CATshot Speeds?

[cochise 0]

Hi all, I remember reading somewhere on the forum about how to edit the speed at which aircrafts are shot off of carriers but I can't seem to find it.

I'm currently using the F-14D and getting shot off the boat at close to 300 knots. I'm trying to reduce that speed to a more realistic one of around 150 knots. If anyone could point me in the right direction I would appreciate it.

 

thanks,

 

C

[Fubar512 1,350]

Each individual catapult has an .ini entry. Part of it is this line, "LaunchTime=", which determines the rate of acceleration. I use a value of "3.0" for each of the CVA-63's cats, yielding a rate of acceleration that translates to 170 knots at the end of the cat stroke for a fully loaded Phantom or Tomcat.

[FastCargo 412]

Simple, but takes a little math.

 

Look in your carrier's data.ini and find entries similiar to this:

 

[Cat1]

SystemType=CATAPULT

CatapultID=1

StartPosition=-14.2021,57.8598,19.4

EndPosition=-10.4808,157.5803,19.4

LaunchTime=1.0

LaunchEffect=CatLaunchEffect

CatapultEffect=CatSteamEffect

 

Note the bold areas...those are the lines that you need to look at.

 

And specifically, note the italics...those are numbers that really matter.

 

The Position number reference is in X,Y,Z...where X is left/right, Y is back/forward, and Z is up/down. So it's obvious that since most catapults are back/forward, those are the numbers you look for.

 

Find the difference in the Y numbers...that tells you how long your catapult is. In this case, approximately 100 meters (units are in meters).

 

The time is in seconds...so for this cat, the idea is to make your aircraft travel 100 meters in 1 second (about 360 km/hr = 196 Knots). Technically, this is an acceleration value (because you start from zero), but I find this works decently well to figure out approximately what speed you'll be traveling off the end of the 'pult.

 

So, work backward with the math and simply adjust the time of the catapult shot to increase or decrease your speed. You COULD adjust the end position of the 'pult to do the same thing (which is what I do for my Harrier carriers...make the time short, but make the length less than a meter...result...no velocity so you can do a 'jump jet' takeoff)...but you can also screw up stuff if you're not careful.

 

FastCargo

 

PS Or, you can use Fubar's numbers...since he's done the math already...

[cochise 0]

Ok thanks, I did the calculation to convert Knots to meters per second and it works out to be around 77 mps and then calculated that I should be using about 1.3 seconds

 

I'm pretty sure the maths is correct. I did a check on it too with a speed converter.

[cochise 0]

Ok thanks, I did the calculation to convert Knots to meters per second and it works out to be around 77 mps and then calculated that I should be using about 1.3 seconds

 

I'm pretty sure the maths is correct. I did a check on it too with a speed converter.

 

Ahhhh, I understand where I went wrong. I forgot to factor that it's actually based on acceleration and not just a simple speed calculation.

[cochise 0]

After a bit of experimenting I tested 4.5 as the launchtime. Long I know but it puts the F-14D right at 160 Knots at the end of the shot which is closer to realistic. The problem I'm having now is that the plane still suffers from a lack of lift and sinks after the shot. It also takes a second or two for the elevator to become useable.

[Fubar512 1,350]

After a bit of experimenting I tested 4.5 as the launchtime. Long I know but it puts the F-14D right at 160 Knots at the end of the shot which is closer to realistic. The problem I'm having now is that the plane still suffers from a lack of lift and sinks after the shot. It also takes a second or two for the elevator to become useable.

 

Aircraft "sinK' several yards after a cat shot, in real life. I chose 170 KIAS as an end-speed due to the F-14A being my favorite carrier-based AC model. If you're using the F-14A, I suggest you set your flaps to full prior to the cat shot.

 

One of the limitations of this series is that we cannot define aero values for every stage of wing sweep. We can only fudge them a bit, working from an average obtained from combined sweep angles, in conjunction with a lift variable that would hopefully compensate for this.

 

Anyway, here's something you might find entertaining: http://findarticles.com/p/articles/mi_m0FK...ag=artBody;col1

[cochise 0]

Thanks for the reply. I actually got the Airspeed readout off of a few recorded CAT shots and tried to beef up the speed a little more for fudge factor and lag.

Loved the article too. Maybe they thought he took too much time tying up the CAT

[+Typhoid 231]

I've generally used 2 seconds as a generic for all types. If you are flying a particular aircraft then yes, you absolutely need to make sure you are at the right end speed.

 

even these guys sink a little......

 

http://br.youtube.com/watch?v=EZRMpxUniOw

 

http://br.youtube.com/watch?v=BrtRcnrnPK8

 

and of course the return trip

 

http://br.youtube.com/watch?v=cqLXmZSa8FI&...feature=related

 

[+malibu43 142]

After seeing this thread, I went back and played with my cat shot times a little. I found that 3 seconds seemed to be about in the right spot. With 30-35 kts head wind, it puts the aircraft right at about 170 kts off the bow of the ship. That's just enough for fully loaded A-7's and A-6's, so I'm going to call it good.

[cochise 0]

This is a compilation of CAT shots from "Speed and Angels". The last shot (1:18 - 1:40) is the best and it also gives a good indication of the airspeed readout on the HUD during and after the shot.

Enjoy!

 

http://br.youtube.com/watch?v=36S7-0HI6C0