Gulfstream testing fly-by-wireless flight controls

Gulfstream is flying their G550 flight control testbed with three different control linkages on it until May of 2009. The outboard spoilers are fly-by-wire controlled. The inboard spoilers are fly-by-light controlled. The midinboard flight spoilers are fly-by-wireless. They've been flying since September, using fly-by-wireless as a backup to regular flight controls.

Gulfstream says it will continue testing a fly-by-wireless system on its G550 advanced flight controls aircraft until mid-2009, but is optimistic that the control systems and architecture could become a "feasible" back-up control system. The company in September began testing wireless in parallel with other more traditional control methods for spoiler control, using fly-by-light for the inner spoilers and fly-by-wire for the outboard spoilers.

Source

Hi Zaphod long time since we spoke.

This is an interesting yet logical development. However I question the relevance of doing it at all. A wireless system will still need a power source to run actuators (on the assumption that you move to using them instead of hydraulics/pneumatics), which means a cable/wiring is necessary anyway. A far better method would be to simply piggyback the control signals onto this existing line. This would also tend to make the need for fly-by-wire/light redundant as well. Unless the power source was physically cut you wouldn't have the back up need of a wireless system, and if it was severed you couldn't use the actuator/ flight control surface anyway. You would gain redundancy through multiple channels on the wire and a second power/control wire again with multiple redundant channels as a backup mirror system.

I would be interested to see what Gulfstream's motivation is for this and what sort of reasoning they have seen that makes this a viable system.

LEE.

But you SHOULD be able to do wireless to the actuators, and then the cables from the actuators to the controls themselves. Which cuts out part of the control run. As I was telling my better half, in the case of United 811, the control cables on the left side of the aircraft were physically cut when the floor collapsed. This only left them with the cables on the right side. The wireless would have given them a backup system in case.

According to Gulfstream this is going to be a backup system. This just gives them more redundancy in the case of a physical break in the system.

I hope to hell they don't use Netgear.

Mine starts having seizures just trying to download ringtones. I would hate to think what it would be like sending signals to control surfaces.

Wireless flight controls..interesting. Anyone know if this is the first wireless flight control on any plane? Who is the manufacturer? For the record wireless seems like a bad idea.. Give me some hard and fast electrons and copper any day.

It's the first that *I* know of. The manufacturer is Gulfstream, they make buisness jets. These would only be back up controls. There would be either fly by wire, or fly by light controls that would be the primary controls. This would be a backup in case of a break in the cables, or some kind of emergency where the flight controls stopped responding to the cables.

OK I didn't note the backup role of these. I doubt there have been many issues with cables breaking or have there been? Maybe a cost thing. At least for engine controls they are dual redundent. Assuming the flight controls are also dual redundent that further makes me question why?

reply to post by BlackProjects


Because fly - by - wireless is the redundant backup system. It saves weight rather than having cables strung everywhere, and also makes it more failure resistant. Why not?

reply to post by BlackProjects


There haven't been many no, but it has happened. United 811 landed in Honolulu after suffering the cargo door opening in flight and peeling all the way up the side to the top of the fuselage. The left side of the floor collapsed severing all the control cables on that side of the aircraft.

Yeah fair enough Zaph it would cut out some of the control run and a bit of weight. However you can bet that whilst this is now seen as only a backup in the long run they will progressively want to use it on more primary systems.

Another recent example of cables being cut was on the recent Qantas VH-OJK O2 bottle explosion. The pilot lost all his primary instruments but still had all controls functioning. The co-pilot had instruments but lost some of his control cables. The reason this happened was the exploding bottle severed a good portion of the wiring loom in the lower right wire raceway when it exited the aircraft. The control cable damaged was caused when the bottle went through the floor, glanced off door2R and through the roof paneling where the cable run is located.

LEE.

I'm sure eventually they'll want to, you're right. But I have the feeling that's years away. It's probably going to be AT LEAST another 5 years before we even see it installed as a backup system.

I like the idea of fly-by-wireless but it concerns me regarding jamming electronically by terroists or those trying to sabotage an aircraft. What about electrical interference from high-power lines or powerful cell phone towers emiting frequencies that interfere with the electrical signal ? It could cause lack of control of the aircraft or even a catastrophic crash of an aircraft. More testing and development is surely needed. I'm an optimist, but I don't want to ride in an aircraft at this stage with that type of system ( not just yet, until they get the bugs out and have the system shielded from interference ). Its still in testing phase and it will be quite some time before they get it perfected, and then some crazy lunatic will devise an electronic jamming system that could "down" an aircraft. Scary !!!!!! The electrical system needs a power suppy ( either battery or generator ). If the power supply fails, then the system goes dead and so are YOU !!! Please don't take my comments as being pessimistic but rather precautious and a great deal of R & D is needed before this becomes the norm in manned aircraft. One glitch or electrical short in the system and its all over. Its a great weight saver and great for lack of cables and push-rods , but it also invites more problems. Imagine if a Boeing 777 is fitted with this system or a Boeing 787 or Airbus A380 or other should crash because of a simple electrical interference or jammmed signal or electrical failure. Even with a backup system , the power source can fail. I like the idea, but I hope they do an extreme amount of testing before it becomes mainstream. Nice website. Just my 2 cents. G-man