View Full Version : brabazon

victor tango
5th Oct 2014, 18:31
I was wondering if the Bristol Brabazon had something to do with the creation of the Bristol Britannia.
Did Bristols feel peeved at the failure of the mighty Brabazon and said, lets get back to the drawing board and produce an a/c that works and pass on some of the better points to the new Brit.
I feel there is a similarity in the two a/c or should I get my coat:sad:

5th Oct 2014, 18:53
They were both assembled in the same hanger.

The Brabazon, even though it was a commercial failure before construction, did pioneer advances in aircraft construction and operation used in later aircraft, including the Britannia. I don't think the Britannia depended on the Brabazon ideas, they were being incorporated world wide by the time the Brittania got into it's stride.

5th Oct 2014, 23:07
Brabazon was a government programme, postwar reconstruction and all that. It just developed such inertia that it could not be cancelled, despite Bristols wanting to pull the plug. The Brab was assembled alongside the servicing of Connie's, which were already doing the transatlantic route, in the adjacent hangar bay. Embarrassing.

The Britannia was I think private enterprise and certainly used lessons learned from the Brab programme. Alas it was delayed by icing problems in the Proteus engine ironically caused by the requirement for a very short engine to be mounted within the Brab leading edge.

I once saw both aircraft fly over our house in formation, G-AGPW and G-ALBO if I recall correctly.

6th Oct 2014, 06:13

I wish I had a recall as positive as that..!......:D:ok:

Peter R-B

6th Oct 2014, 09:10
Both aircraft were developed from different specifications set by the Brabazon Committee.

The Brabazon was based on the Type I spec for a large trans-Atlantic airliner and the Britannia on the Type III specification for a smaller trans-Atlantic airliner.

6th Oct 2014, 10:49
2/43 Report of the Brabazon Committee recommendations included: Type I, Transatlantic and Type III, Empire. Ministers accepted they would fund such things..."without detriment to the War Effort", which excluded the only design teams with experience of large structure. They were all scheming Big Bombers.

Bristol had bid for one, 11/42, declined for the precise reason that their expertise was in twins. That left them with a Big Wing design and an idle design team. By 2/43 Minister of Aircraft Production was MP for Bristol E. To the consternation of Avro/HP/Short/Vickers, T.167 was funded 3/43, Bristol Centaurus initially: that would offer no benefit over Very Heavy Transports being schemed in US, but (to be) Bristol Theseus propellor-turbine was also being schemed for Big Bombers and would go in a T.167 Mk.II.

Noise from Big Teams caused MAP to release Type III (Empire) only as very Interim derivations of Halifax (as Hermes) and Lancaster (as Tudor), and to defer a proper competitor for DC-4/L-049. Schemes for Medium and Long Range Empire occupied Avro et al into 1947.

1947, time to raze the village of Charlton, to extend Filton's runway for T.167: fortunately Cabinet did not demur - it helped that the President of the Board of Trade was MP for Bristol E.

1947, time to contemplate an enemy: Medium Bomber schemes; and invitation to re-bid MRE, ex-Type III. Avro+HP won the Bomber by 12/47, Short won a back up; 4/48, so did Vickers. So, no-one was left to do MRE. Fortunately the Chancellor of the Exchequer was MP for Bristol E. T.175 was bid with Centaurus, funded 5/7/48, 25 ordered 28/7/49 for BOAC, who converted the order 12/50 to Proteus. That engine was funded for Saro Princess, Brabazon II and (to be) Britannia 100. Otherwise, the only link between 167/175 was the generality of big structure/systems.

Bristol, 1946-48 schemed licenced L-849 Constellation, with Centaurus, then Theseus, but could not extract $. If only...

6th Oct 2014, 12:19
To have been effective Bristol would have needed to work on the Centaurus powered licence built Constellation from 1943. Kelly Johnson gave a talk to British designers at either the SBAC or RAeS in London around 1943 about the benefits of higher wing loadings and thinner aerofoil sections (combined with powerful flaps) (as in the Constellation) but was ignored by the designers of the 'Brabazon' which had a ridiculously over-large wing.
What were the structural advances made in the 'Brabazon'?...I understood that the infrequently-flown prototype suffered from structural cracking which should have been deeply worrying but possibly a valuable lesson in what not to do.

Allan Lupton
6th Oct 2014, 13:35
I'd not come across the Kelly Johnson wing area story before, and I can't see it illuminates the design criteria much.
Based on MTOW the following seem to be the wing loadings (lb/sq.ft.):
Lockheed 049: 52.27
Lockheed 649: 56.96
Avro Tudor I: 53.48
Bristol Brabazon: 54.54
DH Comet I: 54.59

6th Oct 2014, 16:15
I'm relieved I didn't imagine all the story but it was from a C L Johnson technical paper printed in Flight, 1941, not a fictitious talk in London in 1943
1941 | 0959 | Flight Archive (http://www.flightglobal.com/pdfarchive/view/1941/1941%20-%200959.html)

As for the remarkably similar relative wing loadings it certainly looks like I'm shot down! I'll do some more reading

Allan Lupton
6th Oct 2014, 17:36
I didn't do it to shoot you down but thought the comparison might be interesting - which it is.

By the 1960s we were all using around double those wing loadings, e.g.
Boeing 707-320B: 111.15
Douglas DC-8-63: 119.58
Convair 990A: 112.44
Douglas DC-9-40: 113.89
Trident 3B: 103.82
Super VC-10: 114.26

and by now we can offer
A380: 139.78
B787-10: 159.10

7th Oct 2014, 18:50
Think I've mentioned it before, but allegedly the air intakes of the Bristol 404 and 405 motor cars were based on the design of the Brabazon intakes.

The motor cars at the time were made by a division of the aircraft company. I'll try and find some pictures.

Edited to add:

Here's the car (actually a 404) and the intakes:


Both taken from a previous PPRuNe AH&N thread here (http://www.pprune.org/aviation-history-nostalgia/334183-researching-bristol-brabazon.html) which may be useful. ;)

8th Oct 2014, 19:16
...Allan Lupton....no. it was right that I was shot down....I'm quite surprised at the similarity of wing loadings in the days of the Brabazon.... but it did have a bigger thickness/chord ratio at the root (21%) than the Constellation (18% L-1049, 15% L-1649A).

I suppose comparisons are of interest between the Brabazon and the Convair XC-99 which did a few thousand hours useful service with the USAF

9th Oct 2014, 00:45
Certainly the fetish for burring engines in the wing circa late 30's/40's didn't help the Brabazon. To my memory the only big production plane with wing-buried piston engines was the B-36.
Speaking a a maintenance person I was told they were very difficult to maintain. Lots of manhours. The extra weight of gearing two engines together (Brabazon) or incorporating a cooling fan for the pusher configuration (B-36) are a weight penalty you don't need.

10th Oct 2014, 18:28
Interesting transatlantic links:

1. Bill Pegg went to the USA and practised flying a B-36 to get the feel of large aircraft. He found the B-36 used to float a lot when landing, so he insisted on a very long runway, goodbye Charlton village (and Charlton Dairies, who supplied our milk).

2. The Brab had 'gust alleviation' in which a vane next to the cockpit sensed up-gusts and released the ailerons so as to dump lift and reduce structural stresses. When Boeings came to see the Brab they saw the gust alleviation. On their way home they decided to gust alleviate by adding large masses ahead of the wing and rely on aeroelasticity to dump lift. Large masses? Yup, the engines.

14th Oct 2014, 06:35
I asked a B1 pilot at an airshow what the small vane nears the nose was for and he said it was for a computer that 'ironed out' the bumps from air pressure at low level.

joy ride
14th Oct 2014, 07:36
I have always thought that the government and the Brabazon Committee were very far-sighted, especially compared with the Short-termism so obvious in all modern governments! We were still in the middle of a major international conflict and stretched beyond belief financially and in resources yet they looked in great depth at what should be done in UK assuming we would win.

Sadly so many decisions they took turned out not to be good ones, for all sorts of reasons, but I do respect the fact that they did attempt to look into the future and start planning for it.

16th Oct 2014, 22:31

20th Oct 2014, 16:23
Hope this doesn´t upset some people .... !!

I watched the Brabazon take off on its maiden flight with many others watching from the adjacent golf course.

I was 15, & a member of 2152 Squadron ATC, the local unit.

About 2 years later, after an ATC Flying Scholarship at Whitchurch Airport, I had joined 12 RAFVR Flying School at Filton airfield. (I then joined the RAF & eventually civil aviation).

One day at 12RFS I was lucky enough to get into conversation with Brabazon Chief Test Pilot Bill Pegg who was visiting/dining ? there. We talked about flying the Brabazon.

He said, (Quote):-
" It is a noisy, vibrating underpowered heap that only does about 190 knots - as opposed to the 350 (??) it was designed to do. We have been told to fly it over as many towns in the UK as possible in the following months - to show the public where their money went. ... Then we can conveniently scrap it !!"

Yes, I know the engines fitted weren't the ones that it was supposed to have originally - but that is another discussion.