Fly by Wi-Fi

[SLFStuckInTheBack]

Sorry if this has been covered by another thread, but being a techno-geek I saw this link about replacing wires/fibre to the flight controls with wi-fi connections. The full article is here.

http://www.theregister.co.uk/2008/05/27/fly_by_wi_fi/

Thought y'all might be interested!

[G-STAW]

hi,

This technologhy is the logical way forward, it may provide more problems initially than fly-by-wire mainly due to even more dependance on computers and sensitive radio frequencies, but i will deffinatly work....

We wont be seeing this technology withiin the next 20+ years i dont think, but we may see a slow transition from fly-by-wire to fly-be-wifi,

i can see flight controls being tranferred from fly-by-wire to this technologhy in stages rather than a brand new aeroplane with fully fly-by-wifi......

time will tell....

G-STAW

[gr8shandini]

Interesting idea for a backup, but I don't think it'll work out in the end at least as a primary method of directing the flight controls. A low power RF signal is extremely vulnerable to EMI and the weight savings are far too small to justify the risk. And that's just the "atmospheric" radiation. I don't know how computer savvy the terrorist crowd is, but I sure wouldn't want a hacker to be able to bring down a jet with a laptop.

By the way, how are these gadgets going to be powered? The signal is one thing, but an actuator capable of controlling the elevator is going to need a fairly large battery.

[ChristiaanJ]

Quote from the original news item:
"Quite apart from all the obvious issues, it seems that powering the receivers, transmitters and actuators is something of an issue in the lost-engine-power scenarios that Gulfstream are looking at."

He's hit the nail on the head, of course.
This "fly-by-WiFi" would only "solve" the control signals being physically cut. Anything else would still be vulnerable as before.

Looks very much like a "solution looking for a problem".

[gr8shandini]

Hmm. Actually, to answer the author's question (and my own) about power sources, what if you constructed the tailcone out of a composite skin with aluminum longerons? That way, you could use the structure itself to transmit power yet the skin would still insulate ground crews et. al. from getting zapped. And if the burst disc took out the longerons, you'd lose the tail anyway, so who cares if your gizmos lose power?

[ppppilot]

First I would think on digital wired transmisions between all the plane components. Something like a digital network between computers and actuators. That way it could be only a pair of cables all around the plane transmiting and receiving. One would be the main and the other a backup. If that works good then wifi could be next step. :}

[rasobey]

I have difficulty sometimes making the wifi work from my laptop to the router when they're in the same room, separated by nothing but the very air I breathe.

I can't imagine the technical hurdles to get across in making a 100% reliable wi-fi signal work in a huge can of metal.

[ChristiaanJ]

First I would think on digital wired transmisions between all the plane components. Something like a digital network between computers and actuators. That way it could be only a pair of cables all around the plane transmiting and receiving. One would be the main and the other a backup. If that works good then wifi could be next step.It would help the discussion if you found out a bit more about aircraft systems first, before posting.
Digital networks and digital buses in aircraft exist for about the last thirty years, and then some.
And there's more than "a pair of cables". Try to read up on redundancy....

[ChristiaanJ]

I have difficulty sometimes making the wifi work from my laptop to the router when they're in the same room, separated by nothing but the very air I breathe.
I can't imagine the technical hurdles to get across in making a 100% reliable wi-fi signal work in a huge can of metal.
You got it in one.

[OutOfRunWay]

Fly by Wi-Fi? As an emergency backup, maybe. As primary system, I doubt it. There are not that many channels available for transmitting such data. Working out the data protocols if many aircraft in close proximity were constantly transmitting would be an absolute nightmare, and still no guarantee that it would function reliably.

Think of the aircraft behind in the hold getting its signals garbled with yours.. :uhoh:

regards OORW

[ppppilot]

Don’t be cruel ChristiaanJ. The network you are referring to is the Arinc 429 or whatever other arinc. As far as I know that is only a network, between computers in the plane. We are talking here about command to the control surfaces that is to say communication between the sidestick and actuators that actually I believe are totally analogical based on the amperes of the current sent to the actuators. Could be other way in the A380 or 787 (both uses an arinc Ethernet). But I could be wrong.

[gr8shandini]

Yes, the signal to the actuators in a FBW system is analogue, but I don't see how converting to digital would improve things. If you did that, you'd need a separate computer for each actuator to decode the signal and turn it back into an analogue voltage. So now you've gone from two or three computers to dozens which increases cost and weight, introduces lag times, and provides more points for something to fail. To me, it makes much more sense just to run some wires back to the main computers.

Wow, I can't believe I'm only in my early 30's and I'm about to have a "kids these days" comment, but here it goes: I think that over the last few years, there's been a dangerous trend toward looking for a digital solution to every problem. Computers are great, but when it comes to interacting with the physical world, Newton still rules the roost (at least on the scales we're talking about here).

[ppppilot]

I am not saying that it would have any advantage. I am just saying that if you plan to control the actuators via wifi you must first convert the signal to digital.