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Wednesday, May 1, 2013

The New Generation of Offshore Helicopters

AgustaWestland AW189, Bell 525, Eurocopter EC175, Kamov Ka-62 and Sikorsky S-92 are the heavy hitters in the emerging class of large cabin, long-range helicopters.

By Pat Gray

Sabers have been drawn and the battle is on for the deepwater offshore helicopter market that has already emerged. The large energy companies are now drilling exploratory wells in ocean depths of 10,000 feet or more at distances that exceed 200 miles from shorelines all over the world. The history of ocean drilling has always been in a leap-frog fashion with outward movement from shore generally being in stages of maybe 20 miles at a time. There were and are a variety of rigs used for drilling such as jack-ups and semi-submersibles that could be floated to a location and easily stabilized over the seabed. When a paying well was hit, the drilling rig would do a completion, cap the well and move on to a new location.

Eventually a rigid steel platform would be attached to the seabed and production would begin. Other wells would be developed nearby until you had a fully constructed “field” of wells or platforms. When those production platforms were put into service, almost all of them were equipped with a helideck that was certified for a maximum weight, usually around 5,000 or 6,000 pounds. However, the drilling rig helidecks were capable of 10,000 pounds and upward. For many years, 100 miles from shore was about the limit for drilling due to sea depth, lack of technology and government prohibits on the outer shelf.

The 100-mile range is ideal for existing shore-based helicopters in providing crew changes, establishing refueling points just about anywhere, and even basing small helicopters on the platforms, if needed. In many cases, platforms are 20 to 30 miles apart or less, allowing the helicopters to hop about anywhere without worries of fuel availability, navigation or lost communication with the shore. That scenario will stay as it is until all of the close-in oil and gas is depleted.

Shallow well drilling, though still active, is giving way to deepwater and ultra deepwater drilling, and all the conveniences of having stepping stone platforms en route to a deep water rig 200-plus miles out is no longer a certainty. There will be relatively few, if any, fixed platforms in the deep waters. By use of directional drilling, multiple wells will be consolidated on one platform giving it a subsea, spider web-like presence. The operator’s need is for larger capacity and longer-range helicopters that can get the crews transferred in a more efficient manner. Because of their weight, these new helicopters will only be able to take advantage of a few en route refueling points due to helideck weight restrictions.

As it became apparent that the existing fleet of medium and heavy helicopters were not the best fit for this role, the manufactures began looking for ways to accommodate the offshore market and in most cases, went to the operators and their customers for input on needs and desires. The result of that input and other studies indicated a helicopter that would fit between the two.

The new breed of helicopters are being referred to as “medium heavy” class twins or “super medium twins” that will be coming to market with gross weights at or near 16,000 to 17,000 pounds with ranges of at least 400 miles carrying 16 to 19 passengers on board.

The helicopters are powered with engines producing 2,000 horsepower but giving increased fuel efficiency over less-powerful engines. They have navigation and integrated flight control systems that greatly ease pilot workload and ergonomic cockpits that can actually make long helicopter flights comfortable, increasing safety by having the crews more alert. Passenger comfort and safety are also being attended to with such items as four-point safety belts, large pop-out windows, emergency lighting, air conditioning and comfortable seats, some even covered with leather.

The players in this market are the usual regulars—AgustaWestland, Bell, Eurocopter, Russian Helicopters and Sikorsky. It is too early to see how the exact performance characteristics stack up against each other because none except the Sikorsky S-92 and Eurocopter EC225 heavies have reached the market. The S-76, EC155 and AgustaWestland AW139 are not, for the purpose of this article, in the “super twin” category. Some history is needed to make good comparisons on these new models. Let’s see what we do know.

AgustaWestland AW189

The new AW189 arrived via the military AW149, which in turn used the AW139 for much of its design heritage. The AW139 has been around long enough for operators to appreciate the value of the medium twin helicopter. It was one of the first helicopters to give the S-76 real competition in that market, if sales are any measure of success. The AW189 will have seating for 16 to 18 passengers and one or two crewmembers. AgustaWestland is also seeking certification for single-pilot operation. Gross weight will be 17,600 lbs. Engines are two GE C27-2E1 rated at 2,000 hp each. Speed is 140 to 150 knots. These figures may not be accurate because the aircraft is still in development stage and the numbers are subject to change, but this gives an idea of approximate performance.

Bell 525

The Relentless will be a clean-sheet design with no derivatives or other specific helicopters in Bell’s inventory to match it. It is still in the design stage with some sub-assemblies having been built. It will be the only civil helicopter with a fly-by-wire flight control system. Sikorsky is said to be working on a triple redundant fly-by-wire computer module for retrofit onto the S-92 at some future date. A lot of design work has gone into the flight control system and cockpit ergonomics. Like its competitors, there will be a fully integrated and automated flight control system. As an example, if an engine failure occurred, the autopilot system would take over before the pilot could react. Things like fuel shut off, yaw control, altitude hold and power management, to name some. Of course, the pilot could override any or all of the automation if the emergency warranted it.

There are no crew doors for the cockpit, but Bell came up with an innovative approach by allowing the crew seats to swivel 90 degrees or more so that entry and exit can be easily accommodated through the sliding passenger doors. The cyclic control stick is a side controller complete with an armrest—a real treat for short-armed pilots. The collective control has increased sensitivity due to only having a maximum movement of three inches. Garmin is the avionics of choice. One unique feature is a small LED panel that has a touchscreen with aps on it for navigating through most of the systems.

Eurocopter EC175 and EC225

Four pre-production EC175 models have been built and flown for test and demonstration purposes. Still experimental, it made stops in North America on a world tour allowing potential operators to fly and evaluate it. Rotor & Wing was given the opportunity to take a first-hand look as well. Some of the numbers for the EC175 include:

• Gross Weight: 16,535 lbs

• Advertised max speed: 175 knots

• Service Ceiling: 19,690 feet

• Advertised Cruise Speed: 150 knots

• Seating Capacity: 16 passengers, 2 crew (18 passengers optional)

• Fuel capacity internal tanks 685 gals or 715 with pressure fueling (slightly over four hours maximum endurance.)

This should give it an action radius of 200 miles in the SAR configuration, 190 with 12 seats filled and 135 miles with 16 passengers in the offshore version. The helicopter should have no problems getting to the 200-mile range but it would need to refuel on the way home if it went that far. Most likely the drilling rig of destination would have fuel available.

The high points of the EC175 are found in the cockpit. The automation and the avionics suite are so good that they can be compared with any airliner flying today. It’s like the helicopter world has finally arrived. Features include synthetic vision, H-TAWS, coupled TCAS to the AFCS for automatic collision avoidance, four-axis autopilot with dual duplex integration into the AFCS, tail fin cameras that view personnel and cargo loading displayed on the multifunction display (MFD). Auto takeoffs and auto approaches to 30 feet. When flight plans are loaded, course intercepts, headings and altitude holds are precise without hunting. OEI’s are seamless with automatic shutdowns and configuration for continued flight in the mode that the loss took place.

There is some heritage in the EC175 design such as the avionics being based on the EC225 suite and other design features found in the Eurocopter family. The manufacturing is a joint venture with Chinese Harbin Industries who will be producing their version, the Z-15.

The EC225 is the other helicopter working in the heavy twin offshore market. It grosses out at 24,250 and it too carries 19 passengers. The engines are Turbomeca Makila 2A1’s at 1,902 hp. Standard fuel capacity is 674 gallons but it has several options for extra fuel such as side-mounted pods that will give it additional range when needed.

Avionics is a product of Helionix, a part of Eurocopter’s parent company. It has dual flight control computers linked to the MFDs. They are self monitoring and one will take over if the other has a detected error. Another feature is found in the AFCS. When the autopilot is in the cruise mode the pilot can switch it to ground speed mode for use in the approach and can modulate speed even down to a hover. The feature can bring the helicopter down to the landing decision point (LDP) and hover there if needed.

Russian Helicopters Kamov Ka-62

A derivative of the military Ka-60, this is a serious entry into the “small” helicopter market by the Russian manufacturer. It’s sleek, aerodynamic looks are a real selling point, making it comparable to what western manufacturers have been producing for many years. It’s not certain that the Ka-62 is in the super twin category. The stated capacity is 16 passengers and a crew of two. Gross weight is 14,330 lbs and engine power from dual Turbomeca Ardiden 3G engines is rated at 1,282 hp each. The helicopter is making headway with operators in South America, including Brazilian launch customer Atlas Taxi Aero. The Ka-62 is sure to make some European friends as well, but it’s unlikely to find a home in the Gulf of Mexico. Then again, if the price is right, who knows?

Sikorsky S-92

This helicopter has enjoyed a large percentage of the deepwater crew change business. It is considered a heavy twin with a gross weight of 26,500 lbs. It seats 19 passengers in a standup, spacious cabin. The S-92 does the offshore mission well but it is pricey at around $26 million per copy. It takes a lot of fuel to feed the GE CT7-8 engines but it can carry enough to go 200 miles and return without refueling, which is a big plus in the offshore market. Most S-92s are equipped with Rockwell Collins Pro Line IV avionics with all the bells and whistles. Dual MFD, four-axis autopilot, automatic hover mode, dual channel FADEC and coupled auto approaches, to name a few. The word is that Sikorsky is developing a fly-by-wire control system that may be retrofitted to the existing fleet.

The Future

It seems that the manufactures are always behind the curve in designing and building a helicopter for a specific market. Helicopter manufacturers have given us products, over the years, which have almost always had a multi-role objective. The users of these wonderful machines are the ones who have discovered and made markets for their many uses. This is probably a necessary path because no one really knows what the next great market will be when you have a product as flexible as a helicopter, but it is nice to know that at least one or more markets have been defined, and that the manufacturers are striving to provide helicopters that give the operators the needed tool to serve their customers.

Three of the new helicopters—the AW189, EC175 and Bell 525—had a large amount input from customer advisory teams made up mostly of offshore operators from Europe and the U.S. The manufacturers have listened and incorporated many of the suggestions into the airframes and avionics suites. Airframes have been given real corrosion protection in the places normally inaccessible, substituting composite materials where practicable. Maintenance panels have been provided to expose more inspection and work sites. Larger windows for cockpit visibility. Comfortable passenger seats with some actual leg room. Increased baggage areas. Crew stations that provide comfort. Automated flight controls. Externally mounted cameras. Powerful engines that give category A performance for all occasions. This list could go on but as you can see, this is a new way to build helicopters for a market fit.

One point absent until now is cost. The medium heavy helicopters will be priced somewhere around $18 million in 2013 money. When you compare this to the heavy twins at $25 million, there is no doubt where the market will be. The medium heavies will do everything that the heavies do with the exception of the heavies having a range advantage. The difference between one or two passengers should not pose a problem when acquisition and operating costs are factored in.



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