Catching a potential failure of a single bearing inside the transmission of an S-70 Firehawk before it breaks could mean the difference between an $8,000 repair during routine maintenance and a much worse, maybe even fatal scenario.
If the bearing failed in flight, the Firehawk could crash instead of delivering its payload of potentially lifesaving water. At best, onboard systems would detect the failure and trigger a hazardous precautionary landing, exposing the crew to increased risk of injury or death and requiring aircraft recovery as well as a $350,000 replacement of the entire transmission.
Modern health and usage monitoring systems (HUMS) are becoming lighter, more affordable and better at preventing scenarios like this one from occurring. The example above is a real-world demonstration of one such system at work. By employing RMCI HUMS equipment, the unnamed aerial firefighting department was able to stave off a very costly repair — perhaps a tragic accident — 100 hours before the gearbox bearing eventually gave a failure warning.
Founder and President Ken Speaks can now boast RMCI flight data monitoring (FDM) and HUMS systems on more than 3,000 U.S. Army helicopters.
A major issue faced by many HUMS and FDM systems is registering false positives. Speaks says he has demonstrated that RMCI’s have none.
“We got zero false positives,” he told R&WI.
Now the system comes in a 7-pound package for an aircraft like a Kawasaki BK117 and up to 17 pounds for a Sikorsky UH-60 Black Hawk, compared with previous installations of a series of boxes and measuring devices that would add about 130 pounds to the size-weight-and-power equation.
“This firefighting department, they get to say, hey, if we had your system, because we identified that in time for maintenance, we would not have had the firefighting mission aborted and somebody’s house probably burn down,” Speaks said. “We had to land the aircraft on the side of the hill and barely walk away from it. They have to recover the aircraft and then we got to haul it back to the hangar. We had to replace the entire transmission [for] $350,000.”
With the RMCI system, the department preempted all of that hassle and put the aircraft into scheduled preventive maintenance. The system is now certified to fly on various Bell, MD and Airbus helicopters.
“Our goal is to eliminate precautionary landings,” he said.
It’s the same goal HeliOffshore has: remain safe, keep helicopters flying and reduce wear on both pilots and passengers. Airlines have been doing the same for a decade or more with the Aviation Safety Information Analysis and Sharing (ASIAS) program. Helicopter Association International (HAI) has long advocated for the same approach to data sharing within and among the rotorcraft community.
“Every other industry in the world is using data to enhance performance and efficiencies,” HeliOffshore Chief Operating Officer Francois Lassale told R&WI in an interview. “Why wouldn’t we use the same to enhance safety, right? … We’ve been able to do in two years what it took the airline industry 10 years to do. We have made phenomenal advances to the point [where] we’ve now got agreement from almost all the operators in our data-sharing program around the world.”
That encompasses 85 percent to 90 percent of the global fleet of offshore helicopters, bound together by a memorandum of understanding with HeliOffshore to both collect and share flight and aircraft health data, Lassale said.
“We are capturing a fairly large percentage of the global fleet, because a good number of the big players are in the program,” he said. “We do run a pretty strict governance structure and within that is a pay-to-play process.”
Operators pay into the service first with money, then data, but the rewards are multiplied, Lassale said. The FAA has attempted a similar program with ASIAS, but it fell flat and has been reignited in hopes of replicating some of the success HeliOffshore has had. The company is now in league with the FAA, EASA, the Flight Safety Foundation, among other organizations.
“How have we been able to move so quickly? In essence, it’s because the people that give us the data own the program,” Lassale said. “They get to call the shots. They get to set the data we request and the data we don’t request.”
The industry has moved from collecting data reactively to amassing incredible amounts of information proactively. Now, it can and should move toward collecting data predictively, finding and addressing problems before they occur, Lassale said.
Phase 1 involved reactive data analytics and reporting, where helicopter operators feed comprehensive flight data reports into the system, which are then shared to the subscribing community on a “lessons-learned basis,” Lassale said. Phase 2 is the proactive part, where the company actively collects health and usage data directly from the helicopters themselves, again, at the operators’ discretion.
“Rate data is the key … return-to-base data,” he said.
HeliOffshore partnered with GE Digital and a U.K. Company called Tonic Analytics and then began collecting data on 80 percent of the AW139 fleet during the last half mile approaching oil platforms, “which we thought was the most risk-full profile.”
“We asked them to go appraise their data, pull out the most relevant event sets, send it to us, we put it into our platform … and then feed that aggregated data back into the industry so each helicopter operator could now benchmark and measure himself against a global picture,” Lassale said.
When companies opt out of equipping helicopters with FMD and HUMS, the worst-case scenario is an accident, which is costly in lives, money and operating expenses for the entire industry. Lassale says a single high-profile helicopter crash can cost the industry $2 billion in the long term.
“Over a period of time … when you correlate all that, that's a lot of money,” he said. “Safety is an investment. … There’s an old adage, that’s been around for years … safety is expensive, but try an accident, it's kind of partially true.”
Many of those accidents, or responses to things that would cause them, occur when a large helicopterlike a Sikorsky S92 or Airbus EC225 takes off with a crew of oil workers, heads out to sea, experiences some sort of failure or failure warning and is forced to return to base. It is the offshore-oil version of having to abort a firefighting mission.
The 2016 crash of a Bristow-owned H225 Super Puma in Norway brought health and maintenance data monitoring into the helicopter industry’s collective consciousness. The country’s accident investigation board ultimately found the crash, which killed 13 people, was caused by unanticipated faults in the aircraft's manufacturing. Not only was gear fracture the accident’s most likely cause, but it appeared to have developed in a way that certification processes may not have foreseen and maintenance procedures may have been unable to detect.
When an AW169 went down just after a Leicester Football Club game in England, the investigation focused on spalling on a main bearing, which eventually caused catastrophic failure of the tail rotor system.
Speaks says modern HUMS technology can catch those types of failures before they occur, though he understandably chooses not to swear the equipment will save lives. The U.S. Army agrees with the systems’ value and now has the RMCI HUMS systems on more than 3,000 helicopters, which at any given time store 1,000 flight hours of flight data, he said.
The system is particularly useful on helicopters like the Firehawk that pull heavy loads and fly at the limit of their flight envelopes.
“Particularly firefighting, because you get the cycles of heavy loading, which puts excess wear on the drive train,” he said.
Power companies are another. They typically fly small helicopters, like the MD530, very near heavy-gauge electrical cables suspended high in the air while people hang from the doors to adjust or repair equipment. Tremendous stress is applied to the aircraft and its components and it is best if they did not fail and send the aircraft, pilot and crew into the transmission lines.
“An MD helicopter, you know, seven feet from the 750- to 100-kilowatt highline is a liability, it is an increased margin of risk and safety,” Speaks said.