Narrative: On Tuesday, July 7, 2020 at approximately 1216 MST, a UH-1H helicopter, N623PB, impacted terrain with one occupant on board. The aircraft was performing long-line cargo delivery operations in support of fire suppression on the Tonto National Forest when the mishap occurred. The aircraft was under exclusive use contract with the USFS.
The NTSB investigation into this accident is ongoing. At this time, there are no indications of immediate safety concerns with other similar make/model of aircraft. All matters related to public information must be disseminated through the NTSB.
Mr. Boatman flew for Airwest Helicopters out of Glendale, Arizona. He leaves behind his wife Elizabeth Marie Boatman and his 8-year old daughter Claire Elizabeth Boatman. The family chose to hold a private funeral service. Donations in his memory may be made to the Wildland Firefighter Foundation (wffoundation.org).
The Australian Transport Safety Bureau determined that the Air-Crane helicopter that crashed into a lake January 28, 2019 in Victoria, Australia was a victim of vortex ring state (VRS). The accident occurred on a firefighting mission as it descended to draft water at a narrow lake with steep sides.
From the report released April 17, 2020:
The topography, high rate of powered descent, and steep flare that reduced the airspeed, created conditions conducive to the onset of VRS. The crew reported that the rapidity of onset and dimensions of the dip site did not provide enough time or space to maneuver sideways to effect a recovery.
If the helicopter was attempting to hover to draft water to refill its tanks, the fairly narrow section of the lake with what appears to be steep rising terrain nearby may have been a factor in the confined space. The Air-Crane has six blades on the main rotor with a diameter of 72 feet. It may have encountered what helicopter pilots refer to as a “Vortex Ring State” or VRS. The canyon slopes may have prevented the massive rotor wash from diffusing and could have caused the cushion of air beneath it to become chaotic as the helicopter neared the water surface, reducing lift.
VRS in addition to density altitude was a factor in the crash of the MH-X Silent Hawk that transported Seal Team 6 as they attacked the hideout of Osama bin Laden in Pakistan in 2011. The helicopter was landing inside a yard surrounded by high walls when it lost lift. The pilots had practiced landing in a full-scale model of the site, but the walls in the model were represented by chain link fencing material, and were not solid like the walls around Osama bin Laden’s house. The rotor wash would have been more easily diffused through the chain link fence during the rehearsals.
…After a number of water drops, the aerial attack supervisor (AAS) re-tasked the crew to fight a flame front further north, which was east-northeast from the dip site. Each drop was also incrementally further north. This resulted in the crew gradually tightening the approach to the dip site.
During the occurrence approach, the tighter approach resulted in a greater than normal flare to arrest the aircraft at the aiming point in the dip site. The higher nose pitch up prompted the SIC to advise the PIC to move forward of the trees before descending any further to ensure tail rotor clearance. Clear of the trees, the flare was increased.
While descending with a nose-high attitude, the aircraft struck the water tail-first, submerging and removing the tail rotor, causing rapid rotation to the right through one and half turns. While rotating, the main rotor blades separated as they contacted water. The right cockpit door separated from the fuselage, and the aircraft came to rest on its left side, submerging the cockpit.
Each crewmember recalled the rehearsed drills from their helicopter underwater escape training (HUET). They identified their seat belt and nearest exit to orientate themselves in the aircraft. They all waited until the last moment to draw a breath, and did not unbuckle and exit the helicopter until motion had ceased. The crew reported that it was not possible to see anything underwater, and that jet fuel contamination was present.
The SIC in the right seat exited through his doorway, from which the door was already missing. The PIC could not open his door so he swam across the cabin (up) and was assisted by the SIC to exit through the right hand door. As the rear door was jammed, the crew chief in the aft seat pushed out a window from the rear of the cabin, and exited through it.
Neither pilot unplugged their helmet. However, the extension cords from the aircraft to the helmet plug allowed the plug to release, preventing the helmets from snaring the pilots. All three crew escaped, and inflated their life jackets. Two crew were uninjured, and one crewmember sustained a knee injury.
At the time of the accident, crews aboard S-76 and S-61N helicopters were assessing the potential of the dip site for later use in night operations. An AAS aboard the S-76 relayed details of the accident to an incident controller who enacted the emergency response plan. Neither the S-76 nor the S-61N was equipped or able to provide direct assistance, other than monitoring, and relaying information. Following exit from the helicopter, the only form of communication available to the Skycrane crew was hand signals. They gave thumbs-up indications to the crew of the overhead S-61N to advise that they were okay. The Skycrane crew then swam to shore and trekked through dense bush to a road where they were met by rescuers.
Findings These findings should not be read as apportioning blame or liability to any particular organization or individual.
The crew conducted a tight descending right hand turn into the dam [lake], inside the upper margins of the flight envelope. This approach required a steep flare on arrival and likely resulted in the rapid onset of vortex ring state.
The dam’s [lake’s] steep sides and narrow tapered body provided limited opportunity for vortex ring state recovery actions, contributing to collision with water.
The Crew Chief’s presence aboard the aircraft during firebombing operations exposed him to unnecessary risk.
All crewmembers credited their survival to skills learned and practiced in Helicopter Underwater Escape Training. In addition, the helmet cord extension cables detached easily from the aircraft, contributing directly to the crew’s egress from the flooded cockpit.
The Australian Transport Safety Bureau has released an Occurrence Brief regarding the Bell 214B that crashed while it was on a water dropping mission near Pechey, Queensland, Australia November 13, 2019.
The pilot suffered minor injuries and was flown to a hospital by another helicopter.
Below is the complete text of the Brief. (We added the photo taken by 9News):
Occurrence Briefs are concise reports that detail the facts surrounding a transport safety occurrence, as received in the initial notification and any follow-up enquiries. They provide an opportunity to share safety messages in the absence of an investigation.
What happened On 13 November 2019, a Bell 214B helicopter was water bombing during fire control operations near Pechey, Queensland. At 1344 Eastern Standard Time, the helicopter approached the bushfire downwind and down hill from the north-west at about 60 knots, and made a descending right-hand turn back into wind over the fire.
The descent was continued towards the drop zone. The airspeed was further slowed and the height was reduced to about 150 feet above ground level (50 feet above treetop level). The pilot then released the load of water before departing the drop area into rising terrain. The pilot heard the low rotor RPM warning and had insufficient altitude and clearance from obstacles to recover the rotor RPM and continue flying. He was concerned that further actions required to recover the rotor RPM would result in the helicopter possibly striking trees or ending up in the actively burning fire.
In maintaining the climb to avoid rising ground, trees and fire, the rotor RPM appeared to decay further. As the helicopter cleared the trees, it began to descend, yawed to the right and the left-hand skid collided with the ground. The helicopter rolled onto its left side resulting in substantial damage. The pilot was able to turn off the fuel to stop the engine and exited the helicopter via the overhead window with minor injuries. Neither the g-force activated ELT beacon or flight tracking alarm were triggered.
The distance from the last water drop to the impact point was less than 100 metres and the recovered aircraft showed little evidence of damage from forward moment.
Operator’s investigation and comments Based on the pilot’s account of the accident and assessment of the recovered aircraft, mechanical malfunctions were ruled out as a contributing factor. The operator determined that the accident was most likely the result of a loss of rotor RPM that the pilot was unable to recover, due to a downwind descending turn, low altitude for the water drop, and a departure into rising terrain. The pilot had to make a decision between putting the helicopter into tall trees and active bushfire or climbing over the trees to clear ground. In choosing the latter, the rotor RPM decayed further and the helicopter contacted the ground.
The operator stated that the helicopter type is renowned for its ‘hot and high’ performance making it a very effective firefighting platform. Firefighting combines a number of factors which result in flying that is close to the performance limits of the aircraft – high gross weights, low airspeeds, low altitude, close quarters manoeuvring, high work rate environment and adverse weather conditions. In this case the combination of factors immediately leading up to the accident resulted in the helicopter operating outside its performance envelope without having enough space and height to recover.
Safety action As a result of this occurrence, the aircraft operator has advised the ATSB that they are taking the following safety actions:
The operator has provided a briefing to all of their pilots on the circumstances and the outcome of this accident. The pilot involved in this accident will be involved in future training and checking to enable the recognition and avoidance of the circumstances that saw the limitations and flight envelope exceeded. This training will become part of the operator’s annual training for all pilots conducting fire control operations.
Safety message Fire control flying operations can involve challenges and complexities that require crews to maintain a heightened awareness of their aircraft’s operating limits and the environmental conditions. Flying within operating limits can ensure pilots have a performance margin to react to unforeseen circumstances.
About this report Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.
Today the Australian Transport Safety Bureau released a preliminary report about the crash of Air Tanker 134, an EC-130Q, that occurred January 23, 2020 while fighting a bushfire in New South Wales. The location was 50 km north-east of Cooma-Snowy Mountains Airport (near Peak View). All three members of the crew perished, First Officer Paul Clyde Hudson, Captain Ian H. McBeth, and Flight Engineer Rick A. DeMorgan Jr.
Below is the complete text of the report.
Preliminary report published 28 February 2020
Sequence of events On 23 January 2020, at about 1205 Eastern Daylight-saving Time, a Lockheed EC130Q (C‑130) aircraft, registered N134CG and contracted to the New South Wales (NSW) Rural Fire Service, departed Richmond RAAF Base, NSW. The crew had been tasked with a fire retardant drop over the ‘Adaminaby Complex’ bush fire.
After approaching the Adaminaby complex fire, the drop was unable to be completed and the aircraft was diverted to a secondary tasking, to drop retardant on the ‘Good Good’ fire (Figure 1). Witnesses reported seeing the aircraft complete a number of circuits, prior to completing the retardant drop. The drop was conducted on a heading of about 190°, at about 200 ft above ground level, with a drop time of approximately 2 seconds. The crew released about 1,200 US gallons (4,500 L) of fire retardant during the drop.
Witness videos taken of the aircraft leading up to the accident showed a number of passes conducted at varying heights prior to the retardant drop. Following the retardant drop (Figure 2), the aircraft was observed to bank left, before becoming obscured by smoke after about 5 seconds. A further 15 seconds after this, the aircraft was seen flying at a very low height above the ground, in a left wing down attitude. Shortly after, at about 1316, the aircraft collided with terrain and a post-impact fuel-fed fire ensued. The three crew were fatally injured and the aircraft was destroyed.
A review of the Airservices Australia audio recording of the applicable air traffic control frequency found no distress calls were made by the crew prior to the impact.
Wreckage and impact information The accident site was located on slightly sloping, partially wooded terrain, about 50 km north-east of the Cooma-Snowy Mountains Airport. The wreckage trail (Figure 3) was approximately on a heading of 100°, with the initial impact at an elevation of about 3,440 ft above mean sea level.
The ATSB’s on-site examination of the wreckage, damage to the surrounding vegetation, and ground markings indicated that the aircraft initially impacted a tree in a left wing down attitude, before colliding with the ground. The post-impact fuel-fed fire destroyed the aircraft. The examination also found that an emergency dump of the fire retardant had not been activated.
The engines, propellers, and several other components have been retained by the ATSB for further examination.
Aircraft information The Lockheed C-130 is predominantly an all-metal, high-wing aircraft, largely designed for military operations. The aircraft was manufactured in 1981 and was powered by four Allison T56-A-15 turboprop engines, fitted with Hamilton Sundstrand 54-H60-91 four blade propellers. Previously owned by the United States Navy, the aircraft was re-purposed for firefighting activities and registered as N134CG in 2018 (Figure 4). The modifications included the installation of an avionics package and firefighting tank system known as Retardant Aerial Delivery System XXL (RADS).
The RADS included a 4,000 US gallons (15,000 L) tank system located within the aircraft’s fuselage. The system was capable of delivering discrete quantities of retardant, dependent on the duration that the doors remained open. It was controlled from the cockpit, with drop controls located on both the pilot and copilot yokes. The system also included an emergency dump switch, which, when activated, fully opened the doors and jettisoned the load. The doors remained open until the RADS was reset by the crew.
N134CG arrived in Australia in November 2019, but had previously operated in the country during the 2018‑2019 fire season. The aircraft was designated as a ‘large air tanker’.
Meteorological information A Bureau of Meteorology graphical area forecast, issued at 0924 and valid for the time of the flight, forecast moderate mountain wave activity above 3,000 ft (above mean sea level) in the area of operation from Richmond to Cooma, and included the Adaminaby and Good Good fire grounds. A SIGMET issued at 0947 forecast severe turbulence below 10,000 ft.
The aerodrome forecast for the Cooma-Snowy Mountains Airport was amended at 0948, and indicated wind speeds of 30 kt, gusting to 48 kt, with a mean wind direction of 320°. It also included blowing dust and visibility of 2,000 m, with severe turbulence below 5,000 ft above ground level.
The weather observations recorded at the airport about 11 minutes prior to the accident, indicated a wind speed of 25 kt, gusting to 39 kt, from a direction of 320°, with visibility reduced to 6,000 m.
Cockpit voice recorder Cockpit voice recorders (CVR) are designed on an endless loop principle, where the oldest audio is continuously overwritten by the most recent audio. The CVR fitted to the aircraft was a Universal model CVR-30B, part number 1603-02-03, serial number 1541. This model of recorder used solid-state memory to record cockpit audio and had a recording duration of 30 minutes.
The CVR was recovered from the aircraft and transported to the ATSB’s technical facility in Canberra, Australian Capital Territory, on 25 January 2020 for examination and download. The CVR was successfully downloaded, however, no audio from the accident flight had been recorded. All recovered audio was from a previous flight when the aircraft was operating in the United States.
Further investigation The investigation is continuing and will include consideration of the following:
Engine, gearbox and propeller component examinations
Aircraft maintenance history
Aircraft performance and handling characteristics
Analysis of numerous witness reports
Review and analysis of the available recorded data, including witness videos, aircraft tracking data, audio recordings and any onboard systems
Review and analysis of environmental influences
The crew’s qualifications, experience and medical information
The nature of aerial fire-fighting operations
Operating policies and procedures
Exploring the possible reasons why the CVR did not record the accident flight
The ATSB will continue to consult with the engine and airframe type certificate holders. Accredited representatives from the United States National Transportation Safety Board (NTSB) have been appointed to participate in the investigation.
Acknowledgments The ATSB acknowledges the support of the NSW Police Force, NSW Rural Fire Service, NSW Fire and Rescue, the Australian Defence Force, and those involved with facilitating safe access to an active fire ground and supporting the ATSB’s on-site investigation team.
The information contained in this preliminary report is released in accordance with section 25 of the Transport Safety Investigation Act 2003 and is derived from the initial investigation of the occurrence. Readers are cautioned that new evidence will become available as the investigation progresses that will enhance the ATSB’s understanding of the accident as outlined in this preliminary report. As such, no analysis or findings are included.
Eastern Daylight-saving Time (EDT): Coordinated Universal Time (UTC) + 11 hours.
From the video, it was unclear if the aircraft flew behind the smoke or entered the smoke.
Significant meteorological information (SIGMET): a weather advisory service that provides the location, extent, expected movement and change in intensity of potentially hazardous (significant) or extreme meteorological conditions that are dangerous to most aircraft, such as thunderstorms or severe turbulence.
The Cooma-Snowy Mountains Airport has an elevation of 3,106 ft.
The Wildland Fire Lessons Learned Center has released a Facilitated Learning Analysis for an incident within an incident. Three of the seven smokejumpers that parachuted into the Miner Camp Peak Fire on July 29 east of Meadow, Utah were injured when landing. (Map) Two injuries were to the hand or wrist and the other was diagnosed at the scene as a broken collar bone or at least the potential for one.
The jumpers were evacuated by two helicopters, an air ambulance and a helicopter with hoist capabilities.
The jumpers received the resource order for the fire at 8:30 a.m. on July 29 while they were engaged in physical training. Since some of them “like to run trails in the surrounding area”, they did not get off the ground until 10:30. Due to the delayed departure, the distance they had to fly, and multiple issues related to fuel, the seven jumpers did not arrive on the ground at the fire until 5 p.m.
(Originally published at 9:28 a.m. MDT August 20, 2018)
While researching another topic I ran across a preliminary report about a helitack crew that on July 1, 2018 was extracted by their helicopter after the wind changed on the fire, driving it toward their helispot. This occurred on the Spring Creek Fire in Colorado. Because of the timing of the events and since they had to quickly move 150 yards to another location as dense smoke made it unsafe for the helicopter to land at the helispot, it might be described as a close call. But it appears that the reason the report was written was that the crew decided to leave the water bucket and long line attached as they evacuated in the aircraft. Having passengers in a helicopter with a bucket attached is not consistent with policy.
Below are excerpts from the preliminary report. The photos are also from that document. Our opinion is at the end, following the excerpt.
…The HMGB [Helicopter Manager, Single Resource] called pilot and requested him to land and pick up the crew, thinking there was still plenty of time to load bucket, gear and crew members. At the time of radio call the pilot had just dropped water in view of the crew, and was less than thirty seconds from the helispot. Winds continued to increase from 10 to at least 30-35 mph. At this time fire behavior increased dramatically, causing all the vehicles parked near helispot (approximately six or eight) to mobilize as quickly as possible and drive down the road below.
The IC asked the crew face to face if we were all good before he left. The HMGB considered jumping in the vehicles for a ride but quickly decided not to. The Decision was based on the time it would take to physically get into vehicles, the time it was taking for the vehicles to actually get headed down the road, the location of the fire at the time, and not being familiar with the fire experience of the vehicles occupants. HMGB deemed it best for the helitack crew to stick together.
As aircraft approached helispot, the pilot informed crew that there was too much smoke to land, but had another landing zone in sight downslope. The crew grabbed gear and began hiking towards the aircraft’s hovering location approximately one hundred and fifty yards down down slope. Helitack crew arrived at the new landing zone as the helicopter was landing. HMGB and crew began loading gear on the pilots side, and had full intentions of loading bucket and longline, but HMGB noticed pilot signaling to plug in flight helmet. Crew members continued to load gear and HMGB went around nose of aircraft, opened managers door, stood on skid and plugged in flight helmet. Pilot advised that he recommended loading crew and picking up with the longline and bucket attached to get to a safe location. Pilot made decision based on the fires rapid progression from time crew left helispot and hiked down to the second LZ. HMGB took a quick scan of fire and agreed with pilot that we needed to lift ASAP.
HMGB went back to cargo area and told the two crew members to forget the bucket and load up we would lift with the bucket attached and relocate to a safe location. The crew members understood and agreed and loaded up. The HMGB made sure aircraft doors were secure, confirmed everyone was buckled and told pilot we were ready to lift. As aircraft lifted, the longline and bucket were on the managers side of aircraft. The HMGB relayed the status of longline to pilot until it was out of view and in view of the pilot out the bubble window.
As aircraft flew away, the pilot informed air attack exactly what we had done. The air attack understood and relayed that the fire experienced a microburst, and one hundred percent of the fire perimeter had active fire spread.The aircraft flew about one quarter of a mile well below the fires heel, over sage brush and grass fuel model, and found a safe place to land. Once on the ground the pilot informed crew we had plenty of fuel, and to take our time loading bucket. The aircraft departed landing zone and flew back to airport in Alamosa, CO to RON. The manager met with the rest of the crew and notified the crews superintendent. HMGB conducted an AAR, and notification was made up the chain of command in the region and the home base region.
During the AAR, HMGB commended crew members for their vigilance on the scene of fire. Crew was constantly watching the fires behavior and spread, discussing the wind direction and different options to escape if needed. The black identified as a safety zone had a road going from the helispot up past it and was viable until the wind switched and increased pushing the fire up towards the road edge. The crew identified the helispot’s lack of burnable fuel and deemed it a safe spot. A later flight showed that the helispot did not burn, but when the IC decided to leave the spot, the crew did too. Plus one will never know how much heat was actually funneled over it. There was another open ridge downslope about 500-600 yards with a road leading to it that a helicopter could most likely land. The crew could have gotten a ride down to scout it out before the fire blew up, but that location didn’t have a vantage of the fire.
The crew actively talks with pilot about what to do in emergency situations. The crew had even talked earlier in the week about flying with a longline attached. It was comforting to know that those discussions took place and what to expect and the risk involved. The crew also practices proficiency bucket deployment, and packaging drills almost weekly. (Not with rotors turning) This gives managers and crew members a rough idea of how long it takes to perform these functions in the field. The HMGB on board has worked with the pilot for over eight seasons. The relationship, discussions, and trust built over the years was extremely valuable in the decision made that day.
Colorado DFPC Aviation Unit Chief comments:
Appropriate action taken during the extreme fire conditions and glad there was a positive outcome. Suggest a review of the additional risk decision to fly with the longline and bucket with personnel on board. The cost of a longline and bucket burning up is not worth the additional risk and exposure to employees. This is similar to teaching firefighters to drop their packs prior to deployment of a fire shelter from my perspective.
(end of excerpt from the preliminary report)
The report clearly outlines the fact that the crew felt they did not have time to package and load the bucket and long line, but there is no mention that they considered disconnecting it and taking off without it, leaving it on the helispot. Surely they did think about it, but the replacement cost if it was destroyed in the fire may have been a concern.
I support breaking the rules if there is an urgent, critical need to do so, and if all of the alternatives and possible outcomes are considered. Especially if a person’s life is threatened.
In 2014 on the King Fire east of Placerville, California when a hand crew was in danger of being overrun by flames a helicopter pilot considered using his bucket to extract the personnel. However, he continued to communicate with the crew and escorted them to safety as they walked and ran a considerable distance, orbiting over them and providing constant updates. The whole time he had water in his bucket saving it in case there was a need to protect the crew.
Above: photo of the incident scene, from the report.
(Originally published at 6:55 p.m. MST November 22, 2017)
The French government has released a report about an incident that occurred August 1, 2016 at Ajaccio. As best we can tell from the document, which is in French of course, is that a CL-415 experienced a mechanical failure in the right side landing gear while taxiing and turning left onto a runway before takeoff on a fire mission. When one of the components broke, the gear partially collapsed, causing the aircraft to tip to the right, coming to rest on the float under the wing tip.
Thankfully the crew was not injured.
The report appears to indicate that the problem was related to a maintenance issue due to a translation error in a technical document.
1er août 2016, Ajaccio : accident au roulage du Canadair CL415
Conclusion BEAD-Air «Affaissement du train d’atterrissage droit au roulage, par rupture d’un de ses composants suite à une erreur de maintenance générée par une faute de traduction dans une documentation technique». pic.twitter.com/XmZASZ9UBz
After making multiple attempts to land in brown-out conditions, the buildup of debris on the turbine blades and vanes led to a compressor stall in the left engine, which decreased lift and resulted in the hard landing and fire.
The report found that pilot performance and an improper site survey of the landing zone led to the accident, resulting in the deaths of two and injuries to 20 on board.
The potential for the Osprey to deliver water or personnel to fight wildfires was evaluated by the Marine Corps in tests with a 900-gallon water bucket. They recommended that the aircraft not exceed 90 knots with a bucket and 50 knots when dropping water.
The Osprey is a tilt-rotor aircraft capable of vertical or short takeoff and landing. When airborne, it can cruise at over 300 mph, can carry 24 to 32 troops, or 15,000 pounds of external cargo.