P.Hare Royal Aircraft Factory (Putnam)
Bearing in mind that the F.E.9 was designed about September 1916, as a replacement for the F.E.2 series, it is rather surprising that it was yet another pusher. By that time the availability of gun synchronisation systems had rendered the pusher concept obsolescent, although every possible effort was made to reduce the layout's inherent disadvantages to a minimum.
The F.E.9 was designed around the 200hp geared-drive Hispano-Suiza, and its nacelle was positioned well above the mid-gap position, to afford the observer a reasonable rearward field of fire over the upper wing without the need to resort to the acrobatics required in the F.E.2. Two Lewis guns were provided, each on a pillar mounting, one firing forwards and one to the rear. It was planned that the machine should carry a third gun for the pilot's use, mounted on the starboard side of the nacelle, but no evidence has been found that this weapon was installed. The neat undercarriage had short but effective oleos attached to the lower centre-section, and the tailskid arrangement echoed that of the S.E.5 and R.E.8.
Dual controls were provided, those in the observer's cockpit comprising two control columns, one operating the elevators and the other controlling the rudder, as it was felt that a conventional rudder bar would obstruct the observer's freedom of movement as he performed his normal duties. Since these controls were intended only for use in an emergency, it was not considered necessary to provide any aileron controls, turns being made on rudder alone.
Steel-tube N-struts secured the nacelle to the single-bay wings, which were of unequal span, the upper-wing extensions being supported by bracing wires and inverted triangular kingposts, as was common Factory practice. Ailerons were fitted to the upper wing only, and had large horn balances, being similar to those originally fitted to the B.E.12a. As in the F.E.8, the tailbooms met at the tailplane spar. The fin was almost semi-circular, and the rudder was unbalanced.
With what, unfortunately, turned out to be misplaced confidence, a batch of twenty-four aircraft was put into production 'off the drawing board', using the Factory's own facilities.
The first of these, A4818, was completed by the beginning of April 1917, and test flying was undertaken by Roderic Hill, who found the rate of climb disappointing and the handling unpleasant, particularly during left-hand turns, a characteristic he attributed to the ailerons being over-balanced and the rudder being of insufficient power.
On 6 June Hill flew the aircraft to the Aircraft Depot at St Omer for service trials, apparently without any modification to its control surfaces. Lt Clark of 13 Squadron, an experienced observer who was taken up in it, reported that, from the observer's point of view, the field of fire was very good and that it was easy to fly with its odd controls. Pilots were less enthusiastic, and on 9 June Maj-Gen Trenchard reported that, although the view was excellent, the machine itself was already a year out of date and of no use to the RFC. He recommended that experiments with the F.E.9 should be stopped, and suggested that putting the 200hp Hispano-Suiza into it was a waste of a really good engine. At this stage it appears that the nacelles had been completed for all twenty-four machines, and at least two more airframes were well advanced and were eventually completed.
The Factory's design staff appear to have regarded the type's poor handling as a challenge to be overcome at all cost (perhaps the correct attitude to take in an aeronautical research centre), and when A4818 returned to Farnborough it underwent a lengthy series of modifications to its control surfaces. A new, high-aspect-ratio rudder of reduced area, incorporating a small horn balance, was fitted, and then the fabric was removed from the fin. Later a large balanced rudder of lower aspect ratio was substituted, without a fin. At the same time the aileron balance areas were progressively reduced.
By mid-October A4818 had been joined by the second machine, A4819, which had the high-aspect-ratio rudder and redesigned wings with two-bay interplane bracing, the outer pairs of struts being raked outwards to support the upper wing extensions and thus eliminating the need for kingposts. The ailerons had smaller horn balances than those of A4818. The second machine eventually saw service with No 78 (Home Defence) Squadron, and was written off in a landing accident at Biggin Hill the following winter.
The third and final example, A4820, which was completed ready for inspection on 1 November, also had two-bay wings. By this time a third type of aileron, with the balance area still further reduced, had been fitted to A4818 and, since this type was considered to give a marked improvement in handling, it is probable that it was also fitted to A4820.
The fates of the first and third F.E.9s are unknown, but A4820 is last recorded as undergoing engine tests in January 1918, and A4818 continued to serve as a research vehicle for investigations into aircraft control at least until March of that year. Thereafter the F.E.9 faded into oblivion, the information obtained from its protracted development and testing being used in the design of its successors, most notably the N.E.1.
Powerplant: 200hp Hispano-Suiza V-8
span 40ft 1in (upper);
37ft 9 1/2in (modified ailerons);
29ft 5 1/4in (lower);
wing area 365 sq ft;
length 28ft 3in;
height 9ft 9in.
Weight: 2,480lb (loaded).
max speed 105mph at sea level;
climb 5min to 3,000ft.
H.King Armament of British Aircraft (Putnam)
F.E.9. Provision of a wide field of fire was evidently the governing consideration in the designing of the F.E.9 in the summer of 1916, for not only was this two-seater of pusher layout, but the nacelle was positioned only slightly below the top wing. Following earlier F.E. practice, Lewis guns were provided for frontal and rearward fire. The guns, one in the nose of the nacelle and one behind the gunner's cockpit, were on pillar mountings.
W.Green, G.Swanborough The Complete Book of Fighters
ROYAL AIRCRAFT FACTORY F.E.9 UK
Conceived as a replacement for the F.E.2b in the fighter-reconnaissance role, the F.E.9 was of similar pusher configuration and therefore already obsolescent by the time it appeared in 1917. Emphasis was placed in the design upon providing the gunner with a good field of fire and the pilot a good all-round view. To this end, the nacelle was located close beneath the upper wing and was carried on struts above the shorter-span lower wing. The large overhang of the upper wing brought the F.E.9 almost into the sesquiplane category, and called for bracing wires from triangular kingposts above the interplane struts of the single-bay cellule. A cruciform tail unit was carried on four slender booms, as on the F.E.2, and the Vee-strutted undercarriage incorporated oleo legs. Construction was largely of wood, but pairs of steel tube N-struts linked the nacelle to the upper and lower wings. Power was provided by a 200 hp Hispano-Suiza eight-cylinder V-type water-cooled engine and the planned armament comprised two 0.303-in (7,7-mm) Lewis guns on pillar mounts, ahead of and behind the front cockpit, and both fired by the observer - the latter rearwards over the pilot’s head and the top wing. Installation of a third gun, on the side of the fuselage for use by the pilot, was planned. Authority was given by the War Office for construction of three prototypes and a production batch of 24 in October 1916, and testing began in April 1917. Handling and performance of the prototypes were disappointing, however, and production was cancelled, to allow the Hispano engines to be used in more worthwhile types. Testing of the prototypes continued, in the course of which two-bay wings were tried on the second aircraft, which was also flown for a time by No 78 Home Defence Squadron, RFC.
Max speed, 105 mph (169 km/h) at 10,000 ft (3 050 m), 88 mph (142 km/h) at 15,000 ft (4 570 m).
Time to 10,000 ft (3050 m), 21.35 min.
Service ceiling, 15,500 ft (4 725 m).
Loaded weight, 2,480 lb (1125 kg).
Span, 40 ft 1 in (12,22 m).
Length, 28 ft 3 in (8,61m).
Height, 9 ft 9 in (2,97 m).
Wing area, 365 sqft (33,91 m2).