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Author Topic: Martin-Baker push-pull twin-boom fighter  (Read 10474 times)

Offline Tophe

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Martin-Baker push-pull twin-boom fighter
« on: March 10, 2011, 08:37:06 am »
I found that on the Web, seeming serious. A push-pull interpretation of the twin-boom pusher?
http://www.flickr.com/photos/40933081@N04/5233569371/

Offline Tophe

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Re: Martin-Baker push-pull twin-boom fighter
« Reply #1 on: March 10, 2011, 08:46:38 am »
A provisional drawing of it was in my book "The end of Forked Ghosts" following words of Tony Butler, but I never saw such a precise drawing, and the mention of 2 side-by-side cockpits. I may have to update my drawing collection.

Offline lark

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Re: Martin-Baker push-pull twin-boom fighter
« Reply #2 on: March 10, 2011, 12:52:17 pm »
You're right Tophe,

It's a very good find about a real project.Thanks a lot for sharing.
In a book about Martin-Baker , the cockpit is
described as follow...Enclosed side -by-side seating
in cockpit with clear view bubble canopy...
























Offline lastdingo

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Re: Martin-Baker push-pull twin-boom fighter
« Reply #3 on: March 10, 2011, 01:10:48 pm »
The common reason for counter-rotating propellers is to cancel torque - what's the reason here?

Offline Abraham Gubler

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Re: Martin-Baker push-pull twin-boom fighter
« Reply #4 on: March 10, 2011, 01:19:52 pm »
The common reason for counter-rotating propellers is to cancel torque - what's the reason here?

Reduce the size of the prop disc.
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Offline Tophe

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Re: Martin-Baker push-pull twin-boom fighter
« Reply #5 on: March 10, 2011, 09:43:56 pm »
To reduce the size of the prop disc, a 6-blade single propeller would do as fine as two 3-blade (contra-rotating) propellers, no?
« Last Edit: March 10, 2011, 09:46:02 pm by Tophe »

Offline Orionblamblam

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Re: Martin-Baker push-pull twin-boom fighter
« Reply #6 on: March 10, 2011, 11:00:22 pm »
To reduce the size of the prop disc, a 6-blade single propeller would do as fine as two 3-blade (contra-rotating) propellers, no?

No. To first approximation, the fewer props you have, the more efficient. If you could get away with a  *single* prop, you'd do well. However, the number of props is tricky... it depends on flight conditions, engine power and so on, and these are all over the place for *any* aircraft.

Plus, while a six-bladed prop might be smaller in diameter than a three-bladed prop, that doen't mean it'll weigh less. And it certainly doesn't mean that it'll be less complex or require less maintenance.
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Offline Skyblazer

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Re: Martin-Baker push-pull twin-boom fighter
« Reply #7 on: March 11, 2011, 12:56:55 am »
Plus, while a six-bladed prop might be smaller in diameter than a three-bladed prop, that doen't mean it'll weigh less. And it certainly doesn't mean that it'll be less complex or require less maintenance.

Let's put it this way: if push-pull configurations were THAT efficient and easy to maintain, there probably WOULD be a lot more types using it nowadays! Yet if I'm not mistaken,  there never was any true production type in push-pull configuration anywhere in the world!

Offline Arjen

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Re: Martin-Baker push-pull twin-boom fighter
« Reply #8 on: March 11, 2011, 02:23:54 am »
There's this Cessna 337, not to mention all those nice Dornier flying boats. Push-pull was a big thing in pre-war flying boats.
« Last Edit: March 11, 2011, 02:25:47 am by Arjen »

Offline Skyblazer

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Re: Martin-Baker push-pull twin-boom fighter
« Reply #9 on: March 11, 2011, 02:38:14 am »
Yes, the Skymaster. I'm silly because I was about to mention it in the above post and then forgot about it...

Oh, the Dorniers. Yes! You're right. And they flew pretty well it seems. Now from a technical viewpoint, what is the effect of the front propellers' air stream hitting the rear ones? Is there any consequence, either positive or negative? I should imagine the stream is pretty much absorbed into it and it might even make it work better, but that's pure conjecture, so if anyone with knowledge on the subject could clarify this particular point, I sure would appreciate it.

Offline Arjen

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Re: Martin-Baker push-pull twin-boom fighter
« Reply #10 on: March 11, 2011, 03:20:14 am »
Strictly as a layman: Dornier tried push-pull in the 335 which was one of the fastest prop-fighters ever, De Havilland made an even faster twin-prop with their Hornet. I don't think propellor-efficiency is fundamentally compromised by either configuration.

One big advantage for the Hornet was field of vision, the pilot of a 335 was stuck behind that long nose. Rolling inertia should be smaller for the 335. I guess much depends on what you want to use the aircraft for.

Offline Tophe

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Re: Martin-Baker push-pull twin-boom fighter
« Reply #11 on: March 15, 2011, 10:54:16 am »
I updated my twin-boom 1939-45 collection at http://cmeunier.chez-alice.fr/update_FG.htm
Here is a bigger view:

Offline Thiel

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Re: Martin-Baker push-pull twin-boom fighter
« Reply #12 on: March 21, 2011, 01:07:48 am »
Does anyone know the dimensions of that his aircraft?

Offline lastdingo

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Re: Martin-Baker push-pull twin-boom fighter
« Reply #13 on: March 21, 2011, 01:44:08 am »
Let's put it this way: if push-pull configurations were THAT efficient and easy to maintain, there probably WOULD be a lot more types using it nowadays! Yet if I'm not mistaken,  there never was any true production type in push-pull configuration anywhere in the world!

Dornier Wal, Dornier 18, ...

Offline Skyblazer

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Re: Martin-Baker push-pull twin-boom fighter
« Reply #14 on: March 21, 2011, 02:33:16 am »
Let's put it this way: if push-pull configurations were THAT efficient and easy to maintain, there probably WOULD be a lot more types using it nowadays! Yet if I'm not mistaken,  there never was any true production type in push-pull configuration anywhere in the world!

Dornier Wal, Dornier 18, ...

Yep, all the examples you guys have provided are true, but apart from the Cessna Skymaster, they're all mostly from Dornier, so it's still quite a scarce configuration... and one can hardly call the Wal a "production type"!