Battle of helicopters.

[MattII]

A landing platform on every tanker would have been dead easy. (Useful abd DDs & 'vettes, too, obviously.) There were trials with R-4s OTL. What the helos needed was more power to carry more payload. If Fido could have been put in service sooner, or a smaller, dedicated ASW torpedo or DC developed, helos could have been extremely useful.

Assuming you can have at least one helicopter spooled up and ready to move at all times.

I'd disagree. You'd free up the plane guard tincans, for one thing. A lot of tasks liaison a/c did could be done by helo: FAC, arty spotter, messenger. In fact, give them rockets & you remove the need for a lot of arty & CAS: think Vietnam. (Right at the front line, AA is much less an issue IMO. And helos are harder to hit than you might think.)

Short-ranged, slow, vulnerable (one shot to the pilot, engine, drive-train, etc brings it down, with a plane, you have to shoot the pilot to bring it down with any speed, hitting the engine just puts it into a glide), low payload, etc. Early helicopters had their uses, but also had a lot of faults.

Also, if the Germans have them, equipping them with X-7 for use against T-34s is going to be pretty obvious. (Presuming pods of Föhne aren't enough.)

If the X-7 operates like every other anti-tank rocket of the war then the effect is going to be minimal, rockets just weren't effective weapons, except perhaps against enemy morale, and again, slow, and vulnerable. I, for example, would not want to find myself facing a ZSU-37 or a Möbelwagen

That has important implications to casualty rates everywhere, but especially (on first thought) to the Allies in Normandie: lower infantry losses means no "crisis".

Almost anything that can hurt an infantryman can also down a helicopter, especially if it's going slow.

More than that, tho, better (faster) plane guard means lower aircrew losses. It also has fairly big butterflies when the freed-up DDs are used elsewhere. (How big an influence that is IDK, but it's not trivial.)

Um, how do better plane guards free up destroyers? One or two 250 kg bombs is not going to be real effective against U-boats if the ships don't have sonar/Asdic.

 

[BigWillyG]

Assuming you can have at least one helicopter spooled up and ready to move at all times.

Short-ranged, slow, vulnerable (one shot to the pilot, engine, drive-train, etc brings it down, with a plane, you have to shoot the pilot to bring it down with any speed, hitting the engine just puts it into a glide), low payload, etc. Early helicopters had their uses, but also had a lot of faults.

They would be no slower or vulnerable than the L designation aircraft the Army Air Corp used for spotting in OTL. They used Piper Cubs for artillery spotting in Europe. The Germans wouldn't shoot at them generally and just hid to avoid the artillery fire they could call down. An early helicopter would function in a similar manner and likely have the same radio gear.

 

[MattII]

They would be no slower or vulnerable than the L designation aircraft the Army Air Corp used for spotting in OTL. They used Piper Cubs for artillery spotting in Europe. The Germans wouldn't shoot at them generally and just hid to avoid the artillery fire they could call down. An early helicopter would function in a similar manner and likely have the same radio gear.

Now let's compare the Cub to the R-4. First, max/cruising speeds (Cub, 87/75 mph R-4, 75/65 mph), second, useful load WRT maximum take-off weight (Cub, 455/1220 lb, R-4 483/2581 lb), and finally, engines (Cub, Continental A-65-8 65hp, R-4, Warner R-550 200hp). To add it up then, the Cub, at less than half the loaded weight and about 1/3 the engine power of the R-4, still has almost the same useful load, and is faster.

Yes, helicopters are useful in lots of situations, but the ones where they're going to be in the firing line for anything much heavier than infantry weapons are not among them. They are also, by their basic design, slow and short-ranged, and have more points-of-failure than a normal aircraft.

 

[Just Leo]

They would be no slower or vulnerable than the L designation aircraft the Army Air Corp used for spotting in OTL. They used Piper Cubs for artillery spotting in Europe. The Germans wouldn't shoot at them generally and just hid to avoid the artillery fire they could call down. An early helicopter would function in a similar manner and likely have the same radio gear.

Just 900 of 2,700 L4 Cubs employed were lost to enemy action or accident. Germans didn't always duck. Being slow, unarmored and unarmed doesn't always guarantee safety. I don't think even slower would have helped.

 

[BigWillyG]

Just 900 of 2,700 L4 Cubs employed were lost to enemy action or accident. Germans didn't always duck. Being slow, unarmored and unarmed doesn't always guarantee safety. I don't think even slower would have helped.

Any way to separate combat causes from accidents? The liaison planes were used and abused heavily in every combat theater and in the US. The majority of those loses could easily be non-combat.
Also remember even modern helicopters have fairly high crash numbers both combat and accident but are still central to any modern military.

 

[Just Leo]

Any way to separate combat causes from accidents? The liaison planes were used and abused heavily in every combat theater and in the US. The majority of those loses could easily be non-combat.
Also remember even modern helicopters have fairly high crash numbers both combat and accident but are still central to any modern military.

If there are figures, they wouldn't be any more reliable or pertinent to many other bits of data. Many grasshoppers served non-combat, and adjacent to combat roles, not subject to direct enemy fire. I'm just trying to point out that in-your-face combat is a two-way street. A 20mm Oerlikon has a good range and a high enough rate of fire to put an end to anything hovering in the neighborhood. The employment of helicopters in battle had a long learning curve that had to be paid in blood. The H-21 "Flying Banana" had good payload abilities and was quite versatile, but it was also deemed excessively prone to destruction under enemy fire. The role of helicopter gunship was created to address grievous losses to gunfire which existed in WWII, and the technology they possessed was far in excess of WWII capability. U-boats where well equipped with anti-aircraft weapons, Oerlikons at least, which gave many an attacking aircraft with its own firepower a hard time. Helicopters had a way to go before they achieved a battle capability.

 

[phx1138]

Assuming you can have at least one helicopter spooled up and ready to move at all times.

No more than you needed to have a TSR with engine running at all times OTL.

Short-ranged, slow, vulnerable

Which means you operate them close to the front, where they're being used anyhow. In fact, that makes them more useful: close support available within minutes instead of an hour, & under control of the local commander, makes the effectiveness much higher than fixed-wing. Plus that very slowness makes the effectiveness higher: it means you can put ordnance on target more readily.

If the X-7 operates like every other anti-tank rocket of the war

Do you not know & not bother to look it up? It's wire-guided...

Almost anything that can hurt an infantryman can also down a helicopter, especially if it's going slow.

If you hit it often enough. Or at all...

Um, how do better plane guards free up destroyers? One or two 250 kg bombs is not going to be real effective against U-boats if the ships don't have sonar/Asdic.

That's not what plane guard is. Plane guard picks up downed aircrew....

one shot to the pilot, engine, drive-train, etc

That's true with turbine birds, too. It takes a lot of single rounds to achieve that critical hit...

I, for example, would not want to find myself facing a ZSU-37 or a Möbelwagen

Hitting helos isn't as easy as you may think.

They would be no slower or vulnerable than the L designation aircraft the Army Air Corp used for spotting in OTL.

Agreed. And they're much less vulnerable to ground fire than you seem to think. To get that single critical hit could take a lot of ground fire to achieve.

The employment of helicopters in battle had a long learning curve that had to be paid in blood.

I don't think anybody's arguing there's a learning curve. I do think there are uses they could be put to, even in WW2, that make them very valuable, for the same reasons as OTL: there's nothing else around that can do the job, or do it as well.

Does it mean they're war-winners? No. Does it mean they're invulnerable to enemy action? No. If I were a paratrooper or glider infantryman, I'd be looking at *H-19s & *H-21s & thinking how great it would be to have powered lift in & out. So they take losses. What else is new? It means the idea of gunship *H-19s arises sooner, & so do the *AH-1 & *Mi-24. That's a good thing for the guys who dropped into Arnhem.

And helos generally are a good thing for all the wounded who get evac'd & survive who wouldn't OTL: the survival rate in Korea climbed above 90%, thanks largely to the availability of those H-13s. If the R-4s & *Fl-182s or FA-63s do nothing but casevac, IMO, that's an important, useful, beneficial add to the TO&E.

 

[MattII]

Which means you operate them close to the front, where they're being used anyhow. In fact, that makes them more useful: close support available within minutes instead of an hour, & under control of the local commander, makes the effectiveness much higher than fixed-wing. Plus that very slowness makes the effectiveness higher: it means you can put ordnance on target more readily.

Apart from accuracy of fire (weighed out somewhat by the enemy ability to put fire on you more accurately), why can't that be done with aircraft? Also, 25km back at 75kph means an arrival time of 20 minutes or so, the same as 100km for a 300kph plane.

Do you not know & not bother to look it up? It's wire-guided...

It has a range of 1000m, well inside the range of most flak-cannons of the day, and that chopper is unarmoured and exposed. If you're lucky you make it back to base having hit your target, but don't bet on it.

If you hit it often enough. Or at all...

It's a much slower target than an aircraft, so you don't have to lead it by much.

That's not what plane guard is. Plane guard picks up downed aircrew....

Fair enough, at least the chances of being shot are minimal.

That's true with turbine birds, too. It takes a lot of single rounds to achieve that critical hit...

If a plane loses its engine it can glide, if a helicopter uses its engine, it's dead.

Hitting helos isn't as easy as you may think.

Much easier than planes, especially with a top speed of probably below 100 kph. Of course the helicopter can dodge, but that'll throw off its own aim.

Agreed. And they're much less vulnerable to ground fire than you seem to think. To get that single critical hit could take a lot of ground fire to achieve.

less than with a plane, because a plane has fewer critical spots.

 

[BigWillyG]

If a plane loses its engine it can glide, if a helicopter uses its engine, it's dead.

No many will auto-rotate. It's not a terribly controlled descent but it brings you down about as safely and slowly as you will gliding in your average fixed wing aircraft. The big issue would be losing a tale rotor and going into an uncontrolled spin.

 

[Gannt the chartist]

X-7 and other technical issues

The other small technical feature of the X- 7 is that it was never deployed.

Oh and anything involving S Stoff is a fundamentally bad idea.

Helo on sub requires a different sub design to that used by the KM and while feasible there are trade offs for armament, performance, range that probably make it not worth while. Putting something in the air with a radio near an allied escort with air search radar, HF/DF and hedgehog is probably a bad idea.

Anti sub helo on ship, a bit premature without dipping sonar, sonobuoy and weapons is just a guy with binoculars. Easier and cheaper to ties him to a kite/baloon with a phone line.

In reality with a start of 42 they were used for medevac S&R in Burma but thats probably not an air intense environment and for utility work and S&R in the Pacific. Thats probably the main use in WW2 and while the Germans may decide to waste money on it the allies would do a quick cost benefit and build more fixed wing.

 

[MattII]

No many will auto-rotate. It's not a terribly controlled descent but it brings you down about as safely and slowly as you will gliding in your average fixed wing aircraft.

Mind you, most aircraft could probably crawl home with some of its engine gone (cylinder heads shot up by explosive rounds or the like), a helicopter can much less afford such damage since its operating close to full power the whole time.

 

[BigWillyG]

Mind you, most aircraft could probably crawl home with some of its engine gone (cylinder heads shot up by explosive rounds or the like), a helicopter can much less afford such damage since its operating close to full power the whole time.

Engines are a small target though. Your first and early second generation helicopters are mostly tubing and sheet metal or even cloth. Much like the PO-2s and L designation aircraft you have a craft where a hit to the engine will bring it down but the majority of the target are parts which can take lots of hits to no effect.

 

[BigWillyG]

Anti sub helo on ship, a bit premature without dipping sonar, sonobuoy and weapons is just a guy with binoculars. Easier and cheaper to ties him to a kite/baloon with a phone line.

Considering how much time WWII era submarines spent on the service than just having a helo as "eyes" would help a great deal in ASW. That was a major role of fixed wing patrol aircraft IOTL. Forcing a WWII sub to submerge will diminish it's speed and can cause the boat to lost track of a convoy. At the end of the day the most important thing in something like the Battle of the Atlantic is to get the merchant ships to the UK. Sinking U-boats is just a useful addition.
IOTL The USN and Coast Guard used unarmed blimps to find submarines for some convoys. Light helis could do the same job for every convoy.

 

[phx1138]

Apart from accuracy of fire (weighed out somewhat by the enemy ability to put fire on you more accurately), why can't that be done with aircraft?

Lower delivery speed increases accuracy. (Not sure of all the reasons.)

25km back at 75kph means an arrival time of 20 minutes or so, the same as 100km for a 300kph plane.

And you need to base 25km from the front why? As opposed to 3km? IIRC, MASHes were as close as that; I see no reason temporary LZs couldn't be.

It has a range of 1000m, well inside the range of most flak-cannons of the day

How common is even that 20mm in the hands of front-line infantry? Sov tanks often didn't even have AA MG, let alone 20mm.

that chopper is unarmoured and exposed.

How long do you suppose they stay unarmored? That was because they weren't using 600hp, but more like 250.

It's a much slower target than an aircraft, so you don't have to lead it by much.

Tell that to the German fighter pilots that tried for two hours to shoot down a helo in a WW2 trial OTL, & couldn't.

If a plane loses its engine it can glide, if a helicopter uses its engine, it's dead.

Two things: autorotation. And lower speed & height to begin with means much less hazard of getting killed on impact.

top speed of probably below 100 kph.

Below about 150kph, yes.

less than with a plane, because a plane has fewer critical spots.

Conceded.

The other small technical feature of the X- 7 is that it was never deployed.

Oh and anything involving S Stoff is a fundamentally bad idea.

Both fair points. However, the principle of ATGM is there, & that's what matters.

Considering how much time WWII era submarines spent on the service than just having a helo as "eyes" would help a great deal in ASW. That was a major role of fixed wing patrol aircraft IOTL. Forcing a WWII sub to submerge will diminish it's speed and can cause the boat to lost track of a convoy.

An excellent point. (Fixed wing "scarecrow" patrols with no weapons had just this effect, & worked nicely.)

Helo on sub requires a different sub design ...probably make it not worth while.

Probably.

Anti sub helo on ship, a bit premature without dipping sonar, sonobuoy and weapons is just a guy with binoculars.

Depth bombs or rockets able to catch U-boats surfaced work nicely. And dipping sonar was trialled in 1917-8. It need not be anything fancy...

Also, as suggested upthread, with more hp, the larger payload makes the notional A/S helos more lethal to begin with.

 

[Just Leo]

The Coast Guard experimented with ASW Helos, operating with a destroyer in 1943, and boom, 1954 rolls around and the USN is in action. Inter-service rivalry and the decline in the U-boat threat both played their part. They weren't really great at it until the advent of the Sea King, later still. Powerful turbine engines really made a difference. Might have saved Grissom's Mercury capsule.

The deterrence effect of a helicopter flying over a convoy is as small as a chopper's fuel supply. Blimps were far superior, because, while no blimp sunk a sub, no ship guarded by blimps were lost. Blimps had stamina, and helicopters of the time sure didn't.

As to survivability under fire, Choctaws of the late '50s were unarmored, even though powered by a Wright engine that created 200 hp more than it ever did in WWII. And it's not just engines that are destroyed, but transmissions, hub assemblies, shafts, cables, lines, fuel tanks, and pilots. While you can argue that a helicopter is hard to hit, the rate of fire of an MG42 is very high, and they were fairly common. While a turbine powered helo might carry some armor and a door gunner on the M-60, this was beyond the scope of previous choppers, if they wished to retain any payload capability at all.

The unique attributes of the helicopter are marvellous. Search and rescue, and medivac are two notables. Jungle supply is another proven use. However, advancing capabilities by 20 years to get them into combat is a bit of a stretch. Really. They tried at ten years, and accepted it in twenty. You can argue that they succeeded here, and I can respond that they failed there. Before the turbo-shaft engine, it was not to be.

I have to go. My cows are coming home.

 

[Nicola]

I imagine you'd see a lot of overlap with helicopter use in the Korean War IOTL. Scouting, casevac, carrying small numbers of troops or light loads.
I'll add another vote for ASW use as well. Even without much carrying capacity having a helicopter as "eyes" for a convoy would make life hard for U-boats considering how much time they had to spend on the surface.

as has been suggested that the uses of Helo in the Korean war would be brought forward , in terms of over water ops some ASW/ AsuW would be a possibility

 

[Just Leo]

as has been suggested that the uses of Helo in the Korean war would be brought forward , in terms of over water ops some ASW/ AsuW would be a possibility

The helicopter was not used for ASW during the Korean War. If you saw the movie, "The Bridges at Toko-Ri", the HO3S-1 was used as plane guard, search and rescue, and artillery spotting. The book and movie was based on real incidents. In the movie, only Mickey Rooney's chopper is shot down. In real life, a couple were lost. Nobody was rescued, and Mickey wasn't the only one who died. Ground fire. Another Navy chopper turned back damaged, and an Air Force chopper couldn't get close. Not a happy time for helicopters in combat.

 

[MattII]

Engines are a small target though. Your first and early second generation helicopters are mostly tubing and sheet metal or even cloth.

But are slower than comparatively engined aircraft.

Lower delivery speed increases accuracy. (Not sure of all the reasons.)

Only on some things, RP-3s were less accurate when fired from slower platforms than faster ones.

And you need to base 25km from the front why? As opposed to 3km? IIRC, MASHes were as close as that; I see no reason temporary LZs couldn't be.

Artillery. You may have heard of the stuff.

How common is even that 20mm in the hands of front-line infantry? Sov tanks often didn't even have AA MG, let alone 20mm.

Well ZSU-37s and Flakpanzers were in production fast enough one aircraft became threats.

How long do you suppose they stay unarmored? That was because they weren't using 600hp, but more like 250.

Takes a lot of armour to stop a 37mm explosive round.

Tell that to the German fighter pilots that tried for two hours to shoot down a helo in a WW2 trial OTL, & couldn't.

Now try it with stuff like Möbelwagens

Two things: autorotation. And lower speed & height to begin with means much less hazard of getting killed on impact.

Parachutes were around by the time.

Below about 150kph, yes.

So comparatively long arrival times for any sort of combat roll, Though probably good enough for critical-case medevac if you can get a half-way safe landing zone organised.

 

[Simon]

Before the turbo-shaft engine, it was not to be.

The obvious solution then is to move up the date of the introduction of turbo-shaft engines. Quick search says that the first ones for helicopters were built by the French Turbomeca in 1948, the main problem is going to be possibly moving up jet engine development a number of years and get someone to champion the turbo-shaft. Although if you already have piston engined helicopters of a more advanced design already in service that provides something a driver for that. Even then, assuming you have them for only the final year or so is it possible to advance Frank Whittle's work by four to five years?

 

[KACKO]

Well ZSU-37s and Flakpanzers were in production fast enough one aircraft became threats.

ZSU-37 was in production only from March 1945. Production ended sometimes in 1947/48 and only small amount of vehicle was manufactured. They were never tried in combat against Germans. But of course, in case there is bigger amount of German choppers operating on Eastern front, need may arise sooner and maybe bigger number will be manufactured sooner.