SPAD S.XV

The SPAD S.XV was a single-seat fighter designed and built in France and offered to fulfil a 1918 C1 specification (C1 - Chasseur single-seat).

Design and development
The 1918 C1 specification called for a medium altitude fighter with 220 kg payload and a 6500 m service ceiling, maximum speed of 240 km/h and absolute ceiling of 9000 m. The specification called for the use of several different engine types, one of which was the 160 hp Gnome Monosoupape 9Nc rotary engine. Five aircraft were allocated the Gnome in response to the specification: Morane-Saulnier MoS 27, Morane-Saulnier MoS 29, Courtois-Suffit Lescop CSL-1, Nieuport 28 and SPAD S.XV.

André Herbemont, at SPAD, designed a single-bay biplane with un-staggered, equal span wooden wings and a moulded plywood monocoque fuselage. The closely cowled Gnome engine was mounted in the nose, driving a 2-bladed propeller. Two 0.303 in Vickers machine-guns were mounted in the forward upper decking, firing through the propeller disc, using synchronising gear.

First flown on 31 July 1917, the relatively low power of the Gnome engine limited any performance advantage over the SPAD S.XIII, so production was not authorised. The moulded plywood monocoque fuselage concept, however, was used extensively by Herbemont in subsequent designs due to its light weight and high strength.

Operational history
None of the S.XVs were accepted by the Aviation militaire.

Variants

 * S.XV/1:First S.XV, armed with 2x Vickers machine-guns; one built.
 * S.XV/2:Second S.XV, reportedly completed with a slightly longer span wings and a re-designed tail; one built.
 * S.XV/3:Third S.XV, completed with reduced chord and wing area wings and a lengthened fuselage; one built.
 * S.XV/4:Intended to be powered by a 170 hp Le Rhône 9R, but not completed.
 * S.XV/5:A post-war sporting aircraft, powered by an 80 hp Le Rhône 9C in a large cowling, one built for René Fonck and another for Charles Nungesser; two built.