What Problems Dogged the Blackburn Firebrand?

[Kevin J]

The funny thing is some of Fedden's engineers had to be seconded to Napier to fix problems with the Sabre's sleeves. The question become's was the Centaurus sufficiently sorted to become a contender due to production problems and availability of the Sabre as well? (Fedden was at Bristol long enough to start the Orion as well. And I believe the Centaurus was in production by '43.) The Centaurus may have been a Hobson's choice.

If the Sabre works, who needs the Centaurus and Bristol are free to concentrate on manufacture of the Hercules and development of the Orion?

 

[Zipper730]

I'm curious as to what range and endurance specs were required for the design. I ask because I only have Tony Buttler's book to go on and it reveals litte.

 

[RCAFson]

I'm curious as to what range and endurance specs were required for the design. I ask because I only have Tony Buttler's book to go on and it reveals litte.

The Firebrand had a 168IG main tank, and a 71IG aux internal tank, and a range on max internal fuel of 745m @ 256mph at 10kft. There were provisions for twin external drop tanks of 45IG capacity, each, and/or a 100IG centreline DT in lieu of a torpedo. (Wings of the Navy)

 

[Zipper730]

The Firebrand had a 168IG main tank, and a 71IG aux internal tank, and a range on max internal fuel of 745m @ 256mph at 10kft. There were provisions for twin external drop tanks of 45IG capacity, each, and/or a 100IG centreline DT in lieu of a torpedo. (Wings of the Navy)

That's very informative, and so forth. That said, what range and specifications were stipulated for the design.

Say, I issue a specification for 750 miles at 250 mph. The plane might have a range of 900 miles at 300 mph, but that's not the original specs.

 

[RCAFson]

That's very informative, and so forth. That said, what range and specifications were stipulated for the design.

Say, I issue a specification for 750 miles at 250 mph. The plane might have a range of 900 miles at 300 mph, but that's not the original specs.

This letter outlines the speeds expected from both the two seat Firefly and the Firebrand. Range is not specified but we can safely assume that the incorporated fuel capacity was based upon specification requirements.

" 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.
The 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"
(Jones, The FAA in WW2, p.304)

 

[jetcal1]

If the Sabre works, who needs the Centaurus and Bristol are free to concentrate on manufacture of the Hercules and development of the Orion?

It's all about availability, money and needs. The Centaurus was a bird in hand. Remember it ran in the late '30's. In fact, I think it beat the Griffon by a fair amount of time.

 

[nuuumannn]

The original spec says this about N.11/40's range: "An endurance of 4 hoursat not less than 120 knots at 15,000ft plus 10minutes at maximum power at sea level is required. Tankage for an additional 2 hours at the same economical speed is to be provided as an overload, preferably in a separate tank."

 

[Zipper730]

nuuumannn ,

Now this is the kind of information I was looking for

1. Endurance of 4 hours at 120 knots or greater @ 15000' or greater altitude on internal fuel
2. Provision for 2 additional hours endurance at the same speeds and altitudes as before, preferably in a separate (and internal tank)
3. 10 minutes at maximum power @ S/L

This is an interesting set of requirements: I'm not sure how many aircraft were stipulated to have this level of endurance that I know of (other than the P-61); as for the requirement for 10 minutes of maximum power: What settings are we talking about? MCP is largely indefinite for individual flight purposes; Military Power is usually based on 30 minutes of operation; Emergency Power is usually based on 5 minutes.

My guess is that they wanted an overload tank rather than drop tanks so they don't have to carry all of them onboard.

I'm curious what typical endurance requirements were required for other aircraft such as

1. The Fairey Firefly
2. The Curtiss P-40
3. The Grumman F6F Hellcat
4. The Chance-Vought F4U Corsair

From what I remember, the P-51B/D seemed to see around 6 hours in the air...

Calling the experts...
drgondog fubar57 S Shortround6 swampyankee W wuzak X XBe02Drvr

 

[drgondog]

nuuumannn ,

Now this is the kind of information I was looking for

1. Endurance of 4 hours at 120 knots or greater @ 15000' or greater altitude on internal fuel
2. Provision for 2 additional hours endurance at the same speeds and altitudes as before, preferably in a separate (and internal tank)
3. 10 minutes at maximum power @ S/L

This is an interesting set of requirements: I'm not sure how many aircraft were stipulated to have this level of endurance that I know of (other than the P-61); as for the requirement for 10 minutes of maximum power: What settings are we talking about? MCP is largely indefinite for individual flight purposes; Military Power is usually based on 30 minutes of operation; Emergency Power is usually based on 5 minutes.

My guess is that they wanted an overload tank rather than drop tanks so they don't have to carry all of them onboard.

I'm curious what typical endurance requirements were required for other aircraft such as

1. The Fairey Firefly
2. The Curtiss P-40
3. The Grumman F6F Hellcat
4. The Chance-Vought F4U Corsair

From what I remember, the P-51B/D seemed to see around 6 hours in the air...

Calling the experts...
drgondog fubar57 S Shortround6 swampyankee W wuzak X XBe02Drvr

The P-51B/D combat mission endurance was at least 8 hours - my father's logbook had 10 >6:45 Munich, Ruhland, Stettin), 2>7:20 (Strafing near Prague) 1=8hrs (Piryatin, Ukraine). Max Combat radius on a particular mission was a leg to Steetin, down to Posnan back to Magdeburg ~750 miles. 110 gal externals. Ranges in Pacific w/165 gal externals were greater.

 

[Freebird]

Actually that is why you pay test pilots. To have an opinion. Many test pilots had degrees in engineering or lots of practical experience so they could give feedback to the engineers in technical terms and not truly helpful (not) comments like "it stinks and flys like a barge".

Easy to land though.
(Rather roughly and often involving the fire brigade)

 

[Zipper730]

The P-51B/D combat mission endurance was at least 8 hours

And that usually involved flying at speeds of around 300 mph if I recall...

I assume aircraft designers understood the concept of fuel-fraction on range back in 1939-1940 (or at least the effects on weight change on range)?

 

[Zipper730]

I have two questions

1. The Firebrand was 13643 fueled and gunned up, right?
2. Was Blackburn known producing aircraft that were excessively heavy, or clunky? I ask because
   • Republic was known for producing big, tough, and overweight aircraft (P-47, F-84, F-105)
   • Vultee largely produced fairly clunky aircraft designs (the only design I know of they didn't was the XP-54)
   • Grumman generally was known for producing aircraft of great strength, though they often varied from a little to very heavy

 

[nuuumannn]

Was Blackburn known producing aircraft that were excessively heavy, or clunky?

Clunky maybe, but structurally strong for carrier operations, exemplified by the rugged post war Buccaneer. Robert Blackburn decided during the Great War that he wanted his firm to be the major supplier of combat aircraft to the RNAS, then the RAF controlled FAA and he almost did, but for rival Fairey, who matched his aircraft designs with ingenuity. Despite a reputation for poor designs in WW2, no thanks to George Petty, Blackburn's chief designer, the firm produced a range of good reliable carrier based machines in the 20s and 30s. Most annoyingly for the firm, Blackburn designs continued to be overshadowed by Fairey's in WW2 with the arguably more advanced Shark being superceded by the less sophisticated Swordfish, with Blackburn being the major producer of the type from 1940.