Don't all rush at once

It’s very hard to tell from the pic, but it doesn’t seem to have cans, so would assume its an ASDM.3 or 8.
Though looking at the size/shape of the crate and going from the report I wonder if could be two individual Mambas?

The ASDM.8 (AEW type) is longer than its predecessors as there is an extra compressor stage (11 instead of 10), the distance between the gearbox output shafts (thrust line) of the props is reduced from 11 to 6 inches from the engine centre lines, and it is wider.
The advantage of that in the AEW Gannet was as the aircraft was higher off the ground due to radome clearance, the relative thrust line could lowered in the fuselage, and the upper nose line steepened which allowed for better pilot view.

Edit, dimensions (inches) with installed ancilleries
L W H Weight
ASDM.3 98.67 52.8 44.25 2,716Ib
ASDM.8 109.7 56.55 45.28* 2,500Ib *inc. oil tank

Depends which mark of DM it is, though, as the AS and AEW Gannet variants had quite different engines with the latter being bulkier.

A properly inhibited, zero-houred DM (for an AS-variant I seem to recall) was for many years stored in a big packing crate at RNAY Fleetlands on behalf of RNHF. It was later transferred to FAAM who still own it AFAIK.

Isn’t the “Double Mamba” the best engine name ever?
Not just a Mamba, but a Double Mamba.
😀

Have to agree about the name!

Due to the Armstrong Siddeley Double Mamba being the only production success of the family, it is often forgotten that there was such a thing as a Mamba, there were a few built but they only powered prototypes such as the Short Seamew and S.B.3, A.W.Apollo, Miles M-69 Marathon II, B.P. Balliol, Avro Athena, Breguet Vultur, aswel as various engine test-beds.
In a pure jet form four were fitted to the Swiss EFW Aiguillon fighter.

The initial Double Mamba ASDM.1/Mk.100 (Gannet AS.1 & T.2, and Blackburn Y.B.7) used two Mamba ASM.3s, and is distinctive from the rest of the family in having individual ‘cannular’ combustion chambers.
The ASDM.3/Mk.101 (Gannet AS.4, COD.4, T.5, & ECM.6) used two ASM.5s introduced the annular combustion chamber and other improvements.
The most powerful and final incarnation, the ASDM.8/Mk.112 (Gannet AEW.3) used ASM.6 power sections, as well as many improvements it also featured a lower relative output propshaft line to the previous versions.

Double Mambas were more than just two Mambas bolted to a common gearbox though, and each power unit was carefully matched and set up with the gearbox at the factory, and as such were complete ECU sets.

Where does it say fifteen years?

Sorry missed your post,
Rolls Royce say 10 years apparently for their engines in bags, others may differ, though if on a permit that is a different ball game all together. And that was from RR

Seem to remember a Double Mamba being fitted to and used in a tractor pulling contest some years ago. During one ‘pull’ the drive belt or chain, whichever was being used, let go and flew into the crowd somewhere here in the UK.

Isn’t the “Double Mamba” the best engine name ever?
Not just a Mamba, but a Double Mamba.
😀

A Double Mamba could only be used in one aircraft; The Gannet.

A Gannet, if flying on the civil register would be “Permit to Fly”. The engine would not necessarily need overhaul as it could and would most certainly be released “on condition” by the E4/M4/M5 CAA approved entity responsible for its Permit.

Please show me one engine in this country flying in a vintage jet that has been truly “overhauled” as per the book? I may be wrong, but I don’t think there is one. All, I believe, are flying on old engines that have been inhibited correctly, and when removed from preservation have been found to be airworthy, possibly with minor discrepancies needing to be corrected.

I seem to recall that there’s a guy in Australia ground running a D.Mamba ECU with chopped prop set.

I assumed that with two airworthy Gannet restos that Mambas could be overhauled? Saying that, the gearbox would be something else!

Coventry

Yes, Roger, active they may be – but overhauling and paperworking an engine as complex as this for flight is a whole different ball game.

Theirs would need to be an approved facility too.

It would be fun ground running one, though you would need props to load it up a bit, I would have thought. And have it well bolted down, too (see separate thread on this very matter!:D)

Anon.

…….. There’s probably no-one left in the world who would/could o/haul them or have the tooling to do so………Anon.

RRHT, Coventry Branch are a very active bunch.

Roger Smith.

Double Mamba’s

They’re very pretty – but, I’d say, worth not-a-lot:( – Sorry.

Like many other beautifully made chunks of aeronautical machinery, if nobody uses them or has a revenue-earning purpose for them then they are almost worthless – paperworked or not.

The only chance there may be to obtain some money would be (if they are genuinely in mint, ex-crated condition) to offer them for sale as potential ground-runners. There’s probably no-one left in the world who would/could o/haul them or have the tooling to do so.

Otherwise, there may be an engine collector out there who wants a nice example for his museum and may be prepared to pay two or three grand for one.

Unless someone else thinks/knows differently?

Anon.

Engine Life

Where does it say fifteen years?

Well first thing to use them in anything airworthy, they would need overhauling…
i Believe an engine overhauled with all the paperwork in even a MPV bag only has a 15 year Airworthiness life to it.

Blimey, why don’t I have that kind of luck!
Can’t tell which mark they are but hopefully HFL will have spotted this.

I guess any accompanying paperwork (or not) will dictate cost and demand.

I remember a ‘Flight’ edition in the late ’80s advertising a large stock of Double Mambas, be interesting if these are amongst those!