Avro-746,was it a competitor to Hunting H.126 ?

[hesham]

Hi,

from the Avro Heritage site,the Avro-746 was Jet flap research aircraft.
1x Bristol BE.53. Span 42.4’,Length 43’, Height 16.5’, AUW 10,876lb.And
I am asking that,was this aircraft a competitor to Hunting H.126 for the
Spec. ER.189D ?.

 

[AeroFranz]

Interesting find....
It looks like the vehicle has a conventional nozzle. Didn't the H.126 exhaust all of its massflow through the wing slots? Maybe the -746 could modulate the amount of exhaust going to the wing?
Hard to say with just one side-view ???

 

[Jemiba]

The H.126 by the way had two "direct thrust jet pipes" (see cut away from Aeroplane Monthly
January 1995). As far as I can tell from the side view of the Avro 746, the wing had a much lower
aspect ratio, than the Hunting design. Together with the retractable landing gear, maybe it was
an attempt, more aimed at exploring the practical use of jet flaps, than just doing basic research
of the principle ?

 

[Mike Pryce]

The Avro 746 had the BE.53 turbofan engine, an early Pegasus. Presumably the fan air went to the flaps and the core flow exited from the rear nozzle. With high mounted jet flaps you get a large nose-down pitching moment, so a low mounted jet behind the centre of gravity helps trim this out with a nose-up force.

Seems like a much better idea than ducting hot air through the wings from a turbojet and leaving a bit of thrust over for the trimming jets, as on the H.126 with its Orpheus. But this is with hindsight - presumably the BE.53 was seen as a risk at the time, and the use if fan air may have required bulky ducts etc.

 

[hesham]

Thank you my dears Aerofranz,Jemiba and Harrier;

and by the way,the Hunting H.126 was begun the work of it in 1957 also
as Avro-746 !.

 

[lark]

Several books about Avro including the Putnam volume say
that type 746 ( August 1957)was powered by a Bristol -propeller- turbine/BE.53..

By the way Hunting H.126 was responding to spec.ER189D of 20May 1959
(Roy Sturivant-British Research and Development aircraft.Haynes 1990)

 

[hesham]

Thank you my dear Lark very much.

 

[Mike Pryce]

I was at the Avro Heritage Centre today and saw the 746 brochure. It did indeed use a BE.53 (Pegasus) with the fan flow ducted to the wings and their full span jet flaps, and the core flow exiting at the rear.

Couldn't get a scan, but hope to next time.

Although the heritage centre and staff were great, it was depressing to see the building and airfield where Lancasters, Vulcans, Nimrods and other aircraft were assembled and flown empty and quiet. Not proud to be British today!