Here we see 390mph being anticipated for the Firebrand and 360mph for the two seat Firefly:
" Memorandum from Fifth Sea Lord (1) to Admiralty Board
[ADM 1/13488] 21 June 1940
Requirements for two-seater and single-seater fighters
Proposal to introduce a Single Seater type for certain special functions
———————————
Memorandum for the Board, by the Fifth Sea Lord.
During recent months, lengthy consideration has been given in the light
of war experience to the most suitable type of Fighter Aircraft for the Fleet
Air Arm, and the pre-war conclusion has been confirmed that for normal
and general functions of Fleet Air Arm Fighters, the two-seater type
should be retained in preference to the single-seater alternative.
2. Orders have been placed accordingly for two-seater Fighters to meet
the full estimated requirements. A two-seater eight-gun Fighter, the
'Fulmar', with a top speed of 260–280 m.p.h. is now coming into quantity
production. This, as a stop gap, was converted out of the Fairey P.4/34
light bomber design, and ordered before the war. The Fulmar will be
succeeded by an improved two-seater, N.5/40,(2) with a top speed of up to
360 m.p.h., of which deliveries are expected to begin in about 18 months
time.
3. Both the 'Fulmar' and its replacement, the N.5/40, are of conventional
monoplane design, and their production will be centred in one factory
only, that of Messrs. Fairey at Stockport, near Manchester.
4. Experience has, however, also shown that there are occasions on
which a single seater, on account of its generally superior performance
and notwithstanding its lack of facilities for navigation and wireless
communication, can be employed with advantage. Briefly, these occasions
primarily arise when ships in harbour or Naval bases require defence
against shore based aircraft, for which an interceptor s.s. type operating
(1) VA G. C. C. Royle.
(2) N.5/40 – Fairey Firefly.
from the shore, is best. Single sections can also be employed as Mixed
Units with two-seaters, in certain circumstances at sea.
The defence of Fleet bases is, constitutionally a R.A.F. commitment
for which no provision has hitherto been made in the Fleet Air Arm
programme. Experience shows, however, that in practice it devolves
largely upon the Fleet Air Arm; that it arises at short notice and that it is
likely to continue to do so. The advantages of having a force of high
performance fighters which can be transported readily in a carrier and
which, pending the acquisition of an aerodrome, can be operated from a
carrier, needs no elaboration in the light of recent experiences in Norway.
5. For these reasons it is proposed to introduce as soon as possible a
limited number of high-performance single-seater Fighters to a design
prepared by Messrs. Blackburn with an estimated top speed of up to 390
m.p.h. which might be raised to some 420 m.p.h. at high altitudes with a
suitably rated engine. The new design has been approved by the technical
experts of the Air Ministry and in order to accelerate deliveries it is
proposed to place an order 'off the drawing board', i.e. without passing
the design through prototypes.(1)
6. From the design aspect, deliveries could begin in 18 months to 2 years
but, in view of the desirability at the present time of concentrating on the
production of essential types for the R.A.F., it would not be proposed to
proceed with construction until, in the opinion of the Ministry of Aircraft
Production, this can be done without detriment to other vital requirements.
At the present stage, therefore, the effect of the proposed order would be
to enable the design work to proceed and production to be planned. In
this connection it should be stated that the Ministry of Aircraft Production
are most anxious to keep design staffs in being in order that on a return
to normality, progress in the construction of aircraft of improved design
may be resumed.
7. Under present intentions, the single seater Fighters would be used as
alternative equipment to the two seaters in suitable tactical proportions. It
is proposed to build up a force of single seaters sufficient to arm 4
Squadrons completely, i.e. 48 I.E. aircraft, plus an equal number of reserves.
For this purpose, it is proposed to place an initial order for 100 aircraft of
the new type with Messrs. Blackburn, to be built in their factory at Brough
where the requisite capacity will be available for the Fleet Air Arm.
8. The cost of 100 aircraft to the new design, with the usual allowance
of spare engines, and of operational equipment, is estimated at £1¼
millions, for which Treasury sanction would be necessary. The Ministry
of Aircraft Production would place the order, and the contract would,
(1) This aircraft became known as the Blackburn Firebrand.
presumably, include their usual break clause, whereby the order might be
cancelled or reduced at 3 months' notice.
9. In addition to the tactical aspects outlined above, the proposal would
have other important benefits to the Fleet Air Arm as follows –
(a) The order would give the Fleet Air Arm a semi-alternative source
of supply of Fighter aircraft, against the risk of discontinuance or
interruption by enemy action to Messrs. Fairey's Stockport factory, in
which production of Fighters would otherwise be concentrated; semialternative,
because a single seater would not be a complete substitute for
the standard two seater requirement.
(b) Messrs. Blackburn's design embodies in the wings several new
features which, if successful, would be of great value in improving the
performance of all types of Fleet Air Arm aircraft. These features are still
experimental and not yet sufficiently proved for adoption in the first
production order, for which an orthodox wing design would be specified.
It would be proposed, however, that the experimental wing features should
be developed in one or two aircraft of the new type, so that if the
advantages expected from them were realised they could readily be
incorporated in the subsequent quantity production. This aspect of the
proposal has been strongly endorsed by the Air Ministry (A.0227/40.)
10. It is important that an early decision should be reached."
(Jones, The FAA in WW2 V.1, p.167-169)
Some of the problems faced by the FAA:
"Letter from First Lord of the Admiralty(1) to Minister of Aircraft
Production
[ADM 1/13488] 7 February 1941
Supply of engines for Blackburn Firebrand prototypes
Thank you for your letter of the 7th February. I note with appreciation
that you can let me have two engines for the prototypes, though actually
I need three.
T he rest of your letter, to use an old saying, asks me to rely on the
'sweet by and by'. The need for a fighter of this performance to protect
the Fleet is already apparent, and cannot wait as long as that.
The Navy has a just claim to its share of the best products of the British
aircraft and aero-engine industry. The allocation for which I ask must be
small in comparison with the production which will be provided for the
R.A.F. If we place our order now, we shall still not need Sabres until early
1942. In order that the Fleet may not have to rely on fighters which may
be too slow for their job, I ask you to agree to my placing that order
without delay.
(1)1 The Rt Hon. A. V. Alexander"