HS129 line of sight to be corrected ca. 1° ... 3° downwards for MK101 / MK103

[kraut1]

Hi All,

I have in IL2 GB the same problem as in IL2 1946 with the HS129 with 30mm gun:

-When I try to attack an tank at low level flying with high speed with an shallow dive-angle of ca. 5° ... 20°:

-because the line of sight or the line of the gun is more or less parallel to the planes center-axis:

-If I start aiming at the tank at ca.500m and I keep the tank in the sight the plane looses altitude to fast because the angle of attack of the plane is not sufficient. Because I have to open fire at short range  there is always the danger to collide with the ground /with the tank.

My stop gap solution is to fly during these attacks with flaps 75% to 100% extended to increase the lift. But this makes the plane flying more "wobbly" and aiming much more difficult.

I have to admit that I don`t know how the settings was in the reality.

But I suppose if gun installation and the sight would be adjusted ca. 1° ... 3° to downward the aiming during low level attacks would be much easier.

[Regingrave-]

Did you tried to change gun convergence?

[kraut1]

3 hours ago, Regingrave said:

Did you tried to change gun convergence?

No I did not, I use currently 300m, for 30mm high velocity grenades the trajectory between 50m and 300m should be very flat.

What other convergence would you suggest to try?

On the other hand during the last hour I have flown 2 more missions with extended flaps and with the additional practice now am able to aim with full extended flaps, engines: combat power and speed ca. 220 - 280km/h sufficient accurate to hit an moving tank from the side flying at low level.

The flaps seem to have the desired effect to increase the lift. When aiming at the tank I have to use a bit negative elevator and when I close to the target the problem to loose to fast altitude ist solved. I can shoot up to minimum distance of ca. 50m - 100m and after ceasing fire it is easier now to evade the tank.

Edited February 28, 2023 by kraut1

[LukeFF]

3 hours ago, kraut1 said:

What other convergence would you suggest to try?

 

300 meters is way, way too low of a value. I don't have the original manual in front of me right now, but as I recall it was closer to 800 meters.

 

I'll try to look up the official number when I return home tonight if no one else posts it here first.

5 hours ago, kraut1 said:

Because I have to open fire at short range  there is always the danger to collide with the ground /with the tank.

 

That was normal procedure for Hs 129 pilots. ? Interviews with them after the war variously stated that they flew at "beer bottle height" and "flying so low, they could have shook hands with Ivan."

[JtD]

Sight was supposed to be set for H-Panzergranate (tungsten core ammo) for 800m. This meant that standard AP rounds would cross the sight line first (upwards) at about 250m, then again (downwards) at 500m, and the H-round would cross sight line at 210m first and then again at 800m.

 

If convergence is set to 300m in game and this supposedly marks the distance at which the round first crosses the sight line, the difference is not that big compared to real life. It's just 15 to 30 cm lower at that distance than manual recommendations are.

 

Maybe try setting it to 100m for a steeper angle of fire. It's only going to deviate from the sight line a meter or so max, a tank should still be possible to hit.

 

I was fairly successful busting tanks with the Hs129 in game, but I typically came in at steeper angles than you describe, maybe around 30°. While this requires harder pull outs, it gives you a good enough speed to fly straight and stable for a good hit during the attack run. Also, the higher aicraft speed means a higher projectile speed and therefore better armor penetration.

[JG27*PapaFly]

7 hours ago, kraut1 said:

Hi All,

I have in IL2 GB the same problem as in IL2 1946 with the HS129 with 30mm gun:-When I try to attack an tank at low level flying with high speed with an shallow dive-angle of ca. 5° ... 20°

I blew up a lot of medium and heavy tanks with that plane. I start my attack at around 600m AGL and 1-2 km away from my target, with flaps to the first detent (around 25 percent IIRC). I ease power back to around 50 percent and aim above target during my approach.  As I get to 600 m or so, I let the tank drift under the pipper. I fire at a distance of 500 to 300 m, in a 30 degree dive. The trick is to approach at a speed that provides enough stability for stable aiming, and sufficient lift to clear the target after the gun run.  Also, you have to delay the pitch adjustments for the gun solution until you're really close. Full flaps will slow you down too much,  and make you a wobbly gun platform, especially in combination with the weak engines. Try to fly the same approach again and again, and memorize the trim setting needed at the moment you open fire. Once you have that down, pre-set the trim before you attack. Being a tad tail-heavy will improve your gunnery accuracy.

18 minutes ago, JtD said:

Maybe try setting it to 100m for a steeper angle of fire. It's only going to deviate from the sight line a meter or so max, a tank should still be possible to hit.

I don't recommend that. It means that the round will be above your line of sight at the range you'd want to shoot (500-200m). This means you have to aim your pipper below the tank, and your rate of decent will increase even more. If you want to decrease your rate of decent,  find a convergence setting where the round crosses the LOS at greater distance. The round will be below LOS until that point, i.e. your pipper will be above the target.

Edited February 28, 2023 by JG27_PapaFly

[kraut1]

2 hours ago, JtD said:

Sight was supposed to be set for H-Panzergranate (tungsten core ammo) for 800m. This meant that standard AP rounds would cross the sight line first (upwards) at about 250m, then again (downwards) at 500m, and the H-round would cross sight line at 210m first and then again at 800m.

 

If convergence is set to 300m in game and this supposedly marks the distance at which the round first crosses the sight line, the difference is not that big compared to real life. It's just 15 to 30 cm lower at that distance than manual recommendations are.

 

Maybe try setting it to 100m for a steeper angle of fire. It's only going to deviate from the sight line a meter or so max, a tank should still be possible to hit.

 

I was fairly successful busting tanks with the Hs129 in game, but I typically came in at steeper angles than you describe, maybe around 30°. While this requires harder pull outs, it gives you a good enough speed to fly straight and stable for a good hit during the attack run. Also, the higher aicraft speed means a higher projectile speed and therefore better armor penetration.

 

1 hour ago, JG27_PapaFly said:

I blew up a lot of medium and heavy tanks with that plane. I start my attack at around 600m AGL and 1-2 km away from my target, with flaps to the first detent (around 25 percent IIRC). I ease power back to around 50 percent and aim above target during my approach.  As I get to 600 m or so, I let the tank drift under the pipper. I fire at a distance of 500 to 300 m, in a 30 degree dive. The trick is to approach at a speed that provides enough stability for stable aiming, and sufficient lift to clear the target after the gun run.  Also, you have to delay the pitch adjustments for the gun solution until you're really close. Full flaps will slow you down too much,  and make you a wobbly gun platform, especially in combination with the weak engines. Try to fly the same approach again and again, and memorize the trim setting needed at the moment you open fire. Once you have that down, pre-set the trim before you attack. Being a tad tail-heavy will improve your gunnery accuracy.

I don't recommend that. It means that the round will be above your line of sight at the range you'd want to shoot (500-200m). This means you have to aim your pipper below the tank, and your rate of decent will increase even more. If you want to decrease your rate of decent,  find a convergence setting where the round crosses the LOS at greater distance. The round will be below LOS until that point, i.e. your pipper will be above the target.

Thanks very much for your help!

My low level approach with full flaps works now in respect of gun aiming and close shooting range, but I will try the 30 degree dive as proposed by you both. I think it is better to have sufficient speed to escape from aa fire.

 

[JtD]

11 hours ago, JG27_PapaFly said:

I don't recommend that. It means that the round will be above your line of sight at the range you'd want to shoot (500-200m). This means you have to aim your pipper below the tank, and your rate of decent will increase even more. If you want to decrease your rate of decent,  find a convergence setting where the round crosses the LOS at greater distance. The round will be below LOS until that point, i.e. your pipper will be above the target.

 

Yeah, true. Short range convergence is only beneficial to steeper, faster approaches, where you don't have a sinking problem, but rather a climbing problem.

 

The shallowest projectile path would be at a convergence of around 400m (depending on projectile), then the projectiles only come up to touch the sight line and will fall down again. If you go longer or shorter, it will cross the sight line twice, as described above. Mind you, these are all margins of a few cm in the medium ranges.

[Roland_HUNter]

 

[kraut1]

21 hours ago, Roland_HUNter said:

 

Thanks very much!!!

You are a very good pilot and marksman.

I need more time to get the sight on the target, so currently I prefer flying very low with flaps, similar as in your video your attack on the KV1, and shoot at short distance (and be more vulnarable to aaa fire due to lower speed)

Edited March 2, 2023 by kraut1

[Roland_HUNter]

5 hours ago, kraut1 said:

Thanks very much!!!

You are a very good pilot and marksman.

I need more time to get the sight on the target, so currently I prefer flying very low with flaps, similar as in your video your attack on the KV1, and shoot at short distance (and be more vulnarable to aaa fire due to lower speed)

Thank you for the kind words, but I think that goes to the video maker, this video is not mine
It has helped me a lot in many ways, so I dare to recommend it to you!
I suggest you check out his channel.
You will find a lot of useful information.
Glad I could help. ?