The P.B.23 was designed in 1915 as a single-seat biplane scout, with a fuselage nacelle strut-mounted between the wings.
The nacelle had an open cockpit for the pilot at the front and at the rear an 80 hp (60 kW) Le Rhône 9C engine driving a pusher propeller.
Twin fins and rudders were mounted on a wide-span tailplane with an elevator attached, all connected to the wing structure with four tailbooms.
The P.B.25 had swept-back wings, a modified landing gear and a revised fuselage nacelle and although originally powered by a 110 hp (82 kW) Clerget rotary engine, the 20 RNAS aircraft were fitted with Gnome Monosoupape 9 Type B-2 rotary piston engines.
Data from The British Fighter since 1912[1]General characteristics Performance Armament