Helicopter - The H175

Soft Launch for Airbus H175

by Mark Huber

 - May 25, 2015, 8:52 AM

AIN sat in on a demonstration of the H175 earlier this year in Houston with oil and gas producer (OGP) company pilots who fly to rigs in the Gulf of Mexico. (Photo: Airbus Helicopters)

After several years of delays, Airbus Helicopters delivered its first H175 super-medium twin late last year and is slowly ramping up production while it campaigns the finished helicopter on a worldwide marketing tour. AIN sat in on one such demonstration earlier this year in Houston with oil and gas producer (OGP) company pilots who fly to rigs in the Gulf of Mexico. OGP and search-and-rescue operators provided key design input on the H175. In general, they praised the helicopter’s handling, utility of its intuitive Helionix avionics suite (developed in cooperation with Rockwell Collins), auto hover, roomy and comfortable cockpit, cabin layout (including ease of passenger egress), and low cabin vibration and low exterior noise levels.

Airbus emphasized the latter during the successful demonstration of a low-noise IFR approach to Toulouse-Blagnac Airport in southwestern France in May. The approach procedures were flown using accurate lateral and vertical guidance provided by Egnos, the European satellite-based augmentation system (Sbas), and in the presence of airplane traffic simultaneously approaching and departing to/from airport runways, which proved the suitability of these helicopter-specific procedures to achieve simultaneous non-interfering aircraft and rotorcraftIFR operations at a medium-size commercial airport.

MORE FUNCTIONALITY COMING

While the H175 produces less exterior noise than older helicopters, noise inside is more in line with that inside traditional helicopters, a trade-off for the expansive windscreen and large pop-out passenger windows that facilitate rapid egress in the event of a water ditching. The H175 has a few notable other misses. The positioning of the emergency float system, robust enough to handle Sea State 6, required that the cargo door be positioned fairly high up the fuselage, necessitating the use of a ladder for loading and unloading, a process that can be a little awkward. The pipework for the single-point refueling, while shrouded, intrudes into the baggage hold. And while the oversized passenger windows provide the opportunity for rapid egress and spectacular views, they do make it difficult for the air conditioning to keep up with what typically is found on an airliner; however, the cooling is noticeable. It is a two-zone system that precludes the typical Hobson’s choice of freeze or fry in the cockpit and each passenger has his own individual overhead gasper. The H175 does not have an auxiliary power unit, but one engine can be run on the ground while declutched, providing power to cool the cabin before aircraft loading.

As customary throughout the industry when a new helicopter is first delivered, not all systems and capabilities are complete. Notably, on the H175, the rotor anti-icing remains in flight-test and full system approval is not expected until 2018 or 2019, according to François De Bray, Airbus H175 marketing product manager. A test aircraft was recently snow testing at Courchevel in the French Alps, where one of its Pratt & Whitney CanadaPT6-67E turboshafts was removed and replaced after exceeding operational limits in the approved flight envelope. The SAR kit and inlet barrier filters will be available in 2017, De Bray said. In SAR configuration, the baggage hold can be accessed from the cabin.

The H175 is currently certified for single-pilot VFR operations; De Bray said Airbus is investigating single-pilot IFRapproval, but it “is not a priority” as most OGP and SAR operators fly with two pilots. The Helionix system features redundant flight computers, a four-axis autopilot and an easy-to-use auto hover that automatically corrects for wind. Other noticeable features automatically keep the helicopter stable in challenging situations such as brown-out or inadvertent IMC encounters. Toggling two beeps on the cyclic activates the “recovery mode” that restores the latest heading, speed and altitude; and automatic hover can kick in at 150 feet.

All the switchology and controls in the comfortable cockpit are located along the panel and pedestal and can be equally accessed from either pilot position. The instrument panel has lots of extra space for add-ons such as a landscape format multifunction display that could be used to display infrared imagery on SAR-equipped aircraft.

Thanks to the Pratts (1,776 shp each), the H175 has good one-engine-inoperative performance and easily meets the Category A, PC1 requirements for takeoff at maximum weight of 17,180 pounds. The H175 has already established several time-to-climb records, most notably 19,685 feet (6,000 meters) in just 6 minutes, 54 seconds. Test pilots said that they had experienced maximum climb rates in the region of 4,500 fpm.

The maximum usable fuel load from the five-tank system is 695 U.S. gallons, more than 4,500 pounds. That gives the H175 a maximum range of 600 nm and a good radius of action under a variety of load conditions: 265 nm with seven passengers plus 10 percent and a 30-minute reserve or 136 nm with 16 passengers plus 10 plus 30. And that’s with the passengers weighted at 242 pounds each, so there’s not a lot of creative math pumped into the equation. A high-density layout is available with 18 passengers. The main cabin volume is 434.37 cu ft and the baggage compartment adds another 95.35 cu ft.

The H175 has held up well under stress so far; launch customer NHV, an OGP company that operates in the North Sea, placed its first two aircraft into operation a week after delivery last December and are reporting a dispatch rate of better than 90 percent.

The H175 was designed to meet the MSG3 maintenance standard. Its tall cowling facilitates access to a variety of systems, and the flared exhaust stacks help whisk heat away more quickly from the work area. A variety of ladder attach points are built into the fuselage, enabling quick climbing. The engines, main gearbox and rotors all have an initial TBO of 5,000 hours.

De Bray said the H175 is 5 to 7 percent less expensive to operate than competitive aircraft. “Yes, this helicopter was late, but what we have now is a really mature helicopter that is entering service,” he said. “It fits well with the Gulf of Mexico.”