PDA

View Full Version : Question regarding auto bombsight



TheCrux
06-22-2010, 10:58 AM
I'm slowly getting the hang of it in theory and can actually get good hits, provided it's a rally big target. The trouble is the crosshairs of the sight tend to drift higher or lower by the time I get to the auto drop-point, and so I have trouble arresting this drift and hitting smaller specific targets.

Full disclosure: I am aware that you use TAS not IAS and that altitude is actual height above target.

If anyone here is proficient at it, what's the best way to keep the sight steady?

Say the sight is drifting up ( forward ) from the intended point: Is it better to increase speed of the actual A/C or should I decrease the TAS velocity value of the sight? Vice-versa for a lagging sight. Or do I have it backwards? Can I change the speed values while the automated mode is on, or do I have to toggle the auto mode off. There's a lot of stuff happening near the drop point and I get confused and panicky with the sudden need to crunch a bunch of keys and usually make a mess of the run...unless it's a big, spread-out target.

I'd just like to tap the vast resource of knowledge here http://forums.ubi.com/images/smilies/11.gif

( Shameless plug )

Thanks

TheCrux
06-22-2010, 10:58 AM
I'm slowly getting the hang of it in theory and can actually get good hits, provided it's a rally big target. The trouble is the crosshairs of the sight tend to drift higher or lower by the time I get to the auto drop-point, and so I have trouble arresting this drift and hitting smaller specific targets.

Full disclosure: I am aware that you use TAS not IAS and that altitude is actual height above target.

If anyone here is proficient at it, what's the best way to keep the sight steady?

Say the sight is drifting up ( forward ) from the intended point: Is it better to increase speed of the actual A/C or should I decrease the TAS velocity value of the sight? Vice-versa for a lagging sight. Or do I have it backwards? Can I change the speed values while the automated mode is on, or do I have to toggle the auto mode off. There's a lot of stuff happening near the drop point and I get confused and panicky with the sudden need to crunch a bunch of keys and usually make a mess of the run...unless it's a big, spread-out target.

I'd just like to tap the vast resource of knowledge here http://forums.ubi.com/images/smilies/11.gif

( Shameless plug )

Thanks

Romanator21
06-22-2010, 11:30 AM
Once you have the sight auto tracking you should correct course with rudder trim to throwing the sight out of alignment (whenever bank is greater than 4 degrees). It can take several seconds to come back online.

In order to adjust the cross hairs forward and backward, as you asked, you should adjust the sight speed as it is tracking. Increasing the sight velocity will move it backwards, decreasing it will move it forwards.

Nicholaiovitch
06-22-2010, 11:41 AM
You will probably get varying ideas as everyone settles into their own way of achieving a result.
This is what I find the easiest:-

1) Assign all the necessary keys for using the sight. I find it easiest to use the Shift+/Shift- keys for varying the TAS as this is how you should stop the sight from sliding up or down in Auto.
2) Download and use a conversion table for IAS/TAS. Here is one for metric, but there are many if you look:-

<pre class="ip-ubbcode-code-pre"> http://mission4today.com/index...Base&op=show&kid=334 (http://mission4today.com/index.php?name=Knowledge_Base&op=show&kid=334) </pre>

3) Prior to Take-off, set the altitude and TAS for the expected drop. (You need to know what IAS speed you are going to drop for each type)
4) Approaching target, align approximately with target as far out as possible whilst in pilot's seat.
5) Engage wing leveler and retire to bomb aimer position.
6) Raise sight view to approx 80deg. Make any necessary direction changes with the rudder trim (this is active from bomb aimer position)
7) If you have time, you can run a practice lock-on to a target (anything will do) before reaching the desired target to monitor sight drift (correct with shift+/shift- changes to TAS.
8) Re-select "manual" after checking drift and raise sight to target.
9) Lock on to target and keep cross-hairs in place by only small changes to TAS entry and rudder trim

Good luck old chap! (and watch your 6!)

Nicholaiovitch http://forums.ubi.com/images/smilies/10.gif

ytareh
06-22-2010, 01:31 PM
Heres a lazy way that can be quite handy :

Set values 'about right' for height and true air speed

As you get quite near target set the Bombsight Automation button/key so as crosshairs are on target

If the crosshair drifts forward of target increase true air speed value and if it drifts backwards decrease it .

Reset the Bombsight Automation to have crosshairs bang on target again

Repeat this procedure as needed a few times

Its a handy trick to know if your ever caught unawares and need to release bombs fast.

Apparently some guy here said that an actual WW2 bomb aimer said they sometimes did something similar with the Norden bomb sight!!!

danjama
06-22-2010, 03:37 PM
The only trick you need to know is this:

Adjust the velocity as mentioned, until the crosshairs are no longer drifting below or above the target. Then, as long as your altitude and path are correct, the bombs will land in the pickel barrel.

TheCrux
06-22-2010, 10:40 PM
Thanks for the advice

Before taking off I generally set the sight settings to an estimated values near where my airspeed and height will be to save workload in flight, and "fine tune" later.

The practice dummy target idea to test drift is a great one; Don't know why I never thought of that.

It seems I had the final adjustments backwards, and for the corrections given in this thread, I thank you all.

I'll watch my 6 alright, if the AA doesn't tear me to bits before I can...............

All the best......

DeerHunterUK
06-23-2010, 04:49 AM
I think Joe90 from 602 squadron made a very good Norden bombsight tutorial.
You can view it here:
http://www.youtube.com/watch?v=1BY3i7BlCPo
Hope this helps.