DT bombing

[SpecteRED]

Bombing in DT mode is not easy for me, and bombs get very close all the time (but that's not enough to destroy the target). A direct hit happens once out of five. Im using MK-82 (pair mode). Therefore, I would like to clarify:

1. do I need a clear aim of the Jester at the target, and when the bomb button is pressed, can I deviate?
2. or, on the contrary, can I use the Jester to aim roughly, and press the bomb button exactly on target?
3. do I need to keep the scope on the target until Jester captures it (he's talking about capturing it 1-2 seconds after the command)?

[Zabuzard]

1. no
2. yes
3. yes

dont forget to enter ur attack profile in the bombing tool previously and hit "tell jester"

[Dragon1-1]

Also, how many bombs are you dropping? If you drop a single pair, your chances of shacking the target aren't best. If you want to drop in pairs, you should drop a stick of two, with a short delay. It'd probably be best to drop more, so that you have a better chance of one of them landing on target. IRL, most of the time nobody drops a single unguided bomb, or a single pair, and seriously expects to hit a point target even today. You can refine your technique and eventually get pretty good drops, but pinpoint is probably too much to expect.

[Stickler]

I have seen the OP's question being asked several times on Discord and these forums, as well as Zabuzard's corresponding and consistent answer.

Based on testing, exemplified by the attached track and screenshots, I can confirm that in Heatblur's F-4E module it is currently not strictly necessary to initially lock the target or the ground close to the target when flying nominal parameters.

All that is needed is a lock itself (or a first-stage track, see next post) so that a release tone is generated once you press the bomb release button (no lock/track, no tone).

Under said nominal conditions, the slant range inserted into the WRCS is apparently the one projected through the pipper onto the target the moment you press the bomb release button, because usually the range bar will be at the location superimposed by the pipper.

Reference the screenshots:

1) Locked the water an estimated few thousand feet short of the target (white speck, Harbor Tug).

2) Sight picture at pickle

3) Hit where the pipper was at pickle, not the originally locked ground return

Correct CB for the release (Level, 580 KTAS, 15300 ft ATL) would have been 1.17; actual setting was 1.15, so no significant difference.

Note that the acquisition symbols / range bar do not actually remain on the originally locked target but move along with the pipper until pickle.

Conversely, further testing (my recorded tracks unfortunately do not show what really happens, but see below screenshot) shows that when placing the pipper on a feature and pickling, the bomb will hit said feature (with the proper CB) even though the acquisition symbols / range bar had been manually moved to and locked on a discrete target beyond or short of the feature beneath the pipper prior to pickle.

Screenshot taken in active pause: Bomb will hit where the pipper is (center of main beam clutter), not the Harbor Tug locked with the acquisition symbols.

lock_dt.trk

Edited March 24 by Stickler
Updated to reflect new test results

[MBot]

12 hours ago, Stickler said:

The slant range inserted into the WRCS is apparently the one projected through the pipper onto the target the moment you press the bomb release button, and NOT the slant range from the aircraft to the locked target / target tracked by the acquisition symbol.

There might be a misunderstanding what locking mans in regards to DT. You do not lock a specific point on the ground that is then being tracked. You lock the ground return in the bore-sighted radar beam. If you move the aircraft, the bore-sighted radar beam moves with it and therefore also the distance of the ground return that is being tracked changes. The moment you press pickle, the current slant range to the tracked ground return in the radar beam (which is aligned with the pipper) is transferred to the WRCS and is subsequently used together with the INS to determine a valid release condition.

The ability of the radar to reliably track the ground return when the radar beam is moved over the landscape is another question though.

[Dragon1-1]

On water in calm weather, it can probably be expected to work. On land, in a complex terrain, it should fail if you move it around too much. Not to mention, getting the radar to actually track the ground, as opposed to some false return, takes some WSO work, too. I don't know if it's implemented yet, but moving the pipper around too much should result in a lost lock.

[Yannick Pancake]

My understanding of the "locking" is, that you just say your Radar and the Weapons Computer where the ground on the Boresight is. You then have to move the Pipper, and therefore the Boresightline, over the Target. Once you press the Pickle Button  the System enters the distance to target to the bombing computer. 

In theory you can lock the ground anywhere, however you might have different return strengths on different areas. So to get the best precision you should "lock" the point you intend to use for the measurement, so most likely your target.

[Stickler]

I've investigated this a bit more.

Contrary to my initial statement, you do not need a lock to get a release tone. Instead, just depressing the first-stage trigger, thus displaying the range strobe, will enable a release. This is correct as per the RL 34-1-1.

However, the advantage of pressing the second-stage trigger is that the range strobe will "snap" or adhere (with some lag) to the strongest radar return in the vicinity of the strobe when the lock is taken. This strongest return happens to be at the center of your pipper. As others have indicated, "locking" does not actually lock a specific point on the ground but commands the radar to track/follow/adhere to the strongest return within its beam. I am not sure whether this is realistic, but it might be.

If you watch the range strobe closely after lock-on (it's easier to see in active pause), the strobe will actually oscillate slightly trying to find the strongest return hit by the radar beam. If there is no good return, this oscillation will be stronger. If you pitch the aircraft up and down while maintaining some clutter on the scope, the strobe - after taking a lock - will follow the clutter with some lag but still attempt to mark the strongest return even if Jester is disabled. If you don't take a lock, the range strobe does not do that. If you pitch the aircraft too quickly or too much, the range strobe is unable to "catch up" with the returns and will get stuck. At lower grazing angles, the ground returns have an insufficient gradient/contrast to cause the range strobe to move in a specific direction. I suppose this is why it is important to stabilize you aim prior to pickling (IRL).

If Jester is enabled, he will move the acquisition symbols onto the strongest part of the main beam clutter even before you have him take a lock. After lock-on, the range strobe's behaviour is the same with enabled and disabled Jester.

As opposed to my first post, the position of the range strobe at pickle does seem to have an effect on the range entered into the WRCS under some conditions which I have not been able to perfectly reproduce.

As described in the previous post, when taking manual control of the range strobe, moving it from the center of the main beam clutter and either locking or first-stage-triggering a different discrete return, the bomb will still hit where the pipper is placed at pickle.

Conversely, the attached track shows different results.

I'm flying level at 500 KTAS, 4000 ft ATL, towards the harbour tug with Jester disabled. CB 1.06 set as per the calculator. As soon as the tug appears on (Air-to-Ground) radar, I manually move the acquisition symbols over the return and lock-on. The return subsequently tracks perfectly down the scope; comparing the distance shown on the label and the radar scope shows that the distance returned by the radar is correct.

Pressing and holding the bomb release button at 5 nm from the target, the bombs release late to impact about 0.8 nm long of the tug. At pickle, the sight is several miles (not just one mile) long of the target. The same or a similar result occurs when the bomb is released from first-stage trigger.

Running this test again, placing the acquisition symbols at 4 nm, command a lock and pickling with the tug at 5 nm, the bombs impact 0.4 nm short. With the symbols locked at 3 nm at pickle, the bombs impact 1.4 nm short.

Therefore, pickling in this instance obviously enters a distance into the WRCS which is neither the distance to the ground beneath the pipper nor the distance indicated by the range strobe; instead, the position of the range strobe seems to affect, but not determine the WRCS range.

Granted this particular release is outside the Dive Toss design limits both in terms of distance to target and dive angle at pickle, I would still be interested where the (incorrect, but not super incorrect) range used for the release comes from. If this is simple inaccuracy introduced into the system for realism that'd be fine, but the miss distance seems to follow some logic.

A related question may be why pointing to the tug blanks out the entire B-sweep at standard gain.

The only theory I have right now that would explain the observations in the previous post and this one is that:

1. pickling on a target at the centre the main beam clutter with a good "lock" (range rate display not significantly oscillating) or first-stage track on the target causes a hit, even if "lock" mode was initially engaged over a different part of the main beam clutter (i.e., the range bar likely moved to the centre of the main beam clutter between entering "lock" mode and pickling),
2. a "bad" lock on (range rate display significantly oscillating), or merely first-stage tracking, a position that is not the target causes bombs to likely miss even with the pipper on target at pickle,
3. a "good" lock on a target outside the main beam clutter, for example on a ship (range rate display not or very little oscillating), will cause the bomb to hit the place superimposed by the pipper at pickle provided that place is at the centre of the main beam clutter. This is a bug or missing feature because in the real jet, the slant range inserted into the WRCS depended solely upon the position of the range bar at pickle (no ground return necessary). If the target is not in the centre of the main beam clutter (for example due to an insufficient grazing angle), the bomb will likely miss.

lock_dt_manual.trk

Edited March 23 by Stickler

[SpecteRED]

@Zabuzard Where did I go wrong? I also attached a track. On the track, this is the third bomb drop from the end. The last 2 drops were similar, including CBU-87 (this is not shown in the video) f4.trk

 

It looks like the bomb hit the exact spot when Jester confirmed the capture (15th second on the video), i pressed bomb release at 21th second. But you said that I can roughly aim with a Jester

Edited March 26 by SpecteRED

[SpecteRED]

Any updates here?