Author Topic: Rockets Bug  (Read 647 times)

Offline Krusty

  • Radioactive Member
  • *******
  • Posts: 26745
Rockets Bug
« on: May 06, 2005, 07:14:32 PM »
I heard about this a while back, but I thought it was fixed. Guess not!

Rockets fly along the path of the aircraft, NOT the direction you are pointing. Took up the 190F8 to test out the panzerblitz rockets... I was lined up, but drifted to the side, way off target, so Iadjusted with rudder, the pipper was dead on, fired off 2 rockets, and Lo, Behold! They landed where my sight was when I found it was drifting. That is to say I had adjusted with rudder but the rockets flew along my PATH, not along my AIM.

That's a half-assed way of having rockets fly, eh? Bullets adjust to rudder input, bombs and rockest should as well, or there's no point. Nobody is ever going to have 100% no-drift aim for rockets every time. Rudder input is necessary.

Offline GunnerCAF

  • Silver Member
  • ****
  • Posts: 946
      • Gunner's Grange
Rockets Bug
« Reply #1 on: May 06, 2005, 09:05:39 PM »
Quote
That's a half-assed way of having rockets fly, eh? Bullets adjust to rudder input, bombs and rockest should as well, or there's no point. Nobody is ever going to have 100% no-drift aim for rockets every time. Rudder input is necessary.


Real physics is anoying :)  I am not an expert on the topic, but I would bet an iron bomb is going to fall in the direction it is moving, not the direction it's pointed.  

Rockets have fins like an arrow, so I would also think they would want to go the direction they are moving (the direction of the plane, not the direction they are pointed).  

Bullets have no fins, and leave the barrell at a high velocity, they should be able to be controled more by Yaw.

I think this is the way it works in the game.

Gunner
Gunner
Cactus Air Force

Offline Krusty

  • Radioactive Member
  • *******
  • Posts: 26745
Rockets Bug
« Reply #2 on: May 06, 2005, 09:48:43 PM »
The rockets are lined up with the fuselage of the craft. they are parallel, let's say. The wings are attached to the fuselage and the rocket rails are attached to the wings. The rockets launch off these rails.

You yaw and fire.. well your plane turns, thus your wings and thus the rocket rails, THUS THE ROCKETS turn! Tada! The rockets are now facing a new direction. So the fins should HELP them fly in that direction, instead of skidding forward.

But the way I heard about the bug, if you're in a flat spin and fire off your rockets they will shoot straight down (the direction you're falling) regardless of the way you are aiming.

Like I said, bass ackwards ;)

Offline GunnerCAF

  • Silver Member
  • ****
  • Posts: 946
      • Gunner's Grange
Rockets Bug
« Reply #3 on: May 06, 2005, 11:51:11 PM »
Say your going 300 mph N, you yaw NNW, when the rocket comes off the rail it is going 300 mph N but pointing NNW.  The rocket has fixed fins and will point back to the N and will accelerate N.

There may be a bug there, but it seems right to me.

Gunner
Gunner
Cactus Air Force

Offline Krusty

  • Radioactive Member
  • *******
  • Posts: 26745
Rockets Bug
« Reply #4 on: May 07, 2005, 10:12:26 AM »
The rocket is not released. It is propelled really fast at a forward rate. A rate determined by the angle it is pointing and stabilized by those fins. A bomb would skid forward yes. But the rockets would auto correct. The rails, the rocket motor, and the fins, all act to make the rocket follow the nose of the plane.

Offline Lye-El

  • Silver Member
  • ****
  • Posts: 1466
Rockets Bug
« Reply #5 on: May 07, 2005, 10:26:13 AM »
Would they not "Weathervane" and attempt to align with the relative wind? i.e. with the direction of travel. At least until the rocket motor overcomes the speed of the aircraft in an off axis shot. I would expect it to not hit where you think it should.


i dont got enough perkies as it is and i like upen my lancs to kill 1 dang t 34 or wirble its fun droping 42 bombs

Offline Clifra Jones

  • Silver Member
  • ****
  • Posts: 1210
Rockets Bug
« Reply #6 on: May 07, 2005, 12:18:09 PM »
Quote
Originally posted by Lye-El
Would they not "Weathervane" and attempt to align with the relative wind? i.e. with the direction of travel. At least until the rocket motor overcomes the speed of the aircraft in an off axis shot. I would expect it to not hit where you think it should.


Yes you correct, they will weathervane untul the motor overcomes the drag of the forward motion "wind". This will cause your aim to be off if you are skidding when you fire.

Krusty, most rockets/missles (now I don't know if this is modeled in AH) are dropped a fraction of a second prior to the motor igniting. I believe this is to prevent the rocket motor from setting the plane on fire. This is why they will **** towards the forward motion of the aircraft. Even the smallest amount of deflaction at the launch point will translate into a large deviation from the intented target depending on range to target.

Offline Krusty

  • Radioactive Member
  • *******
  • Posts: 26745
Rockets Bug
« Reply #7 on: May 07, 2005, 06:36:59 PM »
Correction, most MISSILES are dropped, and those are modern things like AIM-5s and so forth. Most ROCKETS (air to ground stuff) are launched off the rails (like a model rocket kits has loops that slide onto the launch rail), and they are literally slotted onto those rails when put on by the ord crew. This would negate most sliding.

Offline GunnerCAF

  • Silver Member
  • ****
  • Posts: 946
      • Gunner's Grange
Rockets Bug
« Reply #8 on: May 08, 2005, 10:04:39 AM »
Modern rockets are guided and when they are dropped they stear to their target.  The dumb rockets used here are un-guided and have fixed fins.  

The sliding comes from the initial speed and direction.  When you move your rudder, the nose yaws away from your direction of travel.  The rocket is also starting out with that initial speed and slip plus it gets vectored for an instant in the direction it is pointing until it leaves the rail.  When it reaches the end of the rail, it will point back to the direction it is moving.  I agree that the thrust of the rocket will change it course, but it will not continue to travel the direction it's pointed.  The result is when you move the rudder, you don't know where the rockets are going to go. :)

To make a good rocket hit, you need to have your aircraft diving in a clean dive pointing at the target when you release the rockets.  A zero G drop is best to get consistant hits.  The same goes for bombs. It isn't easy.

The good thing... I am sure HTC will see this on Monday and if there is a problem, they will fix it.  I can never hit anything with rockets anyway. :D

Gunner
Gunner
Cactus Air Force

Offline Krusty

  • Radioactive Member
  • *******
  • Posts: 26745
Rockets Bug
« Reply #9 on: May 08, 2005, 11:53:31 AM »
I find it more likely that a rocket launching straight off rails and with stabilizing fins and a powerful rocket motor propelling it along the path of those rails and fins would overcome any sliding momentum almost immediately (we ARE talking about a light weight object with very little surface area, what little inertia it has would be overcome quickly).

However, don't confuse accurate modeling with a flaw in the way AH fires rockets. That doesn't explain rockets firing downward when you're in a flat spin. I'm going to see if I can recreate this event sometime today (when I get the chance)... I think P38 with its infamous spin would be a good test bed.

Offline GunnerCAF

  • Silver Member
  • ****
  • Posts: 946
      • Gunner's Grange
Rockets Bug
« Reply #10 on: May 08, 2005, 12:22:15 PM »
E=1/2MV(squared)

The energy of a moving object is one half the mass times the square of the speed.  As the speed increases, the kenetic energy in the rocket, even if it is relatively light, comes from the speed.  From the energy formula, I have a feeling at high speeds, the kenetic energy of the rocket is is going to have a huge effect on the direction it go.

The same thing may happen if your in a flat spin falling at a high rate of speed.  If you test this, see if you can get in flat spin from high alt dropping at a high speed.  I would guess you may be able to get the rockets to drop down, if the physics are right :)

Gunner
Gunner
Cactus Air Force

Offline Krusty

  • Radioactive Member
  • *******
  • Posts: 26745
Rockets Bug
« Reply #11 on: May 08, 2005, 02:25:25 PM »
No. you're thinking they're unpowered. The rocket motor itself has the greatest impact on the flight of the rocket. Most release speeds are going to be 250-(max)300. The rocket is going at least 500 or more when fired. You can NOT tell me with any seriousness that a plane falling in a flat spin (yawing but upright and falling straight down) is going to fire rockets off rails with stabilizer fins and have them FLY DOWN? *cough*BS*cough*.

The rockets would fly outward in a circular pattern depending where the nose was pointed at the time they were fired.

Puh-leaze

Offline GunnerCAF

  • Silver Member
  • ****
  • Posts: 946
      • Gunner's Grange
Rockets Bug
« Reply #12 on: May 08, 2005, 06:35:21 PM »
Quote
Originally posted by Krusty
No. you're thinking they're unpowered. The rocket motor itself has the greatest impact on the flight of the rocket. Most release speeds are going to be 250-(max)300. The rocket is going at least 500 or more when fired. ...
Puh-leaze


No, I am thinking the rocket motors of WW2 did not accelerate the rockets from 250MPH to over 500MPH in the lenght of the rail (maybe 4 feet)  But I am not a rocket scientist, and I did not stay at a Holiday Inn last night .

I think the force of the rocket motor will be small compared the the kenetic energy of the rocket when it leaves the rail, causing it to turn the direction of the kenetic energy of the rocket (the direction it is moving).  The rocket continues to accelerate, but not in the direction it was pointing when released.  I don't have the specs on the rocket, so I can't prove this.  Even if I did, for some reason, I don't think you would believe me anyway :)

I am thinking the problem is, in real life, the rockets would most likely hang up on the rail when fired in extreme conditions.  

Gunner
Gunner
Cactus Air Force

Offline Krusty

  • Radioactive Member
  • *******
  • Posts: 26745
Rockets Bug
« Reply #13 on: May 08, 2005, 06:42:52 PM »
No, if the rocket motor were so weak that the fins automatically dug into the wind and turned it to the direction of the skewing aircraft, then the thing would drop to the ground. Rocket motors burn fast and die quickly. Anybody that's seen a model rocket in flight knows this. They accelerate within a couple of seconds. They are more powerful than you think. The entire tube of the rocket is the motor (in real life, not model rockets) and the rocket fuel housing. All of that is propelling it forward at high acceleration.
« Last Edit: May 08, 2005, 06:46:04 PM by Krusty »

Offline Krusty

  • Radioactive Member
  • *******
  • Posts: 26745
Rockets Bug
« Reply #14 on: May 08, 2005, 06:44:27 PM »
As a side tangent, and this is in no way proof, but is suggestive, every other game I've ever played made air-to-ground rockets fire at the direction the nose was pointing (whether rail-mounted as in WW2, or pod/tube mounted as in jet era)