Monthly Archives: May 2020

Gems from the Archives 1: Wackett to Parkhill 29/9/37

In my research for my coming Wirraway book, I’ve spent many hours digging through a number of archives, both online and physical. Much of this archival research is fairly mundane and dull, but of course it is all made worthwhile when you come across a previously unseen document or photograph which confirms a hunch or adds to the story line. These are the “gems from the archives”…

Today’s gem is a letter from Lawrence Wackett to Defence Minister Archdale Parkhill on 29 September 1937, in which he proposed that the RAAF should purchase a more advanced (and more costly) version of the NA-16 aircraft. Wackett had just returned from a trip to the United States and the United Kingdom to negotiate manufacturing rights for aircraft and engines, and while he was at North American Aviation, he discovered they had developed an improved version of the NA-16. Of course Wackett wanted the RAAF to have the latest model.

But Parkhill was coming up to an election the following month, and he was already under heavy fire from the Sydney Morning Herald and from Empire-friendly groups in his party and the wider community for agreeing to purchase an American designed aircraft in the first place. How would Parkhill respond to Wackett’s proposal? How would he react to the suggestion of a more costly aircraft?

Unfortunately Parkhill lost his seat of Warringah in the October 1937 election, so he was never able to reply to Wackett’s letter…

The Hon. The Minister for Defence,
Department of Defence,
Victoria Barracks,
MELBOURNE. S.C.1.

Dear Sir,

INITIAL ORDER FOR THE LOCAL MANUFACTURE OF AIRCRAFT

We refer you to your letter of 1st January last and our reply of 12th January, when the matter of the initial order for aircraft was set out in the most advanced form which was possible at that time. Immediately afterwards, Wing-Commander Wackett left for U.S.A. and investigated the matter of licences.

Wing-Commander Wackett has now returned with the necessary information to enable the technical details in connection with the matter to be discussed further.

THE NA-16 TYPE:

On the occasion of the visit abroad of the Aviation Commission in 1936, the product of the North American Aviation Co., known as the NA-16, was considered the most advanced development of this particular type, and the proposals made to the Air Board were primarily based on this type. It was known that certain developments of the type were in hand and the conversion to a retractable undercarriage is sufficiently advanced to enable us to offer it as an improvement, and the Air Board expressed itself as anxious to have this improvement incorporated.

The primary intention which was borne in mind when seeking the licences on the occasion of Wing-Commander Wackett’s second visit to North American Aviation in February last was to cover the NA-16 type with the retractable undercarriage as a development.

NEW TYPE NA-33:

It was discovered that in the period from July, 1936, to February, 1937, the U.S. Army had become sufficiently interested in the type to desire a more advanced development altogether, to be known as a “Basic Combat” type and a competition was scheduled to be held at Dayton in May, 1937, to decide which was the best of several types submitted by various manufacturers. An improvement of the NA-16, known as the NA-33 [actually the NA-26], won this competition and the firm received a large order for 150, delivery of which to the U.S. Army Air Corps was scheduled for March 1938.

The opportunity to take up a very much more advanced version was taken, and the licence finally negotiated covered both the original NA-16 type and the advanced NA-33 type. Sample aircraft of both types were ordered and the Corporation will give the Air Board the opportunity of examining both versions. A sample of the NA-16 type has already been supplied and has been flown. The sample of the NA-33 type has been shipped and will shortly be available.

PROPOSAL FOR IMPROVED TYPE:

It is now possible to propose that the Air Board consider that the order for the initial 40 be confirmed for the most up-to-date version of this type, viz. the NA-33, which has been specially designed as a military type as distinct from the advanced trainer type of the original NA-16.

The new type contains all the most modern developments found on the most advanced military aircraft in any part of the world, such as:-

Retractable Undercarriage.

Geared and supercharged engine of increased output.

Hydraulic operation of flaps and undercarriage.

Constant speed three-bladed propeller.

Internally built in bomb gear.

Rotating seat for the gunner.

Prone bombing facilities.

Electrical installation for radio.

Blind flying practice hood.

In addition to the improvements which are now offered in regard to the aircraft itself, it has also been possible to obtain an improved version of the engine. The engine can be offered rated at 700 h.p. maximum for take off and 600 h.p. continuous output at 7000 feet.

COMPARISON WITH THE ORIGINAL PROPOSAL:

Some of the features now available in the NA-33 version were incorporated in the proposal to include some improvements in the NA-16 so that the additional cost necessary to provide the NA-33 type with all its extras is relatively small in comparison with the advantages to be gained.

Extra provision for a 3-bladed constant speed Propeller with governor & exhaust gas analyser £450

Extra provision for a blind flying hood £18

Extra provision for a swivelling gunner’s seat £35

Extra provision for a internally built bomb rack £45

The extra cost of the NA-33 version now offered is, therefore £548

The original price tendered for the NA-16 was £7200 and £7550 for the version with the retractable undercarriage.

It is now possible to cover the NA-33 advanced type at £8098.

This price has been arrived at on a similar basis to our original quotation, namely, without inclusion of Customs duty or primage, which it is understood would be taken care of by the Government.

It is possible that some of the NA-16 type with fixed undercarriage will be desired for training in accordance with the original suggestion, but it is now submitted for consideration that the main order for 40 should be extended to cover the advanced military version, which can be considered as an effective weapon for air defence.

MILITARY FEATURES:

Some consideration has already been given to the military suitability of the type, and, while maintaining all the excellent flying qualities of the training version, it is possible to increase the gross weight to 5500 lbs. with safety factors of 8.5, and to arrange to carry both front and rear guns, ammunition, and 500 lbs. of bombs while maintaining the full range capacity.

CONCLUSION:

Our technical officers are available to discuss the technical details with the Air Board and the facilities now available at Fishermen’s Bend can now be utilised. All the necessary technical studies, drawings, and a special office for the use of Air Board officers, is now available.

It is requested that consideration be given to the proposals in this letter as it is advisable to arrive at a decision as soon as possible so as to enable production to be planned.

Yours faithfully,

(Signed) L.J. Wackett

M a n a g er

Wirraway batch numbers – Mark III aircraft

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 typeCAC Contract NumberRAAF Contract DemandOrdering entityOrder NumberQuantity deliveredCAC Constructor’s NumbersRAAF Serials
Mk IIICA-16D.A.P. 1007DAPC.S.18001351075 to 1209A20-623 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. 

Figure 1: CAC Wirraway Mark II production showing batch numbers D10 to E5 (Lewis Family Collection, State Library of South Australia, ref  PRG 247/143/13 cropped)

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.

Figure 2: A view of H8 (A20-707) attached to the lifting sling (Australian National Aviation Museum)

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).

Figure 3: Wirraway Mark III A20-728 on the production line (Australian National Aviation Museum)

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 NumberRAAF SerialBatch Number
161075A20-623A1
161076A20-624A2
161077A20-625A3
161078A20-626A4
161079A20-627A5
161080A20-628A6
161081A20-629A7
161082A20-630A8
161083A20-631A9
161084A20-632A10
161085A20-633A11
161086A20-634B1
161087A20-635B2
161088A20-636B3
161089A20-637B4
161090A20-638B5
161091A20-639B6
161092A20-640B7
161093A20-641B8
161094A20-642B9
161095A20-643B10
161096A20-644B11
161097A20-645C1
161098A20-646C2
161099A20-647C3
161100A20-648C4
161101A20-649C5
161102A20-650C6
161103A20-651C7
161104A20-652C8
161105A20-653C9
161106A20-654C10
161107A20-655C11
161108A20-656D1
161109A20-657D2
161110A20-658D3
161111A20-659D4
161112A20-660D5
161113A20-661D6
161114A20-662D7
161115A20-663D8
161116A20-664D9
161117A20-665D10
161118A20-666D11
161119A20-667E1
161120A20-668E2
161121A20-669E3
161122A20-670E4
161123A20-671E5
161124A20-672E6
161125A20-673E7
161126A20-674E8
161127A20-675E9
161128A20-676E10
161129A20-677E11
161130A20-678F1
161131A20-679F2
161132A20-680F3
161133A20-681F4
161134A20-682F5
161135A20-683F6
161136A20-684F7
161137A20-685F8
161138A20-686F9
161139A20-687F10
161140A20-688F11
161141A20-689G1
161142A20-690G2
161143A20-691G3
161144A20-692G4
161145A20-693G5
161146A20-694G6
161147A20-695G7
161148A20-696G8
161149A20-697G9
161150A20-698G10
161151A20-699G11
161152A20-700H1
161153A20-701H2
161154A20-702H3
161155A20-703H4
161156A20-704H5
161157A20-705H6
161158A20-706H7
161159A20-707H8
161160A20-708H9
161161A20-709H10
161162A20-710H11
161163A20-711J1
161164A20-712J2
161165A20-713J3
161166A20-714J4
161167A20-715J5
161168A20-716J6
161169A20-717J7
161170A20-718J8
161171A20-719J9
161172A20-720J10
161173A20-721J11
161174A20-722K1
161175A20-723K2
161176A20-724K3
161177A20-725K4
161178A20-726K5
161179A20-727K6
161180A20-728K7
161181A20-729K8
161182A20-730K9
161183A20-731K10
161184A20-732K11
161185A20-733L1
161186A20-734L2
161187A20-735L3
161188A20-736L4
161189A20-737L5
161190A20-738L6
161191A20-739L7
161192A20-740L8
161193A20-741L9
161194A20-742L10
161195A20-743L11
161196A20-744M1
161197A20-745M2
161198A20-746M3
161199A20-747M4
161200A20-748M5
161201A20-749M6
161202A20-750M7
161203A20-751M8
161204A20-752M9
161205A20-753M10
161206A20-754M11
161207A20-755N1
161208A20-756N2
161209A20-757N3

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.

Wirraway batch numbers – Mark II aircraft

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 typeCAC Contract NumberRAAF Contract DemandOrdering entityOrder NumberQuantity deliveredCAC Constructor’s NumbersRAAF Serials
Mk IICA-3T.456DCB(unknown)6041 to 100A20-43 to 102
Mk IICA-5T.562DCB(unknown)32103 to 134A20-103 to 134
Mk IICA-7A.P.C.1APC(unknown)100135 to 234A20-135 to 234
Mk IICA-8A.P.C.81APC(unknown)200436 to 635A20-235 to 434
Mk IICA-9A.P.C.433APC(unknown)132636 to 766A20-435 to 565
Mk IICA-9A.P.C.739APCC.S.45256767 to 823A20-566 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).

Figure 1: CAC factory floor in mid February 1940, the point of changing from Mark I aircraft to Mark II aircraft (Australian War Memorial, ref 000626/06)

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. 

Figure 2: Early CA-5 production, showing the fins of N8 to P3, corresponding to A20-110 to A20-115 (Author’s collection)

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.

Mark II Wirraways under construction (CA-9 contract)
Figure 3: Mark II Wirraways under construction for the CA-9 contract (Lewis Family Collection, State Library of South Australia, ref PRG 247/143/9, cropped)

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 (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 NumberRAAF SerialBatch Number
341A20-43G1
342A20-44G2
343A20-45G3
344A20-46G4
345A20-47G5
346A20-48G6
347A20-49G7
348A20-50G8
349A20-51G9
350A20-52G10
351A20-53H1
352A20-54H2
353A20-55H3
354A20-56H4
355A20-57H5
356A20-58H6
357A20-59H7
358A20-60H8
359A20-61H9
360A20-62H10
361A20-63J1
362A20-64J2
363A20-65J3
364A20-66J4
365A20-67J5
366A20-68J6
367A20-69J7
368A20-70J8
369A20-71J9
370A20-72J10
371A20-73K1
372A20-74K2
373A20-75K3
374A20-76K4
375A20-77K5
376A20-78K6
377A20-79K7
378A20-80K8
379A20-81K9
380A20-82K10
381A20-83L1
382A20-84L2
383A20-85L3
384A20-86L4
385A20-87L5
386A20-88L6
387A20-89L7
388A20-90L8
389A20-91L9
390A20-92L10
391A20-93M1
392A20-94M2
393A20-95M3
394A20-96M4
395A20-97M5
396A20-98M6
397A20-99M7
398A20-100M8
399A20-101M9
3100A20-102M10
5103A20-103N1
5104A20-104N2
5105A20-105N3
5106A20-106N4
5107A20-107N5
5108A20-108N6
5109A20-109N7
5110A20-110N8
5111A20-111N9
5112A20-112N10
5113A20-113P1
5114A20-114P2
5115A20-115P3
5116A20-116P4
5117A20-117P5
5118A20-118P6
5119A20-119P7
5120A20-120P8
5121A20-121P9
5122A20-122P10
5123A20-123Q1
5124A20-124Q2
5125A20-125Q3
5126A20-126Q4
5127A20-127Q5
5128A20-128Q6
5129A20-129Q7
5130A20-130Q8
5131A20-131Q9
5132A20-132Q10
5133A20-133Q11
5134A20-134Q12
7135A20-135A1
7136A20-136A2
7137A20-137A3
7138A20-138A4
7139A20-139A5
7140A20-140A6
7141A20-141A7
7142A20-142A8
7143A20-143A9
7144A20-144A10
7145A20-145B1
7146A20-146B2
7147A20-147B3
7148A20-148B4
7149A20-149B5
7150A20-150B6
7151A20-151B7
7152A20-152B8
7153A20-153B9
7154A20-154B10
7155A20-155C1
7156A20-156C2
7157A20-157C3
7158A20-158C4
7159A20-159C5
7160A20-160C6
7161A20-161C7
7162A20-162C8
7163A20-163C9
7164A20-164C10
7165A20-165D1
7166A20-166D2
7167A20-167D3
7168A20-168D4
7169A20-169D5
7170A20-170D6
7171A20-171D7
7172A20-172D8
7173A20-173D9
7174A20-174D10
7175A20-175E1
7176A20-176E2
7177A20-177E3
7178A20-178E4
7179A20-179E5
7180A20-180E6
7181A20-181E7
7182A20-182E8
7183A20-183E9
7184A20-184E10
7185A20-185F1
7186A20-186F2
7187A20-187F3
7188A20-188F4
7189A20-189F5
7190A20-190F6
7191A20-191F7
7192A20-192F8
7193A20-193F9
7194A20-194F10
7195A20-195G1
7196A20-196G2
7197A20-197G3
7198A20-198G4
7199A20-199G5
7200A20-200G6
7201A20-201G7
7202A20-202G8
7203A20-203G9
7204A20-204G10
7205A20-205H1
7206A20-206H2
7207A20-207H3
7208A20-208H4
7209A20-209H5
7210A20-210H6
7211A20-211H7
7212A20-212H8
7213A20-213H9
7214A20-214H10
7215A20-215J1
7216A20-216J2
7217A20-217J3
7218A20-218J4
7219A20-219J5
7220A20-220J6
7221A20-221J7
7222A20-222J8
7223A20-223J9
7224A20-224J10
7225A20-225K1
7226A20-226K2
7227A20-227K3
7228A20-228K4
7229A20-229K5
7230A20-230K6
7231A20-231K7
7232A20-232K8
7233A20-233K9
7234A20-234K10
8436A20-235A1
8437A20-236A2
8438A20-237A3
8439A20-238A4
8440A20-239A5
8441A20-240A6
8442A20-241A7
8443A20-242A8
8444A20-243A9
8445A20-244A10
8446A20-245B1
8447A20-246B2
8448A20-247B3
8449A20-248B4
8450A20-249B5
8451A20-250B6
8452A20-251B7
8453A20-252B8
8454A20-253B9
8455A20-254B10
8456A20-255C1
8457A20-256C2
8458A20-257C3
8459A20-258C4
8460A20-259C5
8461A20-260C6
8462A20-261C7
8463A20-262C8
8464A20-263C9
8465A20-264C10
8466A20-265D1
8467A20-266D2
8468A20-267D3
8469A20-268D4
8470A20-269D5
8471A20-270D6
8472A20-271D7
8473A20-272D8
8474A20-273D9
8475A20-274D10
8476A20-275E1
8477A20-276E2
8478A20-277E3
8479A20-278E4
8480A20-279E5
8481A20-280E6
8482A20-281E7
8483A20-282E8
8484A20-283E9
8485A20-284E10
8486A20-285F1
8487A20-286F2
8488A20-287F3
8489A20-288F4
8490A20-289F5
8491A20-290F6
8492A20-291F7
8493A20-292F8
8494A20-293F9
8495A20-294F10
8496A20-295G1
8497A20-296G2
8498A20-297G3
8499A20-298G4
8500A20-299G5
8501A20-300G6
8502A20-301G7
8503A20-302G8
8504A20-303G9
8505A20-304G10
8506A20-305H1
8507A20-306H2
8508A20-307H3
8509A20-308H4
8510A20-309H5
8511A20-310H6
8512A20-311H7
8513A20-312H8
8514A20-313H9
8515A20-314H10
8516A20-315J1
8517A20-316J2
8518A20-317J3
8519A20-318J4
8520A20-319J5
8521A20-320J6
8522A20-321J7
8523A20-322J8
8524A20-323J9
8525A20-324J10
8526A20-325K1
8527A20-326K2
8528A20-327K3
8529A20-328K4
8530A20-329K5
8531A20-330K6
8532A20-331K7
8533A20-332K8
8534A20-333K9
8535A20-334K10
8536A20-335L1
8537A20-336L2
8538A20-337L3
8539A20-338L4
8540A20-339L5
8541A20-340L6
8542A20-341L7
8543A20-342L8
8544A20-343L9
8545A20-344L10
8546A20-345M1
8547A20-346M2
8548A20-347M3
8549A20-348M4
8550A20-349M5
8551A20-350M6
8552A20-351M7
8553A20-352M8
8554A20-353M9
8555A20-354M10
8556A20-355N1
8557A20-356N2
8558A20-357N3
8559A20-358N4
8560A20-359N5
8561A20-360N6
8562A20-361N7
8563A20-362N8
8564A20-363N9
8565A20-364N10
8566A20-365P1
8567A20-366P2
8568A20-367P3
8569A20-368P4
8570A20-369P5
8571A20-370P6
8572A20-371P7
8573A20-372P8
8574A20-373P9
8575A20-374P10
8576A20-375R1
8577A20-376R2
8578A20-377R3
8579A20-378R4
8580A20-379R5
8581A20-380R6
8582A20-381R7
8583A20-382R8
8584A20-383R9
8585A20-384R10
8586A20-385S1
8587A20-386S2
8588A20-387S3
8589A20-388S4
8590A20-389S5
8591A20-390S6
8592A20-391S7
8593A20-392S8
8594A20-393S9
8595A20-394S10
8596A20-395T1
8597A20-396T2
8598A20-397T3
8599A20-398T4
8600A20-399T5
8601A20-400T6
8602A20-401T7
8603A20-402T8
8604A20-403T9
8605A20-404T10
8606A20-405U1
8607A20-406U2
8608A20-407U3
8609A20-408U4
8610A20-409U5
8611A20-410U6
8612A20-411U7
8613A20-412U8
8614A20-413U9
8615A20-414U10
8616A20-415W1
8617A20-416W2
8618A20-417W3
8619A20-418W4
8620A20-419W5
8621A20-420W6
8622A20-421W7
8623A20-422W8
8624A20-423W9
8625A20-424W10
8626A20-425X1
8627A20-426X2
8628A20-427X3
8629A20-428X4
8630A20-429X5
8631A20-430X6
8632A20-431X7
8633A20-432X8
8634A20-433X9
8635A20-434X10
9636A20-435A1
9637A20-436A2
9638A20-437A3
9639A20-438A4
9640A20-439A5
9641A20-440A6
9642A20-441A7
9643A20-442A8
9644A20-443A9
9645A20-444A10
9646A20-445B1
9647A20-446B2
9648A20-447B3
9649A20-448B4
9650A20-449B5
9651A20-450B6
9652A20-451B7
9653A20-452B8
9654A20-453B9
9655A20-454B10
9656A20-455C1
9657A20-456C2
9658A20-457C3
9659A20-458C4
9660A20-459C5
9661A20-460C6
9662A20-461C7
9663A20-462C8
9664A20-463C9
9665A20-464C10
9666A20-465D1
9667A20-466D2
9668A20-467D3
9669A20-468D4
9670A20-469D5
9671A20-470D6
9672A20-471D7
9673A20-472D8
9674A20-473D9
9675A20-474D10
9676A20-475E1
9677A20-476E2
9678A20-477E3
9679A20-478E4
9680A20-479E5
9681A20-480E6
9682A20-481E7
9683A20-482E8
9684A20-483E9
9685A20-484E10
9686A20-485F1
9687A20-486F2
9688A20-487F3
9689A20-488F4
9690A20-489F5
9691A20-490F6
9692A20-491F7
9693A20-492F8
9694A20-493F9
9695A20-494F10
9696A20-495G1
9697A20-496G2
9698A20-497G3
9699A20-498G4
9700A20-499G5
9701A20-500G6
9702A20-501G7
9703A20-502G8
9704A20-503G9
9705A20-504G10
9706A20-505H1
9707A20-506H2
9708A20-507H3
9709A20-508H4
9710A20-509H5
9711A20-510H6
9712A20-511H7
9713A20-512H8
9714A20-513H9
9715A20-514H10
9716A20-515J1
9717A20-516J2
9718A20-517J3
9719A20-518J4
9720A20-519J5
9721A20-520J6
9722A20-521J7
9723A20-522J8
9724A20-523J9
9725A20-524J10
9726A20-525K1
9727A20-526K2
9728A20-527K3
9729A20-528K4
9730A20-529K5
9731A20-530K6
9732A20-531K7
9733A20-532K8
9734A20-533K9
9735A20-534K10
9736A20-535L1
9737A20-536L2
9738A20-537L3
9739A20-538L4
9740A20-539L5
9741A20-540L6
9742A20-541L7
9743A20-542L8
9744A20-543L9
9745A20-544L10
9746A20-545M1
9747A20-546M2
9748A20-547M3
9749A20-548M4
9750A20-549M5
9751A20-550M6
9752A20-551M7
9753A20-552M8
9754A20-553M9
9755A20-554M10
9756A20-555N1
9757A20-556N2
9758A20-557N3
9759A20-558N4
9760A20-559N5
9761A20-560N6
9762A20-561N7
9763A20-562N8
9764A20-563N9
9765A20-564N10
9766A20-565P1
9767A20-566P2
9768A20-567P3
9769A20-568P4
9770A20-569P5
9771A20-570P6
9772A20-571P7
9773A20-572P8
9774A20-573P9
9775A20-574P10
9776A20-575R1
9777A20-576R2
9778A20-577R3
9779A20-578R4
9780A20-579R5
9781A20-580R6
9782A20-581R7
9783A20-582R8
9784A20-583R9
9785A20-584R10
9786A20-585S1
9787A20-586S2
9788A20-587S3
9789A20-588S4
9790A20-589S5
9791A20-590S6
9792A20-591S7
9793A20-592S8
9794A20-593S9
9795A20-594S10
9796A20-595T1
9797A20-596T2
9798A20-597T3
9799A20-598T4
9800A20-599T5
9801A20-600T6
9802A20-601T7
9803A20-602T8
9804A20-603T9
9805A20-604T10
9806A20-605U1
9807A20-606U2
9808A20-607U3
9809A20-608U4
9810A20-609U5
9811A20-610U6
9812A20-611U7
9813A20-612U8
9814A20-613U9
9815A20-614U10
9816A20-615W1
9817A20-616W2
9818A20-617W3
9819A20-618W4
9820A20-619W5
9821A20-620W6
9822A20-621W7
9823A20-622W8

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.

Wirraway batch numbers – Mark I aircraft

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 typeCAC Contract NumberRAAF Contract DemandOrdering entityOrder NumberQuantity deliveredCAC Constructor’s NumbersRAAF Serials
Mk ICA-1T.374DCB(unknown)401 to 40A20-3 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.

Figure 1: Early Wirraway Mark I production at CAC. Batch code C2 is visible on the firewall of this fuselage (Aircraft, August 1, 1939, p. 17)

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.

Figure 2: Wirraway A20-21 on the production line, with batch code D9 visible on the firewall (RAAF Museum).

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.

Figure 3: Wirraway A20-20 in final assembly at CAC (RAAF Museum)

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 above (Figure 1) shows 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

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. 

This then leaves the first five aircraft and two batch numbers, A and B. It is possible that the first five aircraft (which were assembled from imported components manufactured by NAA in California) were batch B and perhaps the two imported airframes (A20-1 and A20-2) were considered as batch A. But this is just speculation. Until further evidence can be found, I will describe the batch numbers of the first five aircraft as “unknown”.

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 NumberRAAF SerialBatch Number
11A20-3Unknown
12A20-4Unknown
13A20-5Unknown
14A20-6Unknown
15A20-7Unknown
16A20-8C1
17A20-9C2
18A20-10C3
19A20-11C4
110A20-12C5
111A20-13D1
112A20-14D2
113A20-15D3
114A20-16D4
115A20-17D5
116A20-18D6
117A20-19D7
118A20-20D8
119A20-21D9
120A20-22D10
121A20-23E1
122A20-24E2
123A20-25E3
124A20-26E4
125A20-27E5
126A20-28E6
127A20-29E7
128A20-30E8
129A20-31E9
130A20-32E10
131A20-33F1
132A20-34F2
133A20-35F3
134A20-36F4
135A20-37F5
136A20-38F6
137A20-39F7
138A20-40F8
139A20-41F9
140A20-42F10

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.