Firefighting AW139 Loss of Control and Tree Impact
Firefighting AW139 Loss of Control and Tree Impact (LAFD N304FD) On 2 September 2017, Los Angeles Fire Department (LAFD) Leonardo AW139 N304FD, was damaged when it struck trees in an accident at Tujunga, California. This occurred after a Loss of Control – Inflight (LOC-I) while being operating single pilot for a public aerial firefighting flight. The two occupants were uninjured. The Accident Flight The US National Transportation Safety Board (NTSB) explain in their safety investigation report, published on the 6 May 2021 (44 months later), that the pilot had arrived at the LAFD base (‘Fire Station 114’) at Van Nuys Airport (VNY), California, about 07:30 Local Time. The pilot, who had c5500 hours of flight time, 545 on type, had worked for the LAFD since 1980 and had been an LAFD pilot since 1997. Shortly after arriving, the pilot was tasked with supporting the La Tuna Canyon brush fire response in the Verdugo Mountains. The pilot received a briefing on his mission, which included the communications plan, the airspace deconfliction plan, and which air and ground assets would be involved. The AW139 was fitted with a Simplex Aerospace Model 326 GII Fire Attack System (FAS), approved under STC SR02351LA, with a belly mounted 450 US gallon tank and snorkel system. The pilot was seated in the right seat and the crewmember, who was not type-rated in the helicopter and was observing the pilot for training purposes, was seated in the left seat. This person joined the flight on a last minute, ad hoc basis. The flight departed VNY and flew to the Green Verdugo helispot about 2 miles northwest of the accident site. After landing at the helispot, the helicopter was filled with a half tank of water. The helicopter departed from the helispot and conducted various water drops. The pilot landed back at the helispot, where the helicopter was refueled, and the firefighting tank was filled with a half tank of water. Upon departure from the helispot, the pilot was immediately tasked with structure protection for a residential complex on a southeast-to-northwest-oriented ridgeline. This complex comprised of two homes at an elevation about 1,970 ft mean sea level (msl). There were ridge lines were to the north and south. The NTSB say the estimated density altitude was about 3,100 ft, “however, this does not account for the superheated gases and radiant heat in and around the vicinity of the smoke columns at the accident site”. The pilot performed a high reconnaissance orbit over the residential complex with the intent of conducting a water drop from south to north. During the reconnaissance, the pilot noted the prevailing wind (variable and from the east), the smoke conditions, the ground obstructions, and his intended approach and departure route for the water drop. The pilot had previously made several water drops in the general location and reported that he was familiar with the terrain. He noted that the smoke conditions at the time were worse than his previous water drops. He concluded that the path into and out of the target area was between two large smoke columns. However, as the helicopter descended to drop the water, at 09:48 Local Time, airspeed progressively reduced to just c 20 knots (about 100 ft above the trees and about 200 ft south of the target). The helicopter began an uncommanded right yaw and the vertical descent increased. The pilot released the water, and the helicopter continued to yaw to the right and descend rapidly. The pilot reported that...
read moreCessna 208B Collides with C172 after Distraction
Corporate Air C208 N926FE Collides with C172 N274MM in Honolulu after Distraction On 31 October 2019 Cessna 208B N926FE, owned by Federal Express (FedEx) and operated under Part 135 by Corporate Air, collided with private Cessna 172 N274MM on the ground at Daniel K Inouye International Airport (HNL) Honolulu, Hawaii. The Cessna 208 sustained minor damage and the Cessna 172 was substantially damages. The occupants were uninjured. The US National Transportation Safety Board (NTSB) explain in their safety investigation report (published on 5 May 2021) that: The pilot of N926FE [aged 68, who had 3500 flight hours, 940 on type] reported that, during taxi to the runway for departure, his airplane was number two on taxiway “C” Charlie holding for runway 26R. He positioned approximately 50 feet behind N274MM (the number one holding airplane for departure), the condition lever was set at low idle and the power lever was set all the way aft at idle. He reported he set the parking brake… …before diverting his attention from outside of the airplane to inside of the cockpit. While his attention was inside of the airplane, he was startled by a noise and vibration. He looked up and realized his airplane had taxied into N274MM. He then shut his airplane down, radioed the control tower to report the collision, and all occupants exited their airplanes. N274MM sustained substantial damage to the left horizontal stabilizer and elevator, the vertical stabilizer and rudder, and left flap. A postaccident examination of N926FE by a Federal Aviation Administration inspector revealed no preaccident mechanical failures or malfunctions with the airplane braking system that would have precluded normal operation. NTSB Analysis Given the absence of any mechanical issues with the Cessna 208B’s brake system, it is likely the pilot inadvertently failed to set the parking brake before diverting his attention inside the airplane, and the airplane subsequently collided with the airplane ahead. The NTSB determined the Probable Cause to be: The pilot of the Cessna’s [sic] failure to set the parking brake before diverting his attention inside the airplane, which resulted in his airplane colliding with the airplane ahead of it on the taxiway. Safety Resources Past Aerossurance articles on the C208 include: Canadian Mining Icing Air Accident (Cessna 208B Caravan) where a cold soaked aircraft took off over gross weight due to accumulated ice from a previous flight. Cessna 208 Forced Landing: Engine Failure Due To Re-Assembly Error Micro FOD: Cessna 208B Grand Caravan Engine Failure & Forced Landing NTSB Report on C208B Caravan Ditching, Molokai, Hawaii, 2013 Flying Control FOD: Screwdriver Found in C208 Controls C208B Force Landing After Inadequate Maintenance Fault Finding Costa Rican C208B Stalled While Trying To Avoid High Ground Other articles include: UK AAIB Report on Two Ground Collisions S-92A Collision with Obstacle while Taxying Ground Collision Under Pressure: Challenger vs ATV: 1-0 Ambulance / Air Ambulance Collision Fatal B206L3 Cell Phone Discount Distracted CFIT UPDATE 30 October 2021: RLC B407 Reverses into Sister Ship at GOM Heliport UPDATE 16 July 2022: Distracted Dynamic Rollover UPDATE 25 March 2023: Managing Interruptions: HEMS Call-Out During Engine Rinse And from Alaska: Fatigue Featured in Anchorage Alaska Air Ambulance Accident US Dash 8-100 Stalled and Dropped 5000 ft Over Alaska Unalaska Saab 2000 Fatal Runway Excursion: PenAir N686PA 17 Oct 2019 Deadly Combination of Misloading and a Somatogravic Illusion: Alaskan Otter Alaskan Mid Air Collision at Non-Tower Controlled Airfield Operator & FAA Shortcomings in Alaskan B1900 Accident All Aboard CFIT: Alaskan...
read moreMilitary SAR H225M Caracal Double Hoist Fatality Accident
Military SAR H225M Caracal Double Hoist Fatality Accident On 29 April 2020, Armée de l’Air Airbus H225M Caracal (formerly an EC725) F-UGSK / 2802 of EH 01.067 Pyrenees, a special forces helicopter squadron, was involved in a fatal hoisting accident during a training mission at the DGA Essais de Missiles Landes missile range, near Biscarosse. The Accident Flight Investigators of the BEA-Etat (BEA-E) explain in their safety investigation report, issued (in French) on 27 April 2021, that on board were a crew of 7 (two pilots, a hoist operator instructor and student, a rescue diver instructor and student, and paramedic). Twelve hoist exercises had already been carried out. These had involved a 60-130 ft cable length. The last exercise involved unwinding 190 ft of cable over sloping ground. During that exercise the Goodrich Type 76368-240-D variable speed hydraulic hoist jammed on the ascent with two personnel, the student rescue diver and paramedic, 5 m below the helicopter. The helicopter manoeuvred at 10 knots towards an open area. While following the emergency checklist, the crew realised the hoist could still pay out cable and so simultaneously started to lower the two stranded personnel. Tragically, after a couple of seconds, the hoist cable broke and the two fell to the ground from c 40 m. The helicopter landed nearby to help the casualties After first aid the casualties were evacuated to the Cazaux air base, 8 minutes away. One was declared dead on arrival and the other died overnight in hospital on Bordeaux. The BEA-E Safety Investigation: Examination of the Goodrich Hoist On this H225M the primary hoist is hydraulic, but there is also an electric back-up mounted outboard. Investigators examined the hydraulic hoist. The remaining cable was found not to be correctly wound, and the host was contaminated with grease and particles. The broken cable was found to be “marked, folded and untwisted” (i.e. the strands had separated) along the upper 1 m of its 20.6 m length. Other damage was “visible along its entire length”. The cable is 4.76 mm in diameter and made of 19 strands, each of 7 wires of galvanized steel with a 1,500 daN (3372 lbf) breaking load. The hoist consists of a hydraulic motor, cable drum, cable & hook, cable brake, cable guide (with a ‘guide finger’ [or ‘shoe’] that translates laterally, driven by a winding screw (or lead screw), to ensure correct cable winding), an extraction device to apply tension to the cable, limit switches, pyrotechnic cutter and a ‘pendant’ hand control unit. The cable is wound onto the drum in four layers (called ‘rows’ by BEA-E) of 31 to 36 turns each (with the last 8 being ‘dead turns’ that are never unwound). The maximum extension is 75 m. The BEA-E give examples of the type of damage a cable may suffer: The BEA-E say that upon examination: The inner face of the hoist housing shows signs of cable friction all around its circumference and about 5 cm on the side opposite the motor. Part of the flange on the side opposite the motor was almost broken. It separated during their extraction of the cable. Traces of friction and material transfers from the cable are present on this piece of broken flange. They also identified a turn of the cable, just a few centimetres before the cable failure, which had looped around the flange. The BEA-E found the first two layers were correctly wound, but the cable was misaligned in the...
read moreLoss of Control, Twice, by Offshore Helicopter off Nova Scotia
Loss of Control, Twice, by Offshore Helicopter off Nova Scotia (CHO Sikorsky S-92 C-GICB) On 24 July 2019 Canadian Helicopters Offshore (CHO) Sikorsky S-92A C-GICB suffered a loss of control during a visual approach to the ExxonMobil Thebaud Central Facility (TCF) in the Sable gas field off Nova Scotia. A high-rate-of-descent and low-airspeed condition developed in low-visibility conditions. As the helicopter descended below 250 feet it was in a steep, 800 fpm descent, at very low airspeed. When the Pilot Flying (PF) instinctively increased the collective, the helicopter’s rate of descent rapidly increased to 1800 fpm. At just 40 feet the helicopter yawed through 845° and the offshore helicopter, with 13 persons on board, came within just 13 ft of the sea before starting to climb. There was then a second loss of control during the subsequent ascent with the aircraft unintentionally descending from 1350 ft to 480 ft. The Serious Incident Flight: First Two Approaches The Transportation Safety Board of Canada (TSB) explain in their safety investigation report (released on 27 April 2021) that the flight had originally been scheduled for 22 July 2019, but was postponed due to low clouds and poor visibility at the destination. The crew reported at 0545 on 24 July 2019 for a 0700 scheduled departure from Halifax/Stanfield International Airport (CYHZ). Low clouds and poor visibility resulted in a further delay. The flight finally departed at 1154 to TCF, approximately 155 nautical miles to the east-southeast. On board were the two flight crew and 11 passengers. The aircraft commander had flown 6713 hours, 2242 on type. The co-pilot was also a captain and had flown 7742 hours, 3196 on type. Oddly the TSB refer to the co-pilot as a ‘first officer’ throughout. At approximately 1240, the weather observer on the TCF informed the pilots that the winds were approximately 300° true (T) at 8 knots, the visibility was 1 statute mile (SM), and there was an overcast ceiling based at 300 feet above ground level (AGL); however, the cloud layer and visibility were fluctuating rapidly. Two instrument [Airborne Radar Approaches (ARA)] approaches were attempted at the platform but both were unsuccessful due to low clouds and poor visibility. For these two approaches, the captain (occupying the right seat) was the pilot flying (PF) and the first officer (occupying the left seat) was the pilot monitoring (PM). The Serious Incident Flight: The Visual Approach and Loss of Control Approximately 15 seconds after initiating the second missed approach, at approximately 300 feet RADALT, the helicopter exited the cloud, horizontally. The PM informed the PF that the helideck, which is 174 feet above the water, was visible above the ragged layer of fog beneath them. Although the TCF was in sight, there was no discernible horizon. As the helicopter climbed away, the PF looked across the cockpit [to the left] and also observed the helideck above the fog layer. …the pilots levelled off (engaged RADALT hold at 500 feet) and commenced a right-hand turn, using the heading hold autopilot mode, to assess the feasibility of conducting a visual approach. While the aircraft was in the turn, the airspeed, which was coupled to 80 KIAS in the climb to 500 feet RADALT, was reduced to 66 KIAS. At 1332:15, approximately 1.1 nm from the TCF, the helicopter rolled out on a heading of 182°M and the crew planned their third approach. As the wind...
read moreSécurité Civile Fatal EC145 CFIT: Night, Low Ceiling and a Change in Route
Sécurité Civile Fatal EC145 F-ZBPZ / Dragon 30 CFIT near Marseille: Night, Low Ceiling and a Change in Route On 1 December 2019 Airbus Helicopters EC145 (BK117C2) F-ZBPZ, callsign Dragon 30, of the Sécurité Civile suffered a Controlled Flight Into Terrain (CFIT) between near Pennes-Mirabeau at 20:47 Local Time while en route from Marseille-Provence (MRS/LFML) to Le Luc-Le Cannet (LFMC). The CFIT followed an Inadvertent entry into Instrument Metrological Conditions (IIMC) during a night Visual Flight Rules (VFR) flight. The three occupants (pilot, flight engineer / winch operator and rescuer) were killed. The Accident Flight Investigators of the BEA-Etat (BEA-E) explain in their safety investigation report (issued in French on 13 April 2021) explain that the aircraft had positioned in Martigues that afternoon due to flooding in the Pertuis area from a so-called ‘Mediterranean Episode‘ weather event. The pilot has 4269 hours of flying experience (219 on type), albeit very little single pilot. The flight engineer had 2500 hours of experience (371 on type). During the day the pilot and flight engineer had made 6 flights. That evening the crew were requested to position to Luc. The crew made a short flight from Martigues to Marseille-Provence, where they conducted a rotors running refuelling. After, the pilot and the flight engineer discussed the sector to Luc: The pilot informed the flight engineer of his intention to go inland rather than by sea. The flight engineer expressed his questions about the weather they would encounter on this route. The pilot replied that he thought that the weather conditions would allow them to carry out the flight, but that it might be difficult at the end. He commented that they will always be able to turn around. Although a positioning flight, transponder code 7014 was set, that would indicate Helicopter Emergency Medical Service (HEMS) flight. The RADALT is initially bugged to alert at 500 ft but the due to the cloud base the helicopter is only flying around 500 ft AGL, so the pilot reduced the setting to 300 ft. The flight engineer started using Night Vision Goggles (NVGs) at this point. Its considered likely the pilot was also using NVGs. After approximately four minutes of flight, the crew determined that the low ceiling would not allow them to reach the Luc by the inland route visual flight. The pilot then announced to ATC that he was making a U-turn and asked to route to the coast for a coastal transit to the Luc. This necessitated crossing the approach to Runway 31 at Marseille-Provence. The controller asked him to take a heading of 160° due to the arrival of an airliner, and that he could then resume a southerly heading after his passage. The pilot replied that he was going to try, but realized after about twenty seconds that the weather did not allow him to follow this heading either, and announced it to the controller. The helicopter reduced speed and held east of the airport until visual with the airliner, after which they were cleared to head south. ATC asked the helicopter to cross the axis of the runway quickly as a second airliner was inbound. A few seconds later the pilot announced to the flight engineer he was flying on instruments. The flight engineer was unhappy, but the pilot reassured him. Shortly after both saw the ground and a few seconds later the helicopter struck a hill in the Estaque massif at about 115 kt and at an altitude of 740 ft. At impact, the helicopter...
read moreA Second from Disaster: RNoAF C-130J Near CFIT
A Second from Disaster: RNoAF C-130J Near CFIT (Recommendations on Risk Management, Safety Culture & Independent Regulation) On the evening of 11 March 2020 a Royal Norwegian Air Force (RNoAF) Lockheed Martin C-130J Hercules with eight people on board nearly crashed into the rocky island of Mosken in Værøy municipality, Lofoten. After a last-minute evasive manoeuvre the aircraft cleared the island by 144 ft, avoiding a Controlled Flight into Terrain (CFIT). The Norwegian Safety Investigation Authority (NSIA) say (emphasis added) : If the manoeuvre…had been initiated less than a second later, it would have resulted in a catastrophic collision… The aircraft was from 335 Squadron, the RNoAF airlift squadron, based at Gardermoen, which operated four C-130Js at the time. The C-130J was introduced to replace the C-130H in 2008/2009. The Serious Incident The NSIA, formerly the Accident Investigation Board Norway (AIBN), explain in their safety investigation report (c 50,000 words, issued in Norwegian on 19 April 2021) that the aircraft the lead of a pair C-130Js, Mustang 31 (MG31) and Mustang 32 (MG32), on low-level navigation exercise (navex) as part of Exercise Cold Response. Planning and briefing followed the standard procedure which included a joint review of the mission for all participating aircraft and formations. However, the low-level navex was introduced part way through the planning at the request of 335 Squadron. The unit wanted to apply a new low-level technique using Night Vision Imaging System (NVIS). ‘Low-level’ here is relative as it was planned at 1,000 ft. The flight was authorised by the Supervisor of Flying (SOF) on the basis the crews would ‘try and see’ if lighting that night would be sufficient to meet a regulatory minimum of 2.2 millilux of light. The crews completed a risk assessment that was counter-signed by the SOF. An instructor was Pilot Flying of MG31 and the aircraft commander sat in the right-hand seat as Pilot Monitoring. Start-up, taxi and departure from Bodø (ENBO) proceeded normally. It was relatively bright at the departure time at 1826 and some crew members chose not to use NVGs during the first part of the trip. It soon became clear that the weather did not allow Visual Meteorological Conditions (VMC) to fly at a planned altitude of 1,000 ft. To avoid flying into the low cloud cover, the formation chose to go down to approx. 500 ft – a height that was maintained until the incident occurred. The C-130J has a Head Up Display (HUD), but navigation uses a digital map on one of four digital screens (the Head Down Display [HDD]) accompanied by a paper map. The crew on the MG31 wanted to use the NVIS illumination in the cockpit, but the HUD on the left side did not have sufficient brightness in this configuration. The crew of the MG31 therefore choose to use normal cockpit lighting which they dimmed manually. In MG32, the NVIS lighting worked as intended. NSIA note that the NVIS amplifies ambient light 5-10 000 times but has some limitations: A critical limitation of operating with NVGs with a nominal 40° FOV is that it seriously degrades the ability to constantly acquire information from the environment, build up a mental picture of the immediate scene out of the NVGs’ FOV, and maintain adequate SA. FOV restriction can thus result in longer spatial task completion, less precision, and degraded cognitive maps. Greater attentional resources are needed to perform with NVGs,...
read moreUnballasted Sling Stings Speedy Squirrel
Unballasted Sling Stings Speedy Squirrel (AS350B3e / H125 F-HLXO doing HESLO in France) On 30 October 2020 Airbus Helicopters AS350B3e (H125) Squirrel F-HLXO of Héliberté suffered an accident during Helicopter External Sling Load Operations (HESLO) in Thiézac when after a change of plan, an underslung steel cable became tangled in the tail rotor when return from delivering a load. The Accident The French Bureau d’Enquêtes et d’Analyses pour la Sécurité de l’Aviation Civile (the BEA) explain in their safety investigation report issued in April 2021 (in French) that: The pilot, holder of a commercial pilot’s license of a CPL (H), had a total of 1,340 hours of flight time and 1,675 load cyles, including 15 hours and 225 lifts in the last 30 days. On the day… …the pilot and two ground staff prepared a sling consisting of a ten-meter wire rope and a two-meter textile extension fitted with a hook. The tasking consists of transporting two tanks of 400 kg and ten bags…(six of about 800 kg and four of about 1,000 kg). After this phase of preparation and the briefing, the pilot takes off and presents the helicopter to hook up the tank, which is the first of the loads to be transported. The ground staff connects the hook of the metal sling to the textile extension which was already attached to the tank. The pilot lifts the load and moves towards the drop zone located 1,700 m away and approximately 230 m higher. Arriving at the drop-off area, the second ground team were unable to open the hook and release the load. After a few minutes and in the absence of an open area nearby allowing the helicopter to land, the ground personnel in consultation with the pilot decided to unhook the textile extension from the metal cable. The pilot returned to the loading area, monitoring the cable via the exterior mirror. As the helicopter picks up speed the metal cable wrapped around the tail boom of the helicopter and the tail rotor. The pilot heard a ‘popping’ noise, realised the anti-torque pedals were ineffective and managed to rapidly land near the loading area. The accident was not however promptly reported to the BEA. Examining photographs the BEA note that the Tail Gear Box (TGB) was partially torn off, the tail driveshaft broken and the tailboom deformed. The BEA concluded the metal cable had wrapped around the tail rotor. Interviews Ground crew interviews revealed that at the loading point: …the textile sling was already hooked onto the tank strap and that they only had to couple the metal sling and the textile strap. They did not notice any anomaly when hooking the straps of the tank to the hook of the textile sling. The second ground crew member indicated that they had had a discussion with the pilot about the need to leave the 15 kg ballast on the sling line. He stated that a joint decision with the pilot to remove the ballast was taken in view of the masses of the….bags which seemed a little high, and after having estimated that the hook of the textile sling must have a mass equivalent to the ballast. The second ground crew member then went to the drop-off area. He went on to explain that: …when the tank was placed in the area, he was unable to open the hook, the straps being too short and they were still under tension. He had no other solution...
read morePlan Continuation Bias & IIMC in Kenyan Police AW119 Accident
Plan Continuation Bias & IIMC in Kenyan Police AW119 Accident (NPSAW 5Y-NPW, Meru, Kenya) On 13 June 2020 Leonardo AW119 Mk II Koala 5Y-NPW of the Kenyan National Police Service Air Wing (NPSAW) was destroyed when it collided with trees in fog while attempting a precautionary landing at Cyompiou, Meru. Two of the occupants were seriously injured, and 4 suffered minor injuries. The Accident The Kenyan Aircraft Accident Investigation Department (AAID) explain in their safety investigation report, issued creditably promptly in March 2021, that the AW119 and an AW139 were tasked with supporting an operation in Badan Arero, Marsabit. The aim was to “reconcile two communities that were embroiled in cattle rustling in the region”. NPSAW operated 13 civil registered aircraft including the AW119, four MI-17s, two AW139s, four Agusta Bell 206Bs and two Cessna 208Bs at the time. NPSAW are considered to operate State aircraft and in Kenya they needed no approval and are not subject to Kenyan CAA oversight of their operations. The AW119 departed from Wilson Airport, Nairobi on a multi-sector Visual Flight Rules (VFR) flight to Badan Arero with three occupants. The aircraft commander (33) had 987 hours of flight experience, 764 on type. The co-pilot (29) had 623 hours, 352 on type. Both where police inspectors and holders of a CPL(H) but neither were instrument rated. Their last proficiency checks were in late 2016 according to the AAID. The aircraft commander undertook factory training on the AW119 in Philadelphia in 2017. The weather forecast for 13 June 2020, valid from 1700 (2100) for 24 hours and issued on 12 June 2020 for Meru and other areas; “Showers are expected over a few places tonight. Cloudy morning with light rains breaking to sunny intervals expected tomorrow. Showers expected over a few places in the afternoon.” The helicopter made a first precautionary landing four miles west of the Ndula marker due to bad weather, however it took off again after conditions improved. It reached Embu after a low level transit and three more passengers boarded. The helicopter then took off for Isiolo rather than Wajir, to refuel before the final sector to Badan Arero. While en route from Embu to Isiolo… At around Meru area, the weather conditions deteriorated prompting the crew to contemplate landing at an identified field within the vicinity, but opted to continue flying hoping that they will be able to break through the clouds for better visibility. Within a short time, they were engulfed in clouds and decided to approach and make a landing in another location identified suitable for landing, with better but deteriorating visibility. However: As they approached the landing area [which was c 4700 ft AMSL], in poor visibility, the pilot flying stated that he noticed overhead electric power line ahead of the flight path at approximately 100 ft above ground level, banked to the left to avoid the same. He elected to land on the second identified landing area to the right. He further stated that the aircraft rate of descent was high, he therefore flared to reduce the ROD. He additionally indicated that though he avoided the cables, the main rotors of the helicopter contacted the trees that led to severe vibrations in the cabin. The helicopter collided with two other trees before it impacted the ground and came to rest on its starboard with the main rotor blades impacting the terrain while still rotating. The PF shut off the fuel valve and switched off the battery. The cockpit crew exited the helicopter from...
read moreUSAF MQ-9A Reaper Lever Confusion: Human Factors
USAF MQ-9A Reaper Lever Confusion: Human Factors On 25 June 2020 US Air Force General Atomics MQ-9A Reaper 15-4295, operated by the 108th Attack Squadron (a New York Air National Guard Formal Training Unit) lost engine power shortly after takeoff from Syracuse Hancock International Airport, New York and impacted the ground just beyond the runway. The USAF Accident Investigation Board reported that: At 13:23:41Z, the Mishap Pilot (MP) applied takeoff power to the MA and began the takeoff down runway 33 Syracuse Hancock International Airport. The MP was qualified as instructor pilot on the MQ-9A. The MP had 705.1 hours of MQ-9A flight time and 145.5 hours of MQ-9A simulator time around the time of the mishap. The MP also had logged 1,971.9 hours of MQ-1B (Predator) flight time from previous assignments. The crew, of a pilot and sensor operator, met the Air Force requirement for a minimum 12-hour rest period prior to the duty period with the opportunity for at least 8 hours of uninterrupted sleep. At 13:24:14Z the MA lifted off the runway and began to climb out for departure. Approximately seven seconds after becoming airborne and about 150 feet above ground level (AGL)…the MC began running the after takeoff checklists. One of the after takeoff checklist steps calls for retraction of flaps from 15 degrees to 0 degrees by moving the Flap Lever forward to the middle neutral position. The Flap Lever and Condition Lever are located approximately an inch apart, without labels, markings, and are the same color. However: The MP pulled the Condition Lever aft or back to the middle detent position instead of moving the required Flap Lever forward to the neutral position. The MP’s action resulted in the Condition Lever being in the middle detent position (fuel cutoff)… [and consequently] the MA experienced a complete loss of engine power. At 13:24:21Z the Heads-Up Display (HUD) displayed a “Check Condition Lever” warning, this indication means that the Condition Lever is not fully forward. Upon realization that the engine had lost power, in accordance with emergency procedures checklist, the mishap crew (MC) consisting of the MP and mishap sensor operator (MSO), began running the Critical Action Procedures (CAPs) for an engine failure. The MP continued to misidentify the appropriate lever and pulled the Flap Lever to full aft or back…which extended the Flaps to a mechanical stop of 45 degrees creating more drag. The MA impacted the ground 21 seconds after loss of engine power. Upon impact the MA struck a portion of airport runway lights, spun 180 degrees, and came to a rest approximately 600 feet off the departure end of runway 33. The AIB used the Department of Defense Human Factors Analysis and Classification System 7.0 (DoD HFACS 7.0) and identified three factors: HFACS AE101 Unintended Operation of Equipment: is a factor when an individual’s movements inadvertently activate or deactivate equipment, controls or switches when there is no intent to operate the control or device (as discussed above). HFACS PC102 Fixation: is a factor when the individual is focusing all conscious attention on a limited number of environmental cues to the exclusion of others. “Witness testimony stated that due to fixation on the HUD and the takeoff profile the MP inadvertently pulled aft or back the Condition Lever instead of the Flap Lever”. HFACS PE204 Controls and Switches are Inadequate: is a factor when the location, shape, size, design, reliability, lighting or other aspect of a control or switch are inadequate. The AIB opines that “The design of the pilot Ground Control...
read moreThe Curious Case of the Missing Shear Pin that Didn’t Shear: A Fatal Powerline Stringing Accident
The Curious Case of the Missing Shear Pin that Didn’t Shear: A Fatal Powerline Stringing Accident (Rogers Helicopters MD 530F [Hughes 369FF] N530KD, near Chalmers, Indiana) Recently a dramatic video of a helicopter crashing after becoming connected to an electricity pylon has been doing the rounds on social media. Invariably the video, in which the pilot dies, was posted ‘for clicks’ without any context or explanation. The US National Transportation Safety Board (NTSB) has in fact reported on this 2017 accident which is certainly of interest for the utility external load sector undertaking so called ‘stringing’ operations. However, very strangely the key component relevant to the accident was never recovered, investigators seem to have misunderstood their own laboratory’s report on another component and the NTSB conclusions omit to identify the evident failure of a shear pin to correctly perform its safety function as a factor. The Accident Flight The NTSB explain in their safety investigation report (issued in March 2019) that MD 530F (369FF) N530KD operated by Rogers Helicopters, was conducting a power line construction flight near Chalmers, Indiana on 14 March 2017. The 53-year-old pilot has 14975 flight hours of experience (prior to 12 October 2016). He flew 336.7 hours for the company in 2016 and 12.6 in the first quarter of 2017. The purpose of the flight was to thread a braided metal sock line through the center of a tower structure and pull the sock line to the next tower. …weather conditions consisted of an overcast cloud layer, light and intermittent snow, and wind gusts of unknown speeds reported by witnesses. The helicopter was equipped with a [Colorado Helicopters] side pull hook assembly [STC SH5230NM] that attached the cargo hook to the left cabin step position on the helicopter. The system is certified for a maximum side pull load of 1,900 lbs., which is safeguarded by a breakaway swivel; the two-piece breakaway swivel is held together with a calibrated shear pin. If the airframe is about to be overloaded, the shear pin is designed to break and allow for the long line to fall away… A 50-ft blue nylon long line with a protective sheath was attached to the cargo hook, and a grappling hook was attached to the other end of the long line. The grappling hook was connected to a large [200 lb] metal needle that enabled the pilot to thread the sock line through the tower structure. The needle was equipped with two hooks that were used to attach it to the tower structure. The aft end of the needle was connected to the metal sock line via metal carabiners and a non-breakaway swivel. To thread the sock line, the pilot hooked the needle to the tower, released the grappling hook, moved the long line to the opposite side of the tower, and picked up the needle with the grappling hook. The sock line is then inserted into the cable drum via a side gate as shown in this video. The tension on the sock line was controlled by a triple drum puller located about 2 miles (and 10 towers) north. Each of the three drums contained sock line for one of the three phases of the tower. The puller featured a manual brake that was operated by a power line construction employee. The employee and the pilot communicated via radio as the pilot would announce his operational intentions. The employee stated that the pilot had threaded the sock...
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