Another STC Under its Belt, Donaldson Looks to the Future

 - March 6, 2015, 11:11 AM


Donaldson Aerospace & Defense announced that its Donaldson Filtration Systems division has received FAA certification for the inlet barrier filter (IBF) system for the Airbus Helicopters EC130T2, the only such system currently available for the helicopter. The IBF helps prevent engine damage in any environment and is approved for year-round operations.

This most recent system features interchangeable filter elements for mixed-fleet operators currently flying both the EC130 and the AS350B3e equipped with Donaldson filters. A key element is the sealed intake plenum, which replaces inlet screens or less effective sand filters/particle separators with minimal modification, according to the manufacturer. The design on display at the company’s Heli-Expo booth (4600) also includes an aft-facing bypass system, which like the filter itself is flush with the upper surface of the cowling.

Donaldson has been manufacturing IBF systems for the past 12 years and now includes kits for a wide variety of models from AgustaWestland, Bell, Airbus Helicopters and MD Helicopters. “It definitely keeps salt out of the inlet, so if you are an offshore operator or you’re anywhere near salt water, it’s very effective, so any kind of particulate, fine sand, ash, salt, it’s going to capture it,” said Bob Stenberg, the company’s director of business development. “The big thing is it keeps the air going into the turbine engine clean, and turbine engines like clean air.” This latest offering, like those of its predecessors, has a simple cockpit switch to indicate activation of the bypass system, as well as an integral filter-maintenance aid, which allows for on-condition inspections between service intervals, eliminating unnecessary filter service.

The Donaldson Company, which is celebrating its centennial this year, clearly predates the birth of the helicopter. In fact, the company’s first filtration product was intended for farm tractors in the early 1900s. Though the company produces aftermarket filtration kits, Stenberg believes that market is changing as OEMs look to take a more interactive approach to the process. “I think they are realizing that they want to be involved, they want to be part of the design and obviously they bring value to the design,” he told AIN. “They don’t want to have a system that doesn’t have that [filtration] capacity and then have to develop it on their own, so they are looking more at working with manufacturers like us.” As a result he sees his company developing into more of a subcontractor role. “Yes, we’ll be more of an OEM supplier in the future, I believe,” he said, noting his company supplies kits exclusively to Bell for the 429 and will do the same on the 525 Relentless and the 505. “Some of the other manufacturers are following suit.”

Airframers and even engine makers becoming involved further upstream in the design process can allow even greater benefits, according to Stenberg. “We can integrate the system into their aircraft much more seamlessly.” Currently in most of Donaldson’s IBF kits, a pressure switch will trigger a light in the cockpit signaling that the filter has reached its life limit, which then would allow the pilot to open the bypass. In its latest systems Donaldson can integrate real-time health data on the IBF into cockpit displays. That ability to feed such information into the aircraft’s engine control will be of great interest to regulators. “Certification of these systems is getting more and more difficult and the authorities in Europe, EASA particularly, require that if you have a filter on your aircraft, you always have to apply the dirty filter charts, and that penalizes the performance of the aircraft,” Stenberg noted. He believes that such on-condition monitoring will help eliminate the guesswork of exactly what impact the filter cleanliness is having on engine performance. “As you see that kind of technology evolving, it will be good for the operator, plus it’s certainly better for us because it will be easier for us to get the system certified,” he said.

While Donalson’s filters are currently comprised of oil-cotton or “wet” media, it plans on introducing a similarly-priced dry-media alternative later this year. “They’re excellent from a standpoint that their cleaning regimen is a lot less than an oil media,” said Stenberg, adding that “dry” filters, which can simply be washed with water and detergent, will dry faster than the oil-cotton type. “It’s hard to believe but the oil media from a pressure-drop and a dirt-holding perspective is almost the gold standard,” he added. “You try to make a dry media that gets to the point where it’s as good as an oil media, we’re getting close, but we’re still not exactly there.” The company believes it could begin offering dry media filters possibly as soon as this summer, likely debuting on the Bell 407. “If you have a big fleet, if you fly in a very dirty environment like a desert, then dry media will probably be good for you,” noted Stenberg. “The transition may not be the case for all operators, but I think for most they are really going to like the dry media.”

With a mandate to nearly double its market from to $180 million in gross sales revenue by the 2021 timeframe, Donaldson plans to roll out five additional products this year. Expected around the time of Heli-Expo is Canadian certification for an IBF for the Sikorsky S-61, developed with Canadian operator Coulson, which is also on display here. The company has also begun work on a filter system for the Robinson R66. “They’re not committed yet if they will offer it on their production line, but they’re willing to help us because we’ve had several customers come to us and say we need a better filter for that platform,” said Stenberg. In addition to several projects for the military, the Minneapolis-based company also has its sights set on the MI-8/17/171 family, which it believes will be able to utilize the same system as the S-61. The Super Puma and the Bell 412 are platforms the company is interested in serving. “We’d love to do a 412,” Stenberg said. “Bell is pretty busy on the 505 and the 525 and they’ve told us once those programs get a little further down the road and they can free up some of their engineering staff, they’ll start working with us.”