A Radial Engined Fighter for the Australians to build (and maybe the Chinese and Indians)

[Shortround6]

Are we giving up on any semblance of practicality in this discussion. The J-22 flew about 4 - 5mths AFTER the CAC Boomerang so why would they consider it?

I just bring it up as a possible alterative to "All metal" modern style construction that most people want to use instead of the Boomerang.
There was nothing outside the box concerning the J-22.
They kept the airframe small,
they accepted two .50 cal guns and two .30 cal guns,
They accepted narrow under carriage to keep the weight down (landing gear attached to fuselage)
They accepted a slightly higher landing speed

they also accepted lower than normal strength.
Never exceed speed: 650 km/h (400 mph, 350 kn) IAS
g limits: +6g (+10g ultimate) at 2,835 kg (6,250 lb)

They did get 355-360mph out it at in the low teens for altitude.
They did NOT get altitude performance

It may not have been practical for Australia but it shows where other choices might have gone compared to the Boomerang.
Lighten the plane up and get rid of the 20mm cannon?
Accept that the plane will be harder to land?
what was the fuel load?

People want to use the P-36/P-40 air frame or the F4F airframe and using a less capable engine turn it into a better/higher performing fighter than the Boomerang and at times, do it sooner.
any good designer had to make choices. The Guys that Built the J22 made choices based on what engine they had available. It may not have been somebody else's choice but they did get 350-360mph out of the engine.

 

[GTX]

Boomerang was first flight in mid-1942 and into combat in 1943, right? I think you could get a Hawk into action about that fast, but maybe not.

As previously mentioned, not without totally disrupting local production of the far more practical Wirraway and thus end up with even later introduction.

 

[Shortround6]

Well that does sound like water-injection is out of reach timewise, though it might keep an existing Oz-hawk somewhat "in the game" in 1944.

Well, that hits one of my pet peeves about "what ifs"

"What if we build a 2nd rate plane and fly it in combat for months (years) so we will be ready when engine XXX shows up and turns our plane into world beater!"

The engine used in the FM-2 would give 1000hp at 17,000ft (about 3,000ft higher than the old R-1820) and since it weighed several hundred pounds less than the two stage R-1830 engine (and didn't use intercoolers) it didn't give up much in performance until you over 20,000ft.
Trouble is you have no idea that version of the R-1820 is ever going to exist in 1941 or 1942 when you are trying to design/build the Australia fighter.

 

[Shortround6]

Well what the 'pooped out' altitude actually was, may be up for debate, but I can provide pilot anecdotes and interviews, particularly from the Middle East, noting that the early Kittyhawks weren't much good above 12-15,000 feet (there is some variation of these estimates or comments). The -81 and later engined P-40s with the higher supercharger gear ratio did a bit better, but I think still far from ideal as far as higher altitude.

we also have the diminish performance in hot weather.

Both planes will suffer in hot weather but the guy flying the P-40s vs the Axis may not know how slowly the 109 or Zero or Ki-43 is climbing, all he knows is that they are certainly outclimbing him.

 

[Shortround6]

As for the date(s) of ostensible "Ozhawk" production, first let me say, that I didn't know enough about this going into it to specify a timeline right off the bat, so I'm really kind of fishing for a time frame based on what was possible.

But that said I think I gave a rough outline for that upthread a few posts. I would see it not so much as an either / or (i.e. produce a world class fighter right out the gate) but more of a gradual thing, starting with a basic Hawk, then adding a better engine, maybe another pair of guns, some armor, then SS fuel tanks and maybe a still better engine. This would be with either Australian produced engines or imported ones, as available.

problem is that the time line covers way too much time. What was possible in 1944 was not possible in 1940 from a manufacturing point of view. Or from an import point of view.

The first perhaps close to the timeline of the Boomerang (maybe that is too ambitious, but as close to it as possible) and then later 'marks' of the Ozhawk as capabilities improved or parts were imported. Anything they made would need to be available in 1942-early 1944 to be of much use. If that kind of timeline is impossible then it is no dice.

Again 2 years or more offers a huge amount of differences in capabilities

Boomerang was first flight in mid-1942 and into combat in 1943, right? I think you could get a Hawk into action about that fast, but maybe not.

The Boomerang used some parts from the Wirraway, perhaps not as much as they hoped?
It used a lot of the same construction techniques.
A Curtiss Hawk requires everything to start from either square one or needs a jump start from Curtiss in the form of parts kits and tooling.

By 1942 Australia was working on starting production of Mosquitos and P-51 Mustangs.

"In December 1942, the Australian War Cabinet made arrangements for the local production of the P-51D Mustang. These arrangements were finalized in November 1943, with Commonwealth Aircraft Corporation to build 690 aircraft through kits supplied by North American Aviation (NAA).[2]​ Only the first 100 unassembled aircraft were delivered, and four reportedly had the "razorback" style canopy of the P-51B/C variant. 80 of the kits were assembled under the designation CA-17 Mustang Mk 20 with Packard V-1710-3 Merlin engines, the remainder being used for spare parts"

Now it might have taken them longer to get this set up and going than they thought. Perhaps they could cut a few months off the start of arrangements and the finalization and a few more months from the fall of 1943 to the spring of 1945 but there is a time line for you and use kits, not 100% manufactured in Australia.

Australia could not support competing programs. The Boomerang offered something in 1942/43 but once the US showed that it could meet the needs the needs of the RAAF (at least mostly) with US manufactured aircraft the "need" for Australian production diminished and got shunted over to the "nice to have track" or "will reduce post war payments" track or "Keeps us less dependent on others" track.
But back in 1940 there was only one engine program is Australia and that was the 600hp P & W R-1340. The Australians stretched that to the R-1830 for Beaufort production. It took a while for another engine to get selected and the Hercules stayed an imported engine.

 

[Farky]

They didn't get P-40K until Oct 1942 but were using them (with Es) in July 1942?

Typo, obviously, already edited, it should read July 1943 of course.

Obviously it's a 'What if" scenario which some people can find inherently frustrating. It is certainly not something which actually happened. Presumably somebody at RAAF would have had to have a lightbulb go off in their head (which didn't actually happen) probably at a very early date in order to make this come together.

No problem with "What if" scenario at all, it can be fun. I am asking for timeline because I think we need some anchor here or we will jump all over the place from early Hawks 75 to engines with Water injection. If we lay timeline, date of decision, than it will be much easier say what was actualy possible or available at this point.
If we really want Australia produce something else than Boomerang than we are talking about decision in January 1942. Or are we talking about earlier date? If so than Boomerang is out of picture. If we are talking about earlier date, what exactly do we mean? 1939? 1940? 1941?

Navy Wildcats in particular were often trying to use tactics like Thach weave. But I don't think you have enough power to do that at 25,000 feet in a P-40E or K.

Not at 25 000 ft +, even Wildcat do not have enough power for Thach wave there and F4F fighting at that altitude over Solmons did belong to USMC, not Navy. Wildcats over Solomons were not dogfighting Japanese at 25 000 ft + , one pass, dive away to gain energy and get rid of any Zeros, than climb back was order of the day there.

What is your source for the operational history of the Mohawk in Burma?

Tomahawk and Kittyhawk Aces of the RAF and Commonwealth (Osprey Aircraft of the Aces No 38). I can cross check it tommorow with "Air War for Burma" if you want, I am pretty sure that Osprey is right tho.

As for the date(s) of ostensible "Ozhawk" production, first let me say, that I didn't know enough about this going into it to specify a timeline right off the bat, so I'm really kind of fishing for a time frame based on what was possible.

I think you should have timeframe and than consider what was possible, not the other way around.

 

[Wild_Bill_Kelso]

On a slightly related tangent, I definitely think that some airframes do better in hot vs cold environments

 

[Shortround6]

I think that is overstating the case quite a bit, both A6M and Ki-43 were still shooting down Corsairs, P-38s, Kittyhawks, Airacobras, etc. even Hellcats in 1943 and 44

They weren't the A6Ms and Ki 43s of 1942. For instance in the fall of 1942 they were building the KI-43 II which had a two speed supercharger instead of a single speed.
However it appears that the Japanese did more than just "add" a 2nd gear to existing supercharger.
They improved the T-O power from 980hp to 1150hp and had 1150hp at 8,040ft in low gear compared to 970hp at 11,155ft. for the older planes.
The real kicker was the 980hp at 18,375ft.
So basically the new engine added about 7,000ft of altitude.

There were about 730 aircraft built with the 1 speed engine, there were almost 5200 Ki 43s built with the 2 speed engines.

 

[Shortround6]

I think you should have timeframe and than consider what was possible, not the other way around.

 

[Wild_Bill_Kelso]

Well, that hits one of my pet peeves about "what ifs"

"What if we build a 2nd rate plane and fly it in combat for months (years) so we will be ready when engine XXX shows up and turns our plane into world beater!"

The engine used in the FM-2 would give 1000hp at 17,000ft (about 3,000ft higher than the old R-1820) and since it weighed several hundred pounds less than the two stage R-1830 engine (and didn't use intercoolers) it didn't give up much in performance until you over 20,000ft.
Trouble is you have no idea that version of the R-1820 is ever going to exist in 1941 or 1942 when you are trying to design/build the Australia fighter.

There is an old joke that if you are in a group of people running from a tiger, you don't have to be faster than the tiger, just faster than at least one of the other people.

The challenge of this scenario would not be to make an aircraft better than a Corsair or a Hellcat, but to make an aircraft better than a Boomerang, but around the same time frame. If possible. The Boomerang was good for what it was, but i feel they hit a wall in terms of the design limitations, precisely because it was based on a trainer aircraft. I suspect another design might have been possible which could have been something with a more realistic avenue for improvement.

I'm personally not that interested in the administrative side of this in terms of when somebody made a decision they didn't actually historically make. To me that is a different kind of discussion which gets into the personalities and politics of different government and corporate offices and individual people. Could be interesting perhaps but personally I'm going to hand wave that.

What I'm interested in here is in the engineering, production, and tactical side of this. What was possible in terms of design, production, logistics etc.

So I think making something better than the Boomerang that is flying and in combat in 1942 is probably impossible. Maybe you can get something as good as a Boomerang in 1943, which could play more of a role in the fighting as a fighter, and have more potential for improvement. I think they did try to improve the Boomerang and landed in a dead end. Maybe a Wildcat or a 'Ozhawk' could have more potential.

 

[Wild_Bill_Kelso]

They changed more than adding the wing fold. Like changed from 4 guns to six guns but restricted the ammo load. A lot of things got slightly heavier.

In fact the F4F-4 gained about 350lbs empty (doesn't include guns) over the F4F-3 and they took about 90lbs worth of flotation gear.

The wing may have been worth about 200lbs?

However even an F4F-3 with 110 gals of fuel and 300rpg was going to go about 7150lbs.

An F4F-4 with 6 guns and with full internal fuel (144 gallons) was just under 8,000lbs which is were the complaints came from.

Right, and I think the Australians could have had some fun with a 7200 lb Wildcat.

 

[Wild_Bill_Kelso]

(Double post)

 

[Wild_Bill_Kelso]

The problem here for everybody concerned was that the WER rating was a rating that was established by a test procedure.
In order for an engine to get a WER rating the test engine on a test stand HAD to survive 7 1/2 hours at the the rated power level in 5 minute bursts alternated with 5 minute cool down periods. If the engine broke they tried again at a lower power level.
The US was not interested in what power level they could get for a 1/2 an hour or even for 2-3 hours running before the engine broke.
WER ratings were NOT done by stories saying that squadron so and so used 66in and squadron X saying they used 68 in and the US Material command saying "sounds good, we will try 60in for safety and see how it goes."

And here is where I think you are wrong.

It's quite clear from the infamous "Allison" memo that the following are true:

1) P-40 flying per the engine limitations as laid out in the (early) manual was a dead duck in combat.
2) Several US and Commonwealth units in the field were flying it well over those limitations in combat.
3) This conferred some risk of destruction of an engine and / or lower number of operating hours per engine.
4) Allison figured how what the realistic increased throttle setting actually was in 1942 - they agreed to a 60" Hg setting (which is quite high).

Obviously they were under pressure from the reports in the field, the near panicked tone in the Allison memo makes that abundantly clear. They came up with what they thought was a reasonable provisional WER setting and then later (after the rigorous testing and evaluation process you described) agreed to new established settings for the various hawk 87 types (hawk 81 being mostly out of action by then, and no longer by US units) 60" for the P-40K, 56" or 57" for the others. They also made the strengthening changes we already discussed.

Clearly there was interplay between the field, the pilots and mechanics at the point of the spear, the military administration, and the manufactuer. Sometimes the impetus for change was in fact coming from the field units.

 

[tomo pauk]

However it appears that the Japanese did more than just "add" a 2nd gear to existing supercharger.
They improved the T-O power from 980hp to 1150hp and had 1150hp at 8,040ft in low gear compared to 970hp at 11,155ft. for the older planes.
The real kicker was the 980hp at 18,375ft.
So basically the new engine added about 7,000ft of altitude.

With the 20 series of the 'Ha 35' engines vs. the 'Ha 25', engine RPM was increased (2700-2800 rpm vs. 2600-2700), impeller was bigger (12 in diameter vs. 11 in), max allowed boost was greater by about 3in Hg (but 87 oct fuel was not allowed now), impeller was turning via a 'faster' gear ratio at higher altitudes (8.44:1 in high gear vs. 7.125:1 in the only gear ratio on the Ha 25). Engine weight went up by some 60 kg - still a featherweight.

(early Sakae as used on Zero was with a bit more capable S/C, resulting with a small increase of engine power vs. altitude when compared with the Ha 25 from the Ki-43-I)

 

[GTX]

If we really want Australia produce something else than Boomerang than we are talking about decision in January 1942. Or are we talking about earlier date? If so than Boomerang is out of picture. If we are talking about earlier date, what exactly do we mean? 1939? 1940? 1941?

Exactly!

 

[Wild_Bill_Kelso]

Typo, obviously, already edited, it should read July 1943 of course.

As long as we are all equally forgiving of minor oversights in a given post

No problem with "What if" scenario at all, it can be fun. I am asking for timeline because I think we need some anchor here or we will jump all over the place from early Hawks 75 to engines with Water injection. If we lay timeline, date of decision, than it will be much easier say what was actualy possible or available at this point.

I don't think I've been that far all over the map. I didn't really know when water injection would eventually be available but I certainly wasn't referring to that for a 1942 or 1943 aircraft. Part of the point of making this thread was to find out that kind of detail. Turns out two speed and two stage engines which could go into a Hawk were available earlier than I thought.

If we really want Australia produce something else than Boomerang than we are talking about decision in January 1942. Or are we talking about earlier date? If so than Boomerang is out of picture. If we are talking about earlier date, what exactly do we mean? 1939? 1940? 1941?

As early as possible, when did they decide they wanted two seat fighters?

Not at 25 000 ft +, even Wildcat do not have enough power for Thach wave there and F4F fighting at that altitude over Solmons did belong to USMC, not Navy. Wildcats over Solomons were not dogfighting Japanese at 25 000 ft + , one pass, dive away to gain energy and get rid of any Zeros, than climb back was order of the day there.

Ok, we can nit pick about which precise altitude a given aircraft could do a Thach Weave or some other equivalent maneuver, but there is no doubt that (at least F4F-3) Wildcat is lighter than a Kittyhawk and producing more power at 20 or 25,000 ft, so in spite of the fact that it was not necessarily faster, it was still a bit more useful in combat at that altitude because it had more power of maneuver, better climb and acceleration, and so on. Whether the threshold for one was 17 and the other 21,000 ft, or if it was 22 vs 26, I really don't know. But I know a Wildcat did a little better up high.

Tomahawk and Kittyhawk Aces of the RAF and Commonwealth (Osprey Aircraft of the Aces No 38). I can cross check it tommorow with "Air War for Burma" if you want, I am pretty sure that Osprey is right tho.

Ok I have that book, i don't think it gives that much detail on the Mohawk but maybe I'm remembering wrong, I'll pull it down.

I think you should have timeframe and than consider what was possible, not the other way around.

I have given a timeframe, but I wanted to know what engineering and production options were available within a certain range of time. Decision for go or no go obviously have to happen well before final uptated design rolls off the factory floor, I think some mixing up of time frames is going on here that isn't coming from me.

 

[Wild_Bill_Kelso]

Exactly!

I think the idea is to replace the Boomerang with something else, so the Boomerang would by definition be out of the picture.

 

[GTX]

As early as possible, when did they decide they wanted two seat fighters?

What 2 seat fighters are you referring to?

 

[Farky]

And here is where I think you are wrong.

It's quite clear from the infamous "Allison" memo that the following are true:

1) P-40 flying per the engine limitations as laid out in the (early) manual was a dead duck in combat.
2) Several US and Commonwealth units in the field were flying it well over those limitations in combat.
3) This conferred some risk of destruction of an engine and / or lower number of operating hours per engine.
4) Allison figured how what the realistic increased throttle setting actually was in 1942 - they agreed to a 60" Hg setting (which is quite high).

Obviously they were under pressure from the reports in the field, the near panicked tone in the Allison memo makes that abundantly clear. They came up with what they thought was a reasonable provisional WER setting and then later (after the rigorous testing and evaluation process you described) agreed to new established settings for the various hawk 87 types (hawk 81 being mostly out of action by then, and no longer by US units) 60" for the P-40K, 56" or 57" for the others. They also made the strengthening changes we already discussed.

Clearly there was interplay between the field, the pilots and mechanics at the point of the spear, the military administration, and the manufactuer. Sometimes the impetus for change was in fact coming from the field units.

Shortround6 is absolutely right. I think what he is saying is that altought impetus for change was in fact coming from the field units, there was procedure before War Emergency Rating was established. Nothing was provisional about WER settings, Allison did not figured out limits for WER, it was USAAF Material Command, Allison agreed with those limits.

-------------
I am done with Wildcat vs P-40.
-------------

After I read your last posts - let's forget about time of decision than. You want some fighter with better performance than Boomerang produced in Australia and this airplane should be available for frontline units at the same time as Boomerang was (spring 1943), right?

 

[Wild_Bill_Kelso]

You can bold your post all you want - I don't read it that way. Both Allison and the War Department were scrambling to react to news from the front line, and had established a much higher provisional rating, per the memo, within weeks of getting news from the combat units. So it's quite clear that the WER or WEP rating was approved in a hurry.

As for the Wildcat vs. P-40 discussion, I was treating it (and you) respectfully, even though it's pretty obvious.

Seems like some of y'all are losing the spirit of this thread, and are just trying to find something to fight about. So I think I am 'done' discussing all this. "What if" threads seem to just make some people angry for no real reason.