{"product_id":"hurel-dubois-hd31-hd32-hd321-technical-documentation-collection","title":"Hurel-Dubois HD.31 \/ HD.32 \/ HD.321 Aircraft — Primary-Source Technical Documentation Collection","description":"\u003ch3\u003eHurel-Dubois HD.31 \/ HD.32 \/ HD.321 — Primary-Source Technical Documentation Collection\u003c\/h3\u003e\n\u003cp\u003eMaurice Hurel's ultra-high-aspect-ratio transport prototypes represent one of the most audacious aerodynamic experiments of the mid-twentieth century. This collection assembles the surviving primary-source documentation for the HD.31, HD.32, and HD.321 airframes — including official French STAé evaluation reports, manufacturer performance brochures, and the complete engine technical libraries for both powerplant families that defined the programme's evolution.\u003c\/p\u003e\n\u003cp\u003eThe HD.32 flew with the Pratt \u0026amp; Whitney R-1830-92 Twin Wasp. The HD.321 stepped up to the Wright Cyclone 982-C9-HE1. Both engine families are covered here in full depth — Parts Catalogs, Service Instruction Handbooks, and Overhaul Manuals — giving restorers, researchers, and serious collectors the complete technical picture in a single acquisition.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003eDocument Manifest\u003c\/h3\u003e\n\u003ch4\u003eHurel-Dubois Airframe Documents (5 documents)\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eHD.32 Performance Brochure\u003c\/strong\u003e — Manufacturer performance data sheet, aerodynamic coefficients, payload-range curves\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHD.321 Manuel\u003c\/strong\u003e — Ref. HD.321.01 — French-language technical manual covering the upgraded single-fin configuration\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHD.32 ALPA Evaluation Report, 1955\u003c\/strong\u003e — Air Line Pilots Association independent flight evaluation; handling, stability, and crew workload assessment\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHD.32 Brochure\u003c\/strong\u003e — Commercial presentation brochure; route economics, passenger capacity, and airline suitability data\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHD.32 Description Brochure\u003c\/strong\u003e — Structural and systems description; wing geometry, strut configuration, empennage layout\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003ePratt \u0026amp; Whitney R-1830 Twin Wasp Engine Documents (3 documents)\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eParts Catalog — Models R-1830-43, -65, -90C, -90D, -92, -92A\u003c\/strong\u003e — (NAVY) AN 02A-10CD-4 \/ (USAF) T.O. 2R-R1830-4 — 1 January 1960, revised 1 October 1958 supersession. Joint USAF\/Navy publication under authority of the Secretary of the Air Force and Chief of the Bureau of Aeronautics\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHandbook Service Instructions — Models R-1830-90C, -90D, -92, -92A\u003c\/strong\u003e — NAVWEPS 02A-10CD-2 — 1 December 1961. Published by direction of the Chief of the Bureau of Naval Weapons. Supersedes NAVAER 02A-10CD-2 dated 1 June 1945 and all subsequent revisions\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHandbook Overhaul Instructions — Navy Models R-1830-90C, -90D, -92, -92A \/ USAF Models R-1830-90C, -90D, -92\u003c\/strong\u003e — (NAVY) NAVWEPS 02A-10CD-3 \/ (USAF) T.O. 2R-R1830-3 — 15 July 1960, revised 1 October 1965. Pratt \u0026amp; Whitney Aircraft, Division of United Aircraft Corporation, Contract NOw 64-0113-k\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eWright Aeronautical Cyclone 9 GC Engine Documents (3 documents)\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstruction Book — Wright Cyclone 9 Aircraft Engine, Series C9-GC\u003c\/strong\u003e — Installation, Operation, and Service Maintenance — Second Edition, September 1942. Wright Aeronautical Corporation (Division of Curtiss-Wright Corporation), Paterson, New Jersey. Provenance: original owner's copy, dated November 1942 in period hand\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOverhaul Manual — Wright Aircraft Engines Cyclone 9 GC\u003c\/strong\u003e — Third Edition, Part No. 114323-N3, October 1943. Wright Aeronautical Corporation, Paterson, New Jersey, U.S.A.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOperation and Service Manual — Wright Cyclone 9, Series C9GA · C9GB · C9GC\u003c\/strong\u003e — Wright Aeronautical Corporation, U.S.A. Original blue softcover field edition\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003eAerodynamic Engineering Notes — The High-Aspect-Ratio Wing\u003c\/h3\u003e\n\u003cp\u003eMaurice Hurel's central thesis was that an aspect ratio exceeding 20:1 would radically reduce induced drag at cruise altitudes, yielding payload-range economics unattainable by conventional wing geometries of the era. The HD.32 and HD.321 validated this in flight:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eInduced Drag Reduction:\u003c\/strong\u003e Aspect ratio of 20.2:1 produced measurably lower induced drag across the cruise envelope\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLifting Struts:\u003c\/strong\u003e Airfoil-section bracing struts contributed positive lift rather than parasitic drag\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInterference Drag:\u003c\/strong\u003e Wind tunnel data confirmed minimal aerodynamic interference at strut-to-wing junctions\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStall Speed:\u003c\/strong\u003e Ultra-long wing chord reduced stall speed to approximately 120 km\/h — exceptional for an 18,700 kg transport\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eEngine Variants by Airframe\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eAircraft\u003c\/th\u003e\n\u003cth\u003eEngine\u003c\/th\u003e\n\u003cth\u003ePower (per engine)\u003c\/th\u003e\n\u003cth\u003eContext\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eHD.31\u003c\/td\u003e\n\u003ctd\u003e2 × Wright Cyclone C7BA1\u003c\/td\u003e\n\u003ctd\u003e800 hp\u003c\/td\u003e\n\u003ctd\u003eInitial proof-of-concept prototype\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHD.32\u003c\/td\u003e\n\u003ctd\u003e2 × Pratt \u0026amp; Whitney R-1830-92 Twin Wasp\u003c\/td\u003e\n\u003ctd\u003e1,200 hp\u003c\/td\u003e\n\u003ctd\u003eUpgraded version; Air France evaluation\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHD.321\u003c\/td\u003e\n\u003ctd\u003e2 × Wright Cyclone 982-C9-HE1\u003c\/td\u003e\n\u003ctd\u003e1,525 hp\u003c\/td\u003e\n\u003ctd\u003eHigh-power variant; single-fin conversion\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eHD.321 Performance Data\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaximum Gross Weight:\u003c\/strong\u003e 18,700 kg (41,226 lb)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEmpty Equipped Weight:\u003c\/strong\u003e 11,112 kg (24,498 lb)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWing Area:\u003c\/strong\u003e 100.0 m² (1,076 sq ft)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAspect Ratio:\u003c\/strong\u003e 20.2:1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCruising Speed:\u003c\/strong\u003e 275 km\/h (171 mph)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaximum Range:\u003c\/strong\u003e 2,200 km (1,400 mi)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRate of Climb:\u003c\/strong\u003e 4.8 m\/s (940 ft\/min)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eHandling \u0026amp; Stability\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eRoll Performance:\u003c\/strong\u003e Narrow-chord ailerons on the 45.3 m wingspan produced a surprisingly high roll rate\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEmpennage Evolution:\u003c\/strong\u003e Initial twin-tail configuration caused stability tracking issues under high power; engineers retrofitted a prominent single fin with auxiliary finlets to counter asymmetric engine-out torque\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLegacy:\u003c\/strong\u003e Air France provisionally ordered 24 units before cancelling in favour of the Caravelle. The design lineage continued in the HD.34 cartographic survey aircraft. Hurel's lifting-strut principles are studied today in contemporary green-aviation research including the Boeing SUGAR Volt concept\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003cp\u003e⚠️ \u003cstrong\u003eRegulatory Notice:\u003c\/strong\u003e Under FAA 14 CFR § 43.13 and EASA Part-M, any mechanic performing maintenance on an active aircraft must use current, manufacturer-approved revision-controlled data. This archival document does not satisfy that requirement.\u003c\/p\u003e\n\u003cp\u003eThis is an archival, static-copy edition fixed at its original publication date. Intended for historical reference, flight simulation, museum restoration, and educational use only. Not approved for active airworthiness maintenance under FAA 14 CFR § 43.13, EASA Part-M, or equivalent international regulations. Operators of active aircraft must use current, revision-controlled publications from the Type Certificate holder or an authorized distributor.\u003cbr\u003e\u003cstrong\u003eLiving Collections with Free Lifetime Updates — Please review our Disclaimer and Export Notice before purchasing.\u003c\/strong\u003e\u003c\/p\u003e","brand":"Online Aviation Library","offers":[{"title":"Default Title","offer_id":53701226365275,"sku":null,"price":59.85,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0955\/4788\/3867\/files\/hurel-dubois-high-aspect-ratio-wing-banner.png?v=1785603989","url":"https:\/\/onlineaviationlibrary.com\/products\/hurel-dubois-hd31-hd32-hd321-technical-documentation-collection","provider":"Online Aviation Library","version":"1.0","type":"link"}