EE Canberra and Martin B-57

[Daryl J.]

Would the Spey engine fit in the Canberra nacelle?

TIA,
Daryl J.

[Geoff]

I was wondering if the Canberra interceptor might also have been equipped with the shorter range AAMs like Redtop and Firestreak for certain missions?
Also does anyone know if the shape of the radome had been decided? 

[Mossie]

Daryl, the Spey was larger than the Avon, you'd need new nacelles.  You can see this in the difference between the DH Comet (powered by Avons) & the Nimrod (powered by Speys).

Geoff, I've wondered too about other missiles.  I think that given Red Deans misgivings, that Red Top might have replaced it.  Saying that, had Red Dean gone into service with all the improvements that were touted, it should have given the P.12 a potent capability.

Using AI.18, I assume it would have adopted a similar shape to the Javelin & Sea Vixens radomes.  The three view in BSP Bombers shows a blunt radome, this same shape was used in early/prototype versions of the Javelin & Sea Vixen (AI.17 & AI.18 respectively) & was changed because it was 'too prone to erosion', according to Air Vectors.

[kitnut617]

Like this I think, it almost fits perfect:

[Geoff]

Thank you Mossie and Kitnut.

I suspect I may do one with Redtops and as a longer range missile, the unguided nuke tipped Genie as IIRC the RAF looked at arming the Lightning with these. (OK I may be getting confused with a Wif by "He Who Cannot Be Named Here").

GeoffP

[Mossie]

Does seem to be the perfect fit.  The only thing I'd say for the Canberra is that you'd need to put in a plug, the radome was of the Interceptor version was slightly longer.  This seems to fit with the real world Canberras fitted with various radar for test & training purposes, they seem to have a slight stretch to the nose.

[norseman]

A Canberra was used as a flying test bed for the Olympus so there were certainly options on fitting bigger engines. The Spey project was very real and a modified nacelle had been designed. A current Canberra would be interesting with a couple of EJ200's in there!

The PR9's were also meant to have been fitted with I think the RR RB.133 which was a development of the RA.24 model Avon though I don't think any ever were.

[Jeffry Fontaine]

A Canberra was used as a flying test bed for the Olympus so there were certainly options on fitting bigger engines. The Spey project was very real and a modified nacelle had been designed. A current Canberra would be interesting with a couple of EJ200's in there!

Maybe do a kit bash with an Airfix Tornado to get the windscreen, canopy and cockpit parts to convert it to a tandem seating arrangement similar to the Martin B-57.

[pyro-manic]

What about the engine used on the new Nimrods? I think it's the RB710?

[norseman]

Would need even bigger intakes than the Spey (a fair bit of jiggering around went into the Nimrod MR4's intake design), a good economical engine though. A couple of late model 17,500lb dry Spey's would do the business or the projected 17,000lb+ dry EJ2xx engines (nice and light option as well).

If production had begun for it a high performance Canberra using two RB.106's would have been a real possibility with approx 16,000lb each dry and drop in replaceable for the Avons.

[Weaver]

The Nimrod MRA.4 engine is the BR.715: basically a BR.710 business jet engine with a corrosion-proof LP compressor/fan stage (can't remember which) and re-arranged accessories for top & bottom access instead of top & side.

It's MUCH fatter than a Spey. The Nimrod MR.2 had the original Comet wing spars with the circular Avon holes ovalised: it's amazing that they didn't have intake problems, given how radically the duct changes section in a short distance. The MRA.4 has a complete new structure with a separate "spectacle frame" section in the spars to accomodate the much larger circular intakes and exhausts.

The BR.715 is shorter than an Avon, so in theory it could fit between the Canberra's wing spars instead of through them, but that still leaves the intake and exhaust to sort out. You'd pretty need new wing spars (no bad thing, mind you) with either two bigger rings in them or a straight front spar that crosses the intake with a fairing around it and a ring for the jetpipe at the rear.

[kitnut617]

I think if I was to install much bigger diameter engines on a Canberra, I wouldn't mess around making 'spectacle' wing spars with all the structural problems that go with them.  I would raise the wing to the shoulder position and have a straight through spar and hang the engines under the wing.  The extended u/c could be accomodated two ways, either have them fold forward into an extended wing root (PR.9 style wing) or have them fold away like the Bristol T.188.

[Chris707]

I'm trying to picture a Canberra with a standard width wing but powered by the RB-57's TF33s....

Chris

[DarrenP]

What if the RB106 had been devloped 2 of those would have fitted the canberra as they were similar size to the Avon but produced nearly twice the power wikipedia describes the output being similar to the Gyron engine.

[DarrenP]

Canberra Maritime Strike