su-27 performance

...Falcon 4.0 avionics are pretty close but the flight model is a joke . ...

You know this stuff is exactly what the Falcon community says about the

lockon flight model? ;)

The worst flight model I've seen so far is the FSX F-18 which does mach1.8, sealevel :P,

and don't forget 25G sustained turns!

Er, no, the Su-27 does NOT have FBW. Unless you're talking the more advanced versions like Su-27SM, etc, which may well have it. The Su-27 has the same type of ACS as the F-15 does, not an FBW.

Interesting input. All sources I've seen state that su-27 has FBW. You would better head over to wiki and do some

modifications of their site. I googled on "Su-27 Fly-by-wire" and there are a lot of posts about how the su-27

has FBW.

Er, no, the Su-27 does NOT have FBW. Unless you're talking the more advanced versions like Su-27SM, etc, which may well have it. The Su-27 has the same type of ACS as the F-15 does, not an FBW.

Actualy it does. It has an analogue system. It works differently and for slighly different purposes that that of digital FBW in the west.

Oops O.o

My bad. Indeed it has the pitch-only analogue FWB.

Oops O.o

 

My bad. Indeed it has the pitch-only analogue FWB.

Pitch only eh? Good to know since it confirms why its there and explains what it doesn't do.

You know guys, I was wandering. I have read in many places how the F-16, Su-27, F-117 and many "newer" aircraft can not fly without their FBW computer, yet you see R/C models flying no problem. How come the R/C models have no problem flying? What would cause the full scale aircraft to require the computer to fly but not the models?

http://www.youtube.com/watch?v=CsuqwkaERl4&feature=related

Because those RC models do not have these instabilities. This has to do with weight distribution as well as aerodynamics, AFAIK.

I think the F-16 is more or less the same (as in, while you fly the whole plane via FBW, only the pitch axis is under constant computer control - notice how it's the only axis you can 'disengage' from the FBW in an emergency like getting out of a stall).

The F-22 has 3D FBW which means it guards the plane from lateral g's as well etc etc.

Pitch only eh? Good to know since it confirms why its there and explains what it doesn't do.

Because those RC models do not have these instabilities. This has to do with weight distribution as well as aerodynamics, AFAIK.

And they aren't made of the same materials and aren't traveling at the same speeds. One day I hope, maybe at the end of the F-16s life, someone will send one up under remote control and suddenly disable ALL FBW at high speed. It would be interesting to watch how it rips itself apart.

I think the F-16 is more or less the same (as in, while you fly the whole plane via FBW, only the pitch axis is under constant computer control - notice how it's the only axis you can 'disengage' from the FBW in an emergency like getting out of a stall).

The F-22 has 3D FBW which means it guards the plane from lateral g's as well etc etc.

All flight control surfaces are control by the DFLCC or FLCC. There is not physical connection between the pilot and the flight surfaces actuators (called ISA in the F-16 for integrated servo actuator) The reason for the pitch override switch is the LEX (leading edge extension) F-16,SU-27,F-18 and MIG-29 all have LEX. According to some book I have read, because of the LEX, aircraft can maintain hight AOA. The LEX help maintain enough pitch control at this AOA. But at certain region of AOA the horizontal stabs have no pitch command. The SU-27 and MIG-29 deal with this by locating the vertical stabilizers to the edge of the airframe, thus reflecting air to the horizontal stabilizers from the wing. At high AOA this causes the nose to pitch forward creating the cobra maneuver (reference:Sukhoi Su-27 Flanker - WarbirdTech Volume 42 (WarbirdTech) (Paperback) ) The F-18 control the pitch at high AOA by angling the vertical stabilizer again to reflecting air to the horizontal stabilizer for pitch control. The F-16 does this by adding pitch override. At hight AOA the aircraft will try to put the nose down on a F-16. But if the pilot is still pulling on the stick the aircraft will continue to get in a higher AOA state. At certain AOA ( I can not remember the number) the stabs loose pitch command and the aircraft can enter a deep stall. By using Pitch override(AKA kick) the pilot can command the nose down and recover from a deep stall.

Here is a interesting article about F-16 FLCC in code one magazine

http://www.codeonemagazine.com/archives/1986/articles/jan_86/f16_control/index.html

nice post mvsgas :)

Other good article about F-16

http://www.codeonemagazine.com/archives/1986/articles/apr_86/f16_aero/index.html

http://www.codeonemagazine.com/archives/1986/articles/july_86/deep_stalls/index.html

I still don't think the the F-16 has a full-axis FBW programming, which is what I meant. I can't recall where I heard that though.

i read somewhere that f-16 has pretty advanced FBW, some rudder movement might even lead the FBW to not allow you to do

certain pitch/roll things . Now would be a good time for Pilotasso's brother to step in and clear things up, if possible ;)

Well GGTharos, I could not tell you man. AFAIK, it has to have full FBW authority. Most Aircraft (an again AFIAK) that have FBW, have a physical connection between the control stick and the flight actuator as a back up. This input are ignore by the computers and only used as back ups. The F-16 does not have this connection so I believe it has to have full FBW control, there is no choice. The side stick only has wire coming out, no push pull cable or rod. It connects to the DFLCC and the same goes to the pedals. The only physical connection is to the engine. Maybe that is what you referring to? The engine uses FBW to but when engine is in SEC it uses the mechanical link (AKA throttle cable) for control inputs.

The Su-27 has true FBW. Like the F-16, its statistically unstable and wouldn't be able to fly without it.

Assuming that you meant by 'statistically unstable' that the Su-27 is unstable & therefore completely imposible to fly without the FBW system, that's not actually true - the Su-27 has 'relaxed' stabilty, but is not actually 'unstable' & could theoretically be flown - carefully & with dificulty - without the assistance of the analogue FCS.

Assuming that you meant by 'statistically unstable' that the Su-27 is unstable & therefore completely imposible to fly without the FBW system, that's not actually true - the Su-27 has 'relaxed' stabilty, but is not actually 'unstable' & could theoretically be flown - carefully & with dificulty - without the assistance of the analogue FCS.

Hmm...so no ass over appetite disintegration like the F-16. I didn't know that, or at least I assumed it would react the same way.

Actually, if all your hydraulics (4 of them I think) fail on Su-27, the sweet lady whispers into your ear that you and here must go your separate ways.. you through the canopy, and she wherever the winds carry her.

Mind you, that's not the same thing as FBW failing.

nscode Actually, if all your hydraulics (4 of them I think) fail on Su-27, the sweet lady whispers into your ear that you and here must go your separate ways.. you through the canopy, and she wherever the winds carry her.

 

Mind you, that's not the same thing as FBW failing.

I wander how many hydraulics systems does it have? Looking in the game cockpit it look like it has 2 systems. I wander how they control the aircraft if one or both systems fail? How do Russian and European type aircraft stop after an emergency landing with no hydraulics? American fighter aircraft (Except for the A-10) have a tail hook to stop on the runway if no hydraulic power is available. Does the SU-27 have a emergency generator like the F-16 EPU