DCS: AJS-37 Viggen Discussion

[Sporg]

I think that it's correct with generator, it generates a force to the stick when you pull it, the force increase as you pull.

Pedals, not stick. But you're right, I went back and checked and "givare" is used in an unusual way here, the device in question is an artificial pedal force generator.

Yes, the flightcontrols had artificial force feedback. There are no force sensors.

Right and wrong. The artificial stick and pedal forces are a thing, yes, but there are force sensors on the stick even though the flight controls are mainly hydro-mechanical and not electronically governed. If you take a look at the English diagram again there's a "stick force sensor" right there, and that is correctly translated. It's used by the autopilot for various things like oscillation dampening, transonic trim, etc.

Ok, interesting.

 

I'm sorry I got it wrong, the Swedish document apparently uses two kinds of "givare", one as a sensor and the second as a force generator.

 

So there's stick and pedal force generators, and different position and roll link sensors.

Edited October 25, 2016 by Sporg

[Goblin]

If you take a look at the English diagram again there's a "stick force sensor" right there

 

Where? Do you mean the stick position sensor?

[renhanxue]

Where? Do you mean the stick position sensor?

Right, sorry, stick position sensor. It's extra confusing because it's "spaklägesgivare" in the Swedish version - "givare" is used in the other sense there.

[Goblin]

Right, sorry, stick position sensor. It's extra confusing because it's "spaklägesgivare" in the Swedish version - "givare" is used in the other sense there.

 

Yes, and this is not a force sensor. It feeds the position of the stick into the artificial feel unit, which outputs a feedback force based on the stick position (and speed, altitude, etc.)

[renhanxue]

Yes, and this is not a force sensor. It feeds the position of the stick into the artificial feel unit, which outputs a feedback force based on the stick position (and speed, altitude, etc.)

How far do you want to take that particular semantics argument? My understanding is that there are stick position and force sensors (but no pedal force sensors, so I was wrong on the original point anyway). Depending on your definition of force sensor, I guess.

 

 

Still the original point of the argument stands; "givare" is used both for a pure sensor and for a device that can both generate stick forces (but perhaps it makes more sense if it can also report back the current force, something that I am not entirely clear on).

[Goblin]

How far do you want to take that particular semantics argument?

 

"Nothing further, you honour!" ;)

 

My understanding is that there are stick position and force sensors (but no pedal force sensors, so I was wrong on the original point anyway). Depending on your definition of force sensor, I guess.

 

Well, yes, I guess you could view the flight control inputs (stick and rudder) as a force sensing unit, since it translates the force, applied by the pilot, into flight control deflection.

 

But I just meant that the translation was correct, and that there were no force sensors in the schematics. :). I just wanted to explain myself. Nothing sinister. ;)

[renhanxue]

Oh, no, sorry if I came off as hostile or something. I just want to understand what is going on here :)

It sometimes does get into the territory of insufferable pedantry, and I should be more aware of that.

Edited October 25, 2016 by renhanxue

[Sporg]

A description of the "Spakkraftsgivare" is found in the AJS-37 Pilot's Manual, Chapter 12, section 3.1.5:

 

 

Basically it says, that since the control surface servos provide all the necessary power to move the control surfaces,

the "spakkraftsgivare" (stick force generator) works to give the pilot feedback on the stick in the form of force (resistance to movement)

proportional to the stick deflection from neutral. It is basically a mechanical cam with springs.

 

In addition there is a trim attenuator that can move the location of the neutral point of the stick.

 

Normally these forces will be 12 N in pitch and 7 N in roll.

 

If the pilot has selected autopilot attitude or altitude hold, the breakout forces are amplified by a magnetic coil to 30 N and 23 N respectively.

 

The pedal force generator works along the same principles except the hold function.

Edited October 25, 2016 by Sporg

[Goblin]

Oh, no, sorry if I came off as hostile or something.

 

Yeah, you scared me..! ;) No, seriously, I was afraid that I came across as hostile. :)

 

It sometimes does get into the territory of insufferable pendantry, and I should be more aware of that.

 

Attention to detail can never be negative! ;)

[outbaxx]

A description of the "Spakkraftsgivare" is found in the AJS-37 Pilot's Manual, Chapter 12, section 3.1.5:

 

Normally these forces will be 12 N in pitch and 7 N in roll.

 

If the pilot has selected autopilot attitude or altitude hold, the breakout forces are amplified by a magnetic coil to 30 N and 23 N respectively.

 

 

 

These forces are the "break out" force that you need to apply to move the stick. The force then increase as you pull further to about 150-170 N at max in pitch depending on what mode is selected.

[Sim Flyer]

I might be an optimist here (and a bit naiv for getting the information from wikipedia) but first of all, someone in here asked if the RBS15 could be used for land targets and the answer was only the new one that was designed to be operated on ships (as stated below).

 

RBS-15 Mk. IIIRange over 200 km, with land attack capability.[2] New warhead (increased penetration and insensitive munitions qualification) from TDW. There is only a ship launched version. Production started in 2004. New oval launch tubes instead of the old box type.[3]

But then i saw the next line and started wondering if this missile was ever used on the Viggen or if it was only used on Gripen.

 

RBS-15F ERAircraft launched version of the Mk. III

Anyone knows anything about this?

[Airbusdriver]

Hi! Been following your discussions a bit. See a bit of confusion about spakkrafts givare, spaklägesgivare, spakkraftstyrning.

In my belief and knowledge about aircraft systems I understand the manual and pictures as follows to help those out that doesn't have swedish as their first language.

Spakkrafts givare= Artificial feel unit. Create natural stick forces for the pilot since a full servo system has no feelback to make manuvering natural.

Spaklägesgivare=Stick position sensor to feed signals to the artificial feel unit about current control input.

Spakkraftsstyrning= A system separate from the previosly two. Electrical force sensors located right beneth the top handle portion of the control stick. Theese signals are transmitted to and added to the autopilot/dampening signals in SPAK mode and transmitted to the outer elevons.

This system creates a very fine and precise manuvering.

Look at a videos were su27s do formation flying and you'll see pilots working the stick like maniacs without any significant path change. In the viggen this system lets you keep e stick almost still as it senses and reacts to your inputs immediatly and comes very natural for the pilot.

Very clever system. Rememer when I helped out dismateling old AJ Viggens, when the top of the stick is removed you can see the electrical pressure sensors located as 12 little dots in a round circle.

I beleve this system was made inoperative on the JA version as they fixed the inner and outer elevons together and instead used a more sofisticaded autopilot/dampner but i'm not sure and I have not seen any documantation describing it in detail.

Anyone that know were I can find the SFI for the JA version?

/

Anders

[RaXha]

I might be an optimist here (and a bit naiv for getting the information from wikipedia) but first of all, someone in here asked if the RBS15 could be used for land targets and the answer was only the new one that was designed to be operated on ships (as stated below).

 

RBS-15 Mk. IIIRange over 200 km, with land attack capability.[2] New warhead (increased penetration and insensitive munitions qualification) from TDW. There is only a ship launched version. Production started in 2004. New oval launch tubes instead of the old box type.[3]

But then i saw the next line and started wondering if this missile was ever used on the Viggen or if it was only used on Gripen.

 

RBS-15F ERAircraft launched version of the Mk. III

Anyone knows anything about this?

 

 

 

The AJS 37 only carried the MkII as far as I know, so it won't be ground target capable. :-)

 

 

Skickat från min iPhone med Tapatalk

[Sim Flyer]

Yea just seen now that it was developed in 2004 and Viggen was retired in 2005 so no sense in making the Viggen capable of using this version all though it would have been awesome :)

 

Someone gotta start making the Gripen for dcs :D

[mattebubben]

Yea just seen now that it was developed in 2004 and Viggen was retired in 2005 so no sense in making the Viggen capable of using this version all though it would have been awesome :)

 

Someone gotta start making the Gripen for dcs :D

 

Well the Viggen in general was retired in 2005.

 

But the AJ/AJS left service between 98-00.

(With the JA 37 Fighter variant leaving service in 2004 and SF/SH Recce variants and the SK 37E Two Seater / Jamming aircraft leaving service in 2005)

 

So it would not have carried any of the later RBS variants.

So the first RBS 15F or maby the RBS 15F Mk II are what we are getting (i would lean towards the Mk 1 RBS 15F since its what we KNOW for sure the AJS 37 carried and there is not much difference between them anyway)

 

But the MK III with the Air-Ground abilities entered service several years after the AJS 37 left service so it will most likely not be an option.

 

(Especially since while Production / Testing of the RBS MK III might have started in 2004 service entry and the Air-Launched variant took several years more).

Edited October 26, 2016 by mattebubben

[BravoYankee4]

It is a shame there isn't any subforum for Viggen with dedicated threads for different topics. There is so much information and knowledge here but since it is all put in one big pile it will be very hard to get to it. Some of us has been active in this thread on a daily basis but coming from the outside will be pretty daunting for anyone that is jumping on the train lately... especially with all different side tracks, which are funny in many ways but they might add to the confusion and make it even harder to follow the actual information and so on.

 

But hey, we can start all over again creating new threads with each and every topic discussed here ;)

Or perhaps a few persons should put together a "best of" list of topics...?

[MikeMikeJuliet]

I bet the problem will be over rather soon. Looking forward to tomorrow, possible information inbound if my speculation is correct.

[Goblin]

Hope you're right, MMJ! Some detailed info and pics would be awesome!

[Sim Flyer]

Well the Viggen in general was retired in 2005.

 

But the AJ/AJS left service between 98-00.

.

 

Did the Gripen take over as a strike aircraft allready at that time or did they think it was not necessary with a strike aircraft as they didnt see any potential enemy?

[mattebubben]

Did the Gripen take over as a strike aircraft allready at that time or did they think it was not necessary with a strike aircraft as they didnt see any potential enemy?

 

The Gripen took over the Strike role.

 

In fact the First Gripens to enter service Took over the AJ/AJS 37s role when it came to Strike / Anti-Ship work where as the fighter JA 37 kept on going for a few more years until it to was replaced as more Gripens where Delivered.

 

(The JA 37 could have stayed in server for several more years as it was still up to date when it came to weapons/Radar etc so it was still a capable air-air platform but it was retired earlier due to a reduction in the size of the airforce.)

 

And the Reason that the Recce Viggens (SH and SF 37) were kept in service longer was due to a delay in the Gripen Recce pod but once those pods were in service those variants were also retired.

 

The JAS 39A was well suited for the Strike role and carried the Same BK90,RBS15 and AGM 65 (RB75/75T) as the AJS 37 had before it but with the addition of LGBs and a targeting pod as well as an internal gun and vastly more advanced systems etc.

Edited October 27, 2016 by mattebubben

[anlq]

Today is 28th Oct. I feel something big will happen today. :lol:

[Sim Flyer]

Yea i have a friend who have a nice theory about today aswell ;)

[QuiGon]

Today is 28th Oct. I feel something big will happen today.

Let's hope you're right :D

I would expect a big announcement by LNS before there will be anything big about the Viggen in EDs newsletter though.

[microvax]

Gib info already ! :DD

 

I cand betray myself anymore that my mirage is close enough to a Viggen. :D

[zerO_crash]

Now now, they will announce it whenever they feel ready. I`m sure they know how much everyone interested wants it already ;)