Level bombing HUD symbology/arming logic

[Noctrach]

As per title: What exactly is the logic for the LEVEL bombing modes?

 

The following is described in manual for CCIP (PLAN/NAV, unsafe)

This fragment zone warning is shown all the way up to ~150 metres AGL for mach 0.75+ release speeds. Is this correct/intended?

As comparison, Mk-82S high-drag 500 lbs bombs in the F-5E weapons deployment manual have a listed safe release altitude of 100ft/30m at 0.75 IMN. This number is for a level release without pull-up.

 

Which brings me to my next question, the manual states the following about the arming time:

However, even at 50m and a fall time of less than 2 seconds, the bombs will explode just fine on impact. Is the arming time correct?

 

Then with the low-drag mode (PLAN/ANF, unsafe)

The manual states a release altitude of about 200m.

 

When following the above steps at speeds of mach 0.75+ at 200m AGL, HUD symbology will rapidly slide below the lowered HUD glas.

At altitudes below 200m AGL, it just disappears altogether. Pulling and holding the trigger will force the symbology back into the centre of the HUD.

 

Fragmentation warnings in the low-drag level release mode aren't given until about 100m AGL, though you can't see it before pulling the trigger for reason mentioned above. This corresponds roughly to the altitude where you risk taking damage if not executing a 4G pull-up post-release. This further highlights the discrepancy in the high-drag fragment warning.

 

What are the reasons for the weird behaviours in these modes? Bugged or working as intended?

[Machalot]

12 hours ago, Noctrach said:

When following the above steps at speeds of mach 0.75+ at 200m AGL, HUD symbology will rapidly slide below the lowered HUD glas.

At altitudes below 200m AGL, it just disappears altogether. Pulling and holding the trigger will force the symbology back into the centre of the HUD.

I have always struggled with low drag PLAN bombing for this exact reason.  I get the right altitude and speed, line up the pipper on the target, hit UNSAFE, and the pipper instantly drops to the bottom of the HUD and disappears right after that.  I see people do it successfully on Youtube, but I have never been able to figure out what they are dong differently. 

 

I switched to using DYK almost exclusively, which works as advertised, but exposes me to SAMs and AAA more than I would like.

[Machalot]

On 4/17/2021 at 11:56 AM, Noctrach said:

Pulling and holding the trigger will force the symbology back into the centre of the HUD.

Does this early trigger pull result in the correct release of bombs?

[Noctrach]

4 hours ago, Machalot said:

Does this early trigger pull result in the correct release of bombs?

No results still seem pretty consistent

[LastRifleRound]

For ANF/PLAN, when you unsafe the trigger you are designating the spot under the pipper as the target. Your job at that point is to fly to keep the pipper on the target. When the timer bar flashes, or the target slides out of view, whichever happens first, pull and hold the trigger. 

 

A steering circle will appear. Now fly to keep the pipper in the steering circle while keeping the trigger held. This is a consent to release mode, so the bombs won't fall until the computer decides it's right.

 

As for the altitude, that guidance is ignorant of AGL, if your QFE is right that will be your barometric altitude over the target. You may want to set your altimeter readout to barometric for this reason so you won't have to pitch dramatically when you designate.

 

The actual altitude it will guide you to depends on 1.) Type of ordinance and 2.) The safety altitude as set as a waypoint property in the mission editor (low, medium, high, default medium). For example slick mk82's safety height for PLAN/ANF is 200m, 400m, and 600m (low, med, high respectively).

 

So, if you have the QFE correctly set, have slick Mk82's and medium safety altitude, and have designated a target with trigger unsafe, the pipper when placed on the target (and later the steering circle when trigger depressed) will guide to an altitude of 400m at the time of release.

 

Hope this helps

[Machalot]

3 hours ago, LastRifleRound said:

For ANF/PLAN, when you unsafe the trigger you are designating the spot under the pipper as the target. Your job at that point is to fly to keep the pipper on the target. When the timer bar flashes, or the target slides out of view, whichever happens first, pull and hold the trigger. 

 

A steering circle will appear. Now fly to keep the pipper in the steering circle while keeping the trigger held. This is a consent to release mode, so the bombs won't fall until the computer decides it's right.

 

As for the altitude, that guidance is ignorant of AGL, if your QFE is right that will be your barometric altitude over the target. You may want to set your altimeter readout to barometric for this reason so you won't have to pitch dramatically when you designate.

 

The actual altitude it will guide you to depends on 1.) Type of ordinance and 2.) The safety altitude as set as a waypoint property in the mission editor (low, medium, high, default medium). For example slick mk82's safety height for PLAN/ANF is 200m, 400m, and 600m (low, med, high respectively).

 

So, if you have the QFE correctly set, have slick Mk82's and medium safety altitude, and have designated a target with trigger unsafe, the pipper when placed on the target (and later the steering circle when trigger depressed) will guide to an altitude of 400m at the time of release.

 

Hope this helps

If the pipper vanishes off the bottom of the HUD immediately upon trigger unsafe, what should the pilot do? Climb, descend, accelerate, decelerate? Edit: After watching a few Youtube videos I think this is a direction to pull up (to the safety altitude) in order to put the pipper back on the target.

 

Is there a way to learn the mission editor safety altitude setting from inside the jet, or the kneeboard?  Edit: Chuck's Guide has the answer. It can be viewed in the kneeboard.

 

Edited April 29, 2021 by Machalot

[LastRifleRound]

If it drops off the second you unsafe, either or both

 

1.) You waited too long to unsafe

2.) You're too far off the altitude to get there on time

 

Provided you have a good designation you should immediately trigger depress. You may be able to use the steering order, but if that's too far off you're better off flying as straight and level as you can, bombs will still hit. Don't chase the cues, they're not needed to be accurate and the CK37 doesn't do well with pitch moments during release. As long as your horizontal positioning is good and you're above frag you should be good.

 

If you're so low you'll be in frag pattern, abort.

 

The closer you already are to the altitude you're supposed to be at when you unsafe the easier it will be.

 

You don't need to worry about what the cue means, as it's a flight director. Pitch the nose to put it on the target and keep it there until you can no longer see the target or the bar flashes. You are correct that if the pipper is not coincident with the target and it's low, you need to pitch up. However, if the pipper is coincident and the target and thus pipper falls off, this is sometimes normal, particularly for the higher safety altitudes. Trigger depress and use the steering order.

Edited April 29, 2021 by LastRifleRound

[Machalot]

Ok, I'll give it another try tonight.  Thanks!