[REPORTED] AUTO bombing inaccurate at high speeds

Just in case it wasn't reported already.

AUTO delivery at high speeds seems to be off.

Here's a snippet from another thread:

I did some tests myself and now I too believe it's bugged.

 

I think I also was able to find the root of the problem - airspeed at drop.

 

 

In the mission there are several containers and a Hornet full of Mk82s.

0 wind.

 

 

2 Drops, both at 9000 ft:

1st drop at 440 Kts - miss (by a lot)

2nd drop at 300 Kts - direct hit

 

 

The only two variables in these drops were airspeed and attack direction (but since there was no wind attack direction didn't matter).

 

 

The track is attached below.

Track:

https://forums.eagle.ru/attachment.php?attachmentid=244338&d=1596808265

See the latest in the original forum thread. It's altitude and speed together. The lower you are the faster you need to go until somewhere around 7k-8k ft and 350ish kts, when it inverts and you need to start slowing down, to the point where if you go high enough you cannot possibly go slow enough to have your aim point be your centerpoint.

We're definitely on to something here and it's definitely bugged. Good work uncovering the connection to speed.

EDIT: I realize I typed this confusingly. Another way to say it is the higher from the ground you are, the slower you need to go. It seems like the speed of 370kts at 7000ft hits reliably whatever you're aiming at (whether it's TPOD or WPDSG). If you are going lower than this, you have to go faster than 370kts. If you go higher, you must go slower. Eventually you'll reach an altitude where you can't go slow enough to hit accurately and will always drop the bombs short. This is why you can drop a string of 10 bombs at 25,000ft and every single one of them will land short. As currently implemented, high altitude dumb bombing is impossible in the Hornet unless you manually designate a guessed point beyond the target.

I bet there's a typo somewhere on the code which results in RP calculation uses some fixed values for speed/altitude and not the actual ones.

Auto release and lofting I have completely failed at despite giving many many hours practice and adjusting technique.......I gave up now.

I bet there's a typo somewhere on the code which results in RP calculation uses some fixed values for speed/altitude and not the actual ones.

Or it's intentional and this is just a placeholder. Either way I hope ED acknowledges this finally and gets it fixed.

Bump. This is a pretty annoying bug that's easily repeatable.

Set down a boiler-house or similar sized object in the ME, place a waypoint on it's center.

Load up Mk82's. Bug also effects Mk83's and 84's but I haven't tested to find their idealized airspeeds at the various altitudes.

In mission, WPDSG that waypoint. Enter auto mode, select bombs in pairs.

Fly level at 7000ft and 370kts. You will hit the target.

Fly level at 7000ft and 440kts. You will land short.

Fly level at 7000ft and 300kts. You will land long.

Fly level at 9000ft and 370kts. You will land short.

Fly level at 5000ft and 370kts. You will land long.

And so on.

Reported, thanks

Reported, thanks

Thank you

I'm glad you guys found some pattern to this error. I still get deviations from any consistent pattern.

Last night I bombed a target located at 18,000 feet of elevation. (Caucuses 'tits')

I flew at 33k, M.88, east to west. No wind. The Mk83's impacted 4 feet short and blew the target away.

Then, just for the hell of it, I turned around and came in from the west and dropped another pair and the error was about 40, 50 feet short. So... I'm thinking Coriolis, hmm

I did another test with the target at 16 ft. MSL and 18k ft release altitude, M.87, no wind. I came in from 4 cardinal directions dropping 2 Mk83's each time and yea... they all hit short but the error was bigger when going west to east. North to south and south to north the error was the same... significantly short and in both cases the impacts were also to the west of the target, by around 50 ft. (?). I'll try to do more tests but it does seem like the earth's Coriolis is simulated... is it?

If it is then it should be also be included in calculations... Heck, the guys shooting 416 Cheytac or above have to consider it;)

The 'short drop' error is still there regardless.

I'll try to do more tests but it does seem like the earth's Coriolis is simulated... is it?

i doubt it is. i never heard of it being simulated. can some one at ED enlighten us?

I'm glad you guys found some pattern to this error. I still get deviations from any consistent pattern.

 

Last night I bombed a target located at 18,000 feet of elevation. (Caucuses 'tits')

I flew at 33k, M.88, east to west. No wind. The Mk83's impacted 4 feet short and blew the target away.

Then, just for the hell of it, I turned around and came in from the west and dropped another pair and the error was about 40, 50 feet short. So... I'm thinking Coriolis, hmm

 

I did another test with the target at 16 ft. MSL and 18k ft release altitude, M.87, no wind. I came in from 4 cardinal directions dropping 2 Mk83's each time and yea... they all hit short but the error was bigger when going west to east. North to south and south to north the error was the same... significantly short and in both cases the impacts were also to the west of the target, by around 50 ft. (?). I'll try to do more tests but it does seem like the earth's Coriolis is simulated... is it?

If it is then it should be also be included in calculations... Heck, the guys shooting 416 Cheytac or above have to consider it;)

 

The 'short drop' error is still there regardless.

What were your airspeeds? Being 10kts too fast is enough to drop short enough to miss

What were your airspeeds? Being 10kts too fast is enough to drop short enough to miss

At 33k - M.88, at 18k - M.87

In these 2 tests I was focusing on additional factors that might add or subtract from the error you guys narrowed down.

The center of all your misses is still short. At 33k, there is no speed you could possibly fly to get them to land not short. The actual differential in elevation is 15k ft between you and the target. Some speed around .45 mach or so is probably needed there.

So here's something you could test. If the target is at 5k ft, and you are at 12k ft, do you get the same result at 370kts you would if you were bombing a target at 16ft and 7kf in altitude? This would rule out target altitude as a factor.

I don't think TGT altitude would play a role, as the error isn't the computed impact point, rather the computed release point. JDAM delivery and CCIP on these targets is still good, it's just AUTO that has an issue.

At any rate, the issue is reported already so they'll be working on it.