 87 º/s, and the ground speed < 20 kt. Fortuitously the landing gear absorbed much of the load...
read moreNight Deck Landing Accident While Training off Brazil
Night Deck Landing Accident While Training off Brazil (Omni Leonardo AW139 PR-OTF) On 2 June 2021 Omni Helicopters Leonardo AW139 PR-OTF, under charter to Petrobras, was involved in an accident landing at night on the SS-75 Ocean Courage Mobile Drilling Unit (MODU) off Brazil. The copilot and an occupational-safety technician who was on the helideck suffered serious injuries. The aircraft commander suffered minor injuries and one other occupant, also a pilot, escaped uninjured. The Brazilian safety investigation agency CENIPA issued their safety investigation report on 17 September 2024. The Accident Flight It appears that at 18:53 Local Time the helicopter departed Jacarepaguá – Roberto Marinho Aerodrome, Rio de Janeiro for the Ocean Courage with three occupants. The sun had set at 17:21. Departure was c 30 mins later than planned because the aircraft commander had become stuck in traffic en route to the airport. Night offshore crew change flights are not permitted in Brazil. However, night emergency flights for medevacs are allowed. CENIPA indicate there was an exemption for night deck training flights and the operator did have approved night training procedures (albeit referencing a regulation repealed in 2018). In the previous 2 years the operator had only done 15 night offshore landings, in contrast to 12,000 daytime offshore landings. Due to the rarity of night flights only a small cadre of pilots were rostered for night standby. CENIPA say that… …there was an understanding within the company that carrying out a nighttime landing in the simulator would be sufficient to provide the pilot with the necessary qualification to conduct the real operation. [At] the time of the occurrence, the ANAC did not determine a specific requirement for night-time operation in helicopters… A further challenge to night training & recency was that Petrobras had not made offshore helidecks available for the 2 previous years. This training flight had been postponed several days so the crew was not the one originally intended, which had included an instructor with greater night recency. Both pilots were captains. The aircraft commander, who was Pilot Flying, had 9,321 hours, 4,073 on type and was also an instructor. He had worked for the company for 11 years. On 5 May 2021 he had completed a simulator session that include a night onshore landing. There were comments in the pertinent records on the concept of stabilized approach, with special attention to night-time flights, including the possibility of spatial disorientation and optical illusion phenomena. However, the flight records did not inform precisely what had occurred during the training. The simulator instructor commented that the aircraft had operated the aircraft safely, complying with the profiles prescribed. His performance was considered “satisfactory”. It does not appear that he had previously conducted an actual night offshore deck landing though. The copilot, the Pilot Monitoring, had 4,863 hours, 3,395 on type. He had completed an onshore night landing in the simulator in January 2021. There were suggestions he had completed 3 night deck landings in 2018 but according to CENIPA no evidence was found that confirmed that. The third occupant was described as onboard to “change the pilot’s seats” when on the deck according to the CEIPA report. This was not elaborated on but is highly likely to be ‘lost in translation’ and they were in fact going to swap with the co-pilot to...
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