A.Jackson Blackburn Aircraft since 1909 (Putnam)

Blackburn Type E

   During 1911 the efforts of Robert Blackburn and other British pioneers produced a number of sturdy aeroplanes with good flying characteristics which challenged the supremacy of French machines to the point where the placing of military contracts for British-built aircraft could not long be delayed. As expected, the War Office issued its first military aircraft specification in November that year and called for a reconnaissance two-seater able to carry a useful load of 350 lb over and above essential equipment and to have an initial rate of climb of 200 ft min, 4 1/2 hr endurance, 55 mph maximum speed and able to maintain 4,500 ft for 1 hr. It also had to be transportable in a crate from one operational area to another. Competing firms were given just nine months in which to design, build and test before the commencement of competitive trials on Salisbury Plain in August 1912.
   To meet these requirements Robert Blackburn designed a two-seat 'military' aeroplane in metal which retained most of the principal features of his successful Mercury series. The mainplane was built up from two 18 swg tubular-steel spars, respectively 2 in and 1/2 in in diameter, with ribs of 1/4 in cottonwood fretted out for lightness and edged with 1 in by 1/4 in ash. A number of light ash strips ran transversely and the leading and trailing edges were reinforced with the same material. The tubular spars were filled at the root ends and securely bolted to steel plates through which passed the stout kingpost carrying the wing warping and bracing wires.
   For durability and to expedite repairs, the triangular fuselage had 32 detachable and interchangeable vertical struts and 58 cross-members, all of oval-section steel tubing, joined by specially riveted clips and covered with sheet aluminium. The tail unit was formed from fabric stretched over a steel-tube framework and ending in an ash trailing edge to which were hinged steel rods carrying the elevator and twin triangular rudders. Control wires ran inside the fuselage, and the much simplified, twin-skid, four-wheeled undercarriage was of oval steel tubing and incorporated built-in anchorages for the flying wires.
   The new monoplane was built in the Balm Road works alongside a singleseater (also with steel-tube fuselage) ordered by Lt W. Lawrence for use in India where he had seen Army service the year before. Both monoplanes consequently earned a place in aviation history as the first aircraft of British design and construction to have metal fuselages. Powered by a 60 hp Green four-cylinder inline water-cooled engine and closely resembling the Blackburn Type B, Lawrence's single-seater was taken to Filey for test in April 1912 and took off in 30 yards with fuel for four hours at approximately the same all-up weight as a standard wooden Mercury. Painted grey overall and bearing the inscription Indian Aviation Co Ltd on the lower rudder, the name L'Oiseau Gris on the engine cowling and with No. 1 painted on the radiator grill, it went to Brooklands for further trials in the following month. Although entered by the owner in the round-London Aerial Derby of 8 June 1912, the aircraft was scratched as 'not ready in time'. As this occurred some two months after the first flights at Filey, teething troubles are suggested which may have been the result of using an engine which required a heavy water cooling system and the reason for the end of Lawrence's interest in it.
   Trouble of this sort was avoided in the military two-seater which appeared later in June 1912 fitted with a vee-8 air-cooled 70 hp Renault. It differed from the first in having a curved top decking, which extended as far aft as the forward tip of the dorsal fin, to accommodate the crew in tandem cockpits with the pilot and his triple control unit in the rear. Extra fuel, increasing the endurance to five hours, was carried in a cigar-shaped tank between the undercarriage struts and, following the precedent set by the Blackburn Type B trainer, the little triangular rudders bore the designation Type E.
   An early intention was for the Eastchurch pilots, Lt Spenser Grey, RN, and Capt R. Gordon, RMLI, to pilot these machines in the British Military Aeroplane Trials, but when the two-seater was taken to Knavesmire, York, for flight testing by Robert's brother Norman Blackburn and R. W. Kenworthy it proved too heavy to leave the ground and in fact never did so. It was taken back to the Balm Road works, and when the entry lists for the Trials were published in July 1912 Blackburn was not represented. The ultimate fate of the 'all-steel' monoplanes is uncertain but later on, in the winter of 1912, the two-seater appeared briefly on the playing fields of Cockburn High School off Dewsbury Road, Leeds, with Spenser Grey and Gordon in attendance.
   A further development of the type was evidently contemplated since the company records refer to an undesignated two-seat military aircraft of 1912-13 with a specification which docs not correspond to that of the Type E.

SPECIFICATION AND DATA
   Manufacturers: The Blackburn Aeroplane Co, Balm Road, Leeds, Yorks.
   Power Plants:
   (Single-seater) One 60 hp Green
   (Type E Two-seater; One 70 hp Renault
   Dimensions:
   (Type E)
   Span 38 ft 4 in Length 31 ft 2 in
   Wing area 290 sq ft
   (Project)
   Span 40 ft 0 in Length 32 ft 0 in
   Wing area 276 sq ft
   Weights: (Type E) All-up weight 950 lb
   Performance: (Type E) Maximum speed 80 mph (Project) 65 mph
   Endurance: (Single-seater) 4 hr (Type E) 5 hr (Project) 5 hr
   Production: Two dissimilar aircraft only:
   1. Single-seater No. 1 L'Oiseau Gris, 60 hp Green, first flown at Filey April 1912, to Brooklands May 1912.
   2. Two-seater military Type E, 70 hp Renault, completed June 1912, never flew.