JA and AJ Engine differences and sound

[Ice_Cougar]

Before I get started, LET ME BE CLEAR... I know LNS is working very diligently to kink-out as many bugs as they can before release, and everything we've seen so far about the AJS is subject to change. Thus, I will not criticizes them on the sound, or anything else we see thats inaccurate about the AJS so far. If anyone disagrees with me and shows any dis-respect for the team or the module (so far)...I kindly will ask you to leave. ;)

 

Okay with that out of the way I was very curious about something. I am aware that there was the Viggens' engine was the Volvo RM8 (Yes I know that the Rolls-Royce Medway was the original candidate but that is besides the point). However there are two variants of the RM8 (As far as I know), the RM8A and the RM8B. As I recall the RM8A was used in AJ Viggens, it simply being a license-built P&W JT8D engine with modifications to the fan-blades and structure to better deal with the stresses of medium to low altitude sustained flight at high subsonic speeds, and a new fuel system for the combustion chamber and the Swedish-built selectable stage afterburner. The RM8B was mostly the same, however it had new fans, a new burner, and yet another fuel system. However it's biggest difference was the "Zero-stage" or "0-stage" (Quote from Wikipedia itself :P),"This led to a new fan-stage (the so-called "0-stage") was introduced, making the engine longer."

 

I've brought this up because I not only want to know about what this new fan stage does, but I want to know if its the reason why "Jakt" Viggens seem to produce this...high-pitched buzzing sound mixed with a growl that I can only compare to the sound of a Fokker 100 taking off or a B707, and if it can be produced by an AJ's engine such as LNS'. (Hence the disclaimer at the top of the thread)

 

Examples:

Go to 9:18 ^ *EDIT* The sound in this video was likely because it was filmed inside an SK-60

 

^ Go to 2:50 for the sound I was talking about as the pilot goes full-mil for the reverser, but at 4:10 I wonder if our AJS will sound like this externally? :D (BTW this video is amazing)

Edited December 22, 2016 by Ice_Cougar

[Ice_Cougar]

BTW guys and gals, please tell me if the links work or not. If they don't, here are the two:

 

Go to 9:18 ^

 

^ Go to 2:50 for the sound I was talking about as the pilot goes full-mil for the reverser, but at 4:10 I wonder if our AJS will sound like this externally? (BTW this video is amazing)

[Agremont]

I'm sorry but the videos aren't working.

 

Edit: There they are.

[Ice_Cougar]

I'm sorry but the videos aren't working.

 

Edit: There they are.

 

Gah! Figured. Check out the first comment of the thread for the links and their instructions :cry:

[unknown]

I don't know anything helpful about the RL Viggen to help you. The only thing i know is that the sound of the Viggen is not final, i think cobra mentioned that they have sounds that needet to be implemented by ED because they don't have the tools to do it themself.

 

For your YT videos, edit your first post like in the attached pic and they will work like intended.

 

 

[Pizzasalladland]

One thing I am pretty certain of is that the first video is most probably filmed from a Saab 105 (SK60) trainer, and that is the engine sound they mostly make. So at 9:18, it should not be the RM8 we are hearing.

[Flappie]

Here's a video of a flight aboard the Saab 105. Pizzasalldland seems right.

 

[Ice_Cougar]

I don't know anything helpful about the RL Viggen to help you. The only thing i know is that the sound of the Viggen is not final, i think cobra mentioned that they have sounds that needet to be implemented by ED because they don't have the tools to do it themself.

 

For your YT videos, edit your first post like in the attached pic and they will work like intended.

 

My god thank you so much :D

[Ice_Cougar]

One thing I am pretty certain of is that the first video is most probably filmed from a Saab 105 (SK60) trainer, and that is the engine sound they mostly make. So at 9:18, it should not be the RM8 we are hearing.

 

Here's a video of a flight aboard the Saab 105. Pizzasalldland seems right.

 

 

I concur with both of you. Thanks for the comments! :thumbup:

[AdurianJ]

According to the now dormant Blog of "Chefsingengören" who is an ex Viggen pilot the JT-8D (RM8A) engine's Afterburner has a 108hp fuel pump and a 10cm(4-inch) fuel line.

It guzzles fuel so quickly you can run out of fuel in the main tank without being out of fuel because the interlinking pumps (to wing tanks etc) can't keep up.