O.Thetford British Naval Aircraft since 1912 (Putnam)
Twenty P.B.25 single-seat scouts entered service with the RNAS at Eastchurch and Hendon during 1916. They had the serial numbers 9001 to 9020 and 9002 is illustrated. The P.B.25 was developed from the P.B.23 'Push-Proj' of 1915 and was armed with a single Lewis gun firing forward. One 100 hp Gnome or 110 hp Clerget engine. Maximum speed, 99 mph. Endurance, 3 hr. Span, 33 ft. Length, 24 ft 1 in.
H.King Armament of British Aircraft (Putnam)
P.B.23E and P.B.25. The P.B.23E pusher 'scout' of 1915 carried a fixed Lewis gun in the nose of the nacelle and was almost certainly the first British aircraft to be armed with a fixed gun. The gun on the P.B.23E was set low in the nacelle; in the succeeding P.B.25 it was raised to the top.
P.Lewis The British Fighter since 1912 (Putnam)
Among the assortment of pusher scouts hopefully produced by various concerns, there appeared in 1915 a single-seater from the drawing-board of Noel Pemberton Billing. A single-bay biplane, powered by the 80 h.p. le Rhone, the P.B.23E was a sprightly-looking machine, with the pilot seated in a finely-formed, metal-covered nacelle suspended between the wings at midgap and containing the single Lewis gun in its nose.
The P.B.23E, soon known from its appearance as the Sparklet or Push-Proj, made its first flight at Hendon early in September, 1915, following which the Admiralty placed an order for twenty of a modified version as the Pemberton Billing Scout.
The revised model, designated P.B.25 by the designer, used wings of swept-back form in place of the straight-edged original style, and the former metal-covered nacelle was replaced by a new one enclosed in fabric. Increased power was provided by the installation of the 100 h.p. Monosoupape Gnome engine and the Lewis gun was raised to a far more accessible position in the top of the fore-decking of the nacelle. The first of the P.B.25s, 9001, received a slight increase in power over the remainder of the batch by having a 110 h.p. Clerget fitted.
Despite its competent performance, which included a top speed of 89 m.p.h. with the Monosoupape Gnome, and its advanced conception, the P.B.25 is not known to have been engaged in any operational role.
F.Mason The British Fighter since 1912 (Putnam)
Pemberton-Billing P.B.23 and P.B.25
In the seven months following the first flight of the P.B.9 in August 1914, Noel Pemberton Billing undertook the design of a further dozen aircraft, none of whose manufacture has been confirmed, although one of these may have been the P.B. Boxkite (said to have been allocated the number 1374, and powered by a 50hp Gnome rotary engine). His P.B.23, a single-engine pusher biplane scout, was almost certainly inspired by Geoffrey de Havilland’s Airco D.H.2, which predated it by more than two months.
However, whereas the D.H.2’s nacelle was mounted directly on the lower wing, the P.B.23 featured a well-streamlined, metal-clad nacelle strut-mounted in the wing gap, with two pairs of plain struts being attached to the upper longerons and the upper wing, and pairs of plain struts to the lower longerons and the lower wing spars. Twin fins and rudders were located inboard on the wide-span tailplane, the entire empennage being carried on four booms which extended aft from the rear spars of the upper and lower mainplanes. The P.B.23 featured parallel-chord unswept wings, the lower wings having pronounced dihedral, but the upper wing being flat. A single, fixed forward Lewis machine gun was located low down in the nacelle’s extreme nose and could, with difficulty, be re-armed from the cockpit.
The 80hp Le Rhone, fitted initially, was obviously underpowered when the P.B.23 first flew in September 1915, and it was proposed to fit a 100hp Gnome monosoupape. The aircraft failed to impress the War Office, but the Admiralty ordered twenty examples of a modified version (allocated the serial numbers 9001-9020). In fact this version, which emerged as the P.B.25, only superficially resembled the earlier aircraft. The nacelle was lengthened and constructed entirely of wood with fabrics covering. Both wings were swept back eleven degrees, and the lower wing’s dihedral much reduced; the lower fuselage/wing mountings now comprised a pair of N-struts. The vertical tail surfaces were increased in area.
The first ‘production’ P.B.25, 9001 (officially termed the Scout) was fitted with an uncowled 110hp Clerget rotary engine driving a two-blade propeller, but 9002 was powered by the 100hp Gnome driving a four-blade propeller, and with the latter the aircraft returned a performance about ten per cent better than that of the D.H.2. Be that as it may, the Airco aircraft had already been selected for production and its continued delivery to the RFC squadrons in France was a matter of considerable urgency, so that the P.B.25 does not appear to have reached any operational unit. Moreover, the Scout quickly gained a bad reputation for being particularly difficult to handle during take-off and landing. Examples are known to have flown with the RNAS at Hendon and Eastchurch, but reliable confirmation that all twenty aircraft ordered were completed cannot be gained.
The accompanying data refers to the Pemberton-Billing P.B.25.
Type: Single-engine, single-seat, single-bay pusher biplane scout.
Manufacturer: Pemberton-Billing Ltd., Woolston, Southampton.
Powerplant: One 100hp Gnome monosoupape nine-cylinder rotary engine; one 110hp Clerget nine-cylinder rotary engine.
Structure: All-wooden construction, fabric-covered.
Dimensions: Span, 33ft 0in; length, 42ft lin; height, 10ft 5in; wing area, 277 sq ft.
Weights: Tare, 1,080lb; all-up, 1,576lb.
Performance: Max speed, 99mph at sea level; climb to 6,000ft, 8 min 30 sec; range, approx 200 miles.
Armament: One 0.303in Lewis machine gun on nose of nacelle immediately forward of cockpit.
Production: Twenty aircraft ordered (9001-9020), but completion of all aircraft has been questioned.
W.Green, G.Swanborough The Complete Book of Fighters
PEMBERTON-BILLING P.B.23E UK
Designed in 1915 by Noel Pemberton-Billing, and built by the company bearing his name, the P.B.23E single-seat pusher fighting scout biplane was of wooden construction, but the nacelle mounted between the wings and accommodating the pilot was unusual for its time in being covered with light alloy sheet metal. Armament consisted of a single 0.303-in (7,7-mm) machine gun mounted in the nose of the nacelle and power was provided by an 80 hp Le Rhone rotary. The P.B.23E was first flown in September 1915, but was not adopted in its original form, being further developed as the P.B.25. No data relating to the P.B.23 appear to have survived.
PEMBERTON-BILLING P.B.25 SCOUT UK
Known officially as the Scout, the P.B.25 was a development of the P.B.23. The most obvious differences were in the design of the nacelle, which was fabric covered, and in the wing cellule, the mainplanes featuring 11 deg of sweepback and inversely-tapered ailerons. Twenty P.B.25s were ordered by the Admiralty, all but one of these being powered by the 100 hp Gnome Monosoupape, the exception having a 110 hp Clerget rotary. Armament comprised a single 0.303-in (7,7-mm) machine gun mounted on the nacelle. The last P.B.25 was delivered to the RNAS in February 1917, by which time this type had acquired an unenviable reputation, the take-off and landing characteristics being particularly hazardous. Apart from poor flying qualities, its performance was inadequate and, being viewed as something of an anachronism, the Scout was quickly discarded.
Max speed, 89 mph (143 km/h) at sea level.
Time to 6,000 ft (1 830 m), 11 min.
Endurance, 2.5 hrs.
Empty weight, 1,080 lb (490 kg).
Loaded weight, 1,541 lb (699 kg).
Span, 32 ft 11 1/2 in (10,04 m).
Length, 24 ft 1 in (7,34 m).
Height, 10 ft 5 in (3,17 m).
Wing area, 277 sq ft (25,73 m2).
Jane's All The World Aircraft 1919
SUPERMARINE PUSHER SCOUT, 1916.
(Commonly called the "Push-Prodge")
Re-designed from original, and fitted with 100 h.p. monosoupape engine; 3 1/2 hours' fuel capacity; Lewis gun and ammunition.
Speed 98 m.p.h.
6,000 ft. 8 1/2 mins.,
15,300 40 1/2 mins.