McClean himself did a fair bit of flying in the first week of August. Flight reported that he was flying ‘his favourite Short biplane,… on which he has done an aggregate of nearly 1,000 miles without any more serious breakage than a broken stay-wire’.
At the end of the month the six-month agreement for the use of McClean’s aircraft to train navy pilots expired. The four airmen had done a considerable amount of flying, Lieutenant Gerrard claiming the world’s record for crosscountry flying with a passenger and Lieutenant Samson establishing a British duration record. Their favourite Short biplane, affectionately known as ‘Little Willy’ (believed to be the S.28), had flown over 4,000 miles, and S.34 and S.38 had logged 3,000 and 2,000 miles respectively. C G Grey was told by ‘those who ought to know best’ that the total cost of breakages in that 9,000 miles of flying ‘would be covered by about £25’.
Twin-engine aeroplanes
Meanwhile, Shorts had been working on two more machines for McClean. The first was the tractor biplane which Horace had designed in conjunction with the late Cecil Grace (S.36) and which Travers had redesigned, and the second was the twin-engine S.39.
The S.39, described by The Aero as ‘a daring and original departure, devoid of freakishness’, was ‘very nearly completed’ by late August. Larger than the standard biplanes hitherto produced by the company, it was a sturdy 45ft-long, 34ft-span three-bay biplane with double-surfaced wings, powered by a pair of 50hp Gnomes mounted at the front and rear of the covered nacelle positioned on the lower wing centre section and driving three propellers. The front engine drove a pair of tractor propellers mounted 24ft apart on the central front struts on each side via long chain drives running in tubular guides à la Wright, the chain on the port side being crossed so that the propellers counter-rotated to eliminate torque. The gear reduction was 2:1. The rear engine had an ungeared ‘high-speed’ pusher propeller attached directly to its driveshaft. The pilot and passenger were seated side-by-side between the engines, the pilot, to starboard, being provided with a pivoted control column topped by a wheel. Turning the wheel operated the ailerons, and fore-and-aft movement of the column worked the elevators attached to the outrigger booms projecting ahead of the wing cellule and to the monoplane tailplane. Rocking foot-pedals worked the triple rudders; there was no fin. Duplicate controls were provided for the passenger. Two cylindrical fuel tanks were carried, each one being fitted between the first pair of interplane struts on each side.
The first multiple-engine aeroplane built for McClean was the S.39, dubbed the ‘Triple Twin’ because its two Gnome engines drove three propellers, one attached directly as a pusher to the rear engine, and two driven by chain drives from the engine mounted on the front of the nacelle. This picture was taken at Eastchurch in late September 1911, at the time of the S.39’s first trials, and McClean is at the controls, ‘just ready to start’. (AUTHOR)
Although it was intended that the engines would be run simultaneously, giving the aircraft a speed of about 55mph, the S.39 was designed so that it could sustain flight on either engine at a speed of about 36mph. The provision of two completely independent powerplants and systems was expected to obviate the risks of an engine failure almost entirely, enabling the pilot to ‘leisurely choose a suitable landing place, where he may descend to make any adjustments to his temporarily disabled engine’.
The Aero said that the initial experiments would be carried out with 50hp Gnomes, but that ‘for experimental purposes’ it was expected that one or both of them would give way to a 70hp unit. The magazine added: ‘Messrs. Short Brothers and Mr Frank Maclean [sic] must be congratulated upon their enterprise in bringing into being the machine which, although admittedly experimental, indicates that all British constructors are not mere copyists, but can be original without producing freaks.’
The S.39 was delivered to McClean on Monday 18 September, and he piloted it on its first trial flights that same day. Flight reported that they proved ‘very successful… the machine answering fully the expectations of its constructors’. McClean first made a short, straight solo flight ‘in which the machine showed great buoyancy, rising rapidly into the air in spite of the preliminary run being uphill’. He then flew eight laps of the ground with Samson as his passenger, frequently throttling down either engine. ‘A strong feature of the tactics,’ said Flight, ‘was the large margin of power exhibited by the machine…, it being possible to vary the speed considerably, by throttling down either or both engines without causing a descent.’ The report added: ‘Mr McClean stated afterwards that he found the warping control very effective and the biplane very steady in flight; it also showed a very flat gliding angle when the engines were cut off…’ In 1938 McClean recalled that the S.39 was ‘a perfect lady, without vices and rather slow’.
Three-quarter-front and-rear close-ups of the S.39 during its early flights, showing the front and rear engines and propellers. McClean is at the controls and Lieutenant Charles Rumney Samson is in the passenger’s seat. (AUTHOR)
The trials continued, and on Thursday the 21st McClean took up several naval officers as passengers, making a tour of the island at 600ft. The Aeroplane and Flight reported that he was ‘particularly pleased with the climbing qualities of his new mount; it seems to have unlimited powers in this direction’. In the afternoon of the following day he made flights of more than two hours, making sharp right-and left-hand turns and occasionally flying with both engines throttled down, reducing the aircraft’s speed considerably. On Sunday the 24th McClean in S.39 followed Egerton on a long cross-country flight by way of Sheerness, and on return to Eastchurch made a faultless landing with both engines stopped. In mid-October he flew it from Eastchurch over Capel Hill to Leysdown, along the Swale to King’s Ferry and then skirted Queenborough and Sheerness before returning to Eastchurch. ‘There was a stiff breeze,’ reported Flighty ‘but with the new control system the minor air currents scarcely affected the machine’. The magazine added that Shorts were now building another, similar biplane, and that the company ‘will shortly commence another biplane embodying one or two new features, and fitted with two 100hp engines driving four propellers’.
At Shorts, Horace Short and Travers had indeed been hard at work producing a second twin-engine machine for McClean. Horace was not happy with the effect on lateral control of the outboard slipstream created by the S.39’s tractor propellers, so he decided to investigate the effect of co-axial counter-rotation on stability. Travers was not keen on the chain transmission. However, instead of building a completely new machine they modified the ex-Grace S.27 airframe. An additional 50hp Gnome was mounted in front of the nacelle, with the pilot and passenger sandwiched side-by-side between the two engines, with dual controls, as in the S.39. This time the front engine drove a single propeller attached directly to its driveshaft. As the engines turned in opposite directions, gyroscopic action and torque were cancelled out. Other modifications included extensions to the upper wing, a beefed-up undercarriage and the addition of two extra rudders above the tailplane.
Work on the twin-engine S.27 began on 25 September, and McClean took it up for its first flights on 29 October. Flight and The Aeroplane reported that he ‘… did not attempt any preliminary ground rolling, but took the machine straight into the air and made a lap of the aerodrome at a height of about 100ft. On descending he expressed great satisfaction at the behaviour of the machine, which flew extremely well and at great speed’. That afternoon he made several extended flights, taking up Lieutenant Samson, Lieutenant H V Ger-rard (brother of the aviator Captain Gerrard) and J L Travers. Travers, who had also become a competent pilot by now, was somewhat disappointed, writing to his father: ‘I was originally told that I was to fly it but when it came to the point Maclean [sic], (who after all was paying for it) couldn’t resist taking it up himself. I have done an awful lot of work on the machine, drawing, scheming and hurrying the job through.’
Unhappy with certain aspects of the S.39’s design, Horace Short and J L Tra
vers modified the S.27 to create the ‘Tandem Twin’, with two Gnomes driving tractor and pusher propellers at the front and rear of the nacelle. It first flew in late October 1911. According to McClean’s later accounts this was not a very pleasant machine to fly, though contemporary reports suggested otherwise. (AUTHOR)
Frank McClean at the controls of the S.27 Tandem Twin in 1911. For obvious reasons the machine was familiarly known as the ‘Gnome sandwich’, the ‘filling’ comprising the pilot and passenger! (AUTHOR)
For the final flight of the day McClean took Lieutenant Gregory on a long tour of the island at an altitude of about 600ft, passing over Queenborough and Sheerness. ‘The machine exhibited splendid climbing powers,’ the journals reported, ‘rising with unusual rapidity.’
These glowing accounts of the twin-engine S.27’s performance are at odds with McClean’s later recollections of it. In 1931 he said ‘it flew very well indeed, but, unfortunately, [I] could never make it fly level; you either had to climb and subsequently slide back into the ground with your tail or dive straight away with your nose into the ground’. In 1938 he wrote: ‘She was a disgraceful machine without stability either laterally or fore and aft. She would not fly level but hunted up and down and her landings were promiscuous. The rear air screw was ten inches behind the pilot’s head and his feet were against the front engine.’ He also recalled that it was known as the ‘Vacuum Cleaner’ owing to the draught in the seats between the propellers, alleged to be able to pull the hairs out of a fur coat. This was largely attributable to an open hole in the cockpit floor, the sole means of access.
There was again reference to plans to build a four-propeller aircraft. This machine, designed by Horace, was to have a central pair of 120hp engines driving four propellers arranged in tandem pairs between the biplane wings, with independent chain gears for the front and rear engines. It was never built.
Shortly afterwards, McClean visited C G Grey at The Aeroplane office in Piccadilly, London, and ‘expressed himself as being greatly pleased’ with his latest aeroplane. He said that it flew quite well on either engine, and could attain about 55mph with both working. One peculiarity the S.27 shared with the S.39 was that it did not bank itself naturally ‘going round a corner’, but when banked by use of the ailerons it manoeuvred very easily. ‘Mr McClean… is quite enthusiastic about the possibilities of machines with two engines,’ the magazine reported. McClean and navy pilots continued flying the twin-engine S.27 during November, McClean making a good many passenger flights. On 1 November he took Egerton for a 20-minute flight. This was Egerton’s first flight as a passenger, and he noted: ‘Not very comfortable, and too much wind and oil.’
On the afternoon of Tuesday 21 November a race was arranged between Captain Gerrard on the ‘tandem-twin’ S.27 (also informally dubbed the ‘Gnome sandwich’) and Lieutenant Longmore on the triple-propeller twin-engine S.39, the ‘triple-twin’ (these names appearing in print for the first time in the reports of this event in the 2 December issue of Flight). The aim was to test the relative speeds of the aircraft over a course to Leysdown and back to the aerodrome, but the result was not quite conclusive because Gerrard rounded a different point to Longmore. The S.39 had a slight edge, completing the run at a little over 50mph.
Later that afternoon the advantage of having two engines was dramatically demonstrated. Samson was flying S.39 at 600ft over Bram-bledown, some four miles from Eastchurch, when the rear engine’s magneto came loose and worked out of gear, upsetting the tuning and causing the engine to stop suddenly. Accustomed to single-engine flight, Samson prepared to make a vol plane, scanning the ground for a suitable place to land. This proved unnecessary, however, as the aircraft continued to fly well on the good engine, descending at a very gentle angle. Samson landed safely on the aerodrome, ‘having plenty of room for a turn in order to alight close to the shed’.
In London that day a meeting of a large number of aircraft manufacturers, pilots and RAeC Committee members took place with the aim of considering what action should be taken with regard to the Government’s planned Military Aeroplane Competition for 1912, and the ‘attitude of the War Office toward British constructors’. Horace and Eustace Short and McClean were among them. A resolution stated, in part, that ‘… the Under Secretary for War [Colonel Seeley] should be requested… to consider the advantages to the Government, as well as to the British industry as a whole, of placing conditional orders, with such British firms as are willing to accept them, for an aeroplane or aeroplanes to fulfil the requirements of the War Office; the conditions being that delivery will not be accepted unless the planes carry out the specified tests’. A committee was then appointed to deal with the question of a deputation to Colonel Seeley; it included McClean and Horace Short.
Helping the Terriers fly
That same week it was announced that The London Balloon Company and the Territorial Force had been offered the use of two Short biplanes at the RAeC grounds at Eastchurch ‘for the purpose of instructing members in aviation’. The lender, described as ‘a prominent member of the club’, was of course McClean, who had undertaken to see to the aircrafts’ hangarage and maintenance. Fourteen of the company’s sixty-two members had already volunteered for a course of training towards gaining the Club’s higher aviator’s certificate, and the first pupil was due to start in a few days. ‘Those who cannot afford the time,’ reported the Morning Post, ‘will be taken down to Eastchurch at week-ends to be trained in the handling and care of aeroplanes and their motors.’ ‘Is Mr McClean qualifying for the post of First Lord of the Admiralty?’ asked The Aeroplane.
Travers, who was to undertake the training of the Territorials, adapted S.32 by replacing its ENV engine with a 70hp Gnome and fitting it with side-by-side seats and dual controls. Flight reported that, on Sunday 26 November, Travers was ‘out testing the new [sic] 70hp Gnome-engined Short biplane which has been specially prepared for [the Territorials’] instruction’. Officers, NCOs and men under the command of Captain M M Bidder went to Eastchurch and, acting on the authority received from the County Association, a shed was taken by them. As previously announced, in addition to those who were able to go to the aerodrome during the week for individual training, weekend parties of eight to ten were organised under authority from the GOC 1st Division for ground work and repairs to machines and engines. On Monday 4 and Tuesday 5 December Mr S P Cockerell and Mr A V Barrington-Kennett of the Territorial Balloon Company began their training under Travers on the S.32. Cockerell was already a qualified aviator, but Barrington-Kennett had his first experience of piloting from S.32’s passenger seat, using the dual controls. He flew his first solo the following week. Other Territorials were soon sampling the delights of aviation.
Another ‘biplane Type 38’ was ordered for McClean on 8 December. This aircraft, S.40/Short-Sommer No 10, was to have a particularly interesting career.
The S.27 and S.39 continued to be flown by navy pilots. Shorts’ order book records a series of repair jobs from January 1912 onward, charged to the navy’s account (the RN doing the ‘right thing’ by McClean). A Committee of Imperial Defence subcommittee report in February 1912 recommended the purchase of ‘One twin engine biplane (now in use) from Messrs Short Brothers’ for £1,400. This was the S.39; the S.27 Tandem Twin remained McClean’s property, though he loaned it to the Naval Flying School free of charge.
Later, the Triple Twin was fitted with extensions to its upper wing, as seen here. It was purchased by the Admiralty early in 19 12. (AUTHOR)
The naval aviators expressed their gratitude in the concert room of the Crooked Billet Inn at Eastchurch on the evening of 16 December, when they gave a dinner to the employees of Messrs Short Brothers, and treated them to an ‘impromptu entertainment’. Several toasts were drunk, ‘none with more enthusiasm than that of Mr Frank K. McClean, who, all regretted, was absent….
In its ultimate form the S.39 had four fuel tanks beneath the upper wing centre section. In this picture, taken on 6 Decembe
r 1911, Commander Samson and Captain Gerrard are aboard. The S.39 was serialled B3, T3 and 3 in naval service, and in June 1913 it was rebuilt as S.78, an S.58-Type pusher biplane. (AUTHOR)
Promising new biplane
Upon McClean’s return from Tonga Horace Short had shown him a design for a two-seat tractor biplane powered by a 70hp Gnome, developed from an earlier design drafted to meet a requirement outlined by the late Cecil Grace. McClean ordered one for his private use, and late in 1911 this machine, S.36, was completed. Although it was initially built as a land-plane, it was designed to incorporate a float undercarriage devised by J L Travers, with a large single central float and lateral stabilising air-bag floats towards the lower wingtips.
The S.36 represented a marked change from the company’s pusher biplanes. It had two-bay wings with strut-braced upper-wing extensions and ailerons on the upper wing only. The fuselage was a simple wire-braced girder structure, initially left uncovered apart from the aluminium panels enclosing the tanks and the overhung engine mounting, and the plywood panels alongside the tandem cockpits. It was attached to the middle bay struts in mid-gap, and the lower wing centre section was left uncovered. Its land undercarriage comprised a twin-skid chassis attached to the two lower longerons and carrying two wheels on a rubber-sprung cross-axle. There was a sprung tailskid. A non-lifting tailplane carried divided elevators, and a partly balanced rectangular rudder was hinged on a vertical sternpost. It was a handsome and promising machine.
The S.36 tractor biplane, built for Frank McClean, in January 1912, shortly after completion, with its rear fuselage as yet uncovered. It marked a step change in Short Brothers’ aeroplane design. (FLEET AIR ARM MUSEUM)
Frank McClean Page 9