Flight, February 1926
THE CAPRONI "CA 70" BIPLANE
A New Italian Ground Strafing Machine
WE give below some brief particulars, together with illustrations, of one of the recent military machines produced by the famous Italian aircraft constructing firm Societa
Italiana Caproni, of Milan.
The Caproni "Ca 70" possesses several noteworthy features, visibly apparent as well as otherwise. As regards the former, as will be seen from the accompanying illustrations, the outstanding features most noticeable consist of the fuselage and the arrangement of the wings. The other features are centred around certain constructional details - and here, unfortunately, we have little information at our disposal - and the fact that this particular model is fitted with a 400 h.p. Bristol "Jupiter" engine. It will be remembered that we published in FLIGHT for September 17, 1925 a description of another Caproni machine fitted with Bristol "Jupiters" - the Caproni 80 night bomber.
In some ways the Caproni "70" is a smaller version of the "80," except that it is a single-engined machine and that its top plane is much larger than the bottom one - exactly opposite to the arrangement adopted in the "80." The "70" is intended for co-operation with the infantry at low altitudes - ground strafing - or it can also be employed as a night fighter. For either purpose, it possesses great advantages, mainly on account of the excellent field of vision its general lay-out provides.
Like in the Caproni "80," it will be observed that the "fuselage" is designed on the lines of a flying-boat hull, and is similarly disposed. The "70" is, however, strictly a land machine, and is fitted with a somewhat unusual type of landing gear. Details of the latter are lacking, but as far as we can gather each wheel (there are two) is carried by a stout "semi-axle" hinged to the side of the "hull" and raked slightly forward; then from the wheel hub a shock-absorbing device extends up to the lower plane, at the point of attachment of the front interplane strut. There is also a radius strut extending rearwards from the wheel hub up to the rear spar of the wing.
The "hull" is of good streamline shape, of comparatively narrow and not very deep rectangular cross section. The pilot's cockpit is located just forward of the wings, and immediately beneath the engine. Half-way along the "hull," and well clear of the wings, is the observer's or gunner's cockpit, which is provided with two machine guns - one mounted on a gun ring on the cockpit mouth, and the other mounted in the floor of the cockpit, firing downwards and rearwards. Two other machine guns are carried, one firing forward through the nose of the "hull" and the fourth firing downwards and forward.
This machine being intended for ground attack, it is armoured with Poldi steel - but whether this is confined to the body only we cannot say.
As previously stated the top plane is considerably larger than the lower one, as regards span, but equal in chord. Both are without dihedral angle. The top plane is supported by two pairs of N struts attached to the lower plane a short distance from the body. These struts, together with another pair extending up from the body, also serve to carry the engine. From the lower attachments of the N struts a pair of interplane struts extend outwards up to the top plane, and except for the incidence bracing on these latter truts there is no other external wire bracing.
Balanced ailerons are fitted to the top plane only, while the horizontal tail surface and elevators are mounted midway up the vertical tin and therefore well above the stern of the "hull."
The Bristol "Jupiter" engine is mounted in a neat streamlined nacelle attached to, and flush with, the underside of the top plane centre section. It is located in front of the plane and drives a tractor screw.
The main characteristics of the Caproni "Ca.70" are :-
Span (top) 14 m. (45 ft. 11 ins.)
Span (bottom) 8.m. (26 ft. 3 ins.).
Chord 2-50 m. (8 ft. 2 ins.).
Area of main planes 55 sq. m. (593 sq. ft.).
Weight empty 1,310 kgs. (2,888 lbs.).
Useful load 820 kgs. (1,808 lbs.).
Weight laden 2,130 kgs. (4,696 lbs.).
Wing loading 38-7 kgs./m2 (7-9 lbs./sq. ft.).
Power loading 53 kgs./h.p. (11-7 lbs./h.p.).
Speed range 90-200 k.p.h. (56-124 m.p.h.).
Safety factor 10.