The other day I heard someone say the words, “power-by-wire” and my spidey-senses perked up and I felt an insatiable tingle of curiosity inside. Side note #1: No wonder my best friend, Deborah, recently gave me a t-shirt to wear in Zoom pandemic meetings that says, “WARNING: MAY SPONTANEOUSLY TALK ABOUT AIRPLANES”.
I took it upon myself to learn what power-by-wire meant, and to see how/if it differs from fly-by-wire. Side note #2: Earlier this year, I wrote an article to teach fellow non-engineers like myself about fly-by-wire. You can see that article here.
So, are the terms power-by-wire and fly-by-wire synonymous? If you said no, you would be correct, although it is kind of a trick question. Power-by-wire is actually a description, or sub-set, if you will, of fly-by-wire. What do I mean? Well, power-by-wire are the mechanical transmission circuits in fly-by-wire flight control systems.
In aircraft such as the F-16, UH-60, and F-35, the aircraft manufacturer, in this case, Lockheed Martin, wanted to eliminate the bulky and heavy hydraulic circuits and replace them with an electrical power circuit. Warning: engineering nerd-type wording next… The power circuits power electrical or self-contained electro-hydraulic actuators that are controlled by the digital flight control computers. All benefits of digital fly-by-wire are retained since the power-by-wire components are strictly complementary to the fly-by-wire components… Glad to get those words out.
There are three main benefits of power-by-wire aircraft: (1) the possibility of redundant power circuits and tighter integration between the aircraft flight control systems and its avionics systems, (2) reduced maintenance costs due to the absence of hydraulics, and finally, (3) the biggest benefit, weight savings.
Way back in October 2000, Lockheed Martin successfully flew an F-16 Power-By-Wire flight without any mechanical back-up. In fact, our company, InterConnect Wiring, played a role in this aircraft’s success. It was a program called J/IST and required InterConnect to make multiple electrical wiring harnesses with many red-line revisions “on the fly” – no pun intended.
Lockheed Martin’s F-16 power-by-wire technology demonstrator made its maiden flight on 24 October 2000, making it the first aircraft to fly with all-electric flight control actuation and no mechanical backup.
I found an article on Power-By-Wire in Aviation Today written by James Ramsey, released on May 1st, 2001. Below is an excerpt of his article:
“A new electro-hydrostatic flight control and power system, intended for the Joint Strike Fighter (JSF), promises to revolutionize fly-by-wire technology. Calling it “power-by-wire,” the Lockheed Martin JSF team developed the system and flew it on a U.S. Air Force F-16 as part of the Joint Strike Fighter Integrated Subsystem Technology (J/IST) program. The electric actuator design actually originated with the U.S. Air Force Research Laboratory.
Lockheed Martin believes the system will be as significant in fighter risk reduction as the F-16 was when it became the first U.S. production fighter aircraft to be equipped with fly-by-wire flight controls, in the 1970s.
“This is the first of a new generation of flight control technologies,” says Dennis Eicke, J/IST program manager for Lockheed Martin Aeronautics Co. “We were successful in the development, integration and test [of the system].”
Lockheed Martin incorporated the power-by-wire system into its X-35 Preferred Weapon System Concept (PWSC) design proposal for the JSF program’s engineering and manufacturing development (EMD) phase.”
Well, that’s just about all I have to share on Power-By-Wire this week. I did find this old SAE journal article interesting, which displays the below old abstract from 1978 on powering aircraft.
Side note #3: Let’s see… in 1978 I was 1-year-old. Okay, not true. Add another 10 to that. ☹
Let me know if you want to talk about Power-By-Wire or simply request a quotation for your aircraft electrical system.