In my research for the drawings of the Wirraway shown on this site, I collected a range of scale drawings created by other draftsmen. My hope was that I would be able to find some accurate and detailed drawings which I could use as the basis for plans for a flying scale model. But although I discovered many 3-view drawings of the CAC Wirraway, none of them matched measurements which I had taken from A20-10 at the Australian National Aviation Museum at Moorabbin Airport.

So I eventually created my own drawings from scratch, using my measurements plus CAC factory drawings as the source material.

The list below provides some details and comments about the drawings which I collected, based on my analysis and comparison with CAC factory drawings and accurate measurements. The drawings are listed below by publication date, with the earliest at the top.

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Drawing by: F.D. Rogers

Date published: c1957

Source: CAC archives

Comments: This drawing was one of a series of 3-view drawings of CAC aircraft by the CAC draftsman Fred Rogers. The original drawing shows several different views and several different versions of the Wirraway.

Surprisingly for drawings by a factory draftsman, they are not entirely accurate.

When compared with aircraft dimensions and factory drawings, the following inaccuracies are apparent:

• The engine mount is drawn 3″ too short, so the cowl and propeller are 3″ too close to the firewall. The chord-length of the cowl is correct.
• The windscreen angle is too raked
• The antenna mast is drawn 5″ too far forward
• The fairing over the fixed forward guns does not rise sufficiently to the windscreen, so the lower edge of the windscreen is 1.75″ too low

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Drawing by: Chuck Graham

Date published: 1966

Source: IPMS Newsletter

Comments: This drawing shows details for a Wirraway Mk II (produced under the CA-5 contract), in the markings of A20-103 (the aircraft now held at the Australian War Memorial collection).

This drawing was primarily intended to display the colours and markings of A20-103 for scale modelling purposes, but when checked against aircraft measurements, several dimensional inaccuracies are readily apparent:

• Most noticeably, the engine cowl is drawn too long by 10.5″
• The wing chord is drawn 2″ too long and the wing is shown 5″ too far forward
• The wing is drawn around 3.5″ lower than it’s actual location
• In the plan view the fairing between the wing and fuselage is shown becoming wider in a curve towards the trailing edge. The actual fairing follows a straight line parallel to the centre of the aircraft along the top skin of the wing centre section. The curved front section of this fairing is also drawn incorrectly where it meets the wheel housing.
• In the plan view the walk-ways on the wing centre-section are shown as panel lines, but this is incorrect.

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Drawing by: F. Pawlowicz

Date published: December 1973

Source: Aeromodeller magazine

Comments: This drawing shows details for a CA-1 Wirraway Mk I, in the markings of A20-10 (the aircraft now held at the Australian National Aviation Museum in Moorabbin).

At first glance, this drawing looks highly accurate and detailed, with a great deal of surface and panel detail, scrap views and cross-sections. However when compared with factory drawings a large number of inaccuracies become apparent (see the list below).

Also, the drawing shows A20-10 following an upgrade to the late-style oil cooler and carburettor air intake below the cowl (which was introduced by Wirraway Technical Order no. 108 of 26/03/1943, and was standard on the Mk III), so the drawing does not represent an “as-built” CA-1, and this is not explained on the drawing.

The drawing was originally drafted at 1:24 scale (copies can still be purchased from Model Activity Press) and was reproduced in the magazine at 1:48 scale.

When checked against aircraft measurements, several inaccuracies appear on this drawing:

• The tail-plane is drawn about 4″ lower than it’s actual location
• The wing is drawn around 3″ lower than it’s actual location
• The canopy rail is drawn around 3″ lower than it’s actual location
• The angle of the windscreen is too “raked”, at 50° from vertical, wheras it should actually be 44.7° from vertical
• The plan-view shows the fuselage bulging outwards between stations 1 and 6, but in reality the fuselage width is constant between these stations
• The antenna mast is drawn 8″ too far forward
• The fairing between the wing and fuselage is shown becoming wider in a curve towards the trailing edge. The actual fairing follows a straight line parallel to the centre of the aircraft along the top skin of the wing centre section, it does not become wider at the trailing edge. The curved front section of this fairing is also drawn incorrectly where it meets the wheel housing.
• The panel lines on the upper surface of the wing centre-section are incorrect.
• The walk-ways on the wing centre-section are shown as panel lines, but this is incorrect.
• The propeller is listed as a “3 bladed controllable speed metal propeller” but the propeller is in fact “controllable pitch” for “constant speed” operation.
• The configuration of bombs indicated in the scrap-view is incorrect. The larger bombs (500lb Semi Armour Piercing bombs) could only be mounted on the inner universal carriers on the outer wing panels (whereas they are shown mounted on the outer carrier positions).

Given that many of the later drawings listed below feature identical inaccuracies, this drawing was obviously used as a source and traced by later draftsmen without any checking for dimensional accuracy and the errors in this drawing have been propagated across many publications.

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Drawing by: Zbigniew Luranc

Date published: 1987

Source: Unknown

Comments: This drawing also shows the aircraft A20-10 following its cowling changes but lists this as a CA-1, which is a little confusing. The drawings were published at 1:50 scale.

When checked against aircraft measurements, several inaccuracies can be seen on this drawing:

• The tail-plane is drawn about 4″ lower than it’s actual location
• The wing is drawn around 3″ lower than it’s actual location
• The canopy rail is drawn around 3″ lower than it’s actual location
• The plan-view shows the fuselage bulging outwards between stations 1 and 6, but in reality the fuselage width is constant between these stations
• The antenna mast is drawn 8″ too far forward
• The panel lines on the upper surface of the wing centre-section are incorrect.
• The configuration of bombs is incorrect. The larger bombs (500 lb Semi Armour Piercing bombs) could only be mounted on the inner universal carriers on the outer wing panels (wheras they are shown mounted on the outer carrier positions)

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Drawing by: Perry Manley

Date published: 1989

Source: T-6 Texan In Action by Larry Davis; Squadron/Signal Publications, Carrollton Texas, 1989

Comments: A port elevation is included in this book accompanying the chapter on the Wirraway and Boomerang.

When checked against aircraft measurements, several inaccuracies are obvious on this drawing:

• The tail-plane is drawn about 4″ lower than it’s actual location
• The wing is drawn around 3″ lower than it’s actual location, and the outer wing trailing edge is swept forward while the Wirraway trailing edge has no sweep
• The canopy rail is drawn around 3″ lower than it’s actual location
• The antenna mast is too tall
• The engine cowl is drawn around 2″ too far forward, and the air intake is not the correct shape
• The fixed forward machine guns are too high
• The rear flexible machine gun appears to be a Browning gun, on the actual aircraft this was a Vickers GO gun.
• The drawing appears to show a 2-bladed propellor, the diameter of which is too small

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Drawing by: Alex Pedashenko

Date published: 1991

Source: Wirraway, Boomerang and CA-15 In Australian Service by Stewart Wilson, Sydney, 1991

Comments: This 3-view drawing appears in Stewart Wilson’s book, but no draftsman is noted on the drawing. The drawing features the “signature” style of Alex Pedashenko (particularly the tufts of grass on the ground-planes), and Stewart indicated that he had received several drawings from Alex, hence it makes sense that Alex was the draftsman. The drawing is listed as depicting the CA-3 and CA-9 aircraft (Mk II) and correctly shows the CA-9 twin air intake on the lower cowl. However it incorrectly shows corrugated skin on the vertical fin, which was only fitted to Mk I aircraft produced under the CA-1 contract.

When checked against aircraft measurements, several inaccuracies appear on this drawing:

• The tail-plane is drawn about 3″ lower than it’s actual location
• The thrust-line is drawn around 4″ higher than it’s actual location – this results in the entire cowling being around 4″ higher than it should be
• The plan-view shows the fuselage bulging outwards between stations 1 and 6, but in reality the fuselage width is constant between these stations
• The panel lines on the upper surface of the wing centre-section are incorrect
• The antenna mast is drawn 8″ too far forward

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Drawing by: Colin Owers

Date published: 1992

Source: Aviation News magazine, September-October 1992

Comments: This drawing shows details for several different versions of the Wirraway, however the views are not labelled. The drawings were published in the magazine at 1:72 scale.

The same drawings were published in Air Enthusiast 50, alongside Owers’ article about the Wirraway.

When checked against aircraft measurements, several inaccuracies appear on this drawing (many of which are the same as for the Pawlowicz drawing, leading to the conclusion that these drawings may have been traced from the Pawlowicz drawing):

• The tail-plane is drawn about 4″ lower than it’s actual location
• The wing is drawn around 3″ higher than it’s actual location
• The canopy rail is drawn around 4″ lower than it’s actual location
• The plan-view shows the fuselage bulging outwards between stations 1 and 6, but in reality the fuselage width is constant between these stations
• Several features are shown on the starboard side of the fuselage which are not actually there (the fuselage side panels are not symmetrical)
• The panel lines on the upper surface of the wing centre-section are incorrect
• The underside view of the centre section and rear fuselage is not accurate
• The antenna mast is drawn 8″ too far forward

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Drawing by: Joe Vella

Date published: 1995

Source: Air Enthusiast magazine No. 61 Jan-Feb 1996

Comments: A small 3-view drawing by Joe Vella appeared alongside his article about the aircraft of CAC. The drawing depicts the CA-16 aircraft (Mk III) including the dive brakes on the upper surfaces of the outer wings.

When checked against aircraft measurements, several inaccuracies appear on this drawing:

• The tail-plane is drawn about 3″ lower than it’s actual location
• The wing is drawn around 3″ lower than it’s actual location
• The canopy rail is drawn around 3″ lower than it’s actual location
• The angle of the windscreen is too “raked”, at 50° from vertical, wheras it should actually be 44.7° from vertical.
• The antenna mast is drawn 8″ too far forward
• The panel lines on the upper surface of the wing centre-section are incorrect.

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Drawing by: Unknown

Date published: 1997

Source: CAC Boomerang CAC Wirraway by Andre Zbigniewski and Jacek Nowicki; Wydawnictwo Militaria, Warsaw, 1997 (published in Polish)

Comments: This drawing (perhaps drafted by Zbigniew Luranc, or based on his drawing) shows the CA-1 ribbed fin skin, but the later style carburetor and oil cooler air intake below the cowl on the same profile, which is confusing. The drawing does however correctly show the different access panels and covers on the port fuselage side compared to the starboard side.

When checked against aircraft measurements, several inaccuracies appear on this drawing:

• The engine, cowl and propeller have been drawn 4″ above their correct location; it appears the draftsman has laid the thrust-line over the fuselage centre-line (or reference line) when in fact the thrust-line is 4″ below the fuselage centre-line
• The plan-view shows the fuselage bulging outwards between stations 1 and 6, but the actual fuselage width is constant between these stations
• The antenna mast is drawn 8″ too far forward
• The panel lines on the upper surface of the wing centre-section are incorrect.
• The configuration of bombs is incorrect. The larger bombs (500 lb Semi Armour Piercing bombs) could only be mounted on the inner universal carriers on the outer wing panels (wheras they are shown mounted on the outer universal carrier positions)
• The starboard fuselage side panel is shown as one long panel, whereas the actual panel was split into two
• The instument panel layout shown on the drawing is for the CAC Boomerang, not the Wirraway

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Drawing by: Richard J. Caruana

Date published: November 2003

Source: Scale Aviation Modeller International magazine, Volume 9 Issue 11 November 2003

Comments: This drawing also shows details for several different versions of the Wirraway (Mk I, Mk II and Mk III) but the views labelled only as “Early production”, “Standard production” and “Later production”.

The drawings were published in the magazine at 1:48 scale.

When checked against aircraft measurements, several inaccuracies appear on this drawing:

• The tail-plane is drawn about 4″ lower than it’s actual location
• The wing is drawn about 2″ lower than it’s actual location
• The canopy rail is drawn around 3″ lower than it’s actual location
• The angle of the windscreen is too “raked”, at 50° from vertical, wheras it should actually be 44.7° from vertical.
• The plan-view shows the fuselage bulging outwards between stations 1 and 6, but in reality the fuselage width is constant between these stations
• The panel lines on the upper surface of the wing centre-section are incorrect
• Several features are shown on the starboard side of the fuselage which are not actually there (the fuselage is not symmetrical)
• The underside view is not accurate around the tail wheel, rear fuselage and engine oil cooler
• The antenna mast is drawn 4″ too far forward

The aircraft:

The CAC Wirraway Mk I was a licence-built North American Aviation NA-16-2K (also known by its “charge code” NA-33) with numerous changes incorporated at the request of the RAAF. These aircraft were purchased by the RAAF for use as general purpose aircraft, for tasks including Army co-operation, photography, and advanced training (which covered instrument flying, high bombing, dive bombing and air-to-air combat). A total of 40 Mark I aircraft were produced under the CAC internal contract number CA-1. Production details can be found here.

The drawings:

This set of detailed drawings (originally drafted at 1:48 scale) shows details of the Mark I Wirraway, both as produced at the CAC factory as well as the major visible changes and modifications incorporated during RAAF service.

Plate 1a. Wirraway fuselage station diagram

The first plate shows the fuselage stations according to the Maintenance and Repair Manual. The eleven main stations were defined by upright tubes in the welded steel fuselage frame. Click on the image above to open a PDF file formatted for printing on A4 paper (approximately 31 KB).

Plate 1b. Wirraway fuselage framework

This drawing shows the geometry and dimensions of the Wirraway’s welded chrome-molybdenum steel tube fuselage framework. Click on the image above to open a PDF file formatted for printing on A4 paper (approximately 37 KB).

Plate 2a. Wirraway wing station diagram

This drawing shows the geometry of the Wirraway wing structure, including rib stations and airfoil sections. Click on the image above to open a PDF file formatted for printing on A4 paper (approximately 17 KB in size). 

Plate 4a. CA-1 Wirraway side elevations

This drawing shows side elevations of the CA-1 Wirraway, showing the differences between the port and starboard side of the aircraft. Click on the image above to open a PDF file formatted for printing on A4 paper (approximately 17 KB). 

Plate 4b. CA-1 Wirraway plan view

This drawing shows a plan view of the CA-1 Wirraway. Click on the image above to open a PDF file formatted for printing on A4 paper (approximately 17 KB).

Plate 4c. CA-1 Wirraway underside view

This drawing shows the underside view of the CA-1 Wirraway, including details of all the under-wing armament which the Wirraway could carry. Click on the image above to open a PDF file formatted for printing on A4 paper (approximately 17 KB).

Plate 4d. CA-1 Wirraway front and rear views

This drawing shows front and rear views of the CA-1 Wirraway, including details of the Pratt & Whitney R-1340 Wasp engine. Click on the image above to open a PDF file formatted for printing on A4 paper (approximately 17 KB). 

Just a reminder: if you download these drawings, you agree to use them under the Creative Commons Attribution Share-Alike 3.0 Unported License.

Click here for a full description of this license, but in summary it means that you are free to copy, distribute and adapt these drawings on the conditions that you attribute their creation to me and that if you adapt and distribute them you must also license the adapted versions under the same conditions.

You may seek my permission to waive any of these conditions (if, for example, you wish to publish the drawings in any form) by sending me an email.

For reference purposes I’ve collated a list of production batch numbers for the CAC Wirraway aircraft delivered to the RAAF between July 1939 and July 1946. This page contains the batch numbers for Mark III Wirraways, which were delivered under the CA-16 production “contract”. A summary of Mark III production is given in the table below:

Wirraway type	CAC Contract Number	RAAF Contract Demand	Ordering entity	Order Number	Quantity delivered	CAC Constructor’s Numbers	RAAF Serials
Mk III	CA-16	D.A.P. 1007	DAP	C.S.1800	135	1075 to 1209	A20-623 to 757

DAP = Department of Aircraft Production

Batch numbers
Wirraway Mark III production was planned in batches of 11 aircraft. But there was one exception:

• The final batch of production, batch “N” consisted of only 3 aircraft to make up 135 aircraft

Batch numbers consisted of a letter for each batch followed by a number for each aircraft in that batch (e.g. A1, A2, A3, A4, etc)..The letters I, O, Q and V were generally not used as batch numbers, as they could be confused for numbers. The CA-16 contract started with batch “A”.

The definitive source for batch numbers is a ledger book kept by Mr Gordon Parker, Supervisor in the Sales Department, and one of CAC’s earliest employees from 1936. This book is now held in the collection of the Australian National Aviation Museum at Moorabbin Airport.

Unfortunately there are two discrepancies in the last 25 entries in the ledger. Firstly, Parker skipped batch “L” for A20-733 to A20-743 and went straight from “K” to “M”. We know that batch “L” was not skipped in reality, as two surviving data plates reclaimed from airframes at Tocumwal show L2 for A20-734 (c/n 1186) and M5 for A20-748 (c/n 1200). Secondly, Parker stopped recording batch numbers at A20-740, so the batch codes shown in the list below are “extrapolated”. The batch “M” extrapolation is supported by the evidence of the M5 batch number on the A20-748 data plate. This leaves a question as to the last three aircraft – were they N1, N2 and N3, or was batch M continued for three more aircraft, as M12, M13 and M14. I have postulated that a new batch “N” was commenced, since CAC did not expect to end production at 755 aircraft. There were many debates between CAC and DAP over how many aircraft to supply to the RAAF (the original order was for 150 aircraft, and another order had been received for 100 additional “Dive Bomber” aircraft planned as CA-20, but only 135 were delivered under the CA-16 order), so it is logical to presume that the last three aircraft were N1, N2 and N3.

During production, batch numbers were temporarily attached to the firewall and then the rudder (once the engine was mounted). These temporary numbers are sometimes visible in factory photos.

Constructor’s numbers
These were a sequence of numbers allocated to each aircraft in the sequence that they came off the line. Wirraways delivered under the CA-16 contract were given constructor’s numbers from 1075 to 1209.

RAAF stores number
All equipment in the RAAF was allocated a stores number for tracking and accounting purposes. Aircraft were tracked under the category “A” and each aircraft was given a specific number, Wirraway aircraft being allocated the category A20. These numbers are often referred to as the “serial number” of the aircraft in RAAF service.

Linking batch numbers, stores numbers and constructor’s numbers
Here are several photos showing Mark III Wirraways under construction, allowing us to link the batch codes to RAAF stores/serial numbers.

Below we can see a group of camouflaged Mark III Wirraways on the production line. Batch numbers visible include D10 (furthest away, on the left) and E1 to E5 (closest, on the right). In the original photograph, D11 is also visible, sitting between D10 and E1, but pointing tail-on to the camera, so its rudder cannot be seen. These aircraft are A20-665 to A20-671, as evidenced by the three-digit number after the two-digit batch codes. 

Later in the CA-16 contract, below is a view of H8 (A20-707, c/n 1159) attached to the lifting sling. The batch label taped to the rudder showing H8-707 is repeated in the inset at lower right.

The photo below shows late CA-16 production, with the aircraft now painted overall Trainer Yellow.  K7 (A20-728) is visible sitting on dolly wheels, and the rudder of K8 (A20-729) is visible behind the aircraft (shown enlarged in the inset at lower left).

The table below lists batch numbers and construction numbers for all Mark III Wirraway aircraft, delivered under the CA-16 contract. The batch numbers are transcribed from Gordon Parker’s delivery records (with the last 25 entries corrected), and have been cross-checked with photographic evidence (some of which is shown above) and several frames and ID tags held in museums or private collections.

CAC Contract Number CA-	CAC Constructor’s Number	RAAF Serial	Batch Number
16	1075	A20-623	A1
16	1076	A20-624	A2
16	1077	A20-625	A3
16	1078	A20-626	A4
16	1079	A20-627	A5
16	1080	A20-628	A6
16	1081	A20-629	A7
16	1082	A20-630	A8
16	1083	A20-631	A9
16	1084	A20-632	A10
16	1085	A20-633	A11
16	1086	A20-634	B1
16	1087	A20-635	B2
16	1088	A20-636	B3
16	1089	A20-637	B4
16	1090	A20-638	B5
16	1091	A20-639	B6
16	1092	A20-640	B7
16	1093	A20-641	B8
16	1094	A20-642	B9
16	1095	A20-643	B10
16	1096	A20-644	B11
16	1097	A20-645	C1
16	1098	A20-646	C2
16	1099	A20-647	C3
16	1100	A20-648	C4
16	1101	A20-649	C5
16	1102	A20-650	C6
16	1103	A20-651	C7
16	1104	A20-652	C8
16	1105	A20-653	C9
16	1106	A20-654	C10
16	1107	A20-655	C11
16	1108	A20-656	D1
16	1109	A20-657	D2
16	1110	A20-658	D3
16	1111	A20-659	D4
16	1112	A20-660	D5
16	1113	A20-661	D6
16	1114	A20-662	D7
16	1115	A20-663	D8
16	1116	A20-664	D9
16	1117	A20-665	D10
16	1118	A20-666	D11
16	1119	A20-667	E1
16	1120	A20-668	E2
16	1121	A20-669	E3
16	1122	A20-670	E4
16	1123	A20-671	E5
16	1124	A20-672	E6
16	1125	A20-673	E7
16	1126	A20-674	E8
16	1127	A20-675	E9
16	1128	A20-676	E10
16	1129	A20-677	E11
16	1130	A20-678	F1
16	1131	A20-679	F2
16	1132	A20-680	F3
16	1133	A20-681	F4
16	1134	A20-682	F5
16	1135	A20-683	F6
16	1136	A20-684	F7
16	1137	A20-685	F8
16	1138	A20-686	F9
16	1139	A20-687	F10
16	1140	A20-688	F11
16	1141	A20-689	G1
16	1142	A20-690	G2
16	1143	A20-691	G3
16	1144	A20-692	G4
16	1145	A20-693	G5
16	1146	A20-694	G6
16	1147	A20-695	G7
16	1148	A20-696	G8
16	1149	A20-697	G9
16	1150	A20-698	G10
16	1151	A20-699	G11
16	1152	A20-700	H1
16	1153	A20-701	H2
16	1154	A20-702	H3
16	1155	A20-703	H4
16	1156	A20-704	H5
16	1157	A20-705	H6
16	1158	A20-706	H7
16	1159	A20-707	H8
16	1160	A20-708	H9
16	1161	A20-709	H10
16	1162	A20-710	H11
16	1163	A20-711	J1
16	1164	A20-712	J2
16	1165	A20-713	J3
16	1166	A20-714	J4
16	1167	A20-715	J5
16	1168	A20-716	J6
16	1169	A20-717	J7
16	1170	A20-718	J8
16	1171	A20-719	J9
16	1172	A20-720	J10
16	1173	A20-721	J11
16	1174	A20-722	K1
16	1175	A20-723	K2
16	1176	A20-724	K3
16	1177	A20-725	K4
16	1178	A20-726	K5
16	1179	A20-727	K6
16	1180	A20-728	K7
16	1181	A20-729	K8
16	1182	A20-730	K9
16	1183	A20-731	K10
16	1184	A20-732	K11
16	1185	A20-733	L1
16	1186	A20-734	L2
16	1187	A20-735	L3
16	1188	A20-736	L4
16	1189	A20-737	L5
16	1190	A20-738	L6
16	1191	A20-739	L7
16	1192	A20-740	L8
16	1193	A20-741	L9
16	1194	A20-742	L10
16	1195	A20-743	L11
16	1196	A20-744	M1
16	1197	A20-745	M2
16	1198	A20-746	M3
16	1199	A20-747	M4
16	1200	A20-748	M5
16	1201	A20-749	M6
16	1202	A20-750	M7
16	1203	A20-751	M8
16	1204	A20-752	M9
16	1205	A20-753	M10
16	1206	A20-754	M11
16	1207	A20-755	N1
16	1208	A20-756	N2
16	1209	A20-757	N3

I welcome feedback on the table above, with supporting evidence of any possible inaccuracies.

References:

Commonwealth Aircraft Corporation. Sales Department Aircraft Delivery Ledger; Kept by Gordon Parker. CAC Collection, Australian National Aviation Museum.

Commonwealth Aircraft Corporation. Aircraft Drawing Office Manual. Incorporating up to Amendment List No. 2, Melbourne, Australia, 1946.

For reference purposes I’ve collated a list of production batch numbers for the CAC Wirraway aircraft delivered to the RAAF between July 1939 and July 1946. This page contains the batch numbers for Mark II Wirraways, which were delivered under the CA-3, CA-5, CA-7, CA-8 and CA-9 production “contract” numbers. A summary of Mark II production is given in the table below:

Wirraway type	CAC Contract Number	RAAF Contract Demand	Ordering entity	Order Number	Quantity delivered	CAC Constructor’s Numbers	RAAF Serials
Mk II	CA-3	T.456	DCB	(unknown)	60	41 to 100	A20-43 to 102
Mk II	CA-5	T.562	DCB	(unknown)	32	103 to 134	A20-103 to 134
Mk II	CA-7	A.P.C.1	APC	(unknown)	100	135 to 234	A20-135 to 234
Mk II	CA-8	A.P.C.81	APC	(unknown)	200	436 to 635	A20-235 to 434
Mk II	CA-9	A.P.C.433	APC	(unknown)	132	636 to 766	A20-435 to 565
Mk II	CA-9	A.P.C.739	APC	C.S.452	56	767 to 823	A20-566 to 622

DCB = Defence Contracts Board
APC = Aircraft Production Commission

Batch numbers
Wirraway production was generally planned in batches of 10 aircraft. But there were two exceptions:

• At the end of the CA-5 contract, batch “Q” consisted of 12 aircraft, to make up the total of 32 aircraft delivered against this contract
• At the end of the CA-9 contract, batch “W” consisted of only 8 aircraft, to make up the total of 188 aircraft delivered against this contract

Batch numbers consisted of a letter for each batch followed by a number for each aircraft in that batch (e.g. A1, A2, A3, A4, etc)..The letters I, O, Q and V were generally not used as batch numbers, as they could be confused for numbers.

Usually a new contract (such as CA-1, CA-2, etc) started with batch “A”. However the CA-5 contract started with batch “N” (following from the final CA-3 batch which was “M”)

The definitive source for batch numbers is a ledger book kept by Mr Gordon Parker, Supervisor in the Sales Department, and one of CAC’s earliest employees from 1936. This book is now held in the collection of the Australian National Aviation Museum at Moorabbin Airport. The list below is transcribed from the Parker list, and has been checked against photographic records as well as airframes and ID tags held in museums and private collections.

During production, batch numbers were temporarily attached to the firewall and then the rudder (once the engine was mounted). These temporary numbers are sometimes visible in factory photos.

Constructor’s numbers
These were a sequence of numbers allocated to each aircraft in the sequence that they came off the line. For example, Wirraways delivered under the CA-3 contract were given constructor’s numbers from 41 to 100.

RAAF stores number
All equipment in the RAAF was allocated a stores number for tracking and accounting purposes. Aircraft were tracked under the category “A” and each aircraft was given a specific number, Wirraway aircraft being allocated the category A20. These numbers are often referred to as the “serial number” of the aircraft in RAAF service.

Linking batch numbers, stores numbers and constructor’s numbers
Here are several photos showing Mark II Wirraways under construction, allowing us to link the batch codes to RAAF stores/serial numbers.

Mark II Wirraways commenced with the 41st aircraft, A20-44 (c/n 41) and in the photo below we see the last Mark I aircraft (A20-42, on the far side of the factory closest to the doors) and the first Mark II aircraft (furthest to the right, with G1 batch number on the rudder). Workers are pushing G4 in the foreground (A20-46).

Early in CA-5 production the photo below shows six fins and rudders, from the left N8, with A20-110 also labelled, then N9 (batch label hidden) with its tail wheel on the ground, then N10 (batch label hidden), then P1 and P2 and finally P3 with its label hanging half-off. 

The photo below shows a group of Wirraway aircraft under construction, late in the CA-9 contract, around March 1942. Batch numbers taped to the rudder of each aircraft are (from the left) P6-570, P5-569, P1-565, N9-563. These correspond to A20-570, A20-569, A20-565 and A20-563. Incidentally, these aircraft (the last 56 in the CA-9 contract) were originally intended for the RAF, but the War Cabinet decided to retain them in Australia. They were also delivered with two-bladed propellers, as De Havilland had run out of imported “spider” castings for three-bladed propellers.

The table below lists batch numbers and construction numbers for all Mark II Wirraway aircraft, delivered under the CA-3, CA-5, CA-7, CA-8 and CA-9 contracts. The batch numbers are transcribed from Gordon Parker’s delivery records, and have been cross-checked with photographic evidence where possible (some of which is shown above) and several frames and ID tags held in museums or private collections.

Note that it is possible that not all batch numbers correspond exactly according to Gordon Parker’s list as transcribed below. There may have been periods where a welded frame with a given batch number was taken from stock and assembled into an airframe with a different constructor’s number. For example, the first aircraft supplied under the CA-5 contract, the famous A20-103 (C/N 103) in the War Memorial, should have the batch number N1 according to Parker’s list (as shown below), however a collector has a bracelet with the N1 batch number in a private collection. So the frame in A20-103 may not have been the frame labelled N1 as would be expected.

CAC Contract Number CA-	CAC Constructor’s Number	RAAF Serial	Batch Number
3	41	A20-43	G1
3	42	A20-44	G2
3	43	A20-45	G3
3	44	A20-46	G4
3	45	A20-47	G5
3	46	A20-48	G6
3	47	A20-49	G7
3	48	A20-50	G8
3	49	A20-51	G9
3	50	A20-52	G10
3	51	A20-53	H1
3	52	A20-54	H2
3	53	A20-55	H3
3	54	A20-56	H4
3	55	A20-57	H5
3	56	A20-58	H6
3	57	A20-59	H7
3	58	A20-60	H8
3	59	A20-61	H9
3	60	A20-62	H10
3	61	A20-63	J1
3	62	A20-64	J2
3	63	A20-65	J3
3	64	A20-66	J4
3	65	A20-67	J5
3	66	A20-68	J6
3	67	A20-69	J7
3	68	A20-70	J8
3	69	A20-71	J9
3	70	A20-72	J10
3	71	A20-73	K1
3	72	A20-74	K2
3	73	A20-75	K3
3	74	A20-76	K4
3	75	A20-77	K5
3	76	A20-78	K6
3	77	A20-79	K7
3	78	A20-80	K8
3	79	A20-81	K9
3	80	A20-82	K10
3	81	A20-83	L1
3	82	A20-84	L2
3	83	A20-85	L3
3	84	A20-86	L4
3	85	A20-87	L5
3	86	A20-88	L6
3	87	A20-89	L7
3	88	A20-90	L8
3	89	A20-91	L9
3	90	A20-92	L10
3	91	A20-93	M1
3	92	A20-94	M2
3	93	A20-95	M3
3	94	A20-96	M4
3	95	A20-97	M5
3	96	A20-98	M6
3	97	A20-99	M7
3	98	A20-100	M8
3	99	A20-101	M9
3	100	A20-102	M10
5	103	A20-103	N1
5	104	A20-104	N2
5	105	A20-105	N3
5	106	A20-106	N4
5	107	A20-107	N5
5	108	A20-108	N6
5	109	A20-109	N7
5	110	A20-110	N8
5	111	A20-111	N9
5	112	A20-112	N10
5	113	A20-113	P1
5	114	A20-114	P2
5	115	A20-115	P3
5	116	A20-116	P4
5	117	A20-117	P5
5	118	A20-118	P6
5	119	A20-119	P7
5	120	A20-120	P8
5	121	A20-121	P9
5	122	A20-122	P10
5	123	A20-123	Q1
5	124	A20-124	Q2
5	125	A20-125	Q3
5	126	A20-126	Q4
5	127	A20-127	Q5
5	128	A20-128	Q6
5	129	A20-129	Q7
5	130	A20-130	Q8
5	131	A20-131	Q9
5	132	A20-132	Q10
5	133	A20-133	Q11
5	134	A20-134	Q12
7	135	A20-135	A1
7	136	A20-136	A2
7	137	A20-137	A3
7	138	A20-138	A4
7	139	A20-139	A5
7	140	A20-140	A6
7	141	A20-141	A7
7	142	A20-142	A8
7	143	A20-143	A9
7	144	A20-144	A10
7	145	A20-145	B1
7	146	A20-146	B2
7	147	A20-147	B3
7	148	A20-148	B4
7	149	A20-149	B5
7	150	A20-150	B6
7	151	A20-151	B7
7	152	A20-152	B8
7	153	A20-153	B9
7	154	A20-154	B10
7	155	A20-155	C1
7	156	A20-156	C2
7	157	A20-157	C3
7	158	A20-158	C4
7	159	A20-159	C5
7	160	A20-160	C6
7	161	A20-161	C7
7	162	A20-162	C8
7	163	A20-163	C9
7	164	A20-164	C10
7	165	A20-165	D1
7	166	A20-166	D2
7	167	A20-167	D3
7	168	A20-168	D4
7	169	A20-169	D5
7	170	A20-170	D6
7	171	A20-171	D7
7	172	A20-172	D8
7	173	A20-173	D9
7	174	A20-174	D10
7	175	A20-175	E1
7	176	A20-176	E2
7	177	A20-177	E3
7	178	A20-178	E4
7	179	A20-179	E5
7	180	A20-180	E6
7	181	A20-181	E7
7	182	A20-182	E8
7	183	A20-183	E9
7	184	A20-184	E10
7	185	A20-185	F1
7	186	A20-186	F2
7	187	A20-187	F3
7	188	A20-188	F4
7	189	A20-189	F5
7	190	A20-190	F6
7	191	A20-191	F7
7	192	A20-192	F8
7	193	A20-193	F9
7	194	A20-194	F10
7	195	A20-195	G1
7	196	A20-196	G2
7	197	A20-197	G3
7	198	A20-198	G4
7	199	A20-199	G5
7	200	A20-200	G6
7	201	A20-201	G7
7	202	A20-202	G8
7	203	A20-203	G9
7	204	A20-204	G10
7	205	A20-205	H1
7	206	A20-206	H2
7	207	A20-207	H3
7	208	A20-208	H4
7	209	A20-209	H5
7	210	A20-210	H6
7	211	A20-211	H7
7	212	A20-212	H8
7	213	A20-213	H9
7	214	A20-214	H10
7	215	A20-215	J1
7	216	A20-216	J2
7	217	A20-217	J3
7	218	A20-218	J4
7	219	A20-219	J5
7	220	A20-220	J6
7	221	A20-221	J7
7	222	A20-222	J8
7	223	A20-223	J9
7	224	A20-224	J10
7	225	A20-225	K1
7	226	A20-226	K2
7	227	A20-227	K3
7	228	A20-228	K4
7	229	A20-229	K5
7	230	A20-230	K6
7	231	A20-231	K7
7	232	A20-232	K8
7	233	A20-233	K9
7	234	A20-234	K10
8	436	A20-235	A1
8	437	A20-236	A2
8	438	A20-237	A3
8	439	A20-238	A4
8	440	A20-239	A5
8	441	A20-240	A6
8	442	A20-241	A7
8	443	A20-242	A8
8	444	A20-243	A9
8	445	A20-244	A10
8	446	A20-245	B1
8	447	A20-246	B2
8	448	A20-247	B3
8	449	A20-248	B4
8	450	A20-249	B5
8	451	A20-250	B6
8	452	A20-251	B7
8	453	A20-252	B8
8	454	A20-253	B9
8	455	A20-254	B10
8	456	A20-255	C1
8	457	A20-256	C2
8	458	A20-257	C3
8	459	A20-258	C4
8	460	A20-259	C5
8	461	A20-260	C6
8	462	A20-261	C7
8	463	A20-262	C8
8	464	A20-263	C9
8	465	A20-264	C10
8	466	A20-265	D1
8	467	A20-266	D2
8	468	A20-267	D3
8	469	A20-268	D4
8	470	A20-269	D5
8	471	A20-270	D6
8	472	A20-271	D7
8	473	A20-272	D8
8	474	A20-273	D9
8	475	A20-274	D10
8	476	A20-275	E1
8	477	A20-276	E2
8	478	A20-277	E3
8	479	A20-278	E4
8	480	A20-279	E5
8	481	A20-280	E6
8	482	A20-281	E7
8	483	A20-282	E8
8	484	A20-283	E9
8	485	A20-284	E10
8	486	A20-285	F1
8	487	A20-286	F2
8	488	A20-287	F3
8	489	A20-288	F4
8	490	A20-289	F5
8	491	A20-290	F6
8	492	A20-291	F7
8	493	A20-292	F8
8	494	A20-293	F9
8	495	A20-294	F10
8	496	A20-295	G1
8	497	A20-296	G2
8	498	A20-297	G3
8	499	A20-298	G4
8	500	A20-299	G5
8	501	A20-300	G6
8	502	A20-301	G7
8	503	A20-302	G8
8	504	A20-303	G9
8	505	A20-304	G10
8	506	A20-305	H1
8	507	A20-306	H2
8	508	A20-307	H3
8	509	A20-308	H4
8	510	A20-309	H5
8	511	A20-310	H6
8	512	A20-311	H7
8	513	A20-312	H8
8	514	A20-313	H9
8	515	A20-314	H10
8	516	A20-315	J1
8	517	A20-316	J2
8	518	A20-317	J3
8	519	A20-318	J4
8	520	A20-319	J5
8	521	A20-320	J6
8	522	A20-321	J7
8	523	A20-322	J8
8	524	A20-323	J9
8	525	A20-324	J10
8	526	A20-325	K1
8	527	A20-326	K2
8	528	A20-327	K3
8	529	A20-328	K4
8	530	A20-329	K5
8	531	A20-330	K6
8	532	A20-331	K7
8	533	A20-332	K8
8	534	A20-333	K9
8	535	A20-334	K10
8	536	A20-335	L1
8	537	A20-336	L2
8	538	A20-337	L3
8	539	A20-338	L4
8	540	A20-339	L5
8	541	A20-340	L6
8	542	A20-341	L7
8	543	A20-342	L8
8	544	A20-343	L9
8	545	A20-344	L10
8	546	A20-345	M1
8	547	A20-346	M2
8	548	A20-347	M3
8	549	A20-348	M4
8	550	A20-349	M5
8	551	A20-350	M6
8	552	A20-351	M7
8	553	A20-352	M8
8	554	A20-353	M9
8	555	A20-354	M10
8	556	A20-355	N1
8	557	A20-356	N2
8	558	A20-357	N3
8	559	A20-358	N4
8	560	A20-359	N5
8	561	A20-360	N6
8	562	A20-361	N7
8	563	A20-362	N8
8	564	A20-363	N9
8	565	A20-364	N10
8	566	A20-365	P1
8	567	A20-366	P2
8	568	A20-367	P3
8	569	A20-368	P4
8	570	A20-369	P5
8	571	A20-370	P6
8	572	A20-371	P7
8	573	A20-372	P8
8	574	A20-373	P9
8	575	A20-374	P10
8	576	A20-375	R1
8	577	A20-376	R2
8	578	A20-377	R3
8	579	A20-378	R4
8	580	A20-379	R5
8	581	A20-380	R6
8	582	A20-381	R7
8	583	A20-382	R8
8	584	A20-383	R9
8	585	A20-384	R10
8	586	A20-385	S1
8	587	A20-386	S2
8	588	A20-387	S3
8	589	A20-388	S4
8	590	A20-389	S5
8	591	A20-390	S6
8	592	A20-391	S7
8	593	A20-392	S8
8	594	A20-393	S9
8	595	A20-394	S10
8	596	A20-395	T1
8	597	A20-396	T2
8	598	A20-397	T3
8	599	A20-398	T4
8	600	A20-399	T5
8	601	A20-400	T6
8	602	A20-401	T7
8	603	A20-402	T8
8	604	A20-403	T9
8	605	A20-404	T10
8	606	A20-405	U1
8	607	A20-406	U2
8	608	A20-407	U3
8	609	A20-408	U4
8	610	A20-409	U5
8	611	A20-410	U6
8	612	A20-411	U7
8	613	A20-412	U8
8	614	A20-413	U9
8	615	A20-414	U10
8	616	A20-415	W1
8	617	A20-416	W2
8	618	A20-417	W3
8	619	A20-418	W4
8	620	A20-419	W5
8	621	A20-420	W6
8	622	A20-421	W7
8	623	A20-422	W8
8	624	A20-423	W9
8	625	A20-424	W10
8	626	A20-425	X1
8	627	A20-426	X2
8	628	A20-427	X3
8	629	A20-428	X4
8	630	A20-429	X5
8	631	A20-430	X6
8	632	A20-431	X7
8	633	A20-432	X8
8	634	A20-433	X9
8	635	A20-434	X10
9	636	A20-435	A1
9	637	A20-436	A2
9	638	A20-437	A3
9	639	A20-438	A4
9	640	A20-439	A5
9	641	A20-440	A6
9	642	A20-441	A7
9	643	A20-442	A8
9	644	A20-443	A9
9	645	A20-444	A10
9	646	A20-445	B1
9	647	A20-446	B2
9	648	A20-447	B3
9	649	A20-448	B4
9	650	A20-449	B5
9	651	A20-450	B6
9	652	A20-451	B7
9	653	A20-452	B8
9	654	A20-453	B9
9	655	A20-454	B10
9	656	A20-455	C1
9	657	A20-456	C2
9	658	A20-457	C3
9	659	A20-458	C4
9	660	A20-459	C5
9	661	A20-460	C6
9	662	A20-461	C7
9	663	A20-462	C8
9	664	A20-463	C9
9	665	A20-464	C10
9	666	A20-465	D1
9	667	A20-466	D2
9	668	A20-467	D3
9	669	A20-468	D4
9	670	A20-469	D5
9	671	A20-470	D6
9	672	A20-471	D7
9	673	A20-472	D8
9	674	A20-473	D9
9	675	A20-474	D10
9	676	A20-475	E1
9	677	A20-476	E2
9	678	A20-477	E3
9	679	A20-478	E4
9	680	A20-479	E5
9	681	A20-480	E6
9	682	A20-481	E7
9	683	A20-482	E8
9	684	A20-483	E9
9	685	A20-484	E10
9	686	A20-485	F1
9	687	A20-486	F2
9	688	A20-487	F3
9	689	A20-488	F4
9	690	A20-489	F5
9	691	A20-490	F6
9	692	A20-491	F7
9	693	A20-492	F8
9	694	A20-493	F9
9	695	A20-494	F10
9	696	A20-495	G1
9	697	A20-496	G2
9	698	A20-497	G3
9	699	A20-498	G4
9	700	A20-499	G5
9	701	A20-500	G6
9	702	A20-501	G7
9	703	A20-502	G8
9	704	A20-503	G9
9	705	A20-504	G10
9	706	A20-505	H1
9	707	A20-506	H2
9	708	A20-507	H3
9	709	A20-508	H4
9	710	A20-509	H5
9	711	A20-510	H6
9	712	A20-511	H7
9	713	A20-512	H8
9	714	A20-513	H9
9	715	A20-514	H10
9	716	A20-515	J1
9	717	A20-516	J2
9	718	A20-517	J3
9	719	A20-518	J4
9	720	A20-519	J5
9	721	A20-520	J6
9	722	A20-521	J7
9	723	A20-522	J8
9	724	A20-523	J9
9	725	A20-524	J10
9	726	A20-525	K1
9	727	A20-526	K2
9	728	A20-527	K3
9	729	A20-528	K4
9	730	A20-529	K5
9	731	A20-530	K6
9	732	A20-531	K7
9	733	A20-532	K8
9	734	A20-533	K9
9	735	A20-534	K10
9	736	A20-535	L1
9	737	A20-536	L2
9	738	A20-537	L3
9	739	A20-538	L4
9	740	A20-539	L5
9	741	A20-540	L6
9	742	A20-541	L7
9	743	A20-542	L8
9	744	A20-543	L9
9	745	A20-544	L10
9	746	A20-545	M1
9	747	A20-546	M2
9	748	A20-547	M3
9	749	A20-548	M4
9	750	A20-549	M5
9	751	A20-550	M6
9	752	A20-551	M7
9	753	A20-552	M8
9	754	A20-553	M9
9	755	A20-554	M10
9	756	A20-555	N1
9	757	A20-556	N2
9	758	A20-557	N3
9	759	A20-558	N4
9	760	A20-559	N5
9	761	A20-560	N6
9	762	A20-561	N7
9	763	A20-562	N8
9	764	A20-563	N9
9	765	A20-564	N10
9	766	A20-565	P1
9	767	A20-566	P2
9	768	A20-567	P3
9	769	A20-568	P4
9	770	A20-569	P5
9	771	A20-570	P6
9	772	A20-571	P7
9	773	A20-572	P8
9	774	A20-573	P9
9	775	A20-574	P10
9	776	A20-575	R1
9	777	A20-576	R2
9	778	A20-577	R3
9	779	A20-578	R4
9	780	A20-579	R5
9	781	A20-580	R6
9	782	A20-581	R7
9	783	A20-582	R8
9	784	A20-583	R9
9	785	A20-584	R10
9	786	A20-585	S1
9	787	A20-586	S2
9	788	A20-587	S3
9	789	A20-588	S4
9	790	A20-589	S5
9	791	A20-590	S6
9	792	A20-591	S7
9	793	A20-592	S8
9	794	A20-593	S9
9	795	A20-594	S10
9	796	A20-595	T1
9	797	A20-596	T2
9	798	A20-597	T3
9	799	A20-598	T4
9	800	A20-599	T5
9	801	A20-600	T6
9	802	A20-601	T7
9	803	A20-602	T8
9	804	A20-603	T9
9	805	A20-604	T10
9	806	A20-605	U1
9	807	A20-606	U2
9	808	A20-607	U3
9	809	A20-608	U4
9	810	A20-609	U5
9	811	A20-610	U6
9	812	A20-611	U7
9	813	A20-612	U8
9	814	A20-613	U9
9	815	A20-614	U10
9	816	A20-615	W1
9	817	A20-616	W2
9	818	A20-617	W3
9	819	A20-618	W4
9	820	A20-619	W5
9	821	A20-620	W6
9	822	A20-621	W7
9	823	A20-622	W8

I welcome feedback on the table above, with supporting evidence of any possible inaccuracies.

References:

Commonwealth Aircraft Corporation. Sales Department Aircraft Delivery Ledger; Kept by Gordon Parker. CAC Collection, Australian National Aviation Museum.

Commonwealth Aircraft Corporation. Aircraft Drawing Office Manual. Incorporating up to Amendment List No. 2, Melbourne, Australia, 1946.

For reference purposes I’ve collated a list of production batch numbers for the CAC Wirraway aircraft delivered to the RAAF between July 1939 and July 1946. This page contains the batch numbers for Mark I Wirraways, which were delivered under the CA-1 production “contract” number. This contract number was an internal number used by CAC (similar to the accounting “charge number” system used by North American Aviation) and was not the actual contract number from the Defence Contracts Board.

Wirraway type	CAC Contract Number	RAAF Contract Demand	Ordering entity	DCB Order Number	Quantity delivered	CAC Constructor’s Numbers	RAAF Serials
Mk I	CA-1	T.374	DCB	(unknown)	40	1 to 40	A20-3 to A20-42

DCB = Defence Contracts Board

Batch numbers
During construction, each aircraft was given a batch number, for the ordering of parts and materials. Batch numbers consisted of a letter for each batch followed by a number for each aircraft in that batch (e.g. A1, A2, A3, A4, etc). Wirraway production was generally planned in batches of 10 aircraft. But there were exceptions, as it appears the first 10 aircraft were produced in two batches of five (more on that below).

The letters I, O, Q and V were generally not used as batch numbers, as they could be confused for numbers. Usually a new contract (such as CA-1, CA-2, etc) started with batch “A”.

The definitive source for batch numbers is a ledger book kept by Mr Gordon Parker, Supervisor in the Sales Department, and one of CAC’s earliest employees from 1936. This book is now held in the collection of the Australian National Aviation Museum at Moorabbin Airport.

During production, batch numbers were temporarily attached to the firewall and then the rudder (once the engine was mounted). These temporary numbers are sometimes visible in factory photos.

Constructor’s numbers
These were a sequence of numbers allocated to each aircraft in the sequence that they came off the line. For example, Wirraways delivered under the CA-1 contract were given constructor’s numbers from 1 to 40.

RAAF stores number
All equipment in the RAAF was allocated a stores number for tracking and accounting purposes. Aircraft were tracked under the category “A” and each aircraft was given a specific number, Wirraway aircraft being allocated the category A20. These numbers are often referred to as the “serial number” of the aircraft in RAAF service.

Linking batch numbers, stores numbers and constructor’s numbers
Here are several photos showing Mark I Wirraways under construction, allowing us to link the batch codes to RAAF stores/serial numbers.

The photo below (Figure 1) shows a group of fuselages under construction at the CAC factory. This is very early in the production (note the two Gannet aircraft near the hangar doors), and the batch number C2 can be seen attached to the firewall. Unfortunately no serial codes are evident, and so we can’t definitively connect this batch number to a serial number. But by tracing back from other aircraft in batch C (explained below), C2 would have been A20-9.

Another photograph of early Wirraway production (Figure 2, below) shows A20-21 on the production line, with the batch number D9 on plaques attached to the firewall and also the rudder. The camouflaged Wirraway behind A20-21 has the batch number E1 on its firewall, corresponding to A20-23 which was the first aircraft delivered to the RAAF in camouflage.

Taken immediately beside the photo above, Figure 3 below shows A20-20 on the production line, with its engine installed. The batch number on the rudder is not readable, due to the angle of the rudder. Immediately behind sits another silver-doped Wirraway with batch code D10 on the firewall (corresponding to A20-22, although the serial number is not visible in the photo), the last silver-doped Wirraway.

Unfortunately Gordon Parker only started recording the batch numbers from H8 onwards (A20-60, well into the CA-3 contract). So we need to “reconstruct” the earlier batch numbers based on other evidence including:

• Photograph evidence, including the photo above (Figure 1) showing that D9 was A20-21 (c/n 19)
• The  Clyde Engineering tag on A20-10 at the Australian National Aviation Museum reads “SERIAL 01/3124/C3”, linking batch number C3 to A20-10 (c/n 8)
• A frame in a private collection which is identifiable as a CA-1 forward frame has  the original CAC identification tag which reads “Serial 01-3124-C2“, meaning that C2 was a CA-1 contract aircraft, most likely A20-9 (c/n 7) – see Figure 1 above
• Information from a file in the National Archives of Australia (NAA: A705, 9/15/193, “Wirraway aircraft – Contract and Specification”) on 3/1/1939 describing some missing “joint wrap plates” on the first 9 aircraft confirms their batch identifications as A1, B1, B2, B3, B4, C1, C2, C3, and C4.

Counting back from D9 (A20-21, c/n 19) we can postulate that D1 was A20-13 (c/n 11). If we then assume that batch C was 5 aircraft, then C5 would be A20-12 (c/n 10) and C1 would be A20-8 (c/n 6). This fits with A20-10 (c/n 8) being C3. 

Thus we can arrive at the table below showing the batch numbers for all Mark I Wirraway aircraft delivered under the CA-1 contract.

Caveat lector: These batch numbers were current at the time the aircraft left the factory. During RAAF service, various parts could be changed during repairs, resulting in possible differences between batch numbers and serial numbers as listed below. So one should not expect that this list will perfectly match with frames in existence today, and if trying to identify a particular frame from its batch number tag, additional evidence should be sought.

CAC Contract Number CA-	CAC Constructor’s Number	RAAF Serial	Batch Number
1	1	A20-3	A1
1	2	A20-4	B1
1	3	A20-5	B2
1	4	A20-6	B3
1	5	A20-7	B4
1	6	A20-8	C1
1	7	A20-9	C2
1	8	A20-10	C3
1	9	A20-11	C4
1	10	A20-12	C5
1	11	A20-13	D1
1	12	A20-14	D2
1	13	A20-15	D3
1	14	A20-16	D4
1	15	A20-17	D5
1	16	A20-18	D6
1	17	A20-19	D7
1	18	A20-20	D8
1	19	A20-21	D9
1	20	A20-22	D10
1	21	A20-23	E1
1	22	A20-24	E2
1	23	A20-25	E3
1	24	A20-26	E4
1	25	A20-27	E5
1	26	A20-28	E6
1	27	A20-29	E7
1	28	A20-30	E8
1	29	A20-31	E9
1	30	A20-32	E10
1	31	A20-33	F1
1	32	A20-34	F2
1	33	A20-35	F3
1	34	A20-36	F4
1	35	A20-37	F5
1	36	A20-38	F6
1	37	A20-39	F7
1	38	A20-40	F8
1	39	A20-41	F9
1	40	A20-42	F10

I welcome feedback on the table above, with supporting evidence of any possible inaccuracies.

Updated 4/8/2021 with information about the first 5 batch numbers A1 to B4.

References:

Commonwealth Aircraft Corporation. Sales Department Aircraft Delivery Ledger; Kept by Gordon Parker. CAC Collection, Australian National Aviation Museum.

Commonwealth Aircraft Corporation. Aircraft Drawing Office Manual. Incorporating up to Amendment List No. 2, Melbourne, Australia, 1946

National Archives of Australia, NAA: A705, 9/15/193, “Wirraway aircraft – Contract and Specification”

I’m currently working on a short presentation for the sold-out Aviation Cultures MkIV conference in November…

I’m going to be looking at the difference between the “procurement process” followed for the Wirraway and the process followed for other RAAF aircraft purchases up to that time.

Being the first non-British aircraft procured by the Air Board, the process followed for the Wirraway marked a radical transition……

Aviation Cultures Mk IV conference, November 2018