The Hurel-Dubois and Miles collaboration: Skyvan ancestors

[joncarrfarrelly]

The Shorts Skyvan has Hurel-Dubois roots.

in the mid-50s Miles worked with the French Hurel-Dubois company to create a new small transport using the H-D concept of high-aspect ratio wings for low cruising speed aircraft, the reduced drag of the wing design being beneficial.
The first project was the H.D.M 105 which was an H-D designed wing fitted to a standard Miles Aerovan fuselage:

The aircraft was lost during flight-testing but the results were considered good enough to proceed with a follow-on design, so after the formation of the H.D et M(Aviation) Ltd. joint company the H.D.M. 106 Caravan was designed.

The aircraft was never put into production either by Miles or Hurel-Dubois, but the design was sold to Shorts and was ultimately developed into the SC.7 Skyvan...the wing aspect ratio was reduced from 20.3 to 11.

Cheers, Jon

 

[Jemiba]

The cooperation between Hurel-Dubois and Miles led to several
other projects, one of them was the Miles M.103, a 3-ton freighter
with the wing of the HD.31 (from R.Payne "Stuck On The Drawing Board") .

 

[Stargazer]

The Hurel-Dubois/Miles HDM.105 in pictures:

 

[Stargazer]

An article from Flight about the HDM.105:

 

[Stargazer]

More information about the HDM.106 Caravan:

Miles HDM 106 light transport

The Miles HDM 106 was the product of collaboration between the Miles brothers of Shoreham and Commandant Hurel of La Societe des Avions Hurel Dubois, of Villacoublay in France. The project, which belongs to the early 1950s, sought to combine the utilitarian qualities of the Aerovan aircraft of the 1940s and the very high aspect ratio wing designed by Hurel to produce a versatile and economical short-range transport. A general arrangement drawing of the aeroplane is shown in Fig. B.4. The wing had an aspect ratio of 20, and the long struts were designed in such a way as to contribute to the overall lift/drag by a combination of camber and twist where they met the wing surface. The layout of the aircraft demonstrates the important properties of Eqns (4-8) and (4-8a), for the power loading was around 12—14 lb/hp, while the wing loading was 28.5 lb/ft² (higher than a light and executive aircraft in Table 12-3). The benefit on the side of the power loading (and, therefore, thrust loading) came from the high aspect ratio.

Proof of concept

The HDM 106 was never developed beyond the project stage, but there were schemes for later variants. First was a military version, the HDM 107 Aerojeep, to fit a US Army specification for a STOL light-support aircraft, powered by two 800 shp Lycoming turboprops. Second was the HDM 108, planned as an enlarged HDM 106. Neither progressed beyond the drawing board. The original design of the HDM 106 was sold to Shorts of Belfast, where it was developed as the Short Skyvan. This was a box-like high-winged twin turboprop, with a parallel chord wing, an aspect ratio around 11.0 instead of 20.0, and rear-loading. The Skyvan differed markedly in detail if not in configuration from the HDM 106, which was designed for a gross weight of 9,500 lb (4,318 kg). The Skyvan fuselage was slab-sided, with sharp corners for maximum internal volume, causing it to be nick-named 'The Shed’. It was noisy for normal passenger operations, but was a successful STOL aeroplane which, with its rear-loading ramp, stood up to considerable rough handling in and out of unprepared airstrips. Although shorter in span than the HDM 106, it grew to a useful operational gross weight of 12,500 lb (2,730 kg), the limit for single-pilot operation in the public transport category.

The lineage extended from the ubiquitous Skyvan, of which around 150 were built, to the larger Short SD 330 and 360. Both are heavier and more refined regional transport aeroplanes with twin turboprops and relatively high aspect ratio, strut-braced, parallel-chord wings. The shaping of the wing—strut junctions makes an important contribution to the lift/drag ratio of their configuration, which is utilitarian proof of the efficacy of the original Miles-Hurel Dubois concept.

The family of aircraft which grew from the seed of the HDM 106. The Short Skyvan (a) was a utilitarian transport with rear-loading. From the Skyvan was developed the SD3-30 (b) a feeder-liner and utility transport, also with rear-loading. The SD 360 (c) is a short-range commuter/regional and feeder airliner, with a longer but more streamlined fuselage which permits a lighter, single fin and rudder to be used.

Source: http://www.scribd.com/doc/22121054/The-Anatomy-of-the-Airplane

 

[Stargazer]

The HDM series of projects (info from the Putnam book: Miles Aircraft since 1925).

Following the successful trials of the H.D.M.105, a company called H.D. et M (Aviation) Ltd, was formed jointly by F. G. Miles Ltd and the Société de Construction des Avions Hurel-Dubois to exploit derivates of the H.D.M.105.

The H.D.M.106 was an all-metal civil transport using almost the same wing as the 105 but with a considerably larger fuselage, the freight space being 15 ft by 6 ft 3 in by 6 ft. It was to be powered either by two 290 hp Lycoming GO-480 engines, or by two 340 hp Lycoming GSO-480B engines, or by two 320 hp Turbomeca Astazou engines. In the event, the H.D.M.106 Caravan was never put into production either by Miles or Hurel-Dubois, but the design was sold to Shorts and was ultimately developed into the Short S.C.7 Skyvan, in which the aspect ratio was reduced from 20·3 to 11 with corresponding increase in induced drag.

The H.D.M.107, known as the Aerojeep, was a military version of the 106 designed to the requirements of the US Army for a STOL light support aircraft. It was to be powered by two 800 shp Lycoming T-35 propeller-turbines.

The H.D.M.108 was an enlarged 106 designed by Hurel-Dubois.

 

[Stargazer]

The Shorts PD.36 was a light freighter project based on Hurel-Dubois-Miles HDM.105. It was produced as the SC.7/SD.3 Skyvan series.

 

[taildragger]

More information about the HDM.106 Caravan:

Miles HDM 106 light transport


The family of aircraft which grew from the seed of the HDM 106. The Short Skyvan (a) was a utilitarian transport with rear-loading. From the Skyvan was developed the SD3-30 (b) a feeder-liner and utility transport, also with rear-loading. The SD 360 (c) is a short-range commuter/regional and feeder airliner, with a longer but more streamlined fuselage which permits a lighter, single fin and rudder to be used.

Source: http://www.scribd.com/doc/22121054/The-Anatomy-of-the-Airplane

The tail of the SD 360 may have had structural advantages over it's predecessors, but it was at least partially driven by a desire to prettify the airplane. I recall reading at the time that the vertical tail shape was drafted by an industrial designer rather than the aircraft's designers.

 

[toura]

HI ALL

From an old " le fana de l aviation"
and an old flight

 

[hesham]

From Ailes 7/9/1957,

here is a drawings to HDM.105,HDM.106 & HDM.107.