[INVESTIGATING]F/A-18 gun range and HUD cues are too short

[Spectre1-1]

 

as seen in the picture from Rhino ball 2016 the IN RNG marker is almost at the 9 o'clock position as opposed to the 4 o'clock position in DCS

the gun has not changed in the rhino and the DCS hornet has AGR mode now too

a quick calc with some trig reveals that the range in the picture is approx 6000ft (6096ft) at 70% unwinded range cue, assuming linear scale (for approx. accuracy) the 100% range marker would be 8571ft

(I am still new to the forums so please excuse if the things are spammy)

Edited October 23, 2020 by Spectre1-1

[BarTzi]

It's worth mentioning that the IN RNG marker isn't static. I've seen a few strafing videos of it near the 7 o'clock position. The one in DCS also isn't static. I think what should be brought to their attention is the distance between the pull-up cue and the VV.

[Tholozor]

The IN RNG cue might also change depending on the ballistics of the loaded ammunition.

[Spectre1-1]

It's worth mentioning that the IN RNG marker isn't static. I've seen a few strafing videos of it near the 7 o'clock position. The one in DCS also isn't static. I think what should be brought to their attention is the distance between the pull-up cue and the VV.

 

fair point, but I am yet to see a marker as low as 4 o'clock position whereas that is the avg DCS one

however I got informed that the rhinos use PGU rounds mostly, which I am still investigating

[BarTzi]

 

fair point, but I am yet to see a marker as low as 4 o'clock position whereas that is the avg DCS one

however I got informed that the rhinos use PGU rounds mostly, which I am still investigating

 

This is a recording of Hornets strafing in 91 (gulf war). I think this is something we can use to compare:

[Tom Kazansky]

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as seen in the picture from Rhino ball 2016 the IN RNG marker is almost at the 9 o'clock position as opposed to the 4 o'clock position in DCS

the gun has not changed in the rhino and the DCS hornet has AGR mode now too

a quick calc with some trig reveals that the range in the picture is approx 6000ft (6096ft) at 70% unwinded range cue, assuming linear scale (for approx. accuracy) the 100% range marker would be 8571ft

(I am still new to the forums so please excuse if the things are spammy)

 

[Swift.]

Thanks for the image Tom, looks like we are getting about 3000ft less in DCS(33%).

[Tom Kazansky]

You're welcome. For me it was impossible to get the max range marker significantly further than this. Not by speed and not by other dive angles. I don't have the knowlede whether different ammo can be the reason, though. General Dynamics lists a lot of advantages of their PGU ammunition, but larger range is not on that list explicitly.

 

(But apart form that, I'm always amazed how close DCS is to the real thing. The fact that we are disussing such details is more a compliment for ED than a complaint. imho)

[Swift.]

Oh yeah, it's remarkable that we are even this close. But still...gib gun range fix. ;)

[Frederf]

One of the reasons for in or out of range determination is based on the impact velocity. Different ammo have different sensitivities for terminal effects and/or fuzing. In range would be set

 

F-16 has strafe in range cue at 4000' for M56 ammunition and 8000' for PGU-28 ammunition.

 

I don't know the F-18 pipper but if that's 1000' tick marks out to 12000' then those cues look like 8800' or so in the video stills and 6000' in DCS. Did DCS just take 4000'+8000' / 2 = 6000'?

[BarTzi]

 

As much as I tried, I couldn't replicate this in DCS. IN RNG is always much closer to the target and the pull-up cue is much closer to the VV.

 

[Tom Kazansky]

 

As much as I tried, I couldn't replicate this in DCS. IN RNG is always much closer to the target and the pull-up cue is much closer to the VV.

 

thanks for sharing.

 

interesting that the max range marker of this screenshot is much closer to that we have in DCS. and in the original YT video, we can see that it is not moving as the aircraft pulls up (exactly as expected).

 

and: AGR is not used/displayed here.

 

it seems that there is some influence on the max rage we don't know here yet.

[Spectre1-1]

 

thanks for sharing.

 

interesting that the max range marker of this screenshot is much closer to that we have in DCS. and in the original YT video, we can see that it is not moving as the aircraft pulls up (exactly as expected).

 

and: AGR is not used/displayed here.

 

it seems that there is some influence on the max rage we don't know here yet.

 

keep in mind that is a cruise video, unless there were no TGPs available back then all the planes should be fitted with one for standard ops

the A below alt appears only if there is a ranging method iirc but not entirely sure

[Wesjet]

I have sent some information regarding this to BigNewy a while back now as even the range that you can shoot in DCS with the F-16 and F-18 is different, the F-18's gun shoots shorter under the same conditions (as close as is reasonable). Seeing as how this thread covers nearly the same topic I figured I should add my prior findings to the pool of information that everyone has. I saw this a few days ago but haven't had the time to get to it, so excuse the late addition.

 

You can also take a look at the Jetstream episode where the rookies do the gun training and see they are shooting with the range cue at the 7 o'clock position roughly with AGR active and the rounds are mostly on target, some a hair long due to a slight pull on the stick when depressing the trigger.

 

However, as mentioned here already - taking a shot with the range cue at 7 o'clock in the Hornet leads to short rounds. Do the same with the F-16 and you will be on-target.

Now before we say the cues are different, you can make a mission with both and try it and you will find the range cues indicate the same in clock-terms at near enough as the same altitude, speed and dive angles.

 

What we lack is perhaps a confirmation that our Hornet has different ammunition loaded, if that is perhaps the intended case that would be nice to have confirmed.

 

Tracks and Test Mission included.

 

 

 

Take a look around video time 19:54 and time 22:10 for reference.

VulcanTest.miz

F18-Gunpass-Track.trk

F16Gunpass-Track.trk

[nighthawk2174]

IMO their using PGU rounds, which when did the navy get them and should our jet be using them? But there may be something to the accuracy of the piper over longer ranges in that it should still be able to get a good solution even if your firing from beyond whatever is used to define Rmax here as the rounds can go quite some distance.

[BarTzi]

IMO their using PGU rounds, which when did the navy get them and should our jet be using them?

 

Which is exactly why I posted the video from 2003-4.

[Frederf]

M61 was introduced in 1956. The M50-series ammunition includes several round types (F-18 probably uses the M53). PGU-28 ammunition was introduced in 1988. The PGU ammunition had a slightly higher muzzle velocity (3450 vice 3380 fps) presumably the difference in speed retention is more significant. One brochure mentions "3x the range" although that's qualitative compared to chart to chart comparison.

 

I found one source for M55 ballistics info. It doesn't give very happy velocity after 2000m, basically zero. Certainly that makes 4000' a reasonable 2/3rds of the chart I'm looking at. At this 4000' the velocity is down to a reasonable ~1000fps. Probably the ballistics given are for a level shot like from a rifle. An airplane delivery "downhill" and in thinner air might have slightly better performance.

 

It would be interesting to find out what range/TOF the DCS PGU-28 round drops to the ~1000fps velocity mark.