Something found going through the files, Air Marshall Richard Williams, RAAF representative in Washington, in a letter dated 20 July 1942 to RAAF Australia notes "The improved Mustang with Merlin 61 engine will not be in production until 1943." The first Merlin Mustang flew in Britain on 13 October 1942. It was part of a section discussing the need for fighters with performance at altitude to counter the Zero. Apparently the local USAAF had asked for P-47 and were being sent P-38 "reported everywhere as being heavy in maintenance."
'Can not accept the aircraft as a one hundred percent success' is a far cry from 'prototype unacceptable in current form'. pg 46 "Rolls-Royce and The Mustang" David Birch.
I was quoting from Interceptor Fighters for the Royal Air Force 1935-45 by Michael J.F. Bowyer, it would seem some of the test pilots had a different way of expressing the problems. The early 1943 Australian mission to decide what aircraft to build next report notes (MP450/1 58) the handling difficulties "lack of directional stability and adequate rudder control" in the British experimental version, and that these defects were reported by the British as not present in US version. The report also notes the idea of 1,000 sets of components to Britain which was the genesis for the similar Australian proposal.
Since Bowyer only has a summary, I went looking for any other data I had. Nothing on the performance trials, his statement of 1,000 engineless airframes to Britain seems to be a misunderstanding of 1,000 made in Britain from components proposal. In early 1943 North American was probably happy to offload P-51B airframes but Britain would have similar trouble supplying engines.
Seems after the early tests the Ministry of Aircraft Production people in Washington on 5 November 1942 proposed 400 Mustangs sent to Britain for rapid conversion, despite a lack of Merlin 61, Rolls Royce noted a big engine order was needed soon for the plan to work, or US engines installed, with a lack of fuel pumps given for holding up Merlin 61 production. MAP went and sourced US pumps, which needed modification, when asked to expedite things Rolls Royce asked how given no airframes. MAP decided not even a good report would persuade Rolls Royce large orders would be placed. Then Rolls Royce laid out a conversion using Merlin 28. As noted in early 1943 the reports from North American indicated the US version had fewer problems and of course was assumed to be arriving "soon".
In early 1943 the British recommended Australia build Mustang instead of Spitfire 8, including by the Managing director of Armstrong Vickers.
Consider how long it took NAA to deliver 100 kits to Australia under NA 110.
It was not the timing of the kits according the locals.
Australian Archives series A5954 control symbol 809/1, pages 64 and 65 (online copy at Australian Archives web page) Australian War Cabinet Agenda 177/43 minute 2777 15 April 1943, order for 350 Mustang from Commonwealth Aircraft Corporation plus spare parts amounting to 70 additional airframes, order placed overseas for 408 Merlin series 61 engines and associated propellers, including spares. Plus appendix A equipment and associated spares, either locally or overseas. To be equipment for 1 Operational Training Unit plus six squadrons and reserves by October 1945.
Plus an additional 396 Merlin series 61 engines and associated propellers and spares for the additional 340 Mustang airframes plus spare parts equivalent to 68 airframes, making a total of 690 aircraft plus spare parts equivalent to 138 additional aircraft. Authority given for Commonwealth Government to negotiate with North American Aviation Company for a license to manufacture of Mustang aircraft in Australia. Funds 14,804,600 Australian pounds, including 785,000 pounds for buildings, jigs, tools, fixtures and license fees. (MP450/1 58 says 250,000 for additional buildings, 500,000 for jigs, tools and fixtures, 35,000 for license fees). General MacArthur is to be asked for his endorsement and allotment of the highest possible priority practicable. Apparently General Kenny made a submission in favour of the P-47 but that was turned down in July.
Production schedule as of 1 May 1943 (from MP450/1 58) First Mustang production in June 1944, with 40 built by end 1944, monthly output to reach 35 per month in March 1945 and stay there, so that by end 1945 a total 445 Mustangs would be built, the order for 690 to be completed July 1946. This would enable a force of 10 squadrons, output of 40 per month required for a 12 squadron force. Merlin engines from US under Lend Lease. The OTU to be formed in September 1944, the first squadron in January 1945.
100 complete sets of P-51D airframes from North American Inglewood, order under J the program which was approved June 1943, The December 1943 RC-301 report notes 100 complete sets of P-51D airframes in program, none accepted, by April 1944, 83 complete sets of P-51D airframes accepted to end of month for Australia, rest expected in May. April can be considered the first month of major P-51D production. So by specifying the D version it delayed things into mid 1944 at least, then North American supplied them quite early in D model production, however there were problems, so by the time the first Australian aircraft flew North American Inglewood were about to start P-51D-30 production. I do not have the details of the associated machine tools etc. that also had to be sent which also caused delays. The policy of 20% airframe spares meant 80 of the kits supplied were assembled and 20 used for spares.
MP450/1 178, monthly production reports, notes on local Mustang order
February 1944, Commonwealth Aircraft Corporation reports receipt of sample parts and templates.
April 1944, large number of sample parts arrived.
June 1944, sample aircraft available, engineer on way to US to follow up on supply deficiencies in technical data and drawings, 25% of factory workforce now on Mustang project.
July 1944, tooling one third complete with completion expected by end of year. Assembly of first kit about to commence.
August 1944, a great deal of additional engineering work is needed as a large number of drawings and templates supplied were obsolete or had been superceded, large quantities of the parts supplied also require alterations.
September 1944, The 100 sets of components are full of errors.
October 1944, pilot assembly of the first aircraft from supplied parts has commenced.
November 1944, latest reported modifications from the US incorporated into drawings, 10% of the parts supplied from the US will need to be replaced and others modified.
December 1944, some sub assemblies being slowed by non delivery of a small proportion of components. Delivery schedule from March 1944 says first production now expected in February 1945.
January 1945, Special conference held, first production now expected in May 1945. Over the last 12 months modifications reported from North American amount to 3,000 drawings and 12,000 changes. Add the previously reported parts problems plus delays in supply of machine tools etc. The latter means coolant and oil pipes and some other items will need to come from the US, not local manufacture.
March 1945, project now limited by manpower.
April 1945, assembly time for first 80 aircraft dependent on manpower, engineering resources now devoted to production of aircraft from wholly local components.
RAAF Chiefs of Staff report to Australian War Cabinet, for week ending, Mustang order which stayed at 350 until the post war reduction, entries mentioned here are only where a change was made, from first entry to end August 1945. I suspect the February 1944 start date is an error for 1945.
16-Jul-43, Delivery expected to commence June 1944
17-Sep-43, Delivery expected to commence February 1944
1-Nov-43, Delivery not expected to commence before February 1944
5-Nov-43, Delivery expected to commence February 1944
19-Nov-43, Delivery expected to commence late 1944
28-Apr-44, Delivery expected to commence late 1944. CA-17,18 Manufacture and assembly of tooling proceeding.
23-Jun-44, Delivery expected to commence late 1944 or early 1945
21-Jul-44, Delivery expected to commence late 1944 or early 1945. Detail parts and tooling being received from USA
1-Nov-44, 20 Aircraft are scheduled for delivery by end July 1945
24-Nov-44, 20 Aircraft are scheduled for delivery by end July 1945. Deliveries of detail parts and components from US received. Manufacture and assembly of tooling and production of sub assemblies in wing, engine bearer and empennage proceeding.
29-Dec-44, Deliveries expected to commence in May, 1945.
29-Mar-45, Deliveries expected to commence in May 1945. First of each assembly nearing completion.
13-Apr-45, A68-1 on final assembly line, completion anticipated by 30 April.
4-May-45, A68-1 undergoing flight trials, A68-2 on final assembly line.
18-May-45, First aircraft A68-1 still undergoing flight trials. A68-2, 3 on final assembly line
25-May-45, A68-1, 2 undergoing flight trials, A68-3, 4 on final assembly line
1-Jun-45, A68-1, 2 flight trials completed, A68-3 undergoing flight trials, A68-4, 5, on final assembly line
8-Jun-45, A68-1, 2 delivered, A68-3, 4 undergoing flight trials, A68-5, 6 on final assembly line
15-Jun-45, A68-3 delivered, A68-4, 5 undergoing flight trials, A68-6, 7 on final assembly line
22-Jun-45, A68-4, 5, 6 undergoing flight trials, A68-7, 8 on final assembly line
29-Jun-45, A68-4 delivered, A68-5, 6, 7 undergoing flight trials, A68-8, 9 on final assembly line
6-Jul-45, A68-5, 6, 7, 8 undergoing flight trials, A68-9, 10 on final assembly line
13-Jul-45, A68-5, 6, 7 delivered.
27-Jul-45, A68-8 to 10 delivered.
3-Aug-45, A68-11 delivered.
10-Aug-45, A68-12, 13, 15 delivered.
17-Aug-45, A68-14, 16 delivered.
31-Aug-45, A68-17, 18 delivered.
To compete Mustang things as part of the 1945 allocation of lend lease aircraft the RAAF was allocated 285 from US production to make up for the delays in setting up the local production line.
RAAF Chiefs of Staff first mention the order week ending 29 December 1944, for 285 aircraft, week ending 2 March 1945 order reduced to 284 as 1 lost in transit (crashed in US), week ending 13 April 1945 first arrivals, week ending 6 July 1945 order increased by 215 to 499 aircraft.
The USAAF Statistical Digest notes first P-51 in the Pacific Ocean Areas were in November 1944, in the Far East Air Forces in October 1944. The Mustang was a late arrival in the Pacific.
And while looking for Mustangs, NA.33 license agreement with CAC, $30,000 plus $1,000 per aircraft for the first 25, $800 per aircraft for the second 25, $600 per aircraft for the next 50, then no further payments.