HVAR recoil

[Destroyer37]

Yeah, my gut tells me there has to be something going on when the rocket comes off the rails... but I have no real world experience to say yay or nay...

 

Then perhaps we should leave it up to official documentation, and professional airmen the likes of which typically know what they are talking about...

[NineLine]

Then perhaps we should leave it up to official documentation, and professional airmen the likes of which typically know what they are talking about...

 

Which professional airmen stated this? You guys scoffed at me wanting to try and find a pilot like ED has for the German planes, but we are back to a line from the manual again? I think I am done with this thread, I can do my own (and currently am) research.

[Destroyer37]

Which professional airmen stated this? You guys scoffed at me wanting to try and find a pilot like ED has for the German planes, but we are back to a line from the manual again? I think I am done with this thread, I can do my own (and currently am) research.

 

Best of luck to you sir, just because this is a video game doesn't mean that professional airmen haven't had a say in this thread already.

Edited July 16, 2015 by Destroyer37
added after the ,

[NineLine]

Best of luck to you sir, just because this is a video game doesn't mean that professional airmen haven't had a say in this thread already.

 

Dont start twisting words, you know what I meant, and what I am looking for, if there are any WWII vets here that have fired HVAR's by all means, speak up.

[rcjonessnp175]

Well I think the bottom line is the in game effect should be toned down a bit. It's like the sounds in many aircraft they are overly gamey because we can't feel acceleration and such that's how I see these rockets. Just an over exaggeration of an effect to make you feel it. I vote everybody should have butt kickers and then it will be better with toned down more realistic effects if it is deemed more realistic.

[Destroyer37]

Dont start twisting words, you know what I meant, and what I am looking for, if there are any WWII vets here that have fired HVAR's by all means, speak up.

 

I may have and then again I might not have, unfortunately we have to take everything that is written in this forum as black and white with no interpretation whatsoever. Its hard to get peoples tones or emotions in writing at least for me. Let me know if you find anything interesting as I would love to continue to discuss this with you.

[SmokeyTheLung]

Do you mean 2:47? I see very pronounced yaw during the launch.

 

Yes, around there. Agreed as to the yaw but it's the opposite yaw then we see in DCS ...I think? It's been many months since I've flown the DCS P-51.

It's also interesting that at 4:02 it's much more stable (at least to my eye). It would be amazing to find a pilot from those times and ask him!

[Destroyer37]

It would be amazing to find a pilot from those times and ask him!

 

Agreed, it may be a long shot but has anyone from ED ever tried to contact Chuck Yeager? He is active on facebook...

 

I've sent him a question regarding this subject. I will let you know if he responds

Edited July 16, 2015 by Destroyer37
Contacted Gen. Yeager about the issue revised post.

[rcjonessnp175]

Agreed, it may be a long shot but has anyone from ED ever tried to contact Chuck Yeager? He is active on facebook...

 

I've sent him a question regarding this subject. I will let you know if he responds

 

Lol I posted on his page too think it's awaiting approval

[Destroyer37]

Doesn't hurt to ask right?!?!?

[Sporg]

 

Here's an interesting few clips. Unknown aircraft and weapons. As far as I can tell the pilot(s) are firing single rockets instead of pairs, which seems quite rare going by gun camera archives (it's sometimes hard to tell because of the placement of the gun camera). Maybe you can get some information from watching.

 

Check out 4:02 and 2:43

 

Do you mean 2:47? I see very pronounced yaw during the launch.

 

It's interesting, I wrote a reply earlier, but decided not to post it.

But seeing this movie, especially at 2:47, makes me think again.

 

My conclusion was, that what we should see is a slight yaw forward when the rocket is fired, and for me that is exactly what we see here.

Notice when every single rocket is fired, there is yaw forward from that side.

 

For the clip at 4.02 I am speculating that if the guns are fired at the same time, they have a stabilizing effect due to much larger forces?

 

Here comes my speculation:

 

When looking at the P-51 manual and the description of the launcher, I would agree with OP that at most there should be a slight forward motion when firing a rocket, possibly partially cancelled right after due to effects of the rocket blast hitting the launcher.

But no "recoil" other than that.

 

https://books.google.se/books?id=SfwqCTY9I6MC&pg=PA43&lpg=PA43&dq=p-51+rocket+recoil&source=bl&ots=hPHH0AZMH3&sig=lHYQfBy4mqnqB2xnIp0ZXM2vOiQ&hl=da&sa=X&ved=0CDEQ6AEwAmoVChMI1p_31O3dxgIVp5tyCh0uWg-E#v=onepage&q=p-51%20rocket%20recoil&f=false

 

As I understand it, the HVARs used zero-length rail launchers, which means that the only direct mechanical effect when firing the rocket, would be the forward pull until the safety wire was broken and released the rocket.

 

Trying to break down the order of physical events affecting the wing, I would estimate something like the following:

 

1. Rocket ignition

a) pull forward, cancellation of rocket drag

b) pull forward, against launcher lock mechanism

2. Rocket release

a) slight snap as rocket locking mechanism releases

(cancellation of 1.b)

b) motion forwards due to less drag since the rocket is no longer there

(equal to 1.a)

c) slight motion upwards due to less weight on the wing since the rocket is no longer there.

3. Rocket flight:

a) possible slight push backwards on wing from rocket blast

b) maybe slight loss of lift due to hot fast jet stream and gases passing under the wing

Regarding force 3.a:

I would estimate this force to be less than if the rocket was launched from a tube, since the tube would have a much bigger affected area than the affected underside part of the wing plus the launcher mounts.

 

Estimating the resulting forces, I would make the following conclusions:

1. Force 1.a, elimination of drag, would pull the wing forward

2. Force 1.b would pull the wing forward until release pressure is achieved

When release pressure is achieved, the rest of the force events would happen in short order:

3. Force 1.b would be eliminated by event 2.a

4. Force 1.a would be exchanged with force 2.b

5. Force 2.b would be momentarily reduced by force 3.a

6. Force 2.c would be momentarily reduced by force 3.b

Summarizing the results, my estimation would be, that the pilot would experience the wing being pulled slightly (maybe even negligible) forward when firing a rocket, followed by a snap as the launcher opens.

This force would be equal to the elimination of drag of one rocket plus its release force.

After that he would experience the elimination of drag and weight equal to one rocket.

 

So,the result is:

First force 1.a + 1.b, mechanical snap, then force 2.b + 2.c (= 1.a + 2.c)

Does this make some sense?

 

 

 

PS I of course think that it will be interesting if we can get some WW II pilot feedback on this as well.

[Destroyer37]

It's interesting, I wrote a reply earlier, but decided not to post it.

But seeing this movie, especially at 2:47, makes me think again.

 

My conclusion was, that what we should see is a slight yaw forward when the rocket is fired, and for me that is exactly what we see here.

Notice when every single rocket is fired, there is yaw forward from that side.

 

For the clip at 4.02 I am speculating that if the guns are fired at the same time, they have a stabilizing effect due to much larger forces?

 

Here comes my speculation:

 

When looking at the P-51 manual and the description of the launcher, I would agree with OP that at most there should be a slight forward motion when firing a rocket, possibly partially cancelled right after due to effects of the rocket blast hitting the launcher.

But no "recoil" other than that.

 

https://books.google.se/books?id=SfwqCTY9I6MC&pg=PA43&lpg=PA43&dq=p-51+rocket+recoil&source=bl&ots=hPHH0AZMH3&sig=lHYQfBy4mqnqB2xnIp0ZXM2vOiQ&hl=da&sa=X&ved=0CDEQ6AEwAmoVChMI1p_31O3dxgIVp5tyCh0uWg-E#v=onepage&q=p-51%20rocket%20recoil&f=false

 

As I understand it, the HVARs used zero-length rail launchers, which means that the only direct mechanical effect when firing the rocket, would be the forward pull until the safety wire was broken and released the rocket.

 

Trying to break down the order of physical events affecting the wing, I would estimate something like the following:

 

1. Rocket ignition

a) pull forward, cancellation of rocket drag

b) pull forward, against launcher lock mechanism

2. Rocket release

a) slight snap as rocket locking mechanism releases

(cancellation of 1.b)

b) motion forwards due to less drag since the rocket is no longer there

(equal to 1.a)

c) slight motion upwards due to less weight on the wing since the rocket is no longer there.

3. Rocket flight:

a) possible slight push backwards on wing from rocket blast

b) maybe slight loss of lift due to hot fast jet stream and gases passing under the wing

Regarding force 3.a:

I would estimate this force to be less than if the rocket was launched from a tube, since the tube would have a much bigger affected area than the affected underside part of the wing plus the launcher mounts.

 

Estimating the resulting forces, I would make the following conclusions:

1. Force 1.a, elimination of drag, would pull the wing forward

2. Force 1.b would pull the wing forward until release pressure is achieved

When release pressure is achieved, the rest of the force events would happen in short order:

3. Force 1.b would be eliminated by event 2.a

4. Force 1.a would be exchanged with force 2.b

5. Force 2.b would be momentarily reduced by force 3.a

6. Force 2.c would be momentarily reduced by force 3.b

Summarizing the results, my estimation would be, that the pilot would experience the wing being pulled slightly (maybe even negligible) forward when firing a rocket, followed by a snap as the launcher opens.

This force would be equal to the elimination of drag of one rocket plus its release force.

After that he would experience the elimination of drag and weight equal to one rocket.

 

So,the result is:

First force 1.a + 1.b, mechanical snap, then force 2.b + 2.c (= 1.a + 2.c)

Does this make some sense?

 

 

 

PS I of course think that it will be interesting if we can get some WW II pilot feedback on this as well.

I don't know that 3b would apply, but it is an interesting theory and everything seems to make sense!

[johnv2pt0]

but we are back to a line from the manual again?

 

Not trying to stir the pot, but why is this a bad argument? Things are written in these manuals for a reason. Programming off the manuals should be the rule and not the exception. There can be slight differences between things written for an operator's eyes vs an engineer's eyes, but in this case that would read something like "there's virtually no recoil" or "recoil is marginal."

 

That is, unless ED has had lots of experience with official manuals stating false information?

 

I think a good question here is to ask why ED felt the need to program it this way in the first place? What spurred that change? If it wasn't based off of anything except gut feelings or trying to change gameplay mechanics then it should be changed back to what official documents state without further ado.

[NineLine]

Not trying to stir the pot, but why is this a bad argument?

 

Because there is enough to question what happens when a rocket releases from the rail. Just using examples of other rocket systems both from video or personal experiences.

 

How or why it was programmed the way it was I cant answer, I would assume based on their own experience programming similar systems. So we are at the point that its worth looking into, but to change something, we need a little more. I have requested a number of documents from a source I have found directly related to the subject. I hope I can get those in a timely fashion and they will shed more light on it.

[Destroyer37]

Because there is enough to question what happens when a rocket releases from the rail. Just using examples of other rocket systems both from video or personal experiences.

 

How or why it was programmed the way it was I cant answer, I would assume based on their own experience programming similar systems. So we are at the point that its worth looking into, but to change something, we need a little more. I have requested a number of documents from a source I have found directly related to the subject. I hope I can get those in a timely fashion and they will shed more light on it.

 

I personally think things got off track when people started comparing HVAR rockets to Katushas and other systems that aren't even airborne. I agree with the previous poster that every DCS aircraft and associated system and subsystem should be based off the manual as a rule. But as a supporter of ED and DCS I can say that I am fairly happy with the modules we currently have and I appreciate the team going back to look at this issue.

[Yo-Yo]

I see the yaw you are seeing however if you reference the follow up shots of 2 there is no yaw whatsoever which makes me think that the pilot was hitting his rudder to get onto target at the last second.

 

Rudder never must be used to aim rockets. It's alpha and omega of rocket firing. I mean weathervane effect forcing rockets not to follow plane nose.

[johnv2pt0]

Because there is enough to question what happens when a rocket releases from the rail. Just using examples of other rocket systems both from video or personal experiences.

 

The only evidence I saw was one of the latest videos with two sections of rocket runs. The first 3 shots looks like PIO to me and once he gets coordinated again, the fourth flys true. The second clip shows absolutely zero hint of any type of recoil forces. That's the only evidence I've seen so far...everything else has been different weapons from different platforms. I mean, ED is smart enough to build AFMs so they're smart enough to recognize differences between an air launched weapon and it's minimal interaction with the airframe to a jeep mounted weapon catching most of the blast as the shot is fired.

 

Another avenue to try to confirm the legitimacy of the documentation stating lack of recoil might be to look at the documentation for other airframes that have fired tube launched rockets because we know there's a felt interaction there. I believe someone said he flew with them on a helo back in the day. If that documentation specifically talks about ttps to overcome the "recoil" or whatever yawing moment the pilot feels, then you can be doubly sure the documentation about no recoil from hvars is accurate. There would be guidance for the pilot on how to most effectively counter the inherent problem of recoil (if there was one). If the more modern tube launched system doesn't mention any felt recoil, well then all bets are off on the hvars, and I wouldn't have a problem just letting it be the way it is lacking better info.

 

It will be interesting to see what if anything comes of this regardless. If there is a great reason why it's in the sim I'd love to learn it.

 

Rudder never must be used to aim rockets. It's alpha and omega of rocket firing. I mean weathervane effect forcing rockets not to follow plane nose.

 

Just because you aren't supposed to do something doesn't mean a pilot won't do it anyway in a combat environment...especially when it's something so easy to mess up as being a little hard on the rudder during an attack run.

Edited July 16, 2015 by johnv2pt0

[RoflSeal]

 

First P-47 looks like it fires off 1 rocket off the port wing

[Captain Orso]

 

Here's an interesting few clips. Unknown aircraft and weapons. As far as I can tell the pilot(s) are firing single rockets instead of pairs, which seems quite rare going by gun camera archives (it's sometimes hard to tell because of the placement of the gun camera). Maybe you can get some information from watching.

 

Check out 4:02 and 2:43

 

If you set the speed of viewing the film to 0.25 by going into the settings menu (click on the gear in the lower-right corner) it makes it much easier to analyze the film.

 

In the 2:43 section after the first (right-hand) rocket is fired there is a yaw to the left, but it does not correspond directly to the firing of the rocket for the rocket is far ahead when the yaw starts. After the second (left-hand) rocket is fired the aircraft pulls up some. After the third rocket is fired the nose is pushed down and to the left some, then the fourth rocket fires and the aircraft pulls up. All the airframe motions appear to me to be deliberately controlled.

 

In the 4:02 section of the file after each of the two rockets are fired there is no change to the vector of the airframe at all.

[Captain Orso]

 

First P-47 looks like it fires off 1 rocket off the port wing

 

I've seen that film before too. The reason I haven't posted it is because you cannot see any recoil or yawing, and I cannot say from the fly-by perspective of the film, if there really were recoil or yaw if one might see it in this film. To me, the absence of seeing something from that perspective is not proof of it not being there.

 

Thanks for posting it anyway though :thumbup:

[HeadHunter52]

A view from inside the cockpit, from a fixed camera mount, would be the best indicator, from my opinion. A camera man may not be steady, and is moving to track a fly by.

 

As for rudder, I have no issues using rudder to line up and HOLD position if need be. Sometimes I don't have time to trim the rudder to correct slip. Using rudder pedals to get slip centered is valid - if you can pull it off. Generally, when I'm pressed for time, it is because I'm pretty close to the target, so my accuracy requirements reduce by a tad.

 

Anyway, I sometimes fire 2 or 4 on a pass, very quickly, and they tend to cancel out the recoil motion, especially on the 3rd and 4th. Works for me....

[Schnarre Aggro]

Chuck Yeagers opinion on this subject ;)

 

https://www.facebook.com/pages/Chuck-Yeager/465193060493?fref=nf

 

just my 2cent

[Holbeach]

;2434406']Chuck Yeagers opinion on this subject ;)

 

https://www.facebook.com/pages/Chuck-Yeager/465193060493?fref=nf

 

just my 2cent

 

 

I just love that answer.

 

 

..

[Captain Orso]

;2434406']Chuck Yeagers opinion on this subject ;)

 

https://www.facebook.com/pages/Chuck-Yeager/465193060493?fref=nf

 

just my 2cent

 

Simply that Chuck Yeager answered a forum question, even if indirectly, is the awesome-sauce squared :clap_2:

[Sporg]

;2434406']Chuck Yeagers opinion on this subject ;)

 

https://www.facebook.com/pages/Chuck-Yeager/465193060493?fref=nf

 

just my 2cent

 

Well, that's a pretty clear answer right there. :)

 

Actually, it could be very interesting if ED could have an interview and test flight session with Mr. Yaeger, like they did with Erich Brunotte in "Revisiting The Dora".

Edited July 17, 2015 by Sporg