CA-15 Kangaroo and Lincoln bomber over Melbourne

is it worth throwing in the MB-5 to compare?

Looks wise, with the ventral radiator and basic configuration – to me, there is something quite brutal and attractive about a lot of the late piston engined fighters – you can almost see the horsepower oozing out and the airframes creaking, P-72, the Tempest, Sea Fury and the poor late mark Seafires with all the bulges and extra bits…..

Oh, and as for the ventral radiator, according to “Airwolf” it can carry some kind of laser/rocket launcher on the P-51, maybe thats why they all copied it ?:eek:

Thanks Mark.

Attached a picture of my reworked CA-15 model as it currently stands. I still need to add the pilot and propeller and perhaps a Lincoln as well! 😉

Thanks for the excellent information, Mark! The test pilot’s comments were very interesting. It’s a shame production was delayed till the point where it was too late, but I guess we should be thankful the CA-15 was at least built and flown.

Ah, yes I’ve seen the 1/6th scale model before and especially the last shot is utterly convincing!

The marvellous head-on shot from the Lincoln, while flying over Melbourne and piloted by Lee Archer (this may give a clue as to the date, as the CA-15 flight log has survived somewhere I believe – can’t remember which book it was published in though but either way I don’t have it) can be found in Wings of Fame #4, page 119. It shows the red dots in the roundels so it must have been in 1948 or later.

One feature of the CA-15 has puzzled me for awhile now and that’s the gun ports. It was never armed but from some photos there do appear to be gunports with something(???) in them, while on others they’re not visible at all and in the head-on shot they appear to be covered (tape? puty?). None of the photos I have seen show the spent shell ejection openings in the bottom wing, but I assume these were there as well. Can you or James confirm?

I think the air to air photos from the Lincoln is most likely from the 1948 period of flights, the CA-15 first flew from 4 March 1946 through to 10 December 1946 when it had a forced landing at Point Cook.

The first Lincoln flew on 12 March 1946, and by December 1946 a total of 7 had been delivered, of course to have the then two most advanced products displayed together may have been an opportunity, but it would be expected that many more photo’s on the ground and air would have occurred.

I think the red centre roundals would then certainly date it into the post 1948 flights with ARDU and most likely their allocated Lincoln, and at that time the lincoln had been inservice for some time and of little interest.

The issue of blanked over gun ports actually seems to be miss identification of the ports, they are located outboard of the undercarriage and are not much more than “holes” and therefore very hard to see in some photos, there are some very shiny skin sections directly in front of the undercarriage attach points (perhaps access panels?) and these might be mistaken as the ports being tapped or blanked over?

Regards

Mark Pilkington

One feature of the CA-15 has puzzled me for awhile now and that’s the gun ports. It was never armed but from some photos there do appear to be gunports with something(???) in them, while on others they’re not visible at all and in the head-on shot they appear to be covered (tape? puty?). None of the photos I have seen show the spent shell ejection openings in the bottom wing, but I assume these were there as well. Can you or James confirm?

Well, a quick reference to the Wilson book (you really do need to get a copy! 😀 ) says that ‘the armament was fitted’ in May 1946, if I read the notes correctly. AFAIK, no armament trials were undertaken, so various blanking / covers could well have remained throughout.

The Wilson book also has a lot on the radial development history also…

http://www.abebooks.com/servlet/SearchResults?sts=t&tn=wirraway%2C+boomerang+%26+ca-15&x=75&y=7

Cheers

Thanks for the excellent information, Mark! The test pilot’s comments were very interesting. It’s a shame production was delayed till the point where it was too late, but I guess we should be thankful the CA-15 was at least built and flown.

Ah, yes I’ve seen the 1/6th scale model before and especially the last shot is utterly convincing!

The marvellous head-on shot from the Lincoln, while flying over Melbourne and piloted by Lee Archer (this may give a clue as to the date, as the CA-15 flight log has survived somewhere I believe – can’t remember which book it was published in though but either way I don’t have it) can be found in Wings of Fame #4, page 119. It shows the red dots in the roundels so it must have been in 1948 or later.

One feature of the CA-15 has puzzled me for awhile now and that’s the gun ports. It was never armed but from some photos there do appear to be gunports with something(???) in them, while on others they’re not visible at all and in the head-on shot they appear to be covered (tape? puty?). None of the photos I have seen show the spent shell ejection openings in the bottom wing, but I assume these were there as well. Can you or James confirm?

Colour photo of the CA-15 – no probs – smiles

These are all a 1/6 flying scale model built by Adrian Hopward in Geelong and now on display at the Moorabbin Museum.

Unfortunately the real CA-15 is poorly recorded in photo or film, and most of the drawings were unfortunately thrown out at CAC accidently in the 1980’s according to CAC guru Keith Meggs.

(I still havent nailed which book has the shot of the CA-15 from the Lincoln Turret smiles) – now I have, page 169 of the Stewart Wilson book

Regards

Mark Pilkington

Thanks Mark. I’d just told Skyraider by PM that you’d be able to help further!

Now, can you come up with a colour shot of a CA-15 for us? :diablo:

DETAILS OF CA-15 Radial Engines

Wilson book
page 176
1943
R2800-21 selected to provide high altitude capability
change in role from high altitude interceptor to low-medium altitude fighter resulted in selection of R2800-10W

page 184 quotes:

May 1944
R2800-10W originally planned – advised unavailable May 1944
R2800-22 offered as alternative – rejected
R2800-57W selected – but caused high altitude focus on design

August 1944
R2800-57W advised unavailable
Centaurus considered
Mid Setember
Griffon 120 selected

DETAILS of CA-15 Wing design
page 181
Wing section is NACA 66 laminar flow section with wing span reduced (from original 40′ ) to 36′ due to intended low altitude role.

(The NACA 66 wing airfoil is the same as selected by NAA for the P-51)

DETAILS OF CA-15 Test Flights
In regards to the test flight photos from a Lincoln, these are not referred to, or reproduced in the Wilson book, there are few shots of the CA15 in flight but there is one well known (until you look for it!!) “nose on shot” that is clearly taken from the rear turret of a Lincoln, it is assumed this is during the second period of testing at APU/ARDU between 1948 and 1950.

If that is the case it is most likely to be A73-13 which served with ARDU exclusively with before being burnt at Point Cook, or alternatively A72-41 which was with ARDU for a while for trials of the Merlin 102.

DETAILS of the CA-15 Compared to the P51.

As to the true comparison of the CA-15 to the Mustang, or other aircraft, it was a later generation design which had the benefit of wartime learnings and hindsight, and its performance figures should then be impressive, but those figures – (while unloaded with weapons etc) are from its prototype without any design evolution of engine or airframe as might have happened if it went into production.

It is all a mute point, but the opinion of someone who should know is that of Australian Test Pilot John Miles.

He first solo’ed on an AVro 504K in 1925 and during the war was a pilot with the RAAF Test section, flying experience gained there included Avro Cadet, Anson, Battle, Beaufort, Beaufighter (DAP and Bristol), Demon, Hudson, Lancer, Tigermoth, Mothminor, Kittyhawk, Oxford, Vengeance, Ventura, Spitfire mark V and VIII, Wapiti, Wirraway, Lancaster, Lockheed 12, Norseman, Mosquito, Lightning and Thunderbolt.

In 1944 He became the DAP Test Pilot on Beauforts and Beaufighters at the Fisherman’s bend Factory and in 1946/47 he attended the Empire Test pilots course at Cranfield and flew many UK base aircraft during that time, including the vampire and meteor.

In 1947 became the chief test pilot for both CAC and GAF, in that role he test flew all of the remaining CAC Mustangs from A68-101 onwards to A68-200.

He flew the prototype Pika and Winjeels, the Wright Cyclone powered Beaufighter, long nose Lincoln prototype and first Australian built Canberra.

in 1950 he was back in the UK flying with the RAE at Farnborough and flew the DH108, a Saphire engined Lancaster, python engined Lancaster, and adder engined Lancaster, mamba powered Dakota, Vickers 510 and Hawker P1052, and at Farnborough a ME163 without power – towed by a Spitfire, and by 1953 when he retired he had over 20,000 hours in 200 different types.

In 1950 after the Farnborough display John was given the opportunity to fly many of the Shuttleworth aircraft by “Dicky” Martin, including the 1908 Bleriot, Avro 504K, Sopwith Camel, and SE5a.

I offer all of the above background on John Miles to put his comments below in context, few would be in the position of having flown the CA-15 and his other experienced types to argue with him……….

Page 116, TESTING TIME, John Miles & John Pescott, 1979, Rowick Printers

I must say that it is the finest fighter aircraft with piston type engine I have ever flown. This includes the Spitfire up to mk 8 (I later flew the Spitfire MK 35), the Typhoon, the Tempest, the Kittyhawk types E and N, the Thunderbolt, the Lightning and the Mustang. The CA-15 had a top speed in level flight of 450 MPH and a range of over 2500 miles. Its handling characteristics were delightful and the performance exceeded that of the Mustang.

The rest of us will need to look at photos and imagine

regards

Mark Pilkington

Thanks James!

Yes, the head-on shot was taken from the Lincoln rear turret. Lovely photo it is! I wonder if any colour photos of the CA-15 exist…

My wife will probably kill me if I buy another book, but I’ll look it up 😀
My main references for the CA-15 now are some drawings, photos and data from the internet and Wings of Fame #4.

If the Flightpath magazine is the same as the one that contains my Lee Bottom fly-in report, I should hopefully be getting a copy of it already 🙂

At some point during the CA-15’s testflights it flew formation with a Lincoln bomber over Melbourne for a photo shoot.
Does anybody know on what date(s?) this happened and what the serial of the Lincoln was?
Any additional details would be most welcome.

PS. Were any other formation flights performed with the CA-15?
Did Commonwealth or the RAAF use any chase planes at any time?

I don’t have time to do much checking right now. There are only a couple of air-to-air photos of the CA-15, probably from the same source. There’s a head on shot, over Melbourne, with vertical bars in the pic, probably the Lincoln. Famously it flew over Melbourne at 502mph on 25th May 1948, the fact that was in a dive was not mentioned in the newspapers of the time. 😉 Like a lot of prototypes, particularly a type where jets were coming in, it didn’t fly that much, and was damaged on a couple of occasions and repairs were very slow. However a quick check of the refs don’t throw up that Lincoln flight, sorry.

That’s awesome, I never saw that before either! You got me very tempted to convert my CA-15 model into the R-2800 design now I got an R-2800 modelled already (for my Corsair): http://home.wanadoo.nl/r.j.o/skyraid…rsair_2wip.jpg
Is it specified which sub-model was to be used for the CA-15? There are a good few variations between R-2800 models.

The story’s quite complex; I’ll let you have some info, by PM but the best source is the Stewart Wilson book Wirraway Boomerang & CA-15 in Australian Service. ISBN 0958797889, 1991, Aerospace Publications Pty. Worth trying to track a copy down, as ity tells an interesting story very well. We’ve just published a feature in the latest Flightpath magazine here in Australia, by Glenn Henry.

Check your PMs.

That’s awesome, I never saw that before either! You got me very tempted to convert my CA-15 model into the R-2800 design now 😀 I got an R-2800 modelled already (for my Corsair): http://home.wanadoo.nl/r.j.o/skyraider/gallery/corsair_2wip.jpg
Is it specified which sub-model was to be used for the CA-15? There are a good few variations between R-2800 models.

PS. It’s interesting to see they designed the V-shaped tailplane from the outset. Usually it’s only introduced if stability problems are encountered during flight or wind tunnel testing (Beaufighter, A-20).

Wow!! definitely ‘beefy’! It would be interesting to see the original CAC drawings where the CA-15 was originally planned to be powered by the R-2800.

I just happen to have to hand… From CAC.

Wow!! definitely ‘beefy’! It would be interesting to see the original CAC drawings where the CA-15 was originally planned to be powered by the R-2800.

“Several variations on this powerplant were mooted depending on the specific requirement (high, medium or low altitude) until August 1944 when it was announced no R2800s would be made available for the CA-15.”

The R-2800 info is gleaned/quoted from ‘Military Aircraft of Australia’ by Stuart Wilson, ISBN 1 875671 08 0 … a very nice book I picked up in Melbourne in 98… what I consider a ‘must have’ for ‘Oz’ fans.

Hi James, I don’t have that book unfortunately. I’d love to hear what you can find out about this flight.

To me the Kangaroo looks like a beefed-up P-51, not necessarily ugly. I really like some of its features, like the recessed exhausts, V-shaped tail, tuna-shaped fuselage and I kinda like the “tiny” canopy too. It’s a beast of a plane surely, and indeed one of the last original prop fighters (Yugoslavia made a Yak-lookalike in the late forties and this must’ve been a later design than the CA-15).

Funny enough, for several years now I have had 3D models of both P-51D and CA-15 and I never loaded them up side-by-side for comparison. I just did. Indeed in the sideview the CA-15 is a good bit larger, but the wingspan is very comparable. Have a look:

Your first paragraph is a far better description than mine Mark.

It is better described as a redesign of the Boomerang to achieve Thunderbolt like performance /outputs but then extruded through a P51 shaped template due to neccessity of engine choice.

It grew out of the CA14A turbocharged Boomerang in 1943, which had pushed the basic “NA-16” based steel tube design to its limits, resulting in the need for a new powerplant, new wing and new fuselage construction, ie a new aircraft.

Its original design up until @1944 was based on a long range / high altitude fighter requirement with a large radial engine, initially based on a R2800-21, then a R2000-10, then to a R2800-22 but for low altitude fighter as the Merlin powered Mustang had by then been ordered for the high altitude RAAF role.

Over this time its wing design had evolved from an elliptical wing to a laminer flow wing, reflecting industry evolution or best of breed.

By mid 1944 construction of the prototype was well underway based on the installation of the R2800, when it became clear that engines would not be available from the USA, and instead the aircraft was re-designed to take the RR Griffon 120, this decision was not authorised until late 1944 further delaying the prototype’s completion.

Two Griffon 61’s were lent by the UK for use in the prototype and arrived in April 1945, and the liquid cooled engines need for a radiator added the mustang inspired ventral intake.

From Early 1945 the end of war was in sight and the introduction of jet aircraft being contempated for the future, the CA-15 was relegated to a design implentation project rather than a serious pre-production prototype, it struggled to avoid outright cancellation at the end of the war, but commenced taxi-ing trials in early 1946, and commenced flying trials with the RAAF later that year. An unfortunate wheels up landing in December 1946 saw the aircraft’s flying trials abruptly halted, and due to low priority was not rebuilt and re-flown until may 1948 with a limited flight test program before retirement and scrapping in 1950, as probably the worlds last piston engined fighter development?

Despite its Mustang appearance it has little in common with the P51 other than basic layout, it is substantially larger in fuselage depth and length than the P51, but is effectively a “clipped wing” in comparison.

There are no interchangeable parts, the CA-15 undercarriage is unique due to the long reach it required to clear the propellor on take-off, the tailplane has diehedral, the fuselage cross-sections are totally different, the engines are different, the engine mounting methods completely different, the wing aerofoils may be similar due to the mustang’s success with Laminer flow (which continued on into Jets such as the F86), the radiator location was inhereted or inspired by the Mustang as perhaps the most efficient? of the various options previously tried? (in the lower cowl (P40) under the wings (Spitfire) or in the wing roots (Mosquito / Firefly) )

………………………..CA-15………………..P-51(D)

Length………………….36.5’………………….32.25′

Wing Span……………..36’…………………….37′

Height…………………..12′ *………………….13.66′ *
(* note: prop height not airframe)

Weight (empty)………..7,540 lb……………7,635 lb

max T/O Weight………12,340 lb…………..12,100 lb

Engine HP……………….2,035……………….1,695

Speed (max)…………..448 mph……………..437 mph

Regards

Mark Pilkington

Why do I always think the CA-15 looks like a badly hacked about P-51?Looks as though they kept the worst points of the P-51 and lost the good bits.

Have you got Stewart Wilson’s book on the Wirraway, Boomerang & CA-15? Given the aircraft’s limited career, most of it is very well covered there. Most air-to-air photos are well known, while there are a few lesser known shots of it on the ground.

I don’t have those facts to hand (heading to work) but if no-one else answers in the meantime I’ll look it up later.