Multi-person rescues

“It was only possible to use one helicopter at a time because of turbulence from the other helicopter. Under optimal conditions, it is possible to hoist more people per hour, but it would not normally be necessary to evacuate a ship under optimal weather conditions.”

According to Mike Gall, Business Development Manager of Capewell Aerial Systems, multi-person ‘hoistable’ devices include forest penetrators, multi-person harnesses and the Billy Pugh Rescue Net. “Each of these devices has a maximum capacity of three persons and requires one of them to be a trained rescuer for safe operations,” he said. “The Heli-Basket, Billy Pugh, and the Airborne Tactical Extraction Platform (AirTEP) are the human external cargo (HEC) sling load devices that are being used in the search and rescue community today.”

Regarding HEC operations, McGrath, whose company, Integral Risk Global, is the exclusive distribution and training partner for the Heli-Basket, highlighted that the HB2000 Heli-Basket can lift up to 15 persons per lift cycle – or over 2,000 kg in equipment, with the lift cycle taking around about the same time as a single person hoist. “The smaller (six-person) HB1000 Heli-Basket has a maximum operating weight of 720 kgs, so it can be operated by even light or medium helicopters,” he added.

Available and in-development products

Boost Human External Cargo Systems (BHECS) is a Canadian company providing rescue, industry and public safety teams with fully certified human external cargo (HEC) systems. Boost’s systems are pilot controlled/operated, which negates the need for a second crewman to manipulate the system. The dual hook-dual release, low weight and minimal space/sized system also offers heightened redundancy for operators. Derek Thomas, President of Boost Systems, explained: “Our system is extremely versatile for personnel placement and emergency extraction/rescue, as it doesn’t require the open space and additional size/weight required for a basket, and can insert or extract personnel or victims from remote and hazardous terrain, such as mountainsides, dense woodland, anywhere a cable and harness can be lowered, making it a growing favourite for helicopter firefighters and rescue (also including law enforcement), border patrols and defense operators.”

For operators considering their options in multi-person rescue devices, regulatory approval is a must, and in October of 2019, BHECS received approval from Transport Canada for its system on the Bell 206L series, adding to the currently approved types on BHECS’ STC SH15-39. The Bell 206L series (L, L-1, L-3, and L-4) join the Bell 407 and Airbus AS350/55 series as approved helicopter types for the Boost HEC Dual Hook System. Federal Aviation Administration acceptance of the new type addition is in process.

The HB1000 and HB2000 Heli-Baskets are in production right now. “The larger HB3000 (up to 30 persons) and HB5000 (up to 50 persons) variants have also completed their design stage and could be built if required. They are essentially scaled up versions of the two existing variants. The only limiting factor is the performance limitations of the helicopter. In the case of the larger variants, a medium or heavy helicopter would be required to operate them,” said McGrath.

The devices need to maximise rescue efficiency in the amount of lives saved per evolution. “The survival of a person who is exposed to an extremely dangerous situation relies on the promptness of the rescue. It takes between four to six minutes to complete one hoist and during the same time, it would be possible to rescue 10 persons on the AirTEP,” said Gall, whose company, Capewell Aerial Systems, manufactures the AirTEP under licence in the US. “During Hurricane Katrina, helicopter hoisting systems were burning up due to the frequent use of single hoist and short hauls performed in this massive operation of people that were in need of rescue.”

AirTEP was developed as a means to extract multiple persons by helicopter, ranging from victims of flooding, and those in rough terrain conditions, to extractions from very high buildings. Capewell’s solution is designed to be used in situations where helicopter landings are impractical. “This device is designed for any rotary wing aircraft,” said Gall. “In SAR missions, AirTEP improves the rescue capabilities of the operators in all emergency situations. The platform, with its pentagon shape, is designed to avoid gyratory movements.”

Vittone believes that for hoist operations, the LSC rescue basket is a reliable option for hoisting two survivors at the same time into the helicopter. “But that depends on the people. Two large persons (weighing approximately 100 kg each) would not fit well into a rescue basket at all,” he said.

Equipment handling considerations

Because of the safety criticality of hoist and external cargo operations, the rescue devices used need particular care to ensure their proper operation. The Heli-Baskets, for example, can be folded down to reduce their size by approximately half. “What is required is that four quick release pins are removed and the upper half of the frame can then be stored in the lower half – none of the structural strength is carried through the upper half of the frame,” explained McGrath. “Clearly, with the exception of the very largest helicopters, the Heli-Basket would not be stored or carried within the helicopter itself; however, the equipment has been flight tested (by the US military) and cleared to fly at up to 120 kts, so it could easily be flown externally to the rescue site, without slowing the rescue crew’s arrival on scene.”

With a weight of 53 kg and an 82-foot-long polyamide rope using a double tapered eye splice with steel eye reinforcement constructed at each end of the rope, Capewell’s AirTEP can be stored in the helicopter, although it is more likely to be stored at a base in a ready-to-go condition. When it comes to operating, it, Gall explained: “The automatically opening platform can be outfitted with floatation to keep the device at the surface for loading survivors. This device is designed to carry up to 10 people or 3,300 lbs, it uses a descent control mechanism (DCM), and 10 safety belts. The DCM is intended to reduce the speed of descent of the platform and rope in such a manner as to prevent the risk of snatching shock on the mechanical links to the helicopter.”

When using AirTEP on land, the recommendation is to use the DCM to control the rate of descent until the platform touches the ground. “The loadmaster in the cabin then gives the remaining rope slack, removes the rope from the DCM, then jettisons the remaining rope outside the cabin,” explained Gall. “When using AirTEP on water, it is recommended to take off with the AirTEP already deployed, as it requires much practice to get it right the first time. If the automatic opening is missed, operators will have a difficult time opening the AirTEP in the water, even though it can be done on the deck of a vessel.”

The automatic opening of the AirTEP is achieved by proceeding in a controlled free fall (pulling the brake/DCM lever), then releasing the break/DCM lever, making the platform stop. The inertial force activates the opening system in the head of the platform. “Features of the AirTEP include the flexible net surface and safety belts for each rider in its open state, the five webbing wedges provide a riding surface for the evacuees. Each wedge is sized to fit two persons. The load placed on the nets will flex to somewhat conform to the shape of the load,” said Gall. “Flexing will provide for a shallow divot in which the rider will be sitting, and the perception of a rider is that they are not just sitting on a surface but secured in the net. Two safety belts are associated with each platform wedge to help retain the survivors. The safety belts restrict movement to prevent the rider form falling off the edge. A maximum of 3,300 lbs can be carried on the platform with the rope having a 34,845-lb breaking strength.”

Safety considerations

“It is important to note,” said McGrath, “that we do not suggest that rescues are flown significant distances; rather, they are flown to a position of relative safety, where medical attention or further rescue can be initiated. In the case of the MV Viking Sky, the ship was only one km from the coast when it ran into trouble, so in that scenario, rescues would have been carried to the nearest land location, where further assistance would have been delivered. Had the ship been further out to sea, evacuees could have been flown to the nearest vessel.”

An essential part of maintaining safety margins is in sufficient training of the crews that are going to use them. In relation to the use of AirTEP, training is provided for two kinds of users: on-ground operators and line operatives. “On-ground operators are responsible for two levels of maintenance while the third level requires maintenance to be completed by the manufacturer,” explained Gall. “Operational users training is intended to train the driver who is responsible for the platform onboard the helicopter, he leads all the related actions: fitting, opening, guiding on the objective, landing, take-off. This type of training is also addressed to the platform leader – who is responsible for people onboard the platform; the pilot – who must know flight specifications and communications procedures; and the helicopter loadmaster – who must know AirTEP deployment protocol with the DCM.”

Other rescue options

Despite being effective, especially if multiple persons are rescued, helicopter hoist evacuations may not always be possible – for example, due to adverse weather conditions. In such scenarios, other rescue options may need to be pursued. The search and rescue (SAR) system of the Australian Maritime Safety Authority (AMSA) includes a collaborative arrangement between AMSA, Australian Federal Police, Australian Defence Force, state and territory police supported by various volunteer marine rescue organisations, as well as contracted SAR providers. “AMSA has its own dedicated fleet of four Challenger SAR jets, which are capable of locating people in distress, dropping equipment such as life rafts, satellite phones and food stores among other things. They are also equipped to deploy life rafts with capacity for up to 49 people,” said an AMSA spokesperson. “In each SAR situation, AMSA would call upon all available air and marine assets and AMSA would co-ordinate operations throughout the evacuation. Considerations include minimising the risk posed to SAR crews and maximising the safe, efficient transfer of passengers and crew from a stricken ship.”

The UK Maritime & Coastguard Agency (MCA) is committed to the principles of ‘safe return to port’ which was adopted by the International Maritime Organization in 2010. The MCA notes the regulation requires passenger vessels with a length of 120 m or more, or with three or more main vertical zones, to be designed for improved survivability. “It works on the idea that it is safer to make sure that cruise ships and large yachts can get back to port rather than carrying out mass evacuations into lifeboats or onto helicopters,” concluded the MCA.

Rob Munday, Helicopter Hoist Operator for Blackcomb Helicopters, gave AirMed&Rescue some insights into the challenges and solutions he faces when it comes to multiple rescue events

Due to our proximity to the Whistler Blackcomb ski resort (the largest in north America) and their use of the peak-to-peak gondola that can carry up to 28 people per cabin, and there’s 28 cabins – so 750+ people at any one time – should an evacuation be required, it would be a serious undertaking. We also have the sea-to-sky gondola just down the road, which can carry 250 people at any given time. There have been ongoing conversations about the options in the event of a full-scale evacuation, and we think that five at a time on the boost system is probably the most realistic in the short term. We utilise primarily the HEC longline rescue kit for this type of situation, both the Boost and Emergco branded kits are approved in Canada, and have the ability to lift up to five subjects simultaneously, totalling 1,100 lb for Boost and 600 lb (two people) on the Emergco.”

Canada is a very different beast with regards to regulations and approval of equipment; our interpretation of the rules here is that each piece of rescue equipment must be airworthiness approved and unfortunately it can be a real challenge to gain this approval to use.

A system that requires untrained people to be suspended under a helicopter in anything less than a full-body harness presents serious regulatory challenges, so we have to work with what we’ve got. The hoist is still a great option, but when time is of the essence, it’s likely that a longline system would be a faster solution, unless a hoist aircraft could carry a significant number of passengers per cycle, our 212’s may be a viable option but the EC135 we currently have could realistically only carry four subjects at a time, and would be fairly slow.

We have had discussions with guys like Vancouver Fire and the RCMP (police) in the city about rooftop evacuations, which are ongoing, however, there isn’t a clear solution at this time that would meet the legal requirements we’re faced with.

This article first appeared in the March 2020 Firefighting Special Edition.