View Full Version : fly-by-wire
bobjim
26th Jul 2006, 01:22
Does anybody know of a fully fly-by-wire helicopter out there? (Or know anything about the development of one?) I've heard that BAE is developing one from a friend, and I just want to know if its been done before...:confused:
Flingwing207
26th Jul 2006, 01:37
RAH-66 Comanche
Jack Carson
26th Jul 2006, 02:08
NH-90, The FBW S-92 is in development. Sikorsky flew a FBW S-76 (Shadow) 15 years ago.
bobjim
26th Jul 2006, 05:27
Are either of those fully fly-by-wire though? ( ie does the onboard comp make corrections for you?)
Bertie Thruster
26th Jul 2006, 05:48
Chinook? .
Phoinix
26th Jul 2006, 06:57
As far as i know, RAH-66 is fully FBW, Apache only in case of emergency ie. damaged control system, there was a Bolkow 105 that served as a testbed.
noooby
26th Jul 2006, 08:22
Kawasaki have a fully FBW BK117 at their factory. Sort of a reddish pink colour. From memory, the cylic was mounted on the armrest of the P1 seat.
Brilliant Stuff
26th Jul 2006, 17:23
As far as i know, RAH-66 is fully FBW, Apache only in case of emergency ie. damaged control system, there was a Bolkow 105 that served as a testbed.
That BO105 has been replaced with an EC135 flown by the German Flighttest department/
Phoinix
26th Jul 2006, 17:46
This one?
Deutsches Zentrum fuer Luft- und Raumfahrt (http://www.airliners.net/open.file/0670027/L/)
Dave_Jackson
26th Jul 2006, 18:23
Here is a little more information (http://iar-ira.nrc-cnrc.gc.ca/flyers/jun99c_e.html)
NH90 is the only helicopter in production today with full flybywire system as far I know.
NickLappos
26th Jul 2006, 18:58
Aser is correct, but there is FBW and then there is real FBW. The NH-90 has a FBW system, although it has two digital lanes and two analog lanes, so it can only do what an analog computer can do (basic damping and such).
The Comanche system was fully digital, and had advanced sensors and control laws that changed the way the controls work. Literally, the aircraft flew with groundspeed control and the stick was used to command more speed. Big change from attitude control as we are all used to it (and as NH-90 still has). Non-pilots could fly Comanche while doing precise hover and target enganement maneuvers, and little outside reference was necessary.
Phoinix
26th Jul 2006, 19:16
That's no fun... computer sim, a really bad one :(
bobjim
27th Jul 2006, 03:56
ok, that pretty much answers my question I think - the commanche was the only "true" fbw system it seems...thanks for all your help!:D
skadi
27th Jul 2006, 06:29
That BO105 has been replaced with an EC135 flown by the German Flighttest department/
The new EC135 of DLR/Germany ( D-HFHS ) uses "Fly by Light" Tecnologie instead of "Fly by Wire", that means, that optical fibers are used to transmit the signals to the actuators.
The BO105 crashed several Years ago near Stendal/Germany, the Crew was killed.
Gregg
27th Jul 2006, 10:54
While not helicopters, the vertical lift BA-609 and V-22 tiltorotors are fly by wire and the Erica tilt wing will be fly by wire.
HOSS 1
27th Jul 2006, 18:00
Sikorsky had a flying donut rotorcraft called Cypher in the early 90's. Not only FBW but also made some pretty impressive autonomous piloting decisions on its own.
You didn't mention it had to be manned !
Brilliant Stuff
29th Jul 2006, 10:18
The new EC135 of DLR/Germany ( D-HFHS ) uses "Fly by Light" Tecnologie instead of "Fly by Wire", that means, that optical fibers are used to transmit the signals to the actuators.
The BO105 crashed several Years ago near Stendal/Germany, the Crew was killed.
Cheers Skadi.
Dave_Jackson
29th Jul 2006, 17:37
Here's another V-22 fly-by-wire (http://www.mecheng.adelaide.edu.au/robotics_novell/projects/2005/VTOL/VTOL05_Final_Report.pdf)
As HOSS 1 says;
"You didn't mention it had to be manned !" :ok:
______________ Edit ______________
A little more serious;
FBW for the S-92 (http://www.avionicsmagazine.com/cgi/av/show_mag.cgi?pub=av&mon=0304&file=0304s92.htm)
THE DEVELOPMENT OF ROTORCRAFT FLY-BY-WIRE TECHNOLOGY (http://www.kothmann.com/Papers/Impossible-to-Resist.pdf)
Here's another V-22 fly-by-wire (http://www.mecheng.adelaide.edu.au/robotics_novell/projects/2005/VTOL/VTOL05_Final_Report.pdf)
An unmanned V-22. Now that is a step in the right direction, speaking safety. Just don't fly it over my house.
Sikorsky is also featuring FBW on its new X2. Read it here:http://www.sikorsky.com/file/popup/0,9604,1887,00.pdf
And, if we are counting UAVs, there is also the Northrup Grumman Firescout. I think the airframe is built around Schweizer 333 components.
-- IFMU
bockywocky
1st Aug 2006, 20:51
As Acer said a couple of days ago, the NH90 is the ONLY Full Fly-By-Wire helicopter in production today.
The RAH-66 was indeed an advanced FBW system, but the program has been cancelled and therefore it does not count anymore.
The NH90 is using a double attitude reference system with Ring Laser Gyro's which provides the input for the FBW system. There is a third one as backup (if all else fails).
The output to the Main Rotor Actuators is indeed analog, but the control laws can still be tuned to the needs and you can get rid of nasty coupling effects (so it is not only for basic damping etc.).
Of course other manufacturers are experimenting with FBW and in time this will probably be common practice...;)
Jack Carson
1st Aug 2006, 22:40
Has NH Industries flown their aircraft without mechanical backups? All discussions I have seen indicate that their developmental vehicles all had mechanical backups. By comparison the RAH-66 was purely FBW from the get go.
Shawn Coyle
2nd Aug 2006, 00:50
Canada's National Research Council Institute for Aerospace Research has had fly-by-wire in their variable stabilty helicopters for more years than I care to remember. Started with a Bell 206, moved up to a Bell 205, now have a Bell 412. All modes of fly-by-wire can be demonstrated from the right seat - including 4 axis on one control. amazing. Most fun you can have in a helicopter with your clothes on. But the NH-90 is the first production helicopter as far as I know.
NickLappos
2nd Aug 2006, 00:56
bockywocky missed the point that I made. The basic architecture of the NH 90's FBW is that all computations are made in a pair of analog computers that match the outputs of a pair of digital computers. Any miscompare shuts down that lane. This means that the FBW on the NH90 is incapable of doing anything that can't be done with resisters and capacitors. It is therefore relegated to damping and making normal helo flight controls, basically 1975 flight controls, in spite of the fact that it is a FBW.
Nonetheless, it is in production, and so it counts, as does the V22
Ian Corrigible
2nd Aug 2006, 01:10
Jack -
The NH 90 has been flying full-FBW since Dec 2003. Earlier p/types did have the mechnical back-up.
I/C
Dave_Jackson
2nd Aug 2006, 17:04
Analog ~ Digital. They both use wires.
The foundation of a Digital computer is the storage and manipulation of bits [on/off]. Whether that bit is On or Off depends upon the Analog value of the bit's voltage, which is increased, stored, refreshed, decreased, and read.
The 'bit' is a very small capacitor and resistor.
bockywocky
2nd Aug 2006, 18:42
For the record:
The first prototype of the NH90 (PT1) did not have FBW.
The other four prototypes (PT2 - PT5) have or had FBW controls on the left side and mechanical back-up on the right.
Indeed since december 2003 PT3 was the first NH90 to fly Full FBW and later also PT4 was coverted to Full FBW.
All production helicopters of the NH90 have Full Fly-By-Wire controls.
The big advantage that i see with FBW is that you can get rid of the cross-coupling effects of mechanical controls by programming the control laws the correct way.
For your information: it flies very nice :ok: