FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1922
1922 - 0158.PDF
MARCH 16, 1922 THE HUFF-DALAND BIPLANE HUFF, Daland and Co., of Ogdensburg, N.Y., have recently- produced two interesting machines incorporating thick-section wings and several novel constructional features. These two machines are known as the H.D.QA two-seater Army training biplane, and the H.D.8A " Petrel " three-seater commercial biplane. The former was brought out to meet the United States army requirements of" a Type 14 air-cooled-engine training 'plane, and was fitted with a 100 h.p. Anzani engine, whilst the latter is a further development of this machine incorporating the Curtiss O.X.5 water-cooled engine. It was produced to meet the demand for a strong, moderate- powered three-seater of simple construction, capable of being operated and maintained at the lowest possible figure. Except for the changes necessitated by the change of engine and a slightly more streamlined fuselage in the H.D. 8 A, •— . _ •HI j-jjgjgL^i „._„ ffliffnff •"a^'J-jE EjSL. r*M4(gi|0* 1 InB^^B^B^^SHSI^H iffitoii The Huff-Daland H.D.9A Biplane : Three-quarter front view of the 100 h.p. Anzani model. both of these machines follow the same general type of con struction, and the following description more or less applies to both. It is in the fuselage that the most interesting feature of the H.D. machines is to be found. A somewhat unusual, but at the same time exceedingly simple, method of construction has been employed on all the H.D. models—a form of con struction differing from the orthodox braced girder type, as may be seen on referring to the accompanying illustrations. It will be seen that the upper and lower longerons in this case form a triangulated truss between the main planes and the tail, the apex being at the latter—very much after the fashion of the outrigger tail booms of the " box-kite " biplane. Each upper member, or longeron, runs from the rear spar of the top plane, where it is connected with the corresponding lower member by two struts, meeting the latter at the location of the lower plane rear spar and the foremost extremity—• at engine partition—respectively. Other vertical struts connect the upper and lower members at the end of the cockpit, at the tail (leading edge) and midway between these points. Auxiliary longerons extend rearwards from the top of the transverse engine bulkhead and form the pilot's and passengers' cockpit. Aft of the latter the auxiliary longerons are decked over by means of stringers, whilst a curved bottom is similarly formed on the lower members. By this form of construction tail loads and wing loads are carried by direct paths through these rigid members in place of the usual struts and wires. It also greatly reduces the number and weight of parts, whilst the time taken in assembly is likewise reduced. The only wire cross- bracing is between the lower longerons, and these wires are threaded on the ends and carried through holes in the longerons at the strut junctions to a small steel plate and nipple. The use of a large number of turnbuckles is thus obviated. Veneer is used for covering the fuselage from the engine plate to a point aft of the cockpit, and access to the latter is by means of side doors which in no way weakens the fuselage structure. The rest of the fuselage is fabric-covered. The mounting of the 10-cylinder Anzani engine follows that employed on the earlier training model turned out by this firm—the H.D.4. It consists of a circular nose-piece to which the engine is bolted, supported by a system of tubular trussing connected to the forward bulkhead at the longeron junctions. Four large pins connect the unions of these tubes at their attachment to the fuselage, making the removal of the engine unit an easy matter, and allowing the engine to be swung backward for inspection by with drawing two pins on one side or the other. In the case of the Curtiss O.X. 5, in the H.D.8A, the mount ing is as follows :—The fuselage terminates with a solid bulk head and fire-shield, upon which six large pin fittings are mounted. The tubular engine mounting itself, made up in two halves, right and left, is bolted to these fittings without the need of any cross wires or external bracing for support. It may be detached with the engine as a unit in case of quick changes on the aerodrome, while in the shop the engine can be slipped into place along the bearers without having to disturb SP«< %f) . . 29'- O" " (bifTomV 2:' - 6" CHORD (top) S ' - 6" (bottom) 4*- o" LENGTH Z< - O" WiridflRLrt 2 27 £<)p-, HUFFDALAhD HD-SA" PETREL" 90tf> CURTiSS OX-5 THE HUFF-DALAND H.D.8A BIPLANE : General arrangement drawings. 158
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
