W-I: no Hs 129?

[tomo pauk]

As something that gets either a lot of praise, or it is a target of possible (and impossible) upgrades that never materialized, let's explore situation of Hs 129 never coming to fruition, both as a concept and as execution of that concept. The concept being a small-ish twin engined attack aircraft that was supposed to use non-strategic engines. The Fw 189 attack versions also does not come to light here.
Granted, one can wonder whether the economy logic of using two so-so engines instead of one decent on one aircraft (my favorite 'minus' for the concept).
What might substitute the Hs 129, both above frontlines and in Henschel production lines, that will use technology of the day available for Germany, even if it is a spin-off from existing aircraft?

 

[GrauGeist]

Perhaps using a version of the Seibel Fh104?
It was relatively compact with a length of 31 feet and a wingspan of 39 feet, powered by two Hirth Hm508D V-8 engines.

 

[tomo pauk]

I'd go 1-engine...

 

[GrauGeist]

With a twin, you'd have both the lifting power (since we're considering non-strategic engines) and the accuracy of weapons mounted centerline.

 

[tomo pauk]

With a twin, you'd have both the lifting power (since we're considering non-strategic engines) and the accuracy of weapons mounted centerline.

Use of non-strategic engines never happens here:

... let's explore situation of Hs 129 never coming to fruition, both as a concept and as execution of that concept. The concept being a small-ish twin engined attack aircraft that was supposed to use non-strategic engines.

I still consider the use of two smaller 12 cylinder engines instead one bigger 9 or 12 cylinder engine as being false economy. Two 30mm cannons under wings should provide better target effect than a single under centreline.

 

[Dimlee]

I like 2 engines concept because of centerline weapons and (probably) better survivability. In my opinion, 1 nose-mounted cannon could be more accurate than 2 wing mount because of convergency. After all, most targets are very small objects - trucks and light armor. But I might be wrong.

If we stick with 1 engine, I see 2 options:
1. Slow and agile.
a) Improved Hs 123 with a more powerful engine (was it feasible?), improved armor (not the "tub" or Il-2 like, just better pilot protection), MG151, SC50, SD50-70, cluster bombs. Not sure about the landing gear, keep as it was, or make retracted to gain more speed? As I remember, there were voices in LW calling for the return of Hs 123 in 1943 or 1944 but it was too late. (By the way, in VVS I-153 "shturmoviks" had a better loss ratio than Il-2 in 1943).
b) The resurrection of Ar 81?
c) "De-navalised" Ar 95 or Ar 196 or even Fi 167? Without gunner/observer. Armor and armament as Hs 123.
2. Fast and furious.
FW-190F. Build more of them (as long as engines are available). Forget about 30mm cannons and Panzerschreck, but install more 20mm or more MGs. Keep W.Gr.42 for attacks against infantry and transport columns. Small bombs, cluster bombs.

 

[tomo pauk]

How about a 2-phase idea? Instead of the historical & awful Hs 129As, make more Hs 123s. Better versions of BMW 132 were in the offering, the -H was supposed to do 1000 HP for take off, so this can give enough of oomph to carry more armament vs. the historical version that was powered by the 132Dc of 880 PS.
In the mean time, have Henschel to prepare for production of Fw 190, Bf 109 or Ju 87?

 

[tomo pauk]

Going 2-engined - perhaps an attacker based on Fw 187 with radials for Henschel to produce? It might hold it's own against some fighters once bombs are gone, unlike the Hs 129. Conversely, it should carry both powerful guns' armament and bombs/rockets.

 

[Shortround6]

I think we are using the retrospectroscope a bit too much here.

We KNOW the Hs 129 wound up being a gun armed tank buster, However the requirement was issued in 1937 and mockups of it and the Fw 189C were being inspected in 1938. Prototypes flew in 1939 and the Hs 129A-0s with Argus engines were built in early 1940.
Available engines and size of aircraft have to be looked at with that timing.

Was it supposed to be a "light" bomber?
A strafer?
Were two 20mm MG FF cannon considered good enough tank busters in 1938/39?

One reason the Hs 129 was chosen over the Fw 189 was that it cost just over 2/3rds as much.

 

[GrauGeist]

Was it supposed to be a "light" bomber?
A strafer?

The type was intended to be a pure ground attack role, a follow-on to the Hs123, which proved it's value in Spain.

This is why the heavy armor was required, as it's main role was low-level strafing. The bombs it carried would be a supplement to it's ground attack mission.

 

[tomo pauk]

I think we are using the retrospectroscope a bit too much here.

We KNOW the Hs 129 wound up being a gun armed tank buster, However the requirement was issued in 1937 and mockups of it and the Fw 189C were being inspected in 1938. Prototypes flew in 1939 and the Hs 129A-0s with Argus engines were built in early 1940.
Available engines and size of aircraft have to be looked at with that timing.

Was it supposed to be a "light" bomber?
A strafer?
Were two 20mm MG FF cannon considered good enough tank busters in 1938/39?

One reason the Hs 129 was chosen over the Fw 189 was that it cost just over 2/3rds as much.

Most, if not all of this listed are also my reasons to stick with an updated & bit up-armored Hs 123 for starters - Luftwaffe gets perhaps over a 100 of workable attack aircraft instead of loosing too much time on the flop the Hs 129A was.

Ju 87 with 30mm can do the tank busting job once it is required, before going for the historical 37mm armed version.

 

[Shortround6]

The requirement for a non essential engine is what pretty much screwed up the Hs 129A. The Fw 189C using the same engines didn't fly much better.
Take away that requirement and increase the allowable cost of the aircraft and possibilities do open up.
The Germans were also rather interested in small bomb dispensers for close support aircraft.
The Hs 129B could carry six or eight 110lb bombs or six or packs of 24 4.4 lb bombs per pack if the under fuselage gun was not carried. There were a variety of 4.4lb bombs including some hollow charge ones.
The Hs 123 could also carry containers of 4.4 lb bombs or a single 20mm FF Cannon could be hung under each lower wing.

I don't believe the flying anti tank gun role was even envisioned when the original requirements were drawn up. Or at least that any gun much bigger than a 20mm was considered necessary to deal with the tanks of 1938-39.

 

[tomo pauk]

The requirement for a non essential engine is what pretty much screwed up the Hs 129A. The Fw 189C using the same engines didn't fly much better.
Take away that requirement and increase the allowable cost of the aircraft and possibilities do open up.
...

Bingo.
As before - using two, a bit smaller engines and prop vs. 1 bigger engine and prop is faulty economy. It will cost more to make, fuel and maintain; pilot's training will need to be longer for a twin. All the things Germany was ill suited to afford even befor ww2 broke out.

 

[tomo pauk]

Back to a 2-engine attacker idea.
The Hs 129, once it matured with B version, was either-or aircraft: even the 30mm cannon installation precluded any bombs to be carried, and IIRC it was carrying any rockets. Installation of 7.5cm mandated removal of 20mm cannons. The gunpack with 4 LMGs also meant that bombs could not be carried under the fuselage.
Granted, the Ju 87 also 'lost' bombs when 2x37mm were carried.
So let's change the RLM request a bit: okay, you (the companies) can use two air cooled engines of your choosing for the armored attcker, just make sure that investment is worth it. We might end up with an aircraft somewhat bigger than the historic Hs 129 that is powered either by BMW 132 or Bramo 323, but capable to carry both powerful guns' armament and bombs/rockets in the same time. Perhaps 4x50 kg + 1x250 kg, along with 4 LMGs + 2x20mm? Swap some of those guns with a pair of 30mm later, while retaining the bombs/rockets carrying capability? Twin 37mm under the belly?

 

[Dimlee]

With the power of hindsight, I suggest avoiding cannons above 30 mm. I assume that "tank-busting" is more a dream than reality in WW2, and Mk 103 is effective against "soft" targets.
So probably something like that.
Rüstsatz 1: 2x20 mm and 2x13mm (built-in). R2: add 2x20mm underbelly. R3: 2x30mm underbelly. R4: 6(or 8?)x50kg. R5: SD2 as many as possible, probably 144, if space allows. R6: R2 plus 2x50kg. R7: R2 plus 48xSD2.... etc.

 

[GrauGeist]

The BK3.5 37mm was effective, with either the ACPR or HE rounds, though the downside is it's weight @ 650 pounds and limited capacity magazine.

 

[Dimlee]

The BK3.5 37mm was effective, with either the ACPR or HE rounds, though the downside is it's weight @ 650 pounds and limited capacity magazine.

The question is how effective. If I'm not mistaken, Germans were mostly on retreat in the period when this cannon was used in numbers, as on Ju 87G. Hense, limited opportunities to check real results.
VVS has tested 37mm cannons on Il-2 extensively, tried to use operationally but without much success against tanks.

 

[GrauGeist]

The advantage of the BK3.5 armed Stuka and Hs129, was the angled attack they used against armor, placing the rounds where the tank's armor was thinner.
Not sure why, but the cannon armed IL-2s used more of a level attack, which would place the round on the thicker armor, where it wouldn't yeild good results.

 

[Dimlee]

Not sure why, but the cannon armed IL-2s used more of a level attack, which would place the round on the thicker armor, where it wouldn't yeild good results.

Il-2 could dive at up to 60 degrees in theory but the angle was limited to 25-30 degrees in operations for safety reasons. Probably, the installation of 37 mm cannons reduced the angle further.
As for results, the main issue was abysmal accuracy. According to reports on test flights with NS-37 cannons, the ratio of hits (any hits, not always critical) to ammunition spent was less than 3%.
I assume that the central installation at Hs 129 provided better accuracy.

 

[GrauGeist]

Being mounted on the centerline would give the Hs129 much better accuracy, versus the Ju87G's wing-mounted cannon, which, like the IL-2's, had a set range of convergence.