Miles Aerovan variants?

[Jemiba]

[quote author=hesham]Hurel-Dubois with Miles HDM.107 and HDM.108 transport aircraft.[/quote]

The HDM 107 is especially interesting, as it isn't even mentioned in R.Paynes "Stuck
on the Drawing Board", whereas the HDM.108 at least is described as a larger variant
of the HDM.106, with 25 seats or as a freighter, powered by two Turbomeca Bastan
turboprops.

 

[cluttonfred]

OK, some may remember that I am a big fan of Miles aircraft, and I have always has a soft spot for the portly-yet-practical Miles M.57 Aerovan. In terms of variants actually built, there were a couple of marks of M.57 varying slightly by engine installation, etc. and two major derivative designs that flew--the M.68 Boxcar with four smaller engines and a detachable fuselage "cargo pod" and the HDM.105 proof-of-concept design, an Aerovan fitted with a large, high aspect ratio Hurel-Dubois wing.

In terms of unbuilt variants that were planned there is a sketch in Don Brown's book of the Miles M.72--basically the four-engined setup of the M.68 Boxcar applied to a standard Aerovan. Two mentioned in the text, but not illustrated, are "a four-crew AOP [airborne observation post] version" with a lowered wing and tail boom and extensive glazing, and a "flying boat variant in which the normal nacelle was deepened to form a single-step flying boat."

Does anyone have any images of either of these, or any other, unbuilt Aerovan variants?

Cheers,

Matthew

PS--I am off to work now, but I will scan and attach small images of the variants actually built and the M.72 when I get a chance.

 

[Stargazer]

Here are the Aerovan variants I'm aware of:

M.57 Aerovan 1 (L.R.4)
small twin-engined, short-haul, high-wing STOL transport with rear loading door, two 150 hp Blackburn Cirrus Major III; no MAP approval (1945, 1 built)

M.57 Aerovan 2
similar to Mk. 1 but fuselage had 5 circular windows instead of 4 rectangular ones; pod length increased by 18 in. (1946, 1 built)

M.57 Aerovan 3
initial production version; as Mk. 2 but with heavy-duty door lock under rear fuselage; one later modified to Mk. 4 (1946, 7 built, 50 originally planned)

M.57 Aerovan 4
similar to Mk. 3 but with only 4 circular windows; last three completed by Handley-Page at Reading (1946, 1 converted + 45 built); one later converted to HDM-105

M.57 Aerovan 4
second batch of 50, most cancelled; one was fitted with 4x Blackburn Cirrus Minor III engines to become M.72 prototype (1947, 5 partly assembled, the rest was cancelled)

M.57 Aerovan 5
like Mk. 4 but with two De Havilland Gipsy Major engines (1947, 1 built)

M.57 Aerovan 6
like Mk. 4 but with Lycoming engines (1947, 1 built)

M.57A Aerovan
enlarged Aerovan with two 340 hp A-S Cheetah X (not built)

M.68 'Pantechnicon' or 'Boxcar' (none of these names being officially assigned)
four-engined variant of the M.57 Aerovan with detachable cargo container, four 100 hp Blackburn Cirrus Minor II (1947, 1 built)

M.71 Merchantman (U-21)
larger 4-engined, all-metal development of M.57 with four 250 hp D-H Gipsy Queen 30 engines (1947, 1 built)

M.71A Merchantman 1
production version with conventional fuselage, 2x Armstrong Siddeley Cheetah or Alvis Leonides engines (1947, 20 ordered, only 1 built)

M.71A Merchantman 2
production version with detachable freight container, 2x Armstrong Siddeley Cheetah or Alvis Leonides engines (1947, 30 ordered, none built)

M.72 Aerovan
four-engined modification of Aerovan 4, similar to M.68, with four 100 hp Blackburn Cirrus Minor III engines (1948, one converted, but never completed or flown)

HDM.105
experimental Aerovan 4 conversion (G-AJOF, c/n 6403) with Hurel-Dubois wing (1957, one conversion)

HDM.106 Caravan
larger all-metal development, two 290 hp Lycoming GO-/GSO-480/B or 320 hp Astazou; mockup used HDM.105 parts (none built but inspired the Short Skyvan)

HDM.107 Aerojeep
planned HDM.106 version designed to meet requirements for US Army light STOL aircraft (none built)

HDM.108
projected bigger development of the Caravan, two 750 hp Turbomeca Bastan turboprops, 25 passengers (none built)


Attached below are images of the M.72 and M.106 projects.

 

[Stargazer]

The Miles M.68 "Boxcar" in pictures (note that there is also a PDF article from Flight attached at the bottom).

 

[Stargazer]

The Miles M.71 Merchantman in pictures:

 

[Stargazer]

A five-page article from Flight about The Miles M.71 Merchantman (PDF files):

 

[Stargazer]

The Aerovan prototype fitted with a mockup Armstrong Siddeley Mamba nacelle:

 

[Stargazer]

Not strictly variants of the Aerovan but considered as part of the family (because they shared the same general configuration) were the M.61 and M.62 freighter projects:

M.61
single-engined, rear-loading light transport/freighter project (1945, none built)

(mentioned here, too:
http://www.secretprojects.co.uk/forum/index.php/topic,3304.0/highlight,miles+m+61.html)

M.62
all-metal twin-engined, front-/rear-loading freighter project based on M.61, sort of a large Aerovan with two 1,600 hp Wright R-2600 engines (1945, none built)


Attached are pictures and plans of these two projects, along with an article from Flight (third attachment).

 

[cluttonfred]

Thanks very much, Stephane, you've been busy!

You're right, of course, to include more of the HD designs, though by later iterations little of the original Aerovan remained. I had excluded the Merchantman as a substantially larger aircraft, not really a variant of the Aerovan, and the M.61 and M.62 as similar in spirit but not in detail.

Still no sign of the AOP and flying boat versions, though.... I don't think I've ever seen a sketch of the projected HDM-107 Aerojeep either. It would be great fun to find a three-view and get one of the more artistic members of the group to do a rendering in U.S. Army colors. I'll fish around in my files at home tonight and see what I can come up with.

Cheers,

Matthew

 

[robunos]

Still no sign of the AOP and flying boat versions, though...

From 'Postwar Propliners: Miles Aerovan', 'Aeroplane Monthly', April 1995, page 68 :-

"Unbuilt Aerovan projects included a flying boat with a deep hull, retractable stabilising
floats and a loading door above the waterline, and an Air Observation Post with a
lowered fuselage and tail unit, a glazed canopy extending aft to mid-chord, and a glazed
base to the rear fuselage."

The image below shows a painting by Keith Woodcock, of the proposed flying boat version,
from page 64 of the same magazine.


cheers,
Robin.

 

[Stargazer]

Wonderful painting! The Aerovan looks even better as a flying boat I think. Thanks for sharing.

 

[cluttonfred]

From 'Postwar Propliners: Miles Aerovan', 'Aeroplane Monthly', April 1995, page 68...the image below shows a painting by Keith Woodcock, of the proposed flying boat version, from page 64 of the same magazine.

Thanks, Robin, that's a great image and exactly what I was looking for. Does the article give the impression that the painting is of the actual design or just an artist's impression based on the description? Either way, the retractable floats are neat touch. I'd love to get a scan of that article for my files if you have a moment. Cheers, Matthew

 

[robunos]

Does the article give the impression that the painting is of the actual design or just an artist's impression based on the description?

Sorry, there is no information either way. :'(

I have to say, first, that those floats don't look big enough, or to be mounted far enough outboard, to prevent the aircraft from
rolling over when on the water, and second, I would think that there would be a serious problem with spray affecting the engines
and propellers, during take-of and alighting.

I'd love to get a scan of that article for my files if you have a moment.

Send me you email and it's done.......



cheers,
Robin.

 

[Stargazer]

I'd love to get a scan of that article for my files if you have a moment.

Send me you email and it's done.......

Wouldn't mind being on the receiving end myself! ;-)

 

[cluttonfred]

I have to say, first, that those floats don't look big enough, or to be mounted far enough outboard, to prevent the aircraft from rolling over when on the water, and second, I would think that there would be a serious problem with spray affecting the engines and propellers, during take-of and alighting.

I agree completely about the float size, though they might be far enough aft for the spray not to be an issue. I would have thought sponsons would make more sense with a high wing amphibian, though. PM sent with e-mail, thanks.

 

[robunos]

Mole, article sent, Star, let me have have your email...


cheers,
Robin.

 

[robunos]

I would have thought sponsons would make more sense with a high wing amphibian, though.

Agreed, there would also be room for wheels to make a true amphibian, and/or fuel for more range...


cheers,
Robin.

 

[Avimimus]

Hello,

I was wondering if someone could explain the Miles airfoil flap to me?

A number of Miles designs appear to have flaps which are fixed below and behind the wing (similar to the Junkers style), with a gap/slot permanently exposed. However, some footage of the Miles Aerovan seems to show this flap retracted to be flush with the wing.

Is this correct or are my eyes deceiving me? How did these flaps work?

 

[cluttonfred]

Early Miles designs generally had split flaps. A few late WWII designs with STOL roles, notably the M.38 Messenger and the M.57 Aerovan, had permanent external slotted flaps. As far as I know, none of the pre-war or WWII designs had retractable external airfoil flaps, so it may just be that the external flaps are not obvious in photos from certain angles.

 

[Avimimus]

Thank you sir!

 

[cluttonfred]

You're welcome! One caveat, as it was nagging at me that I thought that they had tried retractable, external airfoil flaps on something. Per Wikipedia:

In 1944 the prototype [M.38] was rebuilt as the M.48 Messenger 3 with fully retractable electrically-operated split trailing-edge flaps and a 155 h.p. Cirrus Major III engine. This model was not further developed as it did not provide any advantage over the other variants.