Calling!!! Bruntingthorpe Canberra folk… re: AVON Electric Starter Motors

Cranfield Lightning converted by a gent called Rod Barker. He modified a control panel from the starter system used on the Comet, if memory serves.

Yes it did they have run ht cables somehow and have a trolley with battery set on

Didn’t the Cranfield T.5 Lightning get changed over to electric start?

Other aircraft with 112V DC systems were the Britannia and Victor Mk 1 & Vulcan Mk 1. Not very useful info but might help!

Mid Air converted their canberras over to electric I seem to remember?

Need more information on this as we are now short of carts for two ground based hunters at bruntingthorpe

Brunty’s ex-swiss example was avpin start though?
In my time on military Hunters, I came across Avpin and Cart starts, but no electric… I thought any electric starts were purely conversions as mentioned above by Delta etc?

As far as I know that’s absolutely correct – all Hunter electric starts are civvie conversions.

The only conversion I’ve had anything to do with had a lot of the the ‘gubbins’ (including batteries) installed in the gun pack, with an external connector poking through one of the link ejector chute holes.

I’ve probably got some of the hardware if you need it!

Bruce

Hi – Clicking relays etc.. you’re correct, there is a soft start system… I’v got my hands on one of these too! three relays:

One connects the supply via a big resistor
The second shorts out the resistor after a shore time period (controlled by a timed controller unit)
The third is an undercurrent trip relay to disconnect the supply as and when the engine starts to pull away (and hence the motor current drops)

I’ve been in touch with a flying Hunter group, and had some very useful advice.. to do this conversion for flying aircraft is a big cost, but luckily this project is not flying!

Cheers for all the interest and input! Scott.

Brunty’s ex swiss aircraft will be getting electric start as part of it’s overhaul to flight

Brunty’s ex-swiss example was avpin start though?
In my time on military Hunters, I came across Avpin and Cart starts, but no electric… I thought any electric starts were purely conversions as mentioned above by Delta etc?

G-HUNT was a Danish F-51 aircraft. No idea if its electric start was a civvie conversion though.

Bruce

Bearing in mind that it is nearly 30 years ago and I have had lots of bangs on the head since (including many many centring spike strikes when refuelling Hunters).

I am sure I recall being sent out to do a see off on a red civvy single seat Hunter (G-HUNT I think) for the ’82 air show at Valley. I dropped the Avpin panel as one would on an F6, and upon looking inside no starter was found. Luckily the pilot arrived and put me out of my misery by explaining that the jet was ex Swiss(?) and they were all electric start versions.

Hope this offers a new avenue for research?

Just been thinking about this a bit more and I am pretty sure that during start, the engine had to be self sustaining within 7 seconds (carts) and 10 seconds (Avpin) which possibly equates to 1600 RPM.

On the civvy jet mentioned above, it may have been my imagination but during the electric start cycle there was much clicking of what sounded like fairly big relays so there may have been a soft start system fitted?

Scott,

Delta Jets were pioneers (as I understand it) in the development of electric start conversions for the Hunter, so another avenue for you to try.

As Aerial touched upon ,the massive weight penalties of electric start were a big contributing factor in it never being implemented on the Canberra. Going back to your earlier question about carts though, we are simply using old stock carts – when they’re gone, they’re gone!

Contact for Delta as follows:

[email]office@deltajets.com[/email] – Chris Vaughan is your man.

Scott, I would hate to send you down a blind alley in your search, but the only 112V DC electrical system that I know of was in the Valiant – also equipped with Avons. Perhaps there was a scheme to use them on Canberras in place of the cartridge starters but getting several batteries together to raise 112V is no mean feat and maybe the idea didn’t progress further because of this. See: http://en.wikipedia.org/wiki/Vickers_Valiant What you can do with this information to lead you to the electric starters info I have no idea, but good luck anyway.

Hi mate, the motors I have are rated up to 120V DC (the higher voltage you can safely apply, the lower the current, and hence less chance of cable fires etc.. due to overcurrent), but 112 was also used on the Comet, and apparently also some turboprop aircraft too.

The information I’m after, is simply full load current when cranking an Avon, duration to get the engine up to 1000 RPM etc…. so any info which may contain some technical details would be helpful in designing the electrical system… I’ve found some pretty handsome kit to provide the DC, but I want to do a little maths to be sure i’m on the right track before trying anything “live”!

Cheers, Scott.

Scott, I would hate to send you down a blind alley in your search, but the only 112V DC electrical system that I know of was in the Valiant – also equipped with Avons. Perhaps there was a scheme to use them on Canberras in place of the cartridge starters but getting several batteries together to raise 112V is no mean feat and maybe the idea didn’t progress further because of this. See: http://en.wikipedia.org/wiki/Vickers_Valiant What you can do with this information to lead you to the electric starters info I have no idea, but good luck anyway.

Or try PMing Freebird or HFL on here re Hunter stuff.

Yes, you’re right, there a a few Hunters out there which have been converted, I’ll try and get in touch with some of the Kemble guys…

Cheers, Scott.

ideally you need the manuals that cover the “big” hunter conversion.Cranberry manuals will suffice if its for the large Avon Cranberry.

Sorry old chap, Canberra’s have never been electric start equipped!

We are still starting using lovely dirty cartridges courtesy of Plessey and their triple breach starter 😀

Any talk of electric start was at a feasability study level only I am afraid – alas, it never happened.

Oh ok dude,

Since talking with Rod and the help he supplied for the electric start concept, I just assumed you had gone gown the electric route!!

Do you get your Carts refilled? or new ones made? or is it like Avpin – one day there will be no more…

Cheers, Scott.