Sikorsky’s Rig Approach Eases Tough Job

 - February 27, 2014, 1:05 PM

It’s been three months since Sikorsky announced that its S-92 rig approach system has gone into operation in the Gulf of Mexico with oil and gas transport provider PHI, and here at the show, the airframer is providing demonstrations of the safety enhancement. “Probably the hardest thing we ask the commercial helicopter pilot to do is the offshore approach,” said Ronald Doeppner, chief research and developmental pilot and technical fellow for the Stratford, Conn.-based OEM. “It’s dark outside, it’s a stormy night, they put a 70-foot circle in the side of a skyscraper and they expect you to go land there with revenue passengers. They’ve been doing this for over 20 years and doing it safely, but it’s hard.”

The story of the rig approach began seven years ago with a request from PHI, according to Doeppner, who was involved in the program from the beginning. “They said “make it easier,” he recalled. “That’s a great request. They didn’t tell us how, they didn’t tell us to do this; they just said make it easier.”

Doeppner was familiar with the types of missions the company flew, having helped integrate the S-92 into the PHI fleet when it was first delivered, but the company relied on PHI and others for input in what they would expect out of such an automated system.

Crew Engagement with Automation

In the demonstration at the company’s booth (No. 2822), Doeppner explained that the system is GPS-based. “All we need is a good GPS signal–it doesn’t have to be a Waas signal–and the coordinates of the offshore platform, then our flight control computer essentially creates an offset flight plan and then takes you there.”

The system can be engaged as far as 300 miles from the destination, but is typically activated around 50 miles away, using the most recent wind reports from the rig, as the approaches are flown into the wind, to determine the half-mile offset. During the approach, the helicopter’s weather radar is set to ground map mode so the pilot can identify any possible obstacles in a one-mile swath on either side of the inbound course.

As the system (developed from Sikorsky’s search-and-rescue flight control system) controls the helicopter, the company was keen to keep the flight crew informed. “A key safety interest industry-wide these days is as we get more and more automated, we’re taking the pilots out of the loop,” Doeppner said. “We want the pilot to interact and we also want to automate [the process]. We have to make sure the pilot understands where he is, what the aircraft is doing and what it’s going to do next.” The green information across the top of the screen shows the aircraft’s current status, while information in white gives a preview.

As the helicopter approaches the first turn point, it makes several swift changes. “I’ve flown hundreds of these rig approaches,” noted Doeppner. “They always hit that turn point at 1,500 feet and 80 knots indicated airspeed and they wait until the very last minute, which is unnerving to me, but they always do it.” The explanation for that last minute response is simple: “Time is money; we want to speed up the trip,” said Doeppner. “This is a safety enhancement. If it slows the pilots down, they’d be tempted not to use it.”

Once the helicopter arrives at the missed approach point, pilots have to make a decision: either steer the helicopter visually using the autopilot or push the go-around button if the rig is not in sight. “Once you are visual, you don’t want to decouple [the rig approach system] yet because that’s where people get in trouble,” Doeppner said, instructing pilots to use the beep controllers to get between several hundred yards and a few rotor lengths before taking control from the system and landing.

Having achieved FAA certification last year, the company is expecting EASA and Transport Canada approval for the system in the coming months. The company currently has three customers for the S-92 system in addition to PHI, and its migration to the S-76D is sure thing, according to Doeppner. “[It’s] a couple of years down the road, but we are going to do it. It’s that much of a safety benefit.”