Electromagnetic interference concerns are hampering progress on a Canadian Air Force project.
According to The Canadian Press, the Canadian government has refused to accept four CH-148 Cyclone test helicopters currently parked at the Canadian Forces facility in Shearwater, N.S., on the basis that they are “non-compliant.” Designed by Sikorsky Aircraft Corporation, the twin-engine CH-148 Cyclone helicopters are slated to replace the CH-124 Sea Kings, which have been in operation since 1963.
However, the Canadian news outlet reports, defense sources with intimate knowledge of the program have elaborated on the public report, saying that certain flight systems, including a computer that runs the engines, are not considered sufficiently shielded against powerful electromagnetic waves. The electromagnetic waves could potentially scramble the digital instruments and shut down the engines.
Earlier this year, the directorate of airworthiness at the Department of National Defence and the Canadian Armed Forces cited electromagnetic compatibility, electromagnetic vulnerability and electromagnetic interference concerns in its decision to impose flight restrictions on the CH-148 Cyclone helicopters.
“Each of them [the concerns] are potential show-stoppers,” a defense source, who asked for anonymity, told The Canadian Press.
“The vulnerability depends on the frequency and the strength of the signal. You have the potential of losing your instruments and not knowing where you are, and having to take visual cues from outside your aircraft to get down safely.”
Air Force engineers and government officials are increasingly skeptical regarding whether or not the shielding problem can be sufficiently remedied in a reasonable amount of time. Initially scheduled to be ready for service in 2008, only a few Cyclone helicopters have thus far been delivered for testing. The project is five years behind schedule and over-budget.
“The aircraft was not designed from the ground up with this kind of shielding in mind,” the defense source told The Canadian Press. “Military aircraft, the skin of military aircraft, [is] sometimes embedded with a fine copper screen or mesh to prevent the intrusion of electromagnetic interference.” The CH-148 Cyclone helicopters, however, are based on a less-rugged civilian design.
Sikorsky declined to comment on the technical concerns on the basis that the contract forbids the company from publicly discussing certain aspects of the program. Public Works, who manages the contract on behalf of National Defence, similarly declined to offer specific details, saying only that they are working on the problem.
“At some point, someone should say enough is enough,” defense expert Michael Byers, of the University of British Columbia, said. Byers documented the Conservative government’s struggles with the Cyclones in a report earlier this year. “The question is, when are they going to stop messing around and deliver a highly functioning maritime helicopter for the men and women of the Canadian Forces?”
John Dawson says
Several years ago we tested several Canadian helicopters for compatibility with our US Navy shipboard EM environments. The lesson learned, you get what you specify. If EMC is not integrated into the early design, it’s going to fail. Fixing after the fact, is always cost prohibitive. It’s always cheaper to do it right the first time, then to pay over and over again to build band aids.
Cortland says
US Army standard ADS-37A addresses these problems.
Cortland says
It’s possible some of this is due to an electronic suite new to the S-70 derived airframe.
quote:
CH-148 is equipped with APS-143B radar, the SAFIRE III EO System, L-3 HELRAS sonar and Lockheed Martin AN/ALQ-210 electronic support measure ESM system. Its aircraft management system CMA-2082MH is provided by CMC Electronics.
:end quote
http://www.naval-technology.com/projects/sikorskych148/
The Blackhawk had its own EMI problems
:quote
The Navy prohibited its first 14 Black Hawks – bought for training purposes in 1982 – from coming within a significant number of miles of radio towers for fear of accidents, a senior Navy engineer said. The precise distance is classified.
The Navy later demanded that its future Black Hawks, known as Sea Hawks, be heavily shielded from electronic interference, primarily because its helicopters must fly near ship radars and other electronic emitters. They can now buzz radio towers with impunity.
:end quote
http://articles.philly.com/1987-11-08/news/26175484_1_radio-waves-army-copters-citizens-band/sikorskych148/#sthash.wDiBBLjH.dpuf
Ken Javor says
Dawson’s comment is certainly true in general, but doesn’t seem applicable based on how the article was written.The article reads as if the CH-148s dont meet their EMV requirements. If the Canadians had underspecified the environment and the helicopters met the underspecified limit, it would not be Sikorsky’s problem. If the Canadian Air Force had underspecd the EME and then decided they wanted performance to a higher EME, then they would simply pay Sikorksy for the redesign.
David Cuthbert says
It looks like they’ve identified the problem and the solution. Now it’s time to stop talking about it and implement the solution.