HVAR recoil

[msalama]

What would be acceptable proof?

What little we know so far seems to indicate something is suspect. But if you want to change things, you must be able to quantify the problem exactly or you won't have a proper solution to it. I.e. you either fix it right, or suffer possible unintended consequences later on ;)

[Destroyer37]

Patience is a virtue, I have to agree with Sithspawn on this one. Don't expect anything soon. 2.0 is the big push ATM.

[[DBS]TH0R]

Patience is a virtue, I have to agree with Sithspawn on this one. Don't expect anything soon. 2.0 is the big push ATM.

 

Agreed. Simple confirmation that they may look into it again would suffice for the time being.

[Destroyer37]

Well thank goodness we got that taken care of!

[ShuRugal]

First, nobody has discounted anything as unreliable. Its simple stated that when you have an engineer who knowns the effects of certain things, such as rockets, its fair to question other sources. So the manual wasnt enough to completely disprove what we have modelled. Knee-jerk changes wont get us anywhere.

 

Mr Yeager was kind enough to answer a number of people on a question of recoil of the rockets. As well, I have requested a number of documents on development and testing of the HVAR rockets which I am still waiting on. Once we can gather all that, we can determine the best course of action.

 

Realize that this probably wont be a priority fix, it wont come out till after or during the 2.0 release if a fix is deemed necessary. It may depend on how long it takes to get these new docs. So be patient and dont get carried away with conspiracy theories about ED not wanting to change HVARs, it just has to go through the standard processes.

 

There's no need for documentation or evidence when simple physics will suffice: The wing has no interaction whatsoever with the means of propelling the rocket forward. The rocket is propelled forward solely by the stream of expanding exhaust gasses being accelerated out the rear of the rocket body. This exhaust stream has no interaction with the wing, except for when the plane flies through the very-nearly stationary trail of combustion products. The process of accelerating the rocket forward transfers exactly zero rearward force into the wing.

 

The HVAR release mechanism is solenoid operated, and the rocket motor is ignited simultaneously with the release of the rocket (source), which means that at the time of the rocket being ignited, it is no longer even physically in contact with the launching aircraft. In this condition, it is flat out impossible for the rocket to exert a recoil force on the plane. The only thing the plane would notice is the loss of the weight of the rocket, which is nearly negligible and would certainly NOT kick the wing back and down.

[NineLine]

 

The HVAR release mechanism is solenoid operated, and the rocket motor is ignited simultaneously with the release of the rocket (source)

 

 

Not sure that is how it worked on the P-51 in the 40's, but regardless, as I said... its being looked at.

[Holbeach]

There's no need for documentation or evidence when simple physics will suffice: The wing has no interaction whatsoever with the means of propelling the rocket forward. The rocket is propelled forward solely by the stream of expanding exhaust gasses being accelerated out the rear of the rocket body. This exhaust stream has no interaction with the wing, except for when the plane flies through the very-nearly stationary trail of combustion products. The process of accelerating the rocket forward transfers exactly zero rearward force into the wing.

 

The HVAR release mechanism is solenoid operated, and the rocket motor is ignited simultaneously with the release of the rocket (source), which means that at the time of the rocket being ignited, it is no longer even physically in contact with the launching aircraft. In this condition, it is flat out impossible for the rocket to exert a recoil force on the plane. The only thing the plane would notice is the loss of the weight of the rocket, which is nearly negligible and would certainly NOT kick the wing back and down.

 

Nicely put.

 

I'd like to add.

 

A rocket is self propelling and is the reason why it imparts no rearward force on the launch mechanism and this applies to ALL rockets, not just the HVAR.

 

The DCS recoil is also present in other rockets, e.g. S-24 on the Mig-21 and maybe others.

 

 

..

[Holbeach]

Not sure that is how it worked on the P-51 in the 40's, but regardless, as I said... its being looked at.

 

It's described in the RL P-51 manual.

 

 

..

[Oydoron]

The HVAR release mechanism is solenoid operated, and the rocket motor is ignited simultaneously with the release of the rocket (source), which means that at the time of the rocket being ignited, it is no longer even physically in contact with the launching aircraft. In this condition, it is flat out impossible for the rocket to exert a recoil force on the plane. The only thing the plane would notice is the loss of the weight of the rocket, which is nearly negligible and would certainly NOT kick the wing back and down.

 

Actually if you'd read the thread and the P-51 manual, you'd see that the rocket is released when it's built up enough thrust to snap the retaining cable. This could impart a small reverse recoil.

[Captain Orso]

The force required to break the safety-wire is not enough to affect the flight attitude of the airframe.

[NineLine]

The force required to break the safety-wire is not enough to affect the flight attitude of the airframe.

 

Based on? I am not saying I disagree, but you have to back those statements up. So again, ED is investigating.

[Captain Orso]

Based on? I am not saying I disagree, but you have to back those statements up. So again, ED is investigating.

 

Based on 1. the manuals, and 2. the lack of any other evidence that the manuals are not representing the facts.

 

Maybe I'm just a grumpy ol' bear, but it gets tiring reading all the 'I think it might be...' posts.

 

What does kind of perk my curiosity is what motivated ED to put it in the first place. I would be very surprised if it were based on just an 'I think it might be...'.

[NineLine]

Based on 1. the manuals, and 2. the lack of any other evidence that the manuals are not representing the facts.

 

Maybe I'm just a grumpy ol' bear, but it gets tiring reading all the 'I think it might be...' posts.

 

What does kind of perk my curiosity is what motivated ED to put it in the first place. I would be very surprised if it were based on just an 'I think it might be...'.

 

Well if I were to get nit picky I could say that the manual doesnt say "The force required to break the safety-wire is not enough to affect the flight attitude of the airframe." It says there is no recoil, it doesnt say there isnt other forces on the aircraft/wing/whatever. Anyways, as I said, its being looked at, its not a blocking issue, if anything its a mild annoyance if it is indeed wrong.

 

As for what ED based the current effect on, only ED could truly answer. In things such as poorly documented or hard to find documents, educated guesses might need to be taken based on other weapon systems and such. I am NOT saying that is the case here, but I know some information is hard to come by or lost to the ages.

[Tucano_uy]

Come on guys, documents (manual and videos) and qualified testimony was obtained against the recoil, Sithspawn said that it is being investigated and that he requested some documents, please stop picking on ED and give them some time.

If there's anything like "programmer's pride" as somebody said or " stubborness" as I did, keeping this thread going and going is not going to help. Let's just wait and see.

 

Just my opinion.

[NineLine]

Its purely workload right now, Yo-Yo is extremely busy. It's that simple.

[Tucano_uy]

Yo-Yo is extremely busy. .

 

That surely is a good thing!

[Destroyer37]

Thanks ED and Sith for taking a look at this we all really appreciate it.

[Pilum]

To be honest, I have not read through the entire thread but I don’t think it is as simple as a Newtonian physics analysis looking at the rocket, rail and exhaust plume balance in isolation because the exhaust plume will introduce a ”source” of high speed flow medium being generated in close proximity to the wing. This will change the flow field both behind and (since the flow is subsonic) in front of the wing.

 

So since the flow field will changes around the wing this will most likely produce some up- or downward translational and pitching forces as well as either an acceleration or retarding horizontal force on the plane even if the rocket/rail/exhaust gases were in perfect balance.

 

The question of exactly how large or significant this effect would be would probably best be judged by experiments or CFD but IMHO it is not possible to judge purely by reasoning. :)

[MTFDarkEagle]

Interesting subject and something I felt was wrong all along in DCS..

 

I also went ahead and asked Dudley Henriques. Interested to see what he says on the subject.

[Deano87]

Just to add my 2 cents.

 

My father flew in the RAF for many years in the ground attack role mainly flying Hawker Hunters and went on to becomes a weapons flying instructor on Hunters, Jaguars and Hawks serving in Aden, Bahrain, Germany and Oman.

 

Over his many years of operation he has fired many types of ordinance from various aircraft including the '3 inch drain' from the Hunter and SNEB style rockets from the Jaguar. I have just asked him about recoil and he says that no recoil would be noticed.

 

I asked him about firing a rocket from only one side at a time and he said that in the Hunter you would get no yaw while firing a single rocket from one wing. Assuming you still had a rocket on the other wing you would get a very slight roll towards that wing (because of the weight of the remaining ordinance) , but this would be barely perceptible and corrected instinctively by the pilot.

 

Any other questions you want me to ask him. Let me know.

 

D

[Holbeach]

That's the kind of anecdote I absolutely love.

 

 

..

[Bulldog51]

Just to add my 2 cents.

 

My father flew in the RAF for many years in the ground attack role mainly flying Hawker Hunters and went on to becomes a weapons flying instructor on Hunters, Jaguars and Hawks serving in Aden, Bahrain, Germany and Oman.

 

Over his many years of operation he has fired many types of ordinance from various aircraft including the '3 inch drain' from the Hunter and SNEB style rockets from the Jaguar. I have just asked him about recoil and he says that no recoil would be noticed.

 

I asked him about firing a rocket from only one side at a time and he said that in the Hunter you would get no yaw while firing a single rocket from one wing. Assuming you still had a rocket on the other wing you would get a very slight roll towards that wing (because of the weight of the remaining ordinance) , but this would be barely perceptible and corrected instinctively by the pilot.

 

Any other questions you want me to ask him. Let me know.

 

D

and to second this answer from Yeager himself it should set aside any other further assumptions about recoil. Lets all hope this gets fixed!!

https://www.facebook.com/permalink.php?story_fbid=10155791345370494&id=465193060493

Edited September 21, 2015 by Bulldog51

[ShuRugal]

Any chance of seeing this fixed in the foreseeable future?

[jimcarrel]

If there was recoil, I doubt there would have been many GI's itching to fire a bazooka. same open-ended principal.

[Captain Orso]

If you want to make a reality argument, you cannot say, one rocket-firing weapon system doesn't have recoil, therefore no rocket-firing weapon system has recoil. Correlation does not prove causation.

 

If you want to take the time to read through this thread, you will find numerous gun camera videos of P-51's firing rockets, and these videos show that there was no recoil.

 

Additionally, one of the participants in this thread wrote to Check Yeager on Facebook to ask about recoil and got this answer: HVAR recoil: Post# 159.

 

This all is real evidence of no recoil.