P.Lewis British Bomber since 1914 (Putnam)

Contemporary with the Airco D.H.3 and D.H.3A was the twin-engine tractor Dyott Bomber, developed by G. M. Dyott from his pre-war project for a large biplane evolved for exploring in South Africa. Construction of each of the Dyott designs actually built - his monoplane of 1913 and the Bomber - was carried out by Hewlett and Blondeau. 3687, the initial prototype to the order of the Admiralty, was completed in 1916 with two 120 h.p. Beardmore engines installed as tractors between the equal-span wings. The crew numbered three, the gunners manning Lewis machine-guns disposed in the nose and in a cockpit in the top decking to the rear of the wings. Independent single-wheel undercarriage units were mounted between pairs of skids and struts beneath each engine, and the lengthy tailskid was balanced by a large nosewheel under the front cockpit. Second thoughts about the design brought cowlings to cover the hitherto bare engines, together with frontal radiators and a fore-deck of increased depth. Much heavier armament was fitted in the form of four Lewis guns disposed around the nose cockpit and a fifth carried in the cockpit amidships.
   3687 arrived at Hendon on 17th August, 1916, and 3688 - the second prototype - underwent R.N.A.S. trials at Dunkirk. The Dyott Bomber’s promising appearance, however, was not to result in a production order.

J.Bruce British Aeroplanes 1914-1918 (Putnam)

Dyott Bomber

  G.M. DYOTT was one of the pioneers of aviation in Britain: his Royal Aero Club pilot’s certificate was No. 114 and was granted on August 17th, 1911. Some eighteen months later he designed a neat little monoplane, powered by a 50 h.p. Gnome engine, on which he did a good deal of flying at home and in America.
  Just before the war he designed a large twin-engined biplane which was intended to be used for exploration work in South Africa. It appears that the Admiralty saw possibilities in the type as a bomber, and construction of a modified version of the design was undertaken in 1915 by Hewlett & Blondeau, Ltd., who had built the little Dyott monoplane two years earlier.
  The machine was never adopted for Service use, although it was flown at Chingford in 1916. It seems probable that the Dyott would be underpowered with no more than 340 h.p. provided by two Beardmore engines, especially as flown with all its defensive armament mounted. The retention of the jackets on the Lewis guns seems to indicate a low speed.
  The aircraft was a large biplane with wings of equal span. Upper and lower centre-sections spanned the distance between the engines; the outboard sections of the wings had four bays of bracing. The fuselage accommodated three crew members, and had a nosewheel directly under the front cockpit. Construction appeared to be conventional throughout, and the Dyott was quite a handsome aeroplane.
  The Dyott underwent several detail modifications during its existence. When it first appeared, its engines were uncowled and the radiators were installed as multiple elements above the engines. The long front cockpit was encircled by an elevated rail which connected six separate spigot-mountings for Lewis guns; abaft this cockpit the top-decking was flat and sloped upwards to the pilot’s cockpit.
  At a later stage frontal radiators were fitted, and the engines were cowled quite cleanly; exhaust manifolds were also fitted. The top-decking on the fuselage nose was deepened considerably and apparently came up to the level of the rail surrounding the nose cockpit. The top-decking continued straight back to the pilot’s cockpit.
  In this form the Dyott appeared with the heavy defensive armament detailed in the armament notes below. The nose armament of four Lewis guns was obviously unwieldy and could not have been used effectively in combat. The Dyott was sent to France for Service trials with the R.N.A.S. but did not prove to be sufficiently successful to merit adoption as a standard type.


SPECIFICATION
  Manufacturers: Hewlett & Blondeau, Ltd., Oak Road, Leagrave, Luton.
  Power: Two 120 h.p. Beardmore.
  Armament: Five free Lewis machine-guns. Four were in the nose: two of these were on spigot-mountings above the fuselage and could probably be moved from one mounting to another; each of the other two fired through a porthole on either side of the nose. The fifth gun was on a mounting in the cockpit aft of the wings.
  Serial Numbers: 3687-3688.

H.King Armament of British Aircraft (Putnam)

Dyott

   Dyott Bomber Sometimes styled 'Dyott Twin Bomber' and sometimes 'Fighter' this adventurous aeroplane was originally intended for exploration. Undeniably advanced though it was in design, its two engines delivered no more than 240 hp, and it is difficult to imagine any useful war load additional to the astonishing array of small arms undoubtedly fitted, but possibly never fitted. The Lewis guns had land-service cooling jackets and 47-round ammunition drums. Two were on spigot mountings above the fuselage and another two were stationed at portholes in the fuselage sides. A fifth was mounted aft of the wings. These five guns alone, without ammunition or fittings, would have weighed all of 130 lb.
   There were at least two versions of this aircraft. In the first a conspicuous feature was the gun-rail carried above the top decking of the fuselage and incorporating six spigot mountings, the two upper guns being interchangeable between these mountings. In the second version the decking was built up and the mounting(s) - for the gun installation may have differed from the original were no longer visible.

M.Goodall, A.Tagg British Aircraft before the Great War (Schiffer)

C.Owers British Aircraft of WWI. Vol.7: Experimental Fighters Part 3 (A Centennial Perspective on Great War Airplanes 81)

The Dyott AT "Battleplane"

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  It is reported that before the war Dyott had designed a larger twin-engine aircraft that he proposed to use to explore Africa. After the outbreak of war, he joined the RNAS as a Flight Lieutenant. Whether the Admiralty heard of his design and asked him to continue with it, or whether he pressed his claims himself, is not known. From his autobiography it appears that he pressed his ideas on a number of occasions. Once he had gained permission to build the machine, he was very vocal in its defence.
  In his autobiography he states that after his arrival back in the UK after his experiences with the Germans attack in Belgium and France and the squadron’s continual retreat, he was convinced that every day it became more apparent that the equipment such as we had was not suitable for the demands made upon it. One point in particular struck me very forcibly, and that was the general interest in the scout class entirely eclipsed that of the large battle plane. Many of the older pilots in the squadron were of precisely the same opinion, and when I was in London on a special mission, I again submitted my ideas of a two-engined outfit. At the beginning of the war, when I did this, the reply was that they wanted standard machines and could not afford to experiment. This time it was the reverse, they had made so many experiments they could not undertake anything new, so once more the idea was shelved. For my part I was firmly convinced that the large machine was not receiving our best efforts that I continued developing my ideas without a hitch. Each days work brought new suggestions, and all my evenings and spare time were spent getting out sketches showing details of construction. With money received from the Admiralty for my monoplane, I paid a draftsman in London to work up all my sketches into tangible form, and the few days’ leave which came my way, were spent in pushing the work ahead with all possible speed. Some day we would be obliged to have large machines, therefore I wanted to be ready when that much delayed time arrived.
  Under this Dyott had written in pencil the following notes that appear to be for a following chapter that, if written, is not in the surviving papers.

  Dover Patrol
  Vice Admiral Bacon - on patrol ships his interest and pressure.
  Meeting at Admiralty to consider his statements.
  How many machines. 1 Sir.
  The whole story of building & flying my battle plane. Obstacles of Randall & Brass(?). The Handley Page trick - first disaster my plan from Dunkirk, burned. #1 Retained in England & was used in experiments.

  The following history has been pieced together from the few surviving documents that have surfaced in the British National Archives.
  Dyott enlisted the support of Wing Cdr Lambe and the Admiralty was persuaded to order two prototypes in 1915, the official contract, No. C.P. 106417/16, being issued later. The manufacturer was to be Hewlett & Blondeau of Luton, whom Dyott was familiar with from their work on his monoplane.
  That the Dyott biplane was intended as a fighter is confirmed by the Admiralty Air Department Section Reports where the firm of Hewlett & Blondeau were asked to tender for two Dyott fighters 2 - 120-hp Beardmore Aeroplanes.
  In the terminology of the time the Dyott biplane was a battleplane. The concept of the single engine fighter was still some time off and it was thought that a large machine with a large crew and armament would be able to take the offensive in the air. Another example would be the German A.E.G. K.I. This twin engined biplane developed into a successful G series of day and night bombers. Battleplanes with their load lifting capabilities were prime contenders for conversion to bombers. In the case of the Dyott biplane, there never seems to have been any attempt to adopt it for carrying bombs.
  It has been suggested that the first machine was constructed by private funding, then purchased by the Admiralty and a second one ordered. As the first was finished except for engine fittings by 3 April 1916, it would appear that construction was well in hand by the time the Admiralty asked for tenders. Y Section received the tenders for two Dyott Fighter Aeroplanes in the Week Ending (W/E) 31 March, and recommended that they be accepted, and acceptance was reported for the W/E 5 May 1916, for 2-Dyott fighting biplanes. Contract No. C.P.106417/16 was raised and serial Nos. 3687 - 3688 were allocated to these two machines.
  On Thursday 30 March, Cdr Babington visited regarding the Dyott Fighter. His report noted that the Machine is expected to be ready for trials within a week. It is anticipated that speed of machine will be somewhat low in first machine for practical purposes. No. 3687 was reported as under erection by Hewlett & Blondeau on 12 April 1916, and under test on the 25th.
  Flt Lt Dyott flew No. 3687 on 28 April and 12 May 1916. The report of the Design Section for the W/E 5 May 1916 noted that Stress work has been completed on the Wight 250 R-R machine and on the revised form of the Dyott Biplane. This may be why a Mr Pippard visited Hendon in that reporting period to obtain information on the revised form of the Dyott Biplane. Hewlett & Blondeau were asked to carry out necessary modifications to the second Dyott Fighter in July. The aeroplane was officially delivered to RNAS Hendon on 17 August.
  Hewlett & Blondeau, Ltd, wrote to Flt Cdr Dyott on 26 July 1916, notifying him that the Admiralty had asked them to quote for the extra bracing on front undercarriage, etc., per his earlier communication. This letter is reproduced in detail as it shows that there were tensions between the company and Dyott over the manner in which the construction was carried out.
  The firm wanted drawings as they wanted to carry out the work in a different manner to that of the past which has been prejudicial to both you and ourselves. Delay in the completion and considerable reduction in the cost would have been effected if the work had been left entirely in our hands and we have been deceived over the estimated cost owing to the materials adopted by you whilst in our shops.
  You are of course aware that the design, working drawings and calculations of stresses have been made by our firm when all this important work should have come from yourself.
  You have, on many occasions asked for departures from drawings on work in hand in the shops and without reference to the Firm, with the result that drawings are non existent or not up to date and cannot be put right now.
  It will be in our mutual interest, if when work is in progress, you do not interfere with the men carrying it out under the Firms instructions but refer everything to the Firm as it should be done.
  There were financial problems with the Admiralty paying Hewlett & Blondeau, Ltd for the work done as correspondence between H.E. Hewlett and a Mr F.H. Paget(?) reveal. Paget’s wife had left funds with the firm, subject to recall at any time. Hewlett wrote that they have been trying to get their money from the Admiralty. We are getting on very fast with our new contract & have been pressed to take another at once. He concluded the letter by stating - The plans for George’s machine are going away tomorrow, & the new shop is moving apace. While Paget failed to see how any orders Flt Comdr Dyott could have given you relative to changes in Admiralty machines Nos. 3687 & 3688 can enter into the question of the return of his wife’s money, but he let the subject drop for the moment. Perhaps Paget’s wife was one of the two wealthy benefactors that the Aeronautical Engineer reported as funding the construction of the original Dyott battleplane.
  Dyott had been seconded to the firm to oversee the construction. The financial problems could have arisen from Dyott’s personality. He wrote to his Commanding Officer and various other Admiralty officers complaining about the lack of funding and made himself unpopular. M.H. Goodall reprinted a letter from Dyott to Lambe of 17 March 1916. In it Dyott states that the Work is going ahead nicely, the main wings are finished so also interplane struts and tailplanes. The fuselage has to be covered, also centre section, at the moment we are doing the engine cowling. Lt. Peel sent me a sketch of the camera but omitted the important dimensions which would enable me to make a suitable door for it, so I will have to let the matter drop and install it later.
  The firm received some £1,600 this morning for work done on B.E.’s. No order has been received for my second machine and the letter of conditions referred to on their Admiralty telegram has not arrived, so no quotation can be given. All metal work for the 2nd. Fuselage is finished and the erecting can begin any day; did we know what motors were to be used we could have the entire machine finished in six weeks at the outside.
  Dyott was upset that the Inspector had sent list of requests for information. Personally I cannot see any reason for not writing direct to me, however, to avoid trouble which is going to come quite soon enough I replied that the machine had been modified to suit Admiralty requirements as in my letter to the S.A.C. on November 20th, 1915.
  I put forward that no one is allowed to change, stop or hinder any of my work till the machine has been tested by me. Even if the factor of safety is only two it will be quite safe for test under no load or full load. If the performance and general arrangement meets with approval then it will be time enough to discuss changes if necessary, and higher factors of safety. Furthermore, the firm should receive the £1,000 which had been due them for some time and the balance afterwards, without any arguments. The experiment has been carried out by them and every detail of the work has been passed by me as satisfactory.
  It was originally intended to fit two engines driving opposite handed airscrews, however the two 120-hp Beardmore engines fitted had two-bladed anti-clockwise rotating airscrews.
  The first Dyott, No. 3687, was a handsome parallel-chord, equi-span biplane with the 120-hp Beardmore six-cylinder water-cooled engines suspended between the wings, these being fitted with side radiators. A large centre section spanned the distance between the engines, the outboard sections of the wings having four bays of bracing including that of the engines. Ailerons were carried on all four wings. The undercarriage comprised a single wheel under each engine with a double skid arrangement carrying the axle. A nose wheel was fitted. According to Aeronautical Engineering, the nose wheel was only intended for night use.
  The aircraft was of conventional construction with ply front decking. A crew of three was carried. The pilot sat to port with a large windscreen forward of his position.
  Entry to the front gunner’s cockpit was by a door in the port side of the nose. Armament comprised five Lewis guns. Two were mounted on spigot mounts at the nose above the fuselage, with another two at “portholes” in the nose. On the first version of the type a gun rail, containing six spigot mountings, ran completely around the front gunner’s cockpit above the fuselage. The two Lewis guns could be moved to any of these mounts. The fifth was on a spigot mount behind the wings for the third crew member. Dyott No. 3687 was reported by Hendon as being erected by Hewlett & Blondeau on 11 April 1916. The first machine was modified and it is thought that the second was completed to incorporate these modifications. The engines were cowled with frontal radiators; the top decking was raised and continued at this height back to the pilot’s cockpit. The gun rail is not visible in photographs and it is not known if the same arrangement for the guns was behind the raised decking.
  After engine runs the first aircraft was taken by road to Hendon. Hendon reported that No. 3687 was ready for testing on 24 April 1916, and was under test the next day. On the 28th, it reported that it was flown by Flt Lt Dyott. It had taken to the air on its first flight on 25th. The engines overheated and the cowlings were removed and the radiators mounted above the engines in an attempt to increase cooling. A new tailplane was fitted after testing showed that the original was too small. This was fitted on 27 May. Testing continued. The Aeroplane described activities at Hendon over the weekend of 5-6 August 1916, and although many were missing the pre-war Hendon, flights were still being given, the Grahame-White three-seater being mentioned. On Saturday there were many machines of many kinds in the air, from single seater Caudrons to large Curtiss and even larger Dyott. This must have been No.3687. It is strange that a new experimental machine should have been on public display, in such a fashion, during wartime.
  On 20 September 1916, it was noted that after its trials at Hendon, it was to be allocated to ‘K’ Section, presumably located at Eastchurch, for trials, then to Dunkirk. Its previous allocation to No. 3 Wing was cancelled.
  The second machine, No. 3688, joined the first at Hendon by 2 September 1916, where it was recorded as a great improvement over No. 1 and is fitted with W/T receiver and transmitter.
  Alec Ogilvie was one of the greater figures in the aeronautical movement, his early experiments and experiences leading him to purchase Short-Wright No. 2. He obtained British certificate No. 7 on 15 May 1911. He went to the USA every year and had a close association with the Wrights. He accompanied Frank McClean on his Nile expedition wherein they took Short S.80 from Alexandria to Khartoum.
  Since the end of 1912, he was working on an Air Speed Indicator, that was tested by the Navy at the 1913 Navy manoeuvres. This was later adopted by the air services. He had been granted a provisional Sqn Cdr commission in joining the RNAS in 1915 and placed in charge of instructional flying at Eastchurch. From March 1916 to March 1917, he was in charge of the Aircraft Repair Depot at Dunkirk. Promoted to W/Cdr he was transferred to the Air Board as Controller of the Technical Department when that was set up in early 1917. After resigning his commission, he set up as a consulting engineer in 1919.
  Ogilvie wrote that he had visited Hendon on 26 September 1916, to see Dyott and see how his second machine was getting on. It is most beautifully fitted up for reconnaissance work and has a most formidable array of guns. No doubt much more speed would be obtained by 160 h.p. engines but in no case will the machine have any chance of escaping from a hostile machine. It will have to be able to defend itself by its superior armament. No doubt the only way to prove the point by having the machine on trial at Dunkirk to see how it really gets on in war conditions. The greatest difficulty would be housing it on the French aerodrome, as it is 75 feet wide and unable to fold.
  Both Dyott biplanes remained at Hendon until early October when No. 3687 went to the Experimental Armament Depot on the Isle of Grain. Given the power available and the weight of armament, the machine was underpowered. At some the first machine was fitted with 230-hp BHP engines in an effort to improve the machine’s performance.
  No. 3687 was to be fitted for experiments with a 2-pdr Vickers gun at Grain. For the W/E 28 October 1916, the mounting for 2-pdr in the Dyott fighter was in hand. Neither J.M. Bruce nor H.F. King mention it when discussing the armament of the Dyott, and it is not known if it was ever fitted to the airframe. It was recorded as having flown at Hendon by Flt Lt Johnston on 10 November 1916, and also flown on the 11th. The machine was noted as deleted on 24 March 1917, but was repaired instead and continued on at Grain being recorded there 25 May 1918. Its final fate is unknown.
  The second machine, No. 3688, was delivered to Hendon for erection on 25 August 1916, and flown on 5 October by Flt Lt T.D. Hallam. More information is available in the Weekly Section reports of the Admiralty Air Department:
  W/E 06 Oct 1916. ‘K’ Section. Hendon undergoing designer’s trials.
  W/E 13 Oct 1916. ‘K’ Section. Hendon undergoing designer’s trials.
  W/E 20 Oct 1916. ‘K’ Section. Eastchurch undergoing trials. W/E 27 Oct 1916. Eastchurch awaiting propellers.
  Modifications were apparently made to No. 3688 and it was transferred to Dunkirk for service trials. It returned by 16 November 1916. Sqn Cdr F.K. McClean wrote that the machine is devoid of the necessary flying qualities on this station. This machine to be transferred to another Station or deleted from commission: useful parts as arisings are to be taken on charge at Station as deleted. Engines to be returned to Survey Section.
  In September 1917, Charles Grey of The Aeroplane conducted one of his usual trenchant articles against those in authority. This article, titled ‘On Some Lessons from the Enemy’, he tries to make the case that all the German superior aircraft were all derived from French or British aircraft. The Fokker monoplane was derived from the Morane-Saulnier, but Grey contended that his scout biplanes (were derived) from the Sopwith and Bristol designs, and his two-seaters from the Avro. Whence he stole his Gothas I do not profess to know, but certainly out multiple engine Shorts were long before any German effort with multiple engines, and the Dyott twin-engined machine, designed in 1914, built in spite of official disinclination in 1915, and flown successfully in 1916, when the design was well over a year old, was as near as no matter exactly according to best modern practice, albeit hopelessly underpowered, again thanks to official disbelief at the time. Truly the Dyott was under powered with its first engines, this was known before the machine first flew , however the performance figures for the machine with different engines has not been discovered to date.
  Charles G Grey was never one to let facts stand in the way of his crusade against the Royal Aircraft Factory and the administration of the RFC/RNAS. In the 27 November 1918, issue of The Aeroplane Grey devoted five pages to an attack on the official news releases by the Air Ministry. To the official contention that the first British aircraft specifically designed for Bombing was the Short Bomber he wrote that this was sheer unadulterated nonsense. The twin-engined Dyott of 1915 and the contemporary twin-engined Fairey “Folder” were “specifically conducted for bombing” long before the technical imbeciles of the R.N.A.S. thought about mangling a perfectly good seaplane and turning it into a perfectly hopeless bomber. The poor mangled Short never “did most useful work in France, ” though that was not the fault of Short Brothers, and the type was washed out after only a few trips had been made over the lines on it. The machines, however, were delivered in quantities and burned without being used.
  The Naval "experts” had washed out the Dyott and the Fairey long before that, and so the “first British machine specifically constructed for bombing which ever came into regular use about a year and a half or two years after its energetic designer-constructor had put up wonderful demonstrations of its capabilities and after various young and intelligent officers had got themselves severely disliked by trying to drum its uses into the thick heads of fossilised seniors. It can be seen from this type of reporting at such an early date why the Dyott has been referred to as a bomber rather than a fighter.
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  Given Dyott’s personality, the problems with obtaining powerful engines, the state of aerial fighting and the changes that were developing at such a pace on the Western Front, it is no surprise that the Dyott battleplane was not accepted for development as a fighter. Whether it could have been developed into a serious bomber will never be known.


Dyott AT Battleplane Specifications
Source 1 2 3 All approx
Span 70 ft 0 in - 70 ft
Length 46 ft 3 in - 50 ft
Height - - 12 ft
Chord 6 ft 4 in - -
Span tailplane 20 ft 0 in - -
Light Weight, lbs - 3,800 -
Military load, lbs - 850 -
Gross Weight, lbs - - 7,800
Wing Area - 874 ft2 -
Fuel, gallons - 114 -
Oil, gallons - 91 -
Speed (ground level) - 63.3 kts -
Climb to
1,000 ft - 4 min 23 -
2,000 ft - 9 min 25 -
3,000 ft - 14 min 56 -
4,000 ft - 21 min 29 -
5,000 ft - 29 min 36 -
6,000 ft - 41 min 05 -
Engines - 120-hp Beardmore (130 h.p. @ 1250 rpm) 120-hp Beardmore. Later 230-hp BHP
Sources:
  1. Air Dept drawing. TNA AIR1/716/27/19/30.
  2. RAF Museum J.M. Bruce Collection Box 24.
  3. F.K. Mason data. (Note stated to be approximate).