Mass and Power
October 1, 2010 By Peter Pigott
In the March/April issue of Helicopters magazine, we introduced a special series profiling possible replacements for the aging Canadian Coast Guard fleet.
In the March/April issue of Helicopters magazine, we introduced a special series profiling possible replacements for the aging Canadian Coast Guard fleet. And while the CCG’s 22 aircraft are in good working order and provide safe and effective delivery of CCG programs, the fleet is 25 to 37 years old – and changes are on the horizon. In our latest instalment of this special series, veteran correspondent Peter Pigott profiles the capable Sikorsky S-92.
|Since 2007, four CHC S-92 Search and Rescue (SAR) versions have been stationed at Stornoway on the Isle of Lewis and Sumbugh in the Shetland Islands on behalf of the British Maritime and Coastguard Agency (MCA). (Photo courtesy of CHC)
To appreciate the true capabilities of the search and rescue (SAR) version of the Sikorsky S-92 and its CHC pilots, one has to locate on a map the Western Isles of Scotland – specifically Stornoway on the Isle of Lewis and Sumbugh in the Shetland Islands. Since 2007, four CHC S-92s have been stationed at both places on behalf of the British Maritime and Coastguard Agency(MCA). On interviewing Stornoway Training Captain Richard Dane, one was struck by two things: his nonchalance relating acts of intense bravery and his enthusiasm for the S-92.
Providing SAR up to the Faroe Islands and from the west coast of Scotland into the Atlantic, the former Fleet Air Arm pilot has flown more than 25 rotary- and fixed-wing aircraft, including the V-22 Osprey tilt rotor. Having flown SAR missions in the Sea King with the Royal Navy, he says the S-92 will outperform that helicopter in every respect. “It’s the most suitable SAR aircraft I have ever flown – bar none,” says Dane. “One SAR rescue occurred when one of the crews went out to St. Kildare and rescued a fisherman in high turbulence wind. He had been ‘whacked’ against the cliffs and it required close hovering in the S-92 and close teamwork between the pilots and rear crew to winch him in. It’s just part of the job – that’s what I think.”
| Cougar Helicopters continues to successfully fly the S-92 for its operations in spite of an accident on March 12, 2009, when a S-92A crashed enroute to the White Rose oilrigs off Newfoundland. (Photo courtesy of Cougar Helicopters)
The Sikorsky S-92 became best known to the Canadian public due to unfortunate circumstances. On March 12, 2009, a S-92A operated by Cougar Helicopters crashed enroute to the White Rose oilrigs off Newfoundland. Investigators believe there was a sudden drop in oil pressure, and minutes before the crash, the crew reported mechanical problems involving the aircraft’s gearbox. The media reported investigators from the Transportation Safety Board were examining the possibility of a broken mounting stud in the S-92’s main gearbox filter bowl. On March 24, 2009, the U.S. Federal Aviation Administration (FAA) instructed owners of Sikorsky S-92A helicopters to cancel flights until they had replaced a component that has been associated with a fatal crash off Newfoundland. In accordance with a Sikorsky Aircraft Alert Service Bulletin (ASB), oil filter bowl studs on all Sikorsky S-92A aircraft were immediately replaced with new steel studs. Compliance with this ASB was subsequently mandated by an FAA Airworthiness Directive.
On June 18, 2009, The Transportation Safety Board of Canada issued an Investigation Update into the Sikorsky S-92A Helicopter Accident. In summary, it stated that an examination of the MGB (the main gearbox) indicated there was no loss of main rotor drive and the main rotor blades were rotating at the time of the impact. The investigation revealed that, even though the Sikorsky S-92A MGB was certificated to meet requirements of Part-29 of the Federal Aviation Regulations (FAR-29) of the United States FAA,“. . . there is a perception in some areas of the aviation community that the MGB can be run in a dry state – that is, without lubricating oil – for 30 minutes.”
“FAR-29 does not require run-dry operation of a gearbox to meet the 30-minute continued safe operation. Based on the applicable guidance material at the time of certification, the lubrication failure modes of interest were limited to the failure of external lines, fittings, valves, and coolers. This practice was consistent with industry experience, which had found that loss of lubrication tended to be associated with external devices. Therefore, the possibility of a failure at the oil filter was considered to be extremely remote.” Because of the fracture of the filter bowl-mounting studs, which caused a loss of a large quantity of oil, the certification guidance material was being reviewed.
Nearly a month after the crash, on April 8, 2009, the Canada-Newfoundland and Labrador Offshore Petroleum Board (C-NLOPB) opened, “The Offshore Helicopter Safety Inquiry.” Appointed as Commissioner The Honourable Robert Wells, Q.C., was to recommend improvements to the safety regime to ensure the risks of helicopter transportation of offshore workers in the Newfoundland and Labrador Offshore Area were as low as reasonably practicable. But the mandate of the inquiry does not include an investigation into the cause of the crash of the Cougar Helicopter Sikorsky S92A as that remains the responsibility of the TSB.
The Right Choice
The crash of the S-92 off Newfoundland did little to deter the government of the United Kingdom. It had selected the Soteria consortium a month before as the preferred bidder to provide turnkey search and rescue (SAR) helicopter services for the next 25 years. Soteria is the Greek goddess of safety, deliverance and preservation from harm – a mission statement that fits well with the role of delivering a successful SAR service to an island nation caught between the North Sea and the Atlantic Ocean.
Made up of Sikorsky Aircraft, CHC Thales and the Royal Bank of Scotland, the Soteria contract is backed by the Canadian Commercial Corporation, a crown corporation of the Canadian government that facilitates Canadian exports by negotiating and executing government-to-government contracts.
But until it could begin, on Dec. 13, 2005, an interim five-year contract to provide SAR cover was awarded to CHC Scotia, running from July 1, 2007 to 2012. Replacing the Sea Kings and S-91s in use by the Coast Guard would be four CHC S-92s under contract to the Maritime Coastguard Agency (MCA). Ian McLuskie, SAR business unit leader with CHC, said for the interim contract, they examined all helicopters available; the EH101, the EC225 and even the Russian Mi-17. It was determined, however, that the S-92 best met their requirements for operating in the outer islands.
And just three months after the Sikorsky machines began operations, the crew of a Stornoway-based S-92 was recognized for its bravery when members rescued the 14-man crew of a Spanish fishing boat after it ran aground under cliffs at St Kilda in high winds gusting up to 70 knots. Last year, the S-92 helicopters operating in the United Kingdom performed nearly 750 missions – a SAR record anywhere.
A Canadian Perspective
In a distinct Canadian connection, the previous SAR helicopters the MCA had been using in Scotland were Sea King variants. Both the Canadian Forces and Royal Canadian Navy use the CH-124 Sea King.
| The S-92’s combination of power and safety options makes it an excellent choice not only for the CHC, but for corporations such as the National Australian Bank. (Photo courtesy of CHC)
Captain Alun Tink, MCA deputy chief pilot at Stornoway, says the S-92 is a superior aircraft in many ways, and is better suited for SAR applications.“ The S-92 offers significant advances over the old Sea King,” he says. “It flies faster, higher, has greater performance, and what that means for the casualty is the S-92 will get to them quicker. It has a greater chance of getting to them because of the systems onboard, and being a more modern helicopter, it has significant advances in reliability.”
The S-92 can cruise at 151 knots, he says, with a radius of action of around 200 nautical miles, which means helicopters based in the Shetlands can fly as far as Bergen in Norway or the Faroe Islands and still return to base. Auxiliary tanks fitted in the cabin can almost double the range, although these are bulky and take several hours to install. The engine performance of the aircraft means it can hold hovers even in severe downdrafts coming off cliffs, and single-engined performance is far superior to that of the Sea King.
“When on Aug. 30, 2010, a cruise ship was stranded in the Arctic, there were concerns in the media about what would have happened had there been a need for helicopter-borne SAR services. With its vastness, the Canadian Arctic cannot be compared to other SAR regions in the world. The hydrographic and climatological conditions of the Arctic maritime environment make the provision of SAR services in this region particularly challenging. With global warming, increases in ecotourism activity are forecasted in all of the northern areas, and based on the results of the Canadian Coast Guard SAR Needs Analysis, 2007 – Technical Report, the current SAR system capacity will not be able to meet the increased demand. This is where the Sikorsky S-92, with its increased range, power and versatility will be needed.”
The aircraft’s all-weather performance allows it to launch in conditions that would have grounded its predecessor. And given the severe weather off the coast of Scotland, CHC crews are unanimous in their praise for the S-92’s Rotor Ice Protection System (RIPS). It has computer-controlled heating elements in the rotor blades that are powered by redundant electrical generators. The system precisely delivers power to the blades to automatically shed ice away from the main and tail rotor. Icing would have forced a Sea King crew to take a longer route along the coast, rather than a straight line over land through dangerous conditions. “De-icing means we can fly higher and faster,” Tink said. “In the old Sea Kings, to take a casualty from Stornoway to Inverness, we used to have to fly all the way around the North of Scotland.” With the S-92s, crews are able to fly up to 8,000 feet in –40 degrees Celsius to go from Stornoway across country to Inverness.”
Transport Canada certified in December 2005 that Cougar Helicopters were cleared to fly their S-92s equipped with RIPS into known-icing conditions and the 28 new H-92 maritime helicopters for the Canadian Forces, designated the CH-148 Cyclone, are naval variants of the S-92 and will possess the same icing clearance.
Genesis of the S-92
The Sikorsky S-92 design “evolved” from that of the S-70 Black Hawk and Seahawk aircraft. It first flew on Dec. 23, 1998, having been designed specifically for over-water SAR in difficult environments such as the North Sea and North Atlantic. The S-92 team won the Collier Trophy in 2002 and when it was awarded an FAA type certificate in December 2002, FAA Regional Administrator Amy Corbett called the aircraft “the world’s safest helicopter.”
The first production S-92 was delivered in late 2004 and the aircraft was immediately snapped up by companies that service the resource industry such as Cougar Helicopters Inc., CHC Helicopter Corp., U.S.-based Petroleum Helicopters Inc. and Norsk Helikopter of Norway. Given the helicopter’s potential, it was no surprise that on March 1, 2007, Sikorsky unveiled the first SAR CHC aircraft at Heli-Expo.
The S-92 commercial helicopter has two GE CT7-8A turboshaft engines driving four blades, and a top speed of 280 kilometres per hour. The “airline” configuration of the S-92 helicopter seats up to 19 passengers and has a range for fully loaded flights of up to 476 nautical miles (882 kilometres). Its maximum range without reserves is 999 kilometres and it cruises at an altitude of about 4,000 feet. The cabin is six feet high, 6.58 feet wide and 20 feet long.
Advanced Cockpits and Systems
The higher levels of safety, reliability and maintainability can be seen throughout the S-92’s design, especially in the cockpit, which Sikorsky calls a “modern pilot workstation.” It features a Rockwell Collins avionics package that displays flight-critical data on six-inch by eight-inch, colour, liquid-crystal, multifunction displays and includes dual flight-management systems with integrated control of the flight director.
The SAR S-92 is fitted with a Honeywell Primus 701 full-colour weather/search radar, and has a Chelton 935-11 direction finder. A Saab SAR AIS transponder – an onboard maritime automated identification system – is also fitted. The instrument panel was reduced in width, compared with earlier designs, to improve the pilots’ field of view. Situational awareness can also be enhanced through the addition of weather radar data with a flight path overlay, a forward-looking infrared system and a digital moving map. The cockpit is night-vision-goggle-compatible and can simulate one-engine inoperative conditions for training purposes.
A SkyTrac satellite communications and tracking system allows the aircraft to communicate over long distances or beyond line of sight. Crews regularly use the system to call hikers or climbers in distress on their mobile phones directly, allowing the airmen to assess the situation before they arrive.
A Toshiba Toughbook laptop contains detailed Ordnance Survey and topographical maps, combined with terrain information allowing them to be viewed in 3-D. It allows the crews to plan their routes in and out, particularly during onshore rescues.
But nothing demonstrates the 24/7 reliability of the Sikorsky better than this: At the MCA stations at Stornoway and Sumbugh, the S-92s are maintained at 15 minutes’ notice to launch. “So when it’s scrambled, we have to get up and out within 15 minutes,” explained Dane. “We are on call from eight in the morning to 10 at night. Overnight we are 45-minute standby, which allows the captain to be called at home, given the details of the mission, drive to the base, and brief the crew and scramble the aircraft.” How many callouts the crews do is up to the weather. But Dane maintains it is in the vicinity of 200 callouts annually.
When asked why he thinks the S-92 is the best aircraft for SAR Dane says: “It’s the perfect combination of things: for mountain work, it’s not susceptible to updrafting and down drafting – that’s because of its mass and power. It’s extremely manoeuverable in the mountains – holds its position quite well. It’s not too large or too small; it’s very agile, has good response. The terrain avoidance radar has a 3-D colour map, which gives us excellent terrain awareness, enabling the S-92 to operate with better terrain awareness in a low level environment. And the speed is better than most helicopters today.”
In terms of a SAR platform, Dane was even more enthusiastic. “The S-92 is the most suitable aircraft in a variety of ways: it is extremely powerful, as each engine produces up to 2,750 horsepower. This is needed, especially in poor conditions. It’s also got masses of room in the back – you can stand up inside it – something you need to do for medical care. Standing up in another aircraft is not an option. It can take up to nine to 10 emergency rescue personnel, and we have an internal auxiliary fuel tank which gives up to 6,600 pounds. of fuel, giving the radius of action of about 270 nautical miles. This means we can spend 30 minutes at sea, 15 minutes hovering at speed which is an exceptional radius of action without refuel.”
When asked to illustrate the S-92’s effectiveness, Dane was quick to answer. He recalled one rescue where the crew picked up an injured hiker from the vicinity of the Kyle of Locklash. It was a full IFR transit (across the Minch) at night with very low clouds, in driving rain and pitch darkness.
“We were able to conduct an IMC (Instrument Meteorological Conditions) letdown into very restricted water space,” says Dane. “Then I flew the aircraft using radar in an approach mode just off the beach into this loch. Using infrared combined with the Nightsun searchlight, I flew the aircraft visually up a couple of valleys to get to him and winch him to safety. The S-92 was then climbed out of there virtually vertical and we got him to hospital.”
Carey Bond, president of Sikorsky Global Helicopters, echoes Dane’s assessment of the S-92, adding that the aircraft would be a good choice for any coast guard. “The SAR S-92 helicopters today,” he says, “are doing exactly what our company founder, Igor Sikorsky, always knew that a helicopter would do – save lives.”
Enhanced features to help rescues succeed
The commercial version of the S-92 has a number of safety features that make it Coast Guard-worthy:
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