Rescue helicopter hoists, hooks and winches

Getting a victim into a rescue helicopter safely takes skills, effort and training, and hooks, lines and hoists. James Paul Wallis considers the options available to search and rescue personnel

There’s a well-worn quote from Igor Sikorsky that, ‘if a man is in need of rescue, an airplane can come in and throw flowers on him, and that’s just about all’. The beauty of the helicopter as a rescue aircraft is the ability to be able to lift casualties from the scene and take them to safety. To do this, the ideal gear is a rescue hoist with cable and hook, though a basic capability can be afforded with a fixed line. And the equipment is improving all the time.

 

Hoists

The design of helicopter rescue hoists has improved steadily since they were first put into use in the 1940s, becoming more powerful and more reliable. A hoist comprises a hydraulic or electric drive system that winds a cable around a drum and includes a braking system.

Collins Aerospace is a new name on the block, but its hoists have a long pedigree. It was formed when United Technologies (UTC) acquired Rockwell Collins in November 2018. Readers may recall that UTC acquired Goodrich, a maker of helicopter rescue hoists, back in 2012. Al Killeffer, Senior Public Relations Manager at Collins Aerospace, said the firm’s new fifth-generation hoist, Pegasus, is currently undergoing prototype testing. He said: “Pegasus is our first clean-sheet hoist design in decades and represents a breakthrough in hoist technology for the industry.”

Among the features Collins highlights for the new unit is an improved traction drive, better cable handling and a level-wind system to enhance reliability. As well as mechanical improvements, helicopter rescue hoists have grown more user-friendly over the years. As an example, the Pegasus boasts digital displays for load and fleet angle, a clutch-slip indicator and a health usage monitoring system (HUMS).

 

far from a mere theoretical possibility, dynamic rollout has been the cause of a number of fatal accidents

 

Installing a hoist onto a helicopter is no small undertaking, so a device tends to be a long-term investment, but Collins has sought to make it easy for owners to upgrade. Killeffer explained: “Pegasus will be completely compatible with our existing hoist footprints so it can be easily installed as a drop-in retrofit.”

Collins anticipates that the Pegasus will enter production in 2020. Anyone interested should have been able to get eyes on it at HAI Heli-Expo in March, where a working prototype was on display, said Killeffer.

News from Jenoptik suggests there may be a similar launch time for its SkyHoist 800 electric winch, which will be released under the Vincorion brand, the new name for its mechatronic division. The company told AirMed&Rescue that the new device will be lighter in weight, but with improved lifting capacity and reduced operating and maintenance costs thanks to a modular design. Introducing the model in 2017, Jenoptik highlighted the compact size of the new hoist.

At the time of writing, two fully functional SkyHoist 800 prototypes are undergoing advanced testing in order to verify technical performance. The plan for 2019 is to start qualification tests in preparation for certification, said Jenoptik.

 

Hoist hooks

The hoist hook may seem like a standard item, but it’s hard to overstate its importance in the whole rescue system. One of the big areas of development over the years has been making hooks safer and less likely to release the load (the rescuer and/or casualty) when you don’t want it to. The issue here is not mechanical failure, such as fracturing of the metal, but rather dynamic rollout (also known as ring reversal). The US Federal Aviation Administration (FAA) described dynamic rollout in a 2016 Safety Alert for Operators: “When the ring in the rescue strap and the hook are temporarily relieved of the load, a dynamic condition exists allowing the ring to travel up and flip over the tip of the hook and come to rest on the spring-loaded keeper. The ring is now only supported by the spring-loaded keeper. When the load is re-applied, the ring is forced open and the spring-loaded keeper allows the ring to fall free from the hook, thereby inadvertently releasing the occupant or load.” Far from a mere theoretical possibility, dynamic rollout has been the cause of a number of fatal accidents, and the FAA advised crews to only use rescue hooks that have a mechanical locking keeper or guards to prevent D-ring reversal.

Locking systems have been a key area of development for hook makers. US-based Lifesaving Systems wrote in 2018 that one of the changes since it designed its first hook 20 years ago to feature a locking gate, is that its increasingly common to see several loads all being attached to the same hook, as rescuer, litter, tag lines and medical gear are all lifted together. In general, it is harder for manufacturers to anticipate the kinds of attachment rings that users might put on a hook.

The company set out to redesign its D-Lok Hoist Hook after learning of one particular attachment ring, the SETS Ring, that can make an unintended exit (although it has to be manipulated in a very particular way, said the firm). Mario Vittone, General Manager of Lifesaving Systems, told AirMed&Rescue that the company’s redesigned D-Lok Hoist Hook launches this year. The hook features a double-locking gate. Of the prototype, the firm said: “We performed testing [for] the design against every conceivable ring.  Short of welding the gate shut, everything that can be done has been done to prevent inadvertent activation of the latches. The new gate design (patent pending) fully guards the latches on all sides, making it impossible for any straight or curved metal ring or any length of webbing or rope to activate an auto-locking gate latch. The gate will always stay double-locked, regardless of the ring used in the hook.”

The test will be whether the hook will be as easy to use as Lifesaving Systems claims – the company says the gate is still operated easily with one hand, a vital requirement in time-pressured missions and harsh environments such as open sea rescues. Interestingly, the firm said the new gate can be retrofitted to existing D-Lok hooks, making it possible to adopt as an upgrade rather than a replacement.

The HeliBasket solenoid-operated Remote Cargo Hook with integrated swivel carries an external load under a helicopter using various length lines. It can be operated by the crew in the helicopter and is used to engage, lift, transport and release external loads into and from confined areas. Martin McGrath of Integral Risk Global, HeliBasket’s distribution and training partner, commented: “Our electric long lines support all types of loads and our swivels protect rigging associated with all standard, nonstandard or unique external loads. The Remote Cargo Hook is attached at the lower end of our Electric Long Line strop and is operated by either the pilot(s) or the rear crewman. Each hook has an integrated swivel mechanism to reduce the risk of a twisting load and adding unnecessary fatigue to the long line. Using the Remote Cargo Hook in conjunction with the Electric Long Line allows the helicopter to attach and release loads whilst maintaining a high hover, thereby increasing safety, speed and efficiency.” The Remote Cargo Hook can be operated by the rear crew via the Remote Hand Controller, thereby reducing pilot workload. Furthermore, as the hook is fitted at the lower end of the long line – which might be up to 200 feet in length – it be manoeuvred to the load by ground crew, thereby further increasing speed and efficiency whilst the aircraft remains high enough to avoid ground obstacles and hazards. “Both Electric Long Lines and Remote Cargo Hooks are currently being used by numerous operators around the world,” said McGrath, “the US Army, Tokyo Fire Department’s Hyper Rescue Unit, and Spanish Army SAR units to name just a few.”

Of course, no matter what hook you’ve got, if you can’t see it during a night mission, then it can’t help you. Enter the DarkLight G2, made by Zephyr International, which is an LED device used to illuminate the hook assembly to enhance rescue hoist mission safety during low visibility or night operations. It is equipped with green and red LEDs to be used for increased hook visibility and signalling, as well as IR compatible infrared LEDs, to be used in covert operations. No airworthiness certification is required for its installation.

 

an absolute necessity for breakaway links to be able to be broken by a human and not just by the helicopter

 

 

The weakest link

Looking ahead, could it be that the design of breakaway links (aka weak links) is about to change? The breakaway link ensures that a snared tagline or trail line will separate from the helicopter when a threshold force is reached, preventing what might otherwise develop into a dangerous entanglement. Adam Davies, Manager SART/TAC, Priority 1 Air Rescue, thinks that this aspect of helicopter rescue equipment needs to be rethought. He said: “We see a huge disconnect between modern best practices and devices available. The old concept of ‘because we have always done it that way’ is something that we have been moving away from in helicopter SAR devices in many regards. However, when it comes to breakaway ‘weak’ links we have not seen as much progression.” The company’s founders were familiar with the concept of human rope entanglement as they were practitioners of ground-based rope rescue/rope access, Davies explained: “For us, this bred the early concept of an absolute necessity for breakaway links to be able to be broken by a human and not just by the helicopter.”

In line with this thinking, P1AR’s breakaway links are targeted to break at approximately 100 lbs (45 kg), low enough for a person to break if needed. In contrast, most of the breakaway links currently on the market inherit a military concept of high-breaking strengths. US military branches that do hoisting typically use breakaway links that range anywhere from 300 to 500 lbs (136 to 227 kg) in breaking strength, he said.

The challenge, according to Davies, is changing the mindset of organisations by highlighting what can happen if lines snare: “Organisations and agencies that challenge the notion of lighter capacity breakaway ‘weak’ links typically do so because of a general lack of knowledge and awareness of certain emergency procedures. Specifically, the dangers with the possibility of the aircraft forgetting to release the tagline and flying away (which is a great risk when operators employ dynamic hoisting techniques), or in the event of an aircraft emergency, where the aircraft has to fly away, while a tagline is being employed.” Helicopter SAR practitioners may want to discuss what would happen if they were performing a single hoist extraction of a litter and the aircraft has a power-loss and had to do a fly-away, said Davies. If the rescue specialist on the ground can’t break the weak link and the aircraft flies away with the tagline trailing behind, it could end up in the tail rotor, he warned: “With discussion and trying different breakaway ‘weak’ links in a safe, planned, and controlled training environment, a lot of agencies would probably be more willing to start changing their way of thinking to address these possible issues.”

 

the problem with certifying this equipment is that there are no standards that actually exist for most of what hangs from a hoist hook

 

If the hoist cable gets caught in a ship’s rigging, trees, rocks, railings or worse yet around the rescuer’s neck, the cable needs to be cut quickly. The existing two-handed cable cutters are too slow, ineffective, and not designed for this purpose, says Zephyr International, which has brought its AxelCut product to the market to fill the need for a safe and fast way of cutting the cable. It is unaffected by EMI, lightning, or any other possible hoist system failures and is designed for low cost and a long life, added the company.

Regulation

There may also one day be clarification of the regulation and certification requirements surrounding helicopter rescue equipment. This has long been an issue, which Thomas Knudstrup, CEO/Managing Director of Lite Flite in Denmark, said is exacerbated by the fact that helicopter SAR is increasingly shifting into the civilian sphere, where operators have to comply with standard health and safety law. Whether heli-rescue gear sits in the category of personal protective equipment (PPE) is a grey area, but to be on the safe side, Lite Flite is preparing for the new EU Regulation 2016/425 on PPE, which came into force in April 2018, by recertifying all of its equipment in accordance with the new rules. He said: “Most likely, products will remain the same, but the testing and documentation for type certification will be more comprehensive.”

Vittone of Lifesaving Systems concurred that the problem with certifying this equipment is that there are no standards that actually exist for most of what hangs from a hoist hook: “There is no standardised FAA certification criteria for rescue baskets, or hoistable rescue litters, or quick strops, or rescue slings, yet these devices are of primary importance in the work performed on a daily basis by helicopter crews. Bringing the regulators up to speed with the industry is the biggest challenge that faces us in getting our equipment ‘certified’.”

This is an area that Lifesaving Systems is working on, said Vittone, as is the FAA, and he is optimistic that more certifications will be released over time.

Some US rescue providers that use fixed lines rather than hoists to lift ‘human external cargo’ (HEC) had a nasty surprise in June 2018 when the FAA issued clarification that HEC operations must use an attachment means certified to the requirements of 14 Code of Federal Regulations (CFR) part 27 or 29. However, while this caused problems for some sectors, such as the power utility industry, it did not impact public operators or those who already had certified systems. Examples include the modular system offered by EmergoCo, and Boost Systems offers a certified set-up that incorporates two Onboard Systems cargo hooks. Brendan Fitzpatrick of Onboard Systems explained that the long-line is attached to both hooks as a safety measure: “This way, if one hook inadvertently opens (mechanical or electrical failure or pilot error) the person is still safely retained by the second hook.”

 

Onwards and upwards

No doubt we’ll continue to see minor improvements that all go together to make life easier for the rescuer. For example, in 2017 Capewell began offering its cable splices and rescue hooks with a high-visibility neon yellow finish, making them easier to see in dim light or if submerged. As battery and LED technology improve, we might also see more items with built-in illumination, such as the hook bumper Breeze-Eastern unveiled at HAI HELI-EXPO in Dallas last year. And this year, Lifesaving Systems aims to bring its Quad-Lok release to market, a new quick release designed for HEC rescue operations that Vittone said will be easy to operate, even under load.

Another area to keep an eye on, said Knudstrup, is new technology such as self-flown rescue devices, which could need new designs of rescue equipment. Technological innovations will continue to make rescuers and their victims safer, and hopefully, regulatory bodies will move fast to approve products that do so.

 

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