Although I can find reference to the Eurocopter EC135 being a test bed for fly-by-light, I am not sure if it has entered production with the system [1]. The only confirmed aircraft I can find is the Kawasaki P-1 [2]. I am aware that the F-22, for example, has an optical fibre databus which is used to handle the large volume of data from the RADAR [3]. I am also aware of numerous test beds (the F-18 flown by NASA, the F-15 used in the FLASH program, and many others, but would welcome comments about these in case I have missed any). I am more interested in production aircraft that utilise optical fibre data links for flight control signals. For context, I was told in passing by a flight test engineer that given MIL-STD-1773 exists [4], fibre optic data links are effectively "everywhere". Based on my knowledge this is not correct, and after some research I agree with my assertion; however, maybe someone else has some additional knowledge.

Which production aircraft utilise a fly-by-light control system (other than the Kawasaki P-1)?

3 Spitzer, C. R. (2000). Digital Avionics Handbook. Taylor & Francis. Google Books

4 See for example, MIL-STD-1553 & 1773 DATA BUS PDF (66 kB)

  • $\begingroup$ The A-220 nee C Series is just about the most recent clean slate civil transport to be certified, and it is still FBW, although it is digital. It took a long time for digital FBW to make it from military a/c into civil transports. I can only imagine how massive and expensive a project it would be to certify a fibre-optic data transmission system for primary flight controls on a civil transport. I would expect the same kind of delay in getting the technology from military like the Kawasaki P1 to civilian use. $\endgroup$
    – John K
    Aug 14, 2022 at 0:50
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    $\begingroup$ Your question is already so well researched that you might have trouble finding a better answer :D $\endgroup$
    – U_flow
    Aug 14, 2022 at 9:23
  • $\begingroup$ Thanks John and U. Maybe, just maybe, there are some defence maintenance people that can comment, or even someone who has worked on the EC135. But yes, my literature folder on the topic is now 203 articles on the topic (that I need to read). That sounds like a lot, but the number with the same authors providing annual updates, and to 2 or 3 conferences per year means it is still not that dense in terms of actual aircraft. Although, I still have open the scholar tab for ADOCS, "Advanced Digital Optical Control system", which used a UH-60 Black-Hawk, which I had not previously heard of. $\endgroup$ Aug 14, 2022 at 19:17
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    $\begingroup$ @AerospaceDoctor, I work on the EC135 ACT/FHS Fly-by-wire/Fly-by-light helicopter as a flight control law research engineer. This system is used as the primary flight control transmission path, so it IS fully certified. But I am not sure how to answer your question: The ACT/FHS is a prototype aircraft, the "Light" part is also very much a prototype. It is sometimes difficult to maintain. It did not go into production. I dont know why it did not go into production. But FBW is already expensive an seldomly found on helicopters, FBL even much more so. $\endgroup$
    – U_flow
    Aug 14, 2022 at 21:53


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