Australia should have manufactured the Miles M20. It was perfect for the CBI and the Pacific.

[MiTasol]

"In early 1941, L4448 was converted as a trials aircraft and the combination was considered a success.. The first Australian-assembled Beaufort A9-1 flew on 5 May 1941 with the first Australian-built aircraft A9-7 coming off the production line in August. .

The Beaufort parts book lists A9-1 to A9-52 as having Lockheed Hudson engine mounts, exhausts, dishpans, cowls, gills, carb scoops, etc, etc.

 

[MiTasol]

According to the commentary at Warbirds Down Under at Temora last year it was expected Australia would select the Lysander!

There is a comparison of the Wirraway and Lysander on the Aus Archive site. If I can find it I will post it. My memory is that the Lysander would be fully imported - but memory is always subject to correction.

EDIT
It will not download at present (nbn toooooo sloooooooooowwwww) but here is what to search for - note second file

 

[MiTasol]

I also understand one reason for using R-1830s instead of the Taurus was the specialised maintenance required of sleeve valve engines. Of course later on we used Hercules-equipped Beaufighters, but that was after a lot more experience had been gained.

I have never heard that but the R-1830 was already in production at CAC in Australia and exported to Lockheed as a complete powerplant minus prop so all that was needed to fit the Hudson powerplant to the Beaufort was an adapter structure to go between the front spare and landing gear at the rear and Hudson powerplant at the front. And add a prop though why they went with the Curtiss Electric instead of the deH/Ham Standards on the Hudson is beyond me. They would have needed different blades so maybe deH did not have the time to design it or the ability to produce it and HS likewise.

I was always under the belief that the first shipment of Taurus engines and tools (and gun turrets) was sunk by Uboats and the Brits did not have enough production capacity to replace them. I think there is an Aus archives file on that. These may provide the answer but the nbn is asleep again so I cannot download them.

 

[MiTasol]

Granted the Boomerang and the P-64 both used modified wings compared to the two seat trainers but I believe (could be wrong) that they either clipped the wings or attached the outer wing panels to a shorter center section. Looking at 3 view drawings it appears that the center sections were the same or close. Boomerang ailerons go out into the wing tips though.

I have no idea on what the NAA fighters used for wings but I would expect similar to the Wirraway for the centre section so that they could use the same jigs as much as possible.

The Boomerang centre section has a stronger spar and different corrugations above the fuel tanks but is substantially the same as the Wirraway otherwise and uses the same landing gear so the same jigs would have been used at first.

The outer panels were substantially different being cut away at an angle well before the tip and a whole new tip created plus the guns fitted. Modified Wirraway jigs could have been used. I will try and get photos next week as I pass through Brisbane. Airlines being on schedule that is possible,

 

[MiTasol]

Have a look at this site Mi....| The Australian War Memorial

That document was written in 1962 when a lot of material was still classified and makes all sorts of claims that are not supported by many of those previously classified files. Many thousands of RAAF files are still closed or partially closed making a lot of research difficult.

The AWM and Home page | naa.gov.au is where I get a bit of material and NAA is where I will get this file from - if our wonderful federal public service monopoly single internet provider gets out of slow mode. Ten years ago, pre nbn, Australia had one of the 20 fastest internets in the world and now it is not even in the top 60.

People as little as 20km/12miles from the centre of Brisbane are now on fixed wireless with late 1980s speeds but "labeled" as 25mbs down and 5mbs up. They previously had ADSL which is many time faster. I am 400+km away and this is what I get far too often. Less than the original 1980s dial up speeds when I was on Fidonet.

Before nbn if the service provider failed to deliver you could demand compensation under the Service Guarantee but the nbn is exempt that. Our "hub" is Bundy - 100km away.

 

[MiTasol]

As soon as I can find it I will post an Australian War Cabinet document on re-arming the RAAF. The interesting comment is (from memory) fighters were not required because Australia had total control of the sea.

Refer page 3 paragraph 2. Some people like to think Australia could have held off the Japanese without US help. This file shows what a complete fairy tale that was.

 

[MiTasol]

Re post 62 above

 

[nuuumannn]

The Wackett mission was financed by Essington Lewis.

Indeed and naturally, since he was the driving force behind financing the formation of the CAC, as general manager of Broken Hill Proprietry Ltd.

Have you read any of Stewart Wilson's books on Australian aircraft? There are one or two inaccuracies, but by and large they bring the story of the CAC and its aircraft to life in print. They are long out of print, of course.

 

[nuuumannn]

They would have needed different blades so maybe deH did not have the time to design it or the ability to produce it and HS likewise.

It's possible that the reason Curtiss props were used was because the Curtiss Electric prop was constant speed, as opposed to the DH Propellers (Ham Std) counterweight bracketed prop as fitted to the Beaufort, which was not, being two-pitch controllable only. This is opposed to the Ham Std 'Hydromatic' prop, which, of course was c/s and DH did produce under licence. De Havilland Australia built the Curtiss props under licence.

I doubt blade type has anything to do with it, the Ham Std blades were usually made to a given size and cut down by hand based on their requirement. The same blade types could be used for mutiple aircraft types, just given different part numbers once reshaped.

I have never heard that but the R-1830 was already in production at CAC in Australia and exported to Lockheed as a complete powerplant minus prop so all that was needed to fit the Hudson powerplant to the Beaufort was an adapter structure to go between the front spare and landing gear at the rear and Hudson powerplant at the front.

According to Stewart Wilson, the Beaufort II with the P&W Twin Wasp engines was developed to overcome a shortage of Tauruses, because of issues they suffered in service. This decision was made to power Aussie built Beauforts with the Pratts was made in October 1939. From May 1940, the British grounded their Beauforts for two months. The first 'Aussie' Beaufort powered by Pratts was in fact British built L4448, which first flew with Pratts in May 1941.

 

[MiTasol]

re post 67 - the attachment did not upload due to the nbn sleeping.
Here it is

EDIT - even at 04:23 this will still not upload (times out) as a complete file and it is only 7mb.
Here are the pages as JPGs.
You will note that page 21 says the Lysander was evaluated and rejected prior to the acceptance of the NA-33/Wirraway.
My apologies for the pages being out of order.

 

[MiTasol]

It's possible that the reason Curtiss props were used was because the Curtiss Electric prop was constant speed, as opposed to the DH Propellers (Ham Std) counterweight bracketed prop as fitted to the Beaufort, which was not, being two-pitch controllable only. This is opposed to the Ham Std 'Hydromatic' prop, which, of course was c/s and DH did produce under licence. De Havilland Australia built the Curtiss props under licence.

Ham Std had constant speed counterweight props well before WW2 but they may not have licenced the governors to dH so there would be a strong possibility you are correct there. I believe the only difference was the prop governor. The Australian Mk VAs had constant speed counterweight props but they were not popular as, like any HS bracket prop, they did not feather.

As an aside - when I checked Barcode 3207068 to see if it downloaded correctly the page I opened was about fitting Hydromatics.

I doubt blade type has anything to do with it, the Ham Std blades were usually made to a given size and cut down by hand based on their requirement.

Basically yes but the basic blades also needed the twist changed in many cases and that in turn required Ham Std to determine how much. Not hard to do but you needed HS or dH to do the math on both the twist and the profile.

According to Stewart Wilson, the Beaufort II with the P&W Twin Wasp engines was developed to overcome a shortage of Tauruses, because of issues they suffered in service. This decision was made to power Aussie built Beauforts with the Pratts was made in October 1939. From May 1940, the British grounded their Beauforts for two months. The first 'Aussie' Beaufort powered by Pratts was in fact British built L4448, which first flew with Pratts in May 1941.

Have you read any of Stewart Wilson's books on Australian aircraft? There are one or two inaccuracies, but by and large they bring the story of the CAC and its aircraft to life in print. They are long out of print, of course.

No I do not have any books by that author but a quick check of bookfinder.com shows that Adelaide Booksellers has a copy so I will get that.

I will also read these files as I have always understood the P&W installation to be an Australian innovation and I always prefer primary sources over partly or wholly memory sources.

View attachment 561915

View attachment 561914

 

[P-39 Expert]

I have never understood why the power egg concept wasn't used more often in procurement. Here's the engine, design an airplane around it. No worries about things like cooling etc. That would be the responsibility of the engine manufacturer, period. Seems like it would streamline the process.

 

[Shortround6]

I have never understood why the power egg concept wasn't used more often in procurement. Here's the engine, design an airplane around it. No worries about things like cooling etc. That would be the responsibility of the engine manufacturer, period. Seems like it would streamline the process.

Because the cooling requirements (airflow) can change with intended speed and altitude of the plane. Trying to use a cowl that works on a P-36 might not work so good on a PBY. Not to mention trying to blend a standard cowling to different fuselages. P-35 and P-36?

The power egg has it's place, but it is not a universal cure.

 

[P-39 Expert]

Meant for single engine airplanes, should have been more specific.

 

[nuuumannn]

Basically yes but the basic blades also needed the twist changed in many cases and that in turn required Ham Std to determine how much. Not hard to do but you needed HS or dH to do the math on both the twist and the profile.

By twist I suspect you mean blade angle? The stops on the hubs determined the blade angle and its limits. The bracketed props obviously did not have as much angle, whereas yes, in bigger aircraft you want a feathering prop, as you know, so I suspect that is why the move was made to the Curtiss prop, also I suspect that the Ham Std 'Hydromatic' might have been heavier, with its oil filled hub, whereas the Curtiss was lighter, being electrically actuated.

Ham Std had constant speed counterweight props well before WW2 but they may not have licenced the governors to dH so there would be a strong possibility you are correct there. I believe the only difference was the prop governor. The Australian Mk VAs had constant speed counterweight props but they were not popular as, like any HS bracket prop, they did not feather.

DH props did have a licence for the governor in the UK. And, yes, you are right, the bracketted prop did not feather, which is why the Curtiss was likely to have been chosen, see above. The bracketted prop was also not a c/s prop so didn't require a governor. Just to clarify, the prop governor is fitted to the engine, not the prop and relies on engine oil to actuate a piston, which diverts oil flow to the pitch change mechanism in the prop hub, which alters the angle of the blades to align with the engine's increasing rpm. Obviously, the bracketted two position prop's blade angle was determined by the pilot over two-positions, rather than actuating automatically in line with the changing engine rpm. The counterweights in this aid in the blade actuation. The prop governor doesn't change the blade angle - in the Curtiss prop, this is done electrically (the governor actuates relays that open and close contacts that actuate the blades electrically - it's driven by the aircraft's AC gennie), in the Ham Std Hydromatic prop, this is done with differential oil pressure against a piston in its hub, the governor actuating as described above.

More than anything I'd like the time and resources to be able to access first hand archives, but I just don't. Also, if you know an author is a good one and you can check his sources, in some cases that author might have already done the leg work for you. For me, going to the National Archive at Kew is out of the question, so getting hold of books is the next best thing, with all that that entails.

 

[Admiral Beez]

How does Australia get its Merlins? That's a long way to ship from the UK. Might as well stick them onto crated Hurricanes and send the compete aircraft to Oz.

 

[MiTasol]

By twist I suspect you mean blade angle? The stops on the hubs determined the blade angle and its limits.

No I mean twist. On 3E50 and 23E50 props, as used on the Beauforts and many other aircraft, the blade angle at the 42inch station is usually the angle that is referenced relative to the stops and is the nominal pitch angle for that blade but the angle at every other blade station is different because the angle of attack reduces from coarse at the hub end to fine at the tip. The amount of this twist is vastly different on the blades fitted to a low speed and high speed aircraft and high and low revving props. The stops also vary from aircraft to aircraft, and sometimes even between the same prop fitted to different models of the same aircraft. The amount of twist is designed to suit the individual aircraft model by the prop manufacturer.

The bracketed props obviously did not have as much angle, whereas yes, in bigger aircraft you want a feathering prop, as you know, so I suspect that is why the move was made to the Curtiss prop, also I suspect that the Ham Std 'Hydromatic' might have been heavier, with its oil filled hub, whereas the Curtiss was lighter, being electrically actuated.

I doubt there is much weight difference because the Curtiss prop requires many additional parts such as the brush blocks and holder and support structure, the relay box and the voltage booster and support structure. I can promise you from personal experience the pitch change motor is not much lighter than the empty hydromatic dome assembly and I suspect that the voltage booster goes very close to making up the oil weight though it is mounted elsewhere. The Curtiss governors are also significantly heavier then the constant speed bracket and hydromatic governors. The Curtiss hub is somewhat lighter though the blade clamp and bearing set is much heavier. Still you may well be right overall.

DH props did have a licence for the governor in the UK. And, yes, you are right, the bracketted prop did not feather, which is why the Curtiss was likely to have been chosen, see above. The bracketted prop was also not a c/s prop so didn't require a governor. Just to clarify, the prop governor is fitted to the engine, not the prop and relies on engine oil to actuate a piston, which diverts oil flow to the pitch change mechanism in the prop hub, which alters the angle of the blades to align with the engine's increasing rpm. Obviously, the bracketted two position prop's blade angle was determined by the pilot over two-positions, rather than actuating automatically in line with the changing engine rpm. The counterweights in this aid in the blade actuation. The prop governor doesn't change the blade angle - in the Curtiss prop, this is done electrically (the governor actuates relays that open and close contacts that actuate the blades electrically - it's driven by the aircraft's AC gennie), in the Ham Std Hydromatic prop, this is done with differential oil pressure against a piston in its hub, the governor actuating as described above.

Two pitch, variable pitch and constant speed versions of the HS/dH bracket props all use different control mechanisms. Two pitch is basically a relatively small open/shut valve, usually on the engine nose case. Variable pitch did not last long as the addition of spring loaded counterweights to the primitive VP governors produced the constant speed governor used ever since. Both required a drive pad on the engine, again usually on the nose case but sometimes on the accessory case. Both are a much larger component indirectly connected to the engine prop shaft in order to detect prop/engine rpm. The bracket prop used on the Hudson and Beaufort VA were all constant speed.

A typical constant speed bracket prop you may be familiar with is fitted to the RNZAF Harvards and goes back to around 1936. A constant speed bracket prop governor will not work on a hydromatic and vice versa.

More than anything I'd like the time and resources to be able to access first hand archives, but I just don't. Also, if you know an author is a good one and you can check his sources, in some cases that author might have already done the leg work for you. For me, going to the National Archive at Kew is out of the question, so getting hold of books is the next best thing, with all that that entails.

For years I agreed with you but having worked on many of the aircraft and engines discussed in this forum (I spent a large part of the 60s and 70s on warbirds before it became fashionable) and I have had a gut full of reading that the Allison had no supercharger, that the Merlin was more reliable than the Allison (the UK engine overhaul life control AD in the 60s allowed Merlins a 300hr TBO and Allisons a 600hr TBO), that Zeros had wooden wing spars, etc, etc, etc, including from so called reputable authors (Martin Caiden, etc).

More and more our generation are now able to access material in many countries national and state/provincial archives and museums via the internet, sometimes directly and from other locations via printed pages or pdf files delivered by CD/DVD or a dropbox type service. Likewise there is no shortage of sites like Aircorps Aviation with manuals and technical drawings available for a modest fee.

Some archives and museums charge a modest fee for copies, digital or hard copy. Some provide the same material for free although a few, like Poland, put a heavy watermark on every page to prevent scum from selling what the Muzeum Lotnictwa Polskiego w Krakowie provide FoC. Australia charges the person who asks for the first copy of any file to be provided a very high fee Copying charges | naa.gov.au (compared to overseas) and then provides the same document as a JPG or PDF file to everyone else free AND the quality of the scanned files is often appalling. A 26 page pilots notes I was after recently would have cost me AU$39.90 to have re-scanned (it is available on line but unreadable due bad lighting etc AND is missing the back of some pages). I bought a pristine photocopy from the NASM for under AU$15.00 including postage.

As an aside, aircraft maintenance wise I had LAME (3 countries piston and turbine engine, Airframes including rag and tube through part 121 specific types, E&I but not radio), A&P and IA certificates, all of which have expired due to moving to Quality and Safety management (compliance management as you call it in NZ), plus AS9000 and ICAO Quality Management certificates for my work for international fixed and rotary wing operators with equipment up to B767 and up to Mi-8 in the AMT and MTV variants.

 

[P-39 Expert]

By twist I suspect you mean blade angle? The stops on the hubs determined the blade angle and its limits. The bracketed props obviously did not have as much angle, whereas yes, in bigger aircraft you want a feathering prop, as you know, so I suspect that is why the move was made to the Curtiss prop, also I suspect that the Ham Std 'Hydromatic' might have been heavier, with its oil filled hub, whereas the Curtiss was lighter, being electrically actuated.



DH props did have a licence for the governor in the UK. And, yes, you are right, the bracketted prop did not feather, which is why the Curtiss was likely to have been chosen, see above. The bracketted prop was also not a c/s prop so didn't require a governor. Just to clarify, the prop governor is fitted to the engine, not the prop and relies on engine oil to actuate a piston, which diverts oil flow to the pitch change mechanism in the prop hub, which alters the angle of the blades to align with the engine's increasing rpm. Obviously, the bracketted two position prop's blade angle was determined by the pilot over two-positions, rather than actuating automatically in line with the changing engine rpm. The counterweights in this aid in the blade actuation. The prop governor doesn't change the blade angle - in the Curtiss prop, this is done electrically (the governor actuates relays that open and close contacts that actuate the blades electrically - it's driven by the aircraft's AC gennie), in the Ham Std Hydromatic prop, this is done with differential oil pressure against a piston in its hub, the governor actuating as described above.

More than anything I'd like the time and resources to be able to access first hand archives, but I just don't. Also, if you know an author is a good one and you can check his sources, in some cases that author might have already done the leg work for you. For me, going to the National Archive at Kew is out of the question, so getting hold of books is the next best thing, with all that that entails.

Don't know about the Hamilton Standard, but the Aeroproducts hydromatic propeller was actually 50# lighter than the Curtiss Electric props as they were installed on the P-39F and P-39D.

 

[MiTasol]

Don't know about the Hamilton Standard, but the Aeroproducts hydromatic propeller was actually 50# lighter than the Curtiss Electric props as they were installed on the P-39F and P-39D.

Yes but that was an odd ball prop with three electric motors in the hub and steel blades and other items that make it a difficult one to use in a comparison. The Aeroprop was definitely a much simpler installation and much of the weight difference may have come from the deletion of the additional parts such as the brush block, relay box and the voltage booster and related support structure.

I must admit to a liking of most Aeroprop products. They thought well outside the box for both the prop and the governing system,

 

[nuuumannn]

Excellent and the kinds of answers I wanted to hear - wasn't sure what your background is, MiTaSol. I worked in a propshop once and have workjed on Ham Std props, but not the Curtiss one. I have minimal warbird experience but spend my nights toiling on the line on turboprop airliners for crust.

I have had a gut full of reading that the Allison had no supercharger, that the Merlin was more reliable than the Allison

That's because you are looking in the wrong places! I've learned from a previous career as a professional researcher whom to trust and vice versa. This is now a hobby for me and I still write, but now for a wee pay packet, but I endeavour to get the facts right where I can. Still, access to first hand archival sources would be ideal, but time constraints and finances don't always mean I can. I don't necessarily have the incentive anymore either.

First hand sources are of enormous use, but I have learned that even they cannot be trusted for accuracy everytime. A good researcher states sources and makes his/her own mind up based on what is found, so it can be a minefield.