Rotor & Wing International
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Essential Equipment: Taking on the Night With Cockpit Mods

NVG cockpit modifiers are busy with new technologies, such as white phosphor goggles, and new geographic markets.

Innovation is a buzzword in virtually every industry. Whichever company can innovate the next big thing could unlock untold fortunes. In aviation, original equipment manufacturers have created new positions for innovation leads to guide their teams on the path to the future, with hopes of designing new aircraft, new tools and new methodology.

There’s one area of aviation that does not require a focus on entirely reworking the current technology: night-vision goggle (NVG) cockpit modifications. Although there are new materials for avionics lighting firms to consider, the majority of efforts is elsewhere when it comes to new designs.

“We’re not inventing new light sources every day. But there are new transponder models coming out every day that we have to generate modifications for,” said Aero Dynamix Inc.’s Jessie Kearby, director of engineering and certification. “We constantly have to come up with the greatest possible mod for this greatest piece of avionics equipment — which is coming out constantly. Our challenge is adapting those retrofit options to constantly evolving product lines.”

That includes NVGs. White phosphor goggles have been a market disrupter in that space as an alternative to the standard green phosphor goggles. L3 Warrior Systems - Insight Technology said in January 2017 it became the first company to receive Technical Standard Order (TSO)-C164a authorization, under which the FAA certified the availability of white phosphor goggles to commercial pilots, subject to operational approval. To get the approval, L3 said Aviation Specialties Unlimited (ASU) worked with the FAA to obtain flight approval of L3’s white phosphor M949 goggles.

“Manufacturers, less than five years ago, a majority of their factories were producing just green and less than 1% was white. Now the majority of their production line is white phosphor,” said ASU CTO Joseph Estrera. “We were one of the few companies that literally pushed commercial aviation toward white phosphorus for all the human factor reasons. But now the rest of the world has now from a production standpoint switched over to the white phosphorus. Most of the U.S. high-end military requirements are all white phosphorus.”

Rebtech is also focusing on dual-mode lighting on military and paramilitary contracts.Photo courtesy of Rebtech

Estera said the military has reported better depth perception with white phosphor, compared to green. ASU’s own pilots found the same during early evaluation stages. The technical explanation for why P-45 white phosphor has advantages, which Estera wrote in an ASU white paper, boils down to the fact that P-45 has a broader light output spectrum than P-43 green phosphor.

“I prefer the green — probably more so because of familiarity with that scenery,” said Eric Pacheco, senior pilot in the Los Angeles County Fire Department’s Air Operations Section. “The white phosphor caused a little bit of issue with some of the things we normally can work around. Some of that was contrast with terrain. I liked it, but I still prefer the green over the white.”

Truth be told, it’s all about preference. Pacheco admitted that his preference for green most likely stems from his familiarity with it. Rebtech President and CEO Richard Borkowski concurs that it’s a preference, but also acknowledges that for the business of NVG cockpit lighting modifications, it doesn’t really matter.

“A lot of people still like the old green. Some of the other pilots prefer the higher contrast of the white phosphorus,” he said. “But as far as its impact on Rebtech, there has not been any. We still modify the units the same way.”

Modifications work with both goggles. Estera calls what NVG cockpit modifications do “light regulation.” With proper filtration, the light won’t degrade the performance of the goggles. If the pilot were to look at the instruments through NVG without filtration on the avionics, Estera explained, the pilot would see little brightness and resolution. Rebtech, Aero Dynamix and ASU have unique specialties and methods, but all modifications work with green and white phosphor.

The problem white phosphor presented to the cockpit modification supplemental type certificate (STC) holders came when it was time for certification. Kearby explained that white phosphor NVGs started coming out before the TSO. Some may have thought it harmless to purchase a pair, not understanding that companies like Aero Dynamix hold the STC that allows the lighting to be changed and for the aircraft to be returned to service. The STC is required to specify which goggles have been evaluated and found compatible with the lighting system, Kearby said.

This scenario becomes especially problematic when the FAA does audits, which occurred a few years ago. As a result, Kearby said, there was a two-year period where people were asking for help with updates to the STC.

The L.A. County Fire Department’s aircraft — the unit was an early ambassador for the Sikorsky Firehawk — come equipped with NVG cockpit modifications from the manufacturer.Photo courtesy of Scott L

“This lighting configuration is approved, but you go and change any lighting component on this and you’ve invalidated that approval completely,” he said. “From a certification point of view that becomes a very laborious thing. Companies like us have [memorandums of understanding] with the FAA and very streamlined certification process.”

The FAA is a leader in the world of NVG and associated RTCA DO-275 equipment, along with EASA. But other countries are starting to develop standards and rules, particularly regarding firefighting. Borkowski, who noted how many conferences there have been recently focusing on the topic, explained that NVG is commonly used when an aircraft in the air is directing operations on the ground. Goggles can help the wearer notice hotspots. But some countries have been slow to start using NVG technology because of funding. Borkowski said much of Croatia’s firefighting, for example, is performed by its military.

Australia’s National Aerial Firefighting Centre (NAFC) is doing nighttime firebombing trials to prepare for the longer and more severe fire seasons that are predicted. The center’s general manager, Richard Alder, said it has contracted an NVG-equipped Sikorsky S-61N from Coulson Aviation. He said in February the group was looking to add capabilities in the coming weeks.

Alder added that the expansion of night-vision imaging systems (NVIS) in civilian applications had increased the pool of experienced pilots. Australia also has been using NVGs for reconnaissance and mapping and incendiary work, giving NAFC a good foundation on which to build.

For those missions, the center has on contract an Airbus Helicopters AS350 BA from Professional Helicopter Services and a Sikorsky S-76B from Coulson Aviation. The Rural Fire Service of New South Wales operates an NVG-equipped MBB/Dawasaki BK 117 and an AS350 for those missions. Other firefighting agencies use NVG-equipped aircraft operated by local police or rescue agencies for mapping and reconnaissance, Alder added.

The firebombing trial is being led on the ground by Emergency Management Victoria. It will include a range of flights to demonstrate capability to hover-fill from open water sources in the dark and also to drop water onto a range of controlled targets/fires at designated locations, Alder said.

In July 2017, ASU’s director of operations, Justin Watlington, explained to R&WI that the U.S Forest Service has only one NVG-equipped helicopter: A Bell 205A 1++, operated Helicopter Express and fitted with ASU NVG equipment.

The L.A. County Fire Department’s aircraft — the unit was an early ambassador for the Sikorsky Firehawk — come equipped with NVG cockpit modifications from the manufacturer.

“We’ve been flying with the NVGs in the Los Angeles County Fire Department for about 17 years,” Pacheco said. “Most of us are prior military trained, so we all flew goggles within the military. We understand the advantages, the limitations associated with it and we capitalize and exploit on all of those measures.”

Estera said that while ASU has efforts in both Europe and Asia, much focus is put on the European market.

Borkowski said Rebtech is doing the same. Specifically, the focus for Rebtech is on Eastern Europe: The Czech Republic, Croatia, Slovenia, Slovakia, Poland and Hungary. The company has been successful in Hungary; it has a representative organization based in Budapest.

Even if not in Eastern Europe, Rebtech has worked on some Russian Helicopters aircraft. Some 1.5 years ago, the company fitted a Ka-32T for a customer in South Korea. Egypt, Borkowski said, also has Russian aircraft. Those units required Rebtech to retool because of differently sized threads and bolts.

“The U.S. market is saturated with night-vision,” Borkowski said. “Most of the OEMs that are making the equipment now have the capability to make their equipment with NVG lighting in it, which takes away from my potential work.”

Rebtech, Aero Dynamix and ASU have unique specialties and methods, but all modifications work with green and white phosphor.Photo courtesy of Aero Dynamix

Mostly an aftermarket business, he said customers usually want work done on an aircraft that are a decade old with no NVGs. They would send whole aircraft, and Rebtech would modify it to a nigh-vision STC, train the pilot and get it flying.

“That’s becoming less and less here, but more and more over in Europe,” he said.

Rebtech is also focusing on dual-mode lighting on military and paramilitary contracts. Dual-mode allows landing lights, taxi lights, anti-collision lights, position and navigation lights to be seen by the naked eye, or by NVGs only with infrared light. Brokowski said Rebtech has designed a way to install the lighting without needing to rewire the aircraft.

Along with a focus on converting incandescent panels to LED panels for customers’ fleets, Aero Dynamix is focusing on international markets. They’re all different when it comes to certification, Kearby explained. Some, like Brazil’s ANAC aviation authority, are comfortable following the FAA. If the FAA has validated it, ANAC might only require paperwork and payment. Countries like Australia and South Africa are even more comfortable with FAA approvals. EASA, despite bilateral cooperation it supposedly has with the FAA, wants to review what the FAA has already approved with a focus on flight-testing.

Aero Dynamix is looking to do its first validation with China and a second with Japan. China is still at the stage where it’s learning about NVIS, whereas Japan conducts many analyses with much paperwork.

“Each authority has their own mind set on how they approach the validations,” Kearby said. “And then within that, what level of effort it is going to take.”

For those interested in equipping aircraft with NVG, Kearby said to pay attention to three areas: Piloting, maintenance and product.

Piloting is often forgotten in the process of equipping with NVG. Pilots must be rated to NVG, and the aircraft must be flown to be certified.

Once an aircraft is equipped with NVG, it may no longer be maintained the same way. If NVIS equipment needs to be repaired, it needs to be repaired by a shop that has the authority to return it to service. Or perhaps the inventory system needs to be different, or maybe some training is necessary. Make sure to inform the company instructions for continued airworthiness for the NVIS STC. Simply swapping equipment between aircraft may no longer be possible.

Research the product. With a handful of major companies able to do NVG modifications comes a handful of products. Kearby warns that customers are going to get what they pay for.

Even if DO-275 didn’t require cockpit modifications, it would still be wise to get them. Although perhaps not as glamorous as the goggles that sit on the pilot’s head, instrument lighting is a crucial part of successful nighttime operations.

“If you’re dealing with it, then you’re compensating for it. And if you’re compensating for it, then you’re adjusting for it. And that’s not good if you can tackle that problem and make it compatible right out of the gate,” said Pacheco. “That’s why all of the modding is done. It just makes your job easier.” RWI