British RFC Supermarine Nighthawk

The British RFC Supermarine Nighthawk, an anti-Zeppelin night fighter, used a trainable nose-mounted searchlight, a 1½-pounder (37 mm) Davis gun mounted above the top wing with 20 shells, and two .303 in (7.7 mm) Lewis guns. Power for the searchlight was provided by an independent gasoline engine-driven generator set made by ABC Motors, possibly the first instance of a recognizable airborne auxiliary power unit hybrid.

A searchlight was mounted in the Nighthawk’s nose to help the gunners aim at night (as its name implies, the Nighthawk was designed as a night-fighter), and the aircraft reputedly carried 1016 kg (2240 lb) of fuel for its two 100-hp Anzani engines – enough for it to remain in the air for up to 18 hours while loitering at speeds as slow as 35 mph (56 kph).

Noel Pemberton Billing set up a company, Pemberton-Billing Ltd, in 1913 to produce seagoing aircraft. Its telegraphic address, used for sending telegrams and cables to the company, was; Supermarine, Southampton. It produced a couple of prototypes using quadruplane designs to shoot down zeppelins; the Supermarine P.B.29 and the Supermarine Nighthawk. The aircraft were fitted with the recoilless Davis gun and the Nighthawk had a separate powerplant to power a searchlight. Upon election as an MP in 1916 Pemberton-Billing sold the company to his factory manager and longtime associate Hubert Scott-Paine who renamed the company Supermarine Aviation Works Ltd. The company became famous for its successes in the Schneider Trophy for seaplanes, especially the three wins in a row of 1927, 1929 and 1931.

The P. B. 29E “Battle Plane”

A large quadruplane with a biplane tailplane and three rudders, the P. B. 29E was powered by a pair of 90 h. p. Austro-Daimler engines driving four-bladed pusher propellers. The rear fuselage was of triangular cross-section and had a two-wheel undercarriage with two small nosewheels on outriggers. Above the fuselage, between the third and top wing, was an enclosed position for a gunner armed with a Lewis machine-gun. There were two cockpits, one forward of the wing leading edge, the other just abaft the trailing edge and fitted with intercom and dual control.

After completion the P. B. 29E was delivered to the RNAS station at Chingford in Essex by lorry and was tested by Flt Lt Sidney Pickles on January 1, 1916. A test report was prepared by Flight Commander G. H. Dyott at Messrs Hewlett & Blondeau’s Works, Leagrave, Bedfordshire, and sent to Wg Cdr Lambe at RNAS Dover. The report, which is published here for the first time, ran as follows:

“Following your instructions I proceeded to Chingford on Saturday, January 15 [1916], and examined the new PB quadruplane. Fortunately it was being tried out on the grounds, so I had an opportunity to watch the initial trials.

“The general outline offends one’s sense of mechanical proportion in that the weights are not concentrated near the centre but distributed vertically as well as longitudinally, the former being a most undesirable characteristic. The centre of thrust of the propellers does not lay along the centre of head resistance; this would cause difficulties in the longitudinal balance, which, coupled with this heavy weight in the top plane, might prove a very serious factor in rough weather or extreme positions such as diving at a sharp angle.

“Much larger elevators should be necessary. This was confirmed by Pickles when he made his short hop. Also larger surface for the planes will probably be essential if much fore-and-aft stability is required. A large-area monoplane tail would be better than a small biplane tail of the same area. The ailerons and rudder controls appear quite satisfactory.

“The actual details of construction are very rough indeed, but that is not a serious fault which would affect the machine as an experiment. Structurally I think it is weak in some directions, such, for instance, as the fore-and-aft bracing of the wings to the fuselage. The fuselage is of triangular section which does not give much rigidity and the weights are too far back to give good balance with the passenger in his seat.

“The wing section is rather flat underneath and follows the usual Royal Aircraft Factory outline. With a full load on board, I don’t think the speed is over 60 m. p. h. [97km/h], so when all is said and done, even if it could fly for 10hr on end, it would never cover a great distance. However speed is not everything and the machine should not be condemned on that score. I think results will show that the very large speed variation will not be realised in practice.

“The Third Sea Lord [Rear Admiral Frederick Tudor] was an interested spectator and afterwards enquired of Pickles how the machine handled in the air. `Beautifully, the best machine I ever flew’ was the reply. `Change the elevators and she will be absolutely IT’. Statements such as these are apt to be misleading and do a lot of harm unless received by people like the DAS, who has the happy faculty of listening to opinions and drawing his own conclusions.

“The results of this very brief test were received with the greatest satisfaction and on the strength of it I understand much larger work is to be put in hand. Flight Commander FitchNoyes told me that, as a result, the new `Super Battle Plane’ would be started at once. On enquiries as to what it was like, he told me it had five or six planes, three or four fuselages and weighed about 20 tons [20,320kg]. It would seem rather odd to jump to such sizes when no moderately large machine had yet proved itself to be of any value.

“Personally I was not so enthusiastic as the other observers, for I did not consider such a test capable of demonstrating anything at all, except showing very pronounced errors in the design. If difficulties arise, it will be found in the longitudinal balance when the top tank is full and the top passenger seat occupied.

“On looking at the general construction and outline, I would say that Mr Pemberton Billing had very little to do with it, and my impression is that certain people at the Admiralty were anxious to try out such a type of multiplane and did not want to shoulder the responsibility for another failure as in the case of the [Blackburn] Sparrow, their idea being to get some constructor to work in conjunction with them, and who would get the blame if it was not a success.”

“I should not herald it as a great success . . .” The report continues: “In conclusion, I must say that it is an interesting effort in spite of its bad proportions and no doubt some good information will result from it. Having made a short hop, I should not herald it as a great success and we must wait to see its performance in the air before saying very much further.

“In general, multiplanes have great advantages as regards speed and weight-lifting so the more authentic information we can get in this direction the better. I would like to see the top plane removed altogether and the tank and passenger seat accommodated in a larger and better proportioned fuselage. In this way, the pilot and rear passenger could remain where they are and the additional observer placed in front of the planes. In its present state I think it is too small to permit the observer crawling up in to the top plane seat without affecting the equilibrium of the machine.”

It is believed that it was also test flown by Flight Commander John Seddon. It was never flown operationally, as it was written off in an accident at Chingford later in 1916 and returned to Woolston. Despite Dyott’s rather critical report, it was considered worthy of development and the Supermarine Aviation Works Ltd (as the company was now called) was given an order to build two more heavily-armed machines, to be known as the P. B. 31E. It would appear that the fuselage of the P. B. 29E was scrapped, but that its wings and tailplane (or parts thereof) were incorporated in the first of the new machines, for which the Admiralty issued contract CP 130778/16 on November 24, 1916.

The Nighthawk

It would seem that a development of the P. B. 29E, the “Super Battle Plane”, had been schemed even before it had flown, as Capt K. E. Kennedy RFC, in a lengthy report on the testing of the Davis non-recoil gun dated December 31, 1915, refers to the “P. B. 31” as prospectively being fitted with several Davis guns.

The P. B. 31E was completed in November 1916 and delivered to Design Flight, Eastchurch, in the first week of December; it was test flown by Clifford B. Prodger in February 1917. The Nighthawk When it finally emerged, the new quadruplane, now known as the Supermarine Nighthawk, was a much more substantial aeroplane with a pugnacious look. The wings were a similar version of those used on the P. B. 29E and the tailplane structure was virtually the same but with two rudders. The fuselage was of square cross-section. The gunner’s enclosure was larger and located on top of the fuselage; it had provision for one or more two-pounder Davis guns at the front and Lewis gun(s) on a Scarff mounting at the back.

The extended nose of the fuselage had a Scarff mounting for a Lewis gun. In front of this was a trainable nose-mounted searchlight powered by an independent 5 h. p. ABC engine-driven generator. The first pilot sat in a fully glazed enclosure just forward of the leading edge of the wings and the second pilot sat behind him. The twin 100 h. p. Anzani engines were fitted to the second wing and drove four-bladed propellers.

Although touted as being able to reach 60 mph (121 km/h), the P. B. 31E prototype only managed 60 mph (97 km/h) at 6,500 ft (1,981 m) and took an hour to climb to 10,000 ft (3,048 m), which was totally inadequate for intercepting Zeppelins.

By the time the Nighthawk was delivered it was realised that small single- or two-seat fighters armed with incendiary ammunition could successfully destroy Zeppelins (and later, Gotha bombers) when aided by searchlights and supported by anti-aircraft artillery. Pemberton Billing’s ambitious plans were shelved.

The P. B. 31E, untried in war, was scrapped on March 3, 1917, never having had the opportunity to test Pemberton Billing’s theories of defence against night bombers, which he would revisit two decades later in the early days of the next major European conflict. Pemberton-Billing promised that he would fly over the East End to drop a vote of thanks to the people when they elected him. The East-Enders saved him the trouble by choosing someone else for their Member of Parliament.