DCS: AJS-37 Viggen Discussion

[El Hadji]

Just crack open a can of surströmming, and it'll be just like flying in Sweden.

 

The best of two worlds. Surströmming and Linie! :thumbup:

 

[SpeedStick]

I'm offensive and find this Swedish!

 

Also I'm Swedish and want som surströmming.

(or sillmacka).

[Silver_Dragon]

The Viggen is for the most part feature complete. Mostly bugfixing and missionbuilding in progress.

Artwork has been lagging behind, hence the delay.

 

Yes, we hope to include a JA-37 (even Di) as an AI companion to the AJS. Doing a full-fledged JA-37Di is a lot of work. Perhaps a lite (FC) version down the line or something. No decisions made yet.

The main reason we've spent time with the Di lately is because it's the only Viggen around my parts (Graz). As mentioned previously, we've spent a lot of time in various AJ/AJS cockpits already.

 

Cobra, you talk a future JA-37 AI companion to the module. Expected see some plans about Sweden and/or Russia additional AI Air / Ground / Sea units on the future with the AJS module or future Theater?

[Knock-Knock]

I have no idea if this has been posted in this ginormous thread, but here goes. A really good read about Viggen's intercepting, or trying to intercept SR-71's in the 80's.

 

Its a post on another forum:

http://sturgeonshouse.ipbhost.com/index.php?/topic/40-j35-appreciation-station/#entry26577

[mattebubben]

a Bit off topic but i just love this meme xD.

 

 

And when this module is out you to can be a part of the Glorious Sweden Arming Force xD.

[RagnarDa]

I löve how the Blackbird-pilots helmet covers his whole body :D

[El Hadji]

Makes me remember a story from when I served in Kustartilleriet (today called the Amphibious Corps) in the early 1990's. A high ranking US officer from the Marine Corps was taken on a night ride in one of our combat vessels somewhere in the Swedish archipelago. Of course the boat driver did his best to impress... When they came ashore the US officer said to his Swedish collegue: "Very impressive! How many years did it take that boat driver to get THAT good?!?". The Swedish officer replied: "Yeärs? That böy is a cönscript. He's önly serving 15 mönths in tötäl...".

 

[ame]

[/ame]

[renhanxue]

To make the thread boring again after all this excitement, here are some numbers/talking about the flight envelope limitations, extracted from Aerodynamik III for those who either don't speak ärans och hjältarnas språk or don't feel like reading obscure technical texts from the 1980's in their spare time.

 

For the AJ(S) 37, max permitted alpha is 18° (JA 37: 23°). You will start getting engine surges at around 20° (JA 37: 25°, be jealous of that RM8B) and pitch-up tendencies followed by spin or superstall at around 28-30°. The pitch stability is described as "okay" or "basically undisturbed" up to around 25° for a clean aircraft; payload on the wing pylons worsens this stability somewhat.

 

When it comes to sustained turn performance, the AJ(S) 37 unsurprisingly isn't exactly stellar. At sea level with a clean, light aircraft, you can barely maintain a 3 G turn at 7-800 km/h IAS at military power. With full afterburner, you can reach 6 G's in a pretty narrow band of speeds above 800 km/h IAS. See this graph:

 

 

On the Y axis, drag (D) and thrust (T) in kiloponds. On the X axis, IAS in km/h. The solid lines in the chart that start at the far left are, from bottom and up:

D PLANFLYKT - drag in level flight

T, MAX SLÄCKT - thrust at military power

T, MAX TÄND EBK - thrust at full AB

 

Then there are three solid curved lines starting at around 400 km/h IAS from the top, indicating the drag at G loads of 6, 4 and 3 G's respectively from the top (marked with n(z) in the right margin). The shaded areas show where there's a significant lack of thrust to maintain the desired turn.

[renhanxue]

Okay I'm sorry for killing the thread. Have some funnies and tall tales instead (Viggen stuff starts at the bottom of page 3):

 

[ame]http://www.collectair.co.uk/pdf/interview-hr.pdf[/ame]

[RaXha]

DCS: AJS-37 Viggen Discussion

 

Okay I'm sorry for killing the thread. Have some funnies and tall tales instead (Viggen stuff starts at the bottom of page 3):

 

http://www.collectair.co.uk/pdf/interview-hr.pdf

 

 

 

I like this part:

 

After about 40 minutes, we pulled up into cloud, and the pilot then flew a 4-degree hands-off approach with his hands on his head into a remote airstrip, landed, reversed into a parking bay, did an engine-running refuel without any communication with the people on the ground except hand signals, taxied out and took off in the direc- tion that we’d landed in. Wind direction just wasn’t factored.

[renhanxue]

tall tales, I told you :V

Pilots tend to love good stories just a bit too much.

[mattebubben]

Thanks for the Post =).

 

Ive heard about that story of them testing the Viggen (and what they thought of the experience ^^) but i had never been able to find/read the story itself.

 

But yea even if the AJ might seem to have some basic systems by Todays standard it was a very effective and well liked aircraft through out the 70s/80s

(and though starting to be a bit outdated in the 90s the AJS upgrades extended its capabilities until the JAS 39 was ready to replace it).

 

And internationally the Viggen (both Attack and Fighter Variants) where generally seen as very potent top of the line aircraft.

And most International pilots who got to test it were impressed with its performance (as it usually beat their expectations).

Edited July 17, 2016 by mattebubben

[renhanxue]

It's not at all surprising to me that someone who's only really flown the Jaguar might be very impressed with the Viggen's performance.

[BlackLion213]

Okay I'm sorry for killing the thread. Have some funnies and tall tales instead (Viggen stuff starts at the bottom of page 3):

 

http://www.collectair.co.uk/pdf/interview-hr.pdf

 

Great stories Renhanxue, thank you for sharing. The kind of Viggen flying described here (40' and 650 kts) is unbelievable! I'd say it's a sea story, but I've now read 4 or 5 stories which all describe the same thing (many from exchange tours), not to mention a photo in a book of mine from the 1980s showing a Viggen doing a (as described) 600 knot pass at 30' for a tactical demo (it looks like less than 30' in the photo!).

 

At least some crazy pilot stories appear to be true...:D

 

-Nick

[RaXha]

Great stories Renhanxue, thank you for sharing. The kind of Viggen flying described here (40' and 650 kts) is unbelievable! I'd say it's a sea story, but I've now read 4 or 5 stories which all describe the same thing (many from exchange tours), not to mention a photo in a book of mine from the 1980s showing a Viggen doing a (as described) 600 knot pass at 30' for a tactical demo (it looks like less than 30' in the photo!).

 

At least some crazy pilot stories appear to be true...:D

 

-Nick

 

 

 

Well, they were allowed to fly down to "estimated" 10 meters, and somewhere between 5-15 meters would probably qualify as an "estimated 10". :P

[microvax]

Well, they were allowed to fly down to "estimated" 10 meters, and somewhere between 5-15 meters would probably qualify as an "estimated 10". :P

 

Is that the same kind of estimated 10 meters as estimated missile performance in DCS ? xD

 

*shots fired*

[Farks]

Okay I'm sorry for killing the thread. Have some funnies and tall tales instead (Viggen stuff starts at the bottom of page 3):

 

Sån jävla välfärd!

 

Speaking of air force exchanges, I remember finding an article on a forum a few years back (either SoldF or Skalman) about showcasing the JA 37 and its datalink for british or american pilots in the late '80s. They couldn't believe that a puny northern european country already had a fully operational datalink while theirs was still on the drawing board. Do you know what article I'm talking about?

[renhanxue]

Sån jävla välfärd!

 

Speaking of air force exchanges, I remember finding an article on a forum a few years back (either SoldF or Skalman) about showcasing the JA 37 and its datalink for british or american pilots in the late '80s. They couldn't believe that a puny northern european country already had a fully operational datalink while theirs was still on the drawing board. Do you know what article I'm talking about?

 

Page 21 in this PDF.

[renhanxue]

Great stories Renhanxue, thank you for sharing. The kind of Viggen flying described here (40' and 650 kts) is unbelievable! I'd say it's a sea story, but I've now read 4 or 5 stories which all describe the same thing (many from exchange tours), not to mention a photo in a book of mine from the 1980s showing a Viggen doing a (as described) 600 knot pass at 30' for a tactical demo (it looks like less than 30' in the photo!).

 

At least some crazy pilot stories appear to be true...:D

 

-Nick

Well, I'm sure they did it occasionally, the question is how often and whether it was sanctioned by the higher ups. What I do know as a verifiable fact is during the basic type rating for any Viggen model (that is, conversion from the Sk 60 subsonic trainer), you would have to fly at least two lessons in the Sk 37 (the two-seater Viggen) involving navigation at 50 m AGL and M 0.8. From there, there is of course a long way to 10 meters and M 0.9, but that's the baseline that got taught to pretty fresh cadets as a part of their introduction to the aircraft within their first ~45 flight hours on the type, before you even started training them in tactical flying.

 

The source for the above is anvisningar för typinflygning fpl 37 (ATIS 37); I have the entire thing photographed and I could turn it into a PDF if anyone's interested, but here are the pages that describe the lesson in question.

Edited July 17, 2016 by renhanxue

[mattebubben]

The only numbers ive seen and heard on the question of minimum operational altitude is 10M above water (or extremely flat terrain) and 30M above ground or trees.

 

But again the actual altitude would probably be slightly higher for most lost altitude flying (50-100M) since most terrain in Sweden is never completely flat and even the ocean usually has some altitude differences depending on wind/weather and at such high speeds you would never be able to correct in time for even a slight unexpected rise in the terrain etc.

 

But it is true that the Viggens and especially the attack viggen very often flew at very low altitudes at very high speeds and thats were most of the losses came from for the attack viggen.

Edited July 17, 2016 by mattebubben

[BravoYankee4]

Is that the same kind of estimated 10 meters as estimated missile performance in DCS ? xD

 

*shots fired*

 

There is one incident when a Viggen came back to base with a couple of hundred meter phone wires hanging from the belly tank, after flying in the archipelago. The investigation showed that this specific wire was between two islands at 8 meters height over the water.

So the pilot head was probably at around 10 meters...

 

After that incident the new regulations was raised to 20 meters over water and 30 meters over land as the minimum altitude.

 

By the way, the C-130 guys wanted to join the club as well ;)

[ame]

[/ame]

 

That particular pilot got suspended though. 20 years earlier he would probably have been promoted...

[OziRekt]

Does the Viggen have autotrim, or will we have to do it ourselves?

[mattebubben]

There is one incident when a Viggen came back to base with a couple of hundred meter phone wires hanging from the belly tank, after flying in the archipelago. The investigation showed that this specific wire was between two islands at 8 meters height over the water.

So the pilot head was probably at around 10 meters...

 

After that incident the new regulations was raised to 20 meters over water and 30 meters over land as the minimum altitude.

 

By the way, the C-130 guys wanted to join the club as well ;)

 

That particular pilot got suspended though. 20 years earlier he would probably have been promoted...

 

The problem is that case is probably that the flew that low above ppl (and civilians) rather then the flew that low to start with.

[BravoYankee4]

The problem is that case is probably that the flew that low above ppl (and civilians) rather then the flew that low to start with.

 

Yes, you are probably right.

We have that other example being discussed here before with the Viggen burning some spectators at the end of the runway. So from that perspective I do agree that it was stupid. My point was more that during the cold war era there was perhaps a better understanding for a risky business.

 

By the way, that particular field is where I made my first jump. It was cloudy so the first minute or so I didn't see shit, so just lucky I didn't land in the forest nearby :music_whistling:

Edited July 18, 2016 by BravoYankee4

[renhanxue]

Does the Viggen have autotrim, or will we have to do it ourselves?

 

It's mostly manual, but there is a function called "serietrim" which automatically compensates for most of the big pitch trim changes in the transonic and supersonic regimes.