SBAC Numbers


Any landing you can walk away from, is a good one.
13 January 2009
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Ok, heres one for all of you????

When did the SBAC (Society of British Aircraft Constructors) introduce their designation system.

More importantly, why?

And, does anyone have a complete list?
Hi all,

from my tables.

Y.A. Series
Y.A.1 1945 B-48 Firecrest prototype to Specification S.28/43
Y.A.2 Design study only
Y.A.3 Design study only
Y.A.4 B-55 project for a RR Dart powered 24-seat commercial aircraft
Y.A.5 B-54 anti-submarine two-seater to Specification GR.17/45 with Napier Double Nomad
Y.A.6 1946 B-62 project for Firecrest with AS Python
Y.A.7 Y.A.5 two-seater with RR Griffon 56
Y.A.8 1950 Y.A.5 three-seater with RR Griffon 56
Y.A.9 1947 B-75 feeder-liner with two Blackburn Cirrus Majors or Bombardier

Y.B. Series
Y.B.1 1950 Y.A.8 with AS Double Mamba
Y.B.2 1951 H.P.88 research aircraft using a Supermarine Attacker fuselage and Handley-Page Victor scale model crescent wing
Y.B.3 1955 B-103 (other were NA.39) low-level strike aircraft prototype

G.A. Series
G.A.1 1948 Fighter
G.A.2 Fighter
G.A.3 Fighter, project only
G.A.5 1951 Javelin, interceptor fighter

English Electric
G.A. Series
E.A.1 Canberra B Mk.1
E.A.2 Canberra PR Mk.3
E.A.3 Canberra B Mk.2
E.A.4 Canberra …

S.A. Series
SR.A.1 SR.A/1 (S.44) flying boat fighter

S.A. Series
S.A.1 S.38 Sturgeon PR Mk.1 torpedo bomber/recce
S.A.2 S.39 Sturgeon TT Mk.2 turget tug (Q.1/46)
S.A.3 S.41 naval fighter project to Spec. N7/46
S.A.4 S.42 Sperrin four engined jet bomber for Spec. B.14/46
S.A.5 S.43
S.A.6 S.44 Sealand patrol flying boat
S.A.7 S.46 commercial Flying Boat Project
S.A.8 S.47 commercial Flying Boat Projects
S.A.9 S.48 military glider (X.30/46)

S.B. Series
S.B.1 tailless glider
S.B.2 Sealand II
S.B.3 Sturgeon anti-submarine aircraft
S.B.4 Sherpa experimental wing research aircraft
S.B.5 research aircraft
S.B.6 Seamew AS Mk.1 single engined anti-submarine aircraft ( ≡ P.D.4)
S.B.7 Sealand III amphibian
S.B.8 ultra-light helicopter project for HR.144T
S.B.9 Sturgeon TT Mk.3 carrier-borne target-tug aircraft

S.C. Series
S.C.1 experimental fixed-wing vertical take-off and landing (VTOL) aircraft ( ≡ P.D.11)
S.C.2 Seamew AS Mk.2 for RAF
S.C.3 = P.D.16
S.C.4 converted from Canberra B Mk.28 bomber to pilotless drone aircraft
S.C.5 Belfast C Mk.1 heavy lift turboprop freighter ( ≡ P.D.18)
S.C.7 Skyvan 19-seat turboprop airliner ( ≡ P.D.36)
S.C.8 = P.D.43, a two seat version of the SC.1
S.C.9 Canberra PR Mk.9 converted with AI.23 radar plus IR installations in nose for DH propeller (Red Top AAM) trails

S.D. Series
S.D.2 a licence built Beech Model-1072 RPV
S.D.3 later Shorts-330 transport
Thanks, this is very helpful.

I do need more info on why it was started and when.


hi all

Please answer me: a Fairey F.B.1 (Gyrodyne) is a SBAC designation?

In the Shorts designation thread we had a discussion about the possible structure of the SBAC designation system.,1878.30.html

It appears each manufacturer was allocated a main letter which reflected the first letter of the company's name, e.g. E = English Electric, S = Shorts etc. (Blackburn being Y is an exception).
Each manufacturer would then assign numbers sequentially in blocks of nine. Each block was identified by the letters of the alphabet, A, B,C etc., with a new letter whenever the next batch of nine was begun; e.g. S.A.1 to S.A.9, followed by S.B.1 to S.B.9, followed by S.C.1 etc.
This explains why variants of the same basic airframe often had different numbers through the series.

Why the SBAC chose to keep the designations to single digits is unknown, perhaps to avoid complications with errors with mis-numbered or in copying?

I am not sure to what extent the Ministry of Supply was the driver behind this system, but it seems only projects that were actually tendered or looked likely to be were assigned the next available number and all seem to have an official requirement or development contract associated with them. It is likely that the designation was meant to ease the MoS's admin headaches while keeping track of different variants and projects tendered. The fact that Short's being effectively majority-owned by the MoS persisted with this system the longest is perhaps an indication of the Ministry's desire for the system.

I have some additions to the list above by AM

X.A.8 - Ambassador airliner

Began using the system in 1947, but there are two odd features regarding Auster's use of the system. They seemingly only used the second alphabetic letter without a first letter to identify the company. It is possible these designations should actually be A.A.1 to A.E.1.
Also, they seem to have included all their projects from 1947 for new types unconnected with the pre-war and wartime types.

A.1 - Model M redesignated?
A.2 - Model N redesignated?
A.3 - 1947 light aircraft project
A.4 - 1948 AOP project
A.5 - 1948 AOP project
A.6 - 1948 touring trainer project
A.7- 1948 high-wing pusher project
A.8 - 1948 AOP project
A.9 - 1949 basic trainer project to T.16/48

B.1 - AOP project
B.2 - unknown
B.3 - 1951 pilotless target (production)
B.4 - 1951 prototype ambulance/freighter
B.5 - AOP.9 to A.20/49 (OR.270) and later 9M civil conversion
B.6 - 1953 agricultural aircraft project
B.7 - 1953 tourer project
B.8 - Agricola
B.9 - 1954 ultralight helicopter project to HR.144T (OR.319)

C.1 - 1955 light aircraft project
C.2 - 1955 light helicopter project
C.3 - 1955 light helicopter project
C.4 - Antarctic trainer
C.5 - 1955 ambulance/freighter project
C.6 - Atlantic light aircraft prototype
C.7 - 1956 light helicopter project
C.8 - 1956 light helicopter project
C.9 - 1956 light helicopter project based on B.9

D.1 - 1957 troop transport project
D.2 - 1958 AOP project
D.3 - 1958 light aircraft project
D.4 - D4/108 light aircraft
D.5 - Husky D5/160 light aircraft
D.6 - D6/160 and D6/180 light aircraft
D.7 - 1960 D.5 agricultural variant project
D.8 - 1960 D.6 with tricycle undercarriage project (led to Beagle A109 Airedale)
D.9 - 1960 D.4 with tricycle undercarriage project

E.1 - unknown
E.2 - unknown
E.3 - 1961 Auster 11 A.115

Boulton Paul
P.A.1 - Balliol prototype/T.1 with Dart
P.A.2 - Balliol prototype/T.1T.1 with Mamba
P.A.3 - Balliol, possibly prototype installation of Merlin
P.A.4 - Balliol T.2
P.A.5 - Sea Balliol T.21
P.B.1 - P.111
P.B.2 - P.120

Bristol (these to be confirmed)
R.A.4 - jet pathfinder/bomber project
R.A.6 - jet pathfinder/bomber project

Vic Flintham in Aircraft in British Military Service: British Service Aircraft Since 1945 states FA.1 Rotodyne, F.B.1 Gyrodyne and the F.D. series were SBAC designations, but these were actually Fairey's own designations, e.g. Fairey-Bennett No.1 and Fairey Delta No.1.

Heston Aircraft Company
The J.B. series was unused. There is some doubt whether these are SBAC designations, given many of them appear to be pre-war and so would pre-date the SBAC system, unless they were retrospectively assigned.
J.A.1 - Phoenix
J.A. 2 - Griffin project
J.A.3 - T.1/37 trainer
J.A.4 - T.1/37 project
J.A.5 - Type 5 racer
J.C.1 - T.23/43 project
J.C.2 - unknown
J.C.3 - unknown
J.C.4 - unknown
J.C.5 - A4/45 project
J.C.6 - AOP prototype to A.2/45
J.C.7 - unknown
J.C.8 - unknown
J.C.9 - scale Vickers Swallow VG wing research aircraft project (built but never assembled)

Marshall Flying Services
There is a possibility this was just Marshall's own company designation.
M.A.4 - BLC research aircraft converted from Auster AOP.6

Reid & Sigrist
Vic Flintham in Aircraft in British Military Service: British Service Aircraft Since 1945 states the RS.3 and RS.4 were SBAC designations, but actually these follow on from the RS.1 in 1939 and there seems little doubt RS was simply the firm's own designation using the initials of the company.

Vic Flintham in Aircraft in British Military Service: British Service Aircraft Since 1945 states the VC series of airliners were SABC designations, but actually VC stood for Vickers Commercial and were not part of the SBAC system.

Only two W.A. numbers seem to be known, both licence-built Sikorksy helicopters and paralleling the better-known WS series Westland used publicly.

W.A.4 - S.51
W.A.8 - S.55
Thanks for that.
So as far as we can see the industry 'big hitters': The Hawker Siddeley Group, DH and Vickers-Armstrong, and smaller fry like Folland chose to take no notice of the SBAC initiative.
It seems so, I doubt there was much incentive to use it, except perhaps for some companies that lacked a system of their own. Auster seems to have appropriated it the most thoroughly.

The Heston and Marshall allocations are tantalising if they are true SBAC designations, as they are mid-block with gaps.
Assuming Auster was meant to be 'A', then that might explain why Airspeed was 'X', Blackburn was 'Y' so that assumes another company starting with B was allocated 'B', Bristol perhaps? If Heston was given 'J' then that supposes someone else was allocated 'H'.
I wonder if SBAC had a planned master list or if companies were assigned their letter designations when or if they signed up, first come first served?
Hood said:
.. I doubt there was much incentive to use it, except perhaps for some companies that lacked a system of their own. .....

That sounds more than likely. The only system I know well is that of Vickers and they had had that in place since 1920 and imposed it on Supermarine after the take-over. It was clear, logical and unambiguous, which is no doubt what the SBAC wished to see. With so many sub-contractors and shadow factories in the late 30s and war years anything less could have led to endless problems.
Amazing work my dear Hood,

but we can add;

-for Fairey F.D.3
-for Heston; J.A.1,J.A.3,J.A.4 & J.A.5,also J.C.1,J.C.5
We should be careful not to go off-topic on this thread but for the record there are also (non SBAC) Fairey F.C.1 through to 6, where F.C stands for Fairey Commercial
This is what I have for Heston:

JA 1 = Phoenix
JA 2 = Griffin - a projected development of the JA 1 Phoenix.
JA 3 = T1/37
JA 4 = T7/37 *
JA 5 = Racer
JC 1 = T23/43*
JC 2 = ??
JC 3 = ??
JC 4 = ??
JC 5 = A4/45*
JC 6 = A2/45
JC7 = ??
JC8 = ??
JC9 - small experimental variable geometry aircraft. It was built in sections by Heston and shipped to Weybridge but never assembled and eventually scrapped

Marked * known to be project only. The other unknowns are also presumably just project studies.
The JB series seems to have been unused.

I do not believe any of the Fairey designations were in any way associated with the SBAC system. I also suspect Marshall's just stood for Marshall Aircraft.

Some companies like Auster took to using the principle of the system without using their actual company prefix letter.
Hi all

About Fairey. FB-1 = Fairey-Bennett No.1. It's not a SBAC designation

Many thanks, I've updated my post accordingly.

The Heston series seem likely to be SBAC designations, but many of them are pre-war/war-era and so may actually predate the system unless they were retrospectively assigned. There may be some evidence of this, the Type 5 record racer is better known under that title, whereas the JC.6 seems always to have been the JC.6.
I believe hat to correct, the Heston designations were originally Type 1, 2 etc., being retroactively numbered upon incorporation of the SBAC system. But, why no JB?
Edited my list to include some Boulton Paul information.
Boulton Paul was issued 'P', Blackburn was 'Y', if Bristol was allocated 'R' then it still leaves open the question of who 'B' might have been assigned/earmarked for.
Highly likely as pre-war private venture aircraft from Bristol carried R test series registrations. For example Type 142 'Britain First was R-12, Type 133 fighter R-10. Carrying this forward for projects has a certain logic to it.

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