Top speed 202 km/h Manufacturer Villiers aircraft | Length 10 m | |
The Villiers IV or Villiers 4bis was a French two seat naval floatplane. Only one was built and was later modified into the Villiers XI by replacing the Type IV's twin floats with a single, central one.
Contents
Design
As a shipboard aircraft the Villier IV was required to have, in addition to the normal equipment of a two-seat military machine, folding wings and tow and hoist points. It also had to be well provided with navigation, radio and visual signalling equipment.
It was a single bay sesquiplane. Like most Villiers aircraft, the wingplans were strictly rectangular in plan apart from a shallow cut-out over the forward cockpit; the upper wings had three times the area of the lower. They were built around spruce box spars, fabric covered and braced together by an outward and forward leaning interplane strut on each side. The lower wings were attached to the lower fuselage longerons and braced to the upper longerons with single struts leaning inwards at about 45°. The upper wing was held over the fuselage by a fore and aft pair of W-form struts, one to each of its two spars. Wing folding was achieved with hinges on the rear longerons, immediately outside of the centre section to fuselage struts. There were full span ailerons, fitted only on the upper wing. A pair of upper wing hoisting points enabled the Villier IV to be lifted back on board its ship by a crane.
The fuselage of the Type IV was built around six spruce longerons with stringers, formers and poplar plywood skinning but no internal cross-bracing producing a semi-monocoque structure. Its engine was a 450 hp (340 kW) Lorraine-Dietrich water-cooled W-12 with a Lamblin radiator mounted transversely under it. Aft, the pilot's cockpit was largely under the wing despite the trailing edge cut-out to improve the field of fire from the gunner's cockpit behind him. The gunner had a pair of Lewis guns on a flexible mount and the pilot controlled a fixed pair of synchronised Vickers machine guns firing through the propeller arc. At the rear both fin and tailplane were triangular; the later, placed at the top of the fuselage could be adjusted on the ground. The rudder was curved, broad and reached down to the keel. The elevators were balanced, curved edged and had a cut-out for rudder movement.
The Type IV had a pair of floats, about 7.8 m (25 ft 7 in) and 3.1 m (10 ft 2 in) apart, single stepped, round topped in cross-section and with hard chine but almost flat bottoms. These were mounted on an axle just forward of the wing leading edge, supported at its centre by a V-strut from the lower fuselage longerons and at its extremities by struts at about 45° to the same points. Under the trailing edge a W-form strut linked the longerons and floats, allowing passage for bombs released from the central fuselage underside. Vertical legs transmitted landing forces to the lower wing just inboard of the folding line. The floats were made of spruce and ply covered; on the planing bottoms the ply was 8 mm (0.31 in) thick.
Development
The date of the Type IV's first flight is not known but it was active early in 1926. Before the spring of 1927 it was modified into the Villiers Type XI by replacing the twin floats with a single, 7.5 m (24 ft 7 in), 1.5 m (4 ft 11 in) wide, single-stepped central float more simply mounted on vertical struts to the lower fuselage. Two small stabilizing unstepped floats were attached with longitudinal pairs of outward leaning inverted V-struts from the lower wing below the interplane struts. Apart from the new float and a minor weight increase, the Type XI was very similar to the Type IV.
Operational history
Early in 1926 the Villiers 4bis, flown by Louis Demougeot, set world and national seaplane records. The world record was for speed over 100 km (62 mi) with a 500 kg (1,100 lb) load, set at 203.275 km/h (126.309 mph) on 13 May, which was still standing a year later. The French record was set on 27 April, when he took the Villiers to 4,881 metres (16,014 ft) carrying the same load.
Little is known about the history of the Type XI though it was used or trialled on board a ship.
Variants
Specifications (Type IV)
Data from L'Aérophile March 1927
General characteristics
Performance
Armament