Minute from Prime Minister to First Lord of Admiralty, First Sea Lord and Fifth Sea Lord
[ADM 1/ 11980] 14 April 1942
Comparison between aircraft complement of British and Japanese aircraft carriers
Let me have the estimated aircraft of different patterns borne on each of the five Japanese Aircraft Carriers in the Indian Ocean and in our INDOMITABLE, ILLUSTRIOUS, FORMIDABLE. Let me also have the tonnage on both sides.
What is the explanation why the Japanese are able to carry so many more aircraft than we do? What is the explanation why ships like ILLUSTRIOUS, FORMIDABLE and INDOMITABLE should be described as not fully trained considering they have not been engaged for over a year and have been working up for several months? What are the aircraft for the FORMIDABLE which were left behind at Colombo? What steps have been taken to replenish her and arm INDOMITABLE with Martlets? These issues are causing very considerable concern.
Minute from First Lord of Admiralty to Prime Minister
[ADM 1/ 11980] 16 April 1942
Comparison between aircraft complement of British and Japanese aircraft carriers
I attach a memorandum prepared by the 5th Sea Lord and the Naval Staff in answer to your Personal Minute No. M. 136/ 2 of the 14th April.
Memorandum by Fifth Sea Lord
[ADM 1/ 11980] 16 April 1942
Comparison between aircraft complement of British and Japanese aircraft carriers
With reference to the Prime Minister’s personal minute No. M. 136/ 2 of the 14th April –
I. Let me have the estimated aircraft of different patterns borne on each of the five Japanese Aircraft Carriers in the Indian Ocean and in our INDOMITABLE, ILLUSTRIOUS, FORMIDABLE. Let me also have the tonnage on both sides. The following are the known details of the Japanese carriers, as compared with our own, in the Indian Ocean. The list shows the tonnage on both sides.
II. What is the explanation why the Japanese are able to carry so many more aircraft than we do?
(i) With the possible exceptions of the SHOKAKU and ZUIKAKU, they are unarmoured and are therefore larger for the equivalent weight. (Our COURAGEOUS (unarmoured) Class carried as many, of [sic] not more, than the Japanese carriers of equivalent tonnage.)
(ii) Their actual tonnage is probably in excess of that disclosed.
(iii) Accommodation for personnel is more congested than would be acceptable for Europeans.
(iv) They are possibly carrying and operating a deck cargo of aircraft as is the practice of the U.S.A. aircraft carriers.
III. What is the explanation why ships like ILLUSTRIOUS, FORMIDABLE and INDOMITABLE should be described as not fully trained considering they have not been engaged for over a year and have been working up for several months?
State of training of INDOMITABLE, FORMIDABLE and ILLUSTRIOUS.
INDOMITABLE, from reports received from her late Commanding Officer, from the R.A.A. Mediterranean after his visit to her at Port Sudan, and from Admiralty officers who have recently visited her, is an efficient ship from the air point of view.
This ship had a proper work up period and in spite of the fact that she had to disembark her squadrons whilst carrying out two R.A.F. fighter ferrying trips is still efficient.
FORMIDABLE, left her two T.B.R. Squadrons in the Mediterranean when she sailed for repairs in U.S.A. She took with her one squadron of Swordfish which was a ‘scratch’ collection of pilots due to leave the station. This squadron was left at Jamaica during the refit. ILLUSTRIOUS left her squadrons in the Eastern Mediterranean and took no aircraft when she went to refit in U.S.A.
For one year FORMIDABLE and ILLUSTRIOUS were in dockyard hands, and their squadrons were in the Mediterranean to which station it was intended that they should return.
The Admiralty’s original intention was that FORMIDABLE and ILLUSTRIOUS should return to the Mediterranean with one fighter squadron and one T.B.R. Squadron each, thus increasing the Naval air strength in the Mediterranean by two fighter and one T.B.R. squadron. These squadrons were given sound training in the United Kingdom but it became necessary to re-equip the two fighter squadrons with Martlets and provide two T.B.R. squadrons for each ship, thus bringing them to full aircraft complement before sailing for the Eastern Fleet.
The only way the two additional T.B.R. squadrons could be found was by bringing home the squadron from Jamaica and using a half squadron ex ARK ROYAL. Both these squadrons had to be brought to full strength and worked up in what was known to be an inadequate period.
FORMIDABLE and ILLUSTRIOUS both had to be sailed for the Eastern Fleet without an adequate work up period. Had all the squadrons even been properly worked up before joining the carriers, the latter would still not have been efficient without training at sea. Both with some inadequately trained squadrons the carriers had to start almost from scratch and do their best to work up on the passage out.
The fighter squadrons had to be worked up on the few Martlet aircraft then available in the United Kingdom, and re-equipped with the Martlets brought over by FORMIDABLE and ILLUSTRIOUS. These aircraft were already months behind scheduled delivery dates.
Neither of these two fighter squadrons were in consequence as well trained as was desirable, principally owing to lack of Martlets on which they could train. The deck landing training carrier1 which was available in pre-war days and at the start of the war, became increasingly used for aircraft ferrying from the invasion of Norway onwards. The training carrier is now employed on operational duties at Gibraltar.
When individual pilots untrained in deck landing are embarked, the first line carrier must devote to ‘ab initio’ training valuable time which should properly be devoted to operational training.
SUMMARY.
In conclusion, it is desired to emphasise that a carrier can only be worked up and kept in efficient air training by constant practice at sea. This in turn depends on both the carrier and her aircraft being available.
In the case of FORMIDABLE and ILLUSTRIOUS, neither carrier was available, as they were laid up for repairs and had to be sailed for their operational theatre after an inadequate period for working up. Their aircraft could not be given sufficient squadron training before the carriers arrived from the U.S.A. owing to:–
(a) Insufficient Martlets being available.
(b) Two of their proper T.B.R. squadrons having to be retained in the Eastern Mediterranean, which meant that two inadequately trained squadrons had to be provided in their place.
IV. What are the aircraft for the FORMIDABLE which were left behind at Colombo?
These were two Fulmar squadrons in Colombo which were flown there from the Eastern Mediterranean. Both these squadrons had been flying Hurricanes and had not been one year ashore while the FORMIDABLE and ILLUSTRIOUS were refitting. Many of their pilots were new and had not been trained in deck landing as there was no deck landing training carrier at home nor was there a carrier in the Mediterranean on which to train them.
V. What steps have been taken to replenish her and are INDOMITABLE with Martlets?
Replacement aircraft are now en route to the East Indies direct from U.S.A. in ILLUSTRIOUS, and by freighter from United Kingdom. Reserves of all types, except Martlets which were not available, were already in Ceylon but owing to the lack of R.A.F. aircraft, these reserves, so laboriously built up, are being flown in the defence of Ceylon by spare Naval pilots and those R.A.F. pilots which could be collected.
Seafires, the Naval version of the Spitfire, are being dispatched to replace INDOMITABLE’s Sea Hurricanes. If INDOMITABLE is re-equipped with Martlets the results may well be that those squadrons now equipped with Martlets in FORMIDABLE and ILLUSTRIOUS will have inadequate reserves. If undue wastage is not experienced on Martlets an additional squadron could be formed from those being shipped in mid summer [1942].