February, 1935 AIRCRAFT ENGINEERIN G 43 One of the Competition Types For Use in the Frenc h Military Air Service URING the past few years, French air are balanced statically. They are rigidly craft constructors have produced several controlled, with th e return tubes passing behind new twin-engined monoplanes designated th e rear spar. as multiplace de combat in accordance with a The wings are braced on either side by a programme set forth by the Air Ministry. The pai r of sloping streamlined tubular struts, new machines—of which the three principal extending from the mid-sections of the wing types are the Potez, Amiot and Dyle et t o the stub wings. The rear strut is counter- Bacalan—have been undergoing tests for braced to the rear wing spar by a short tubular acceptance at the Villacoublay Field, near strut . The forward bracing strut is adjustable Paris, of which full details have not yet been b y a thread cut on one end. The bracing struts divulged. The multiplace de combat machine are cross-braced by streamlined wires. The has been designed for three principal purposes— stu b wings are built up round two spars, long-range reconnaissance, short and long-range the forward of which, the principal, is in the bombing, and combat. This means that this form of a box, the rear spar being a simple type of military machine must be well equipped tubula r member. A diagonal bracing member in both offensively and defensively, it must have duralumin tube is placed between them. The high speed, long range and be able to carry stub wings are braced by a pair of sloping a heavy load of bombs, or complete equipment strut s extending from the top of the fuselage, for reconnaissance work, according to the wire-braced together. mission on which it is being used. The fuselage has a length of 15 metres Of these, the Potez 54, a semi-cantilever (49 ft. 3 in.) and a maximum width of 1·40 braced high-wing monoplane of mixed con metres (4 ft. 7 in.). It consists of two sections, struction, is fitted with two Hispano-Suiza joined together in front of the wing, the forward 12 Xbrs 500-h.p. engines. of which is 4·20 metres (13 ft. 9 in.) and the The Machine's Performance PRINCIPA L CHARACTERISTICS: For reconnaissance work this machine is Span .. .. .. .. .. 22·10meters (72½ ft.) equipped with complete radio sending and Length .. .. .. .. .. 16·20 meters (53 ft.1 in) Heigth .. .. .. .. receiving equipment, photographic apparatus .. 3·88 meters (12 ft. 8½ in.) Area .. .. .. .. .. 76 sq. m. (820 sq.ft.) and defensive armament, and has a range Tare weigth .. .. .. 3,727 kg. (8,215 lb.) General equipment .. .. .. .. 27 kg.(60 lb.) of 1,300 kilometres (800 miles) at a speed Fuel for 1,000 km . . 950 kg. (2,094 lb.) of 250 k.p.h. (155 m.p.h.). As a bombing Disposal load .. .. .. .. .. 865 kg. (1,907 lb.) joined by six transverse frames. Each of Gross weight (for reconnaissance duties) 5,569 kg. (12,276 lb.) machine, it can carry a ton of bombs and th e two side panels has two spruce spars cross- Wing loading .. .. . 73 kg./sq. m. (15 lb./sq. ft.) has a range of 1,200 kilometres (746 miles). Power loading .. .. .. braced by diagonal members in wood. It is Maximum speed at 4,000 metres .. 18 kg./h.p. (40 lb./ sq. ft.) For combat service, it is completely armed, covered in plywood. The forward section is Cruising speed .. .. .. .. 270 k.p.h. (168 m.p.h.) both offensively and defensively, and carries 310k.p.h. (192 m.p.h.) Climb to 4,000 meters .. .. partially constructed in U-section duralumin .. .. 10 min. 30 sec. Range at 4,000 metres with 1,500 litres of fuel radio equipment. Its endurance in this members, with high-tensile steel for the more 1,250 kilometres (777 miles) capacity is from four to five hours. heavily stressed parts, the rest being of wooden construction. The Potez 54 has a semi-thick wing externally rea r 10·80 metres (35 ft. 6 in.) long. In the braced on either side to short stub planes forward section are the position of the com The construction of the tail surfaces is which carry the engine mountings. The span manding officer, the bomb release gear, photo analogous to that of the wing. The rudder is 22·10 metres (72½ ft.), and the maximum and elevator flaps are balanced, and the graphic apparatus and the forward gunner's thickness 0·55 metres (1 ft. 10 in.), decreasing stabilizer, adjustable in flight, is braced from position. The rear section includes the pilot's towards the wing tips. The wing is built in position, those of the rear gunner, and the tail. below on cither side t o the botto m of the fuselage four sections, viz., the central portion, or wing A passageway on the starboard side gives b y inverted V struts. proper, the leading edge, the ailerons and the access to all positions. The fuselage is well wing tips. The structure is entirely in metal Power Plant lighted, much of the forward section being with fabric covering. fitted with glazed panels, which also give As alread y mentioned, the Potez 54 multiplace The central portion of the wing is built excellent visibility. The forward gunner is de combat is fitted with two geared and super up round two spars, placed 1·60 metres enclosed in a cupola turret in the nose, and charged Hispano-Suiza 12 Xbrs water-cooled (5 ft. 2 in.) apart. The spars have an I section, th e pilot's position is in an enclosed cabin engines of 500/690 h.p. These are carried on in front of the trailing edge of the wing. The and are built up with duralumin webs and th e stub wings on either side of the fuselage, rear gunner, in addition to the usual position drawn high-tensile steel flanges. There are th e mountings being attached to the forward nine principal ribs with full section, and on the top of the fuselage, has also an under- box spar. The engines drive Ratier three- l\venty-onc secondary ribs, all of which are in slung retractable turret for defence against bladed metal airscrews and are fitted with duralumin. Projection lights are inset in the attac k from below. underslung radiators. Fuel is carried in wing leading edge of the wing. The leading edge tanks , the total capacity of which is 1,500 litres The structure of the fuselage is mainly in is in two sections and has a covering of (330 gallons), or enough for 1,250 kilometres wood, metal being used in the forward section duralumin sheet. The inset ailerons have a (770 miles) a t 4,000 metres (13,000 ft.) altitude, and round the pilot's position. It is rectangular span of 4·80 metres (15 ft. 8 in.) each, and when the machine is being used for recon in section and consists of two side panels naissance work. The undercarriage has a track of 4·80 metres (15 ft. 9 in.), and consists of two independent units which can be retracted into the engine nacelles behind the engines. Each unit con sists of a fork, attached to the front spar of th e stub wing, fitted with an oleo-pneumatic shock-absorber. The fork is braced towards the rea r by a tubula r frame. In the normal position on the ground the undercarriage is automatically locked, raising and lowering of the wheels being effected by a hydraulic piston acting on each wheel. A valve controls three positions, the rising of the wheels, the stop position and the lowering. A castoring tail wheel supports the tail.
Aircraft Engineering and Aerospace Technology – Emerald Publishing
Published: Feb 1, 1935