Kronfeld Drone и Monoplane
В течение 1932 года К. X. Лоув Уайлд - управляющий директор и конструктор компании "British Aircraft Company" (город Майдстоун, графство Кент) - спроектировал на базе одного из выпускавшихся компанией планеров легкий самолет, получивший обозначение BAC Pianette.
Однако в мае 1933 года сам Лоув Уайлд погиб во время происшествия с одним из таких самолетов, после чего его должность занял Роберт Кронфельд, знаменитый в те годы пилот-планерист, австриец по происхождению. В 1936 году компания была переименована в "Kronfeld Ltd", а самолет - модифицирован и переименован в Kronfeld Drone. Всего было построено 33 таких легких самолета, включая несколько машин под обозначением Drone de Luxe - они имели крыло с небольшой стреловидностью и щелевые элероны. В 1937 году был построен и облетан новый самолет Kronfeld Monoplane, в целом конструктивно схожий с модификацией Drone, но оснащенный двигателем Carden-Ford мощностью 30 л. с. и новым хвостовым оперением.
Flight, September 1935
FLYING the NEW DRONE
By H. A. TAYLOR
Impressions of the Latest Version of a Well-established Ultra-light Single-seater
PERIODICALLY during the past fifteen years or more people have talked loosely of the flying machine for the multitude, and even proclaimed its immediately impending arrival. If the various considerations of design or construction and the lack of a suitable engine had not made themselves apparent, the fact that the vast majority of mortals looked upon all forms of aircraft as both expensive and dangerous would once have been enough to prevent such a type from becoming reasonably popular.
Now, however, there are in this country alone some 3,400 licensed pilots, the majority of whom cannot afford to continue to fly or to put in more than a very few hours every year. There is also an infinitely greater number of young people with a passionate desire to get into the air. While the number of prospective owners of ultra-light machines which are inexpensive to operate may or may not be limited - we are all shy of the minor responsibilities of ownership - there should be a very large number of people who would be prepared to fly for sheer amusement if their club flying rate happened to be low enough.
There is no doubt that the B.A.C. Super Drone, as the new model is called, can be operated for an extraordinarily low figure. The makers, in fact, have made some interesting calculations to show that the all-in running costs over three years should amount to rather less than nine shillings an hour. This figure is based on the assumptions that 500 hours are flown in a year and that the machine is completely written-off at the conclusion of the period.
Be that as it may, the new Super Drone is, as a flying machine, a very great improvement on the original model, which, nevertheless, was flown with satisfaction by a number of disinterested pilots. Apart from the facts that it is rather faster, has a greater range, and incorporates a number of interesting refinements, the airframe has been entirely redesigned so that the machine is under full and adequate control both on the ground and in the air right down to stalling point.
Dealing first with the detail improvements, the most important is the fact that the wings can now be folded, reducing the width, for hangarage, to a matter of ten feet. The wings hinge around a point at the rear spar and are supported in the folded position by two jury struts and wires. In later models the wing tips will be firmly held to the fuselage, so that the machine can be safely towed in the folded condition. The wing and strut attachments follow normal practice, and the spars and fittings have been considerably strengthened.
A wider and taller undercarriage, coupled with the use of a steerable castering tail wheel, now allow the machine to be completely and safely controlled on the ground. There is quite a spacious compartment for luggage behind the pilot's seat, which, incidentally, is now adjustable in the fore-and-aft positions.
The new 750 c.c. Douglas engine, which develops a maximum of 28 h.p., has a neatly faired mounting in which the oil tank is incorporated, and the fuel tank is now placed inside the fuselage. This tank holds from 6? to 7 gallons, and the cruising range has, consequently, been increased to a matter of 5 1/2 hours - or, in still air, 300 miles. The cruising endurance is consequently rather better than that of many light aeroplanes that have been regularly flown during the past few years.
So much for what may be called the points of "ground interest." The really important modifications from the pilot's point of view include a washout at the wing tips and larger, mass-balanced ailerons to improve the lateral control (which, it must be admitted, was not too good on the original model), a longer fuselage with a forwardly moved centre of gravity, and increased elevator and rudder area. These modifications have brought the machine into line, so to speak, with accepted ideas of how an aeroplane should handle, and have, at the same time, made it as nearly as possible foolproof. Neither the pilot of normal aeroplanes nor the absolute novice should have any difficulty with the machine either in the air or on the ground.
Last week I had a chance of flying the Super Drone for the first time, and spent a most pleasant and comfortable half-hour or so floating - the word is used in its actual rather than metaphorical sense - around the machine's home at Hanworth aerodrome. Without previous experience either of the original Drone or of more than a quarter of an hour in an intermediate type of glider, I had expected to discover new and interesting difficulties, but in actual fact I treated the machine just as I would treat any normal light aeroplane.
After discovering that the business of taxying was a great deal simpler, with the help of the steerable tail wheel, than it is on most light aeroplanes, I turned into a very light wind and found that the machine was unexpectedly clear of the earth in some ten or twelve seconds. Ten minutes before Mr. Kronfeld himself had taken off in six or seven seconds - it is all a matter of practice. There was little or no tendency to swing during the take-off, and the climb, at about 30-35 m.p.h., was perfectly straightforward, though at such a comparatively low speed there is a tendency for the machine to "wallow" slightly despite aileron and rudder corrections.
The view from the seat is, of course, quite without parallel, and the best impressions are obtained without either helmet or goggles. If it is suspected that someone in a fast aeroplane is coming up behind, one can see through quite wide arcs at the rear by looking under the wings. Meanwhile, the whole earth and sky is stretched out ahead.
This particular prototype Super Drone had, unfortunately, no engine revolution counter, and, after throttling back to what appeared to be a comfortable engine speed, the climb to a thousand feet took some five minutes at the recommended air speed. Actually, this altitude can, with higher revolutions, be reached comfortably in three minutes, and 3,000 feet. Mr. Kronfeld explains, can be topped in ten minutes. The calculated service ceiling is 12,500ft. - a fact which may surprise the cynical. Unfortunately, too, the A.S.I, was suffering from a trouble which prevented accurate reading at the lower end, and both gliding and climbing speeds were held by guesswork complicated by calculation.
No registered stalling speed figures can therefore be given, but the landing was made at a speed which must have been less than 23 m.p.h. In actual fact the stall is of the most innocuous variety; the nose simply drops momentarily and the aileron control remains weak but adequate through the entire phase. At cruising speed - a matter of 55-60 m.p.h. on the clock - all the controls stiffen up, and the machine then ceases entirely to control its own destinies to the slight degree experienced at very low air speeds. Turns can be made practically at the stall, and sideslips are perfectly normal, with a tendency for the nose to fall away at lower speeds. The adequate rudder and aileron control, incidentally, is very valuable for "swish-tailing" away surplus speed.
During my approach in a series of steep gliding turns the air speed, as afterwards discovered by comparison, was definitely on the low side, yet there was little tendency for the Super Drone to take control. A slight reluctance to change bank, perhaps, and that was all.
With the perfect view and the good control the landing is the simplest possible affair. If a novice allowed the machine to stall high the gentle dive could do little more than mild damage. Mr. Kronfeld, in fact, often brings the machine in, for demonstration purposes, in a series of stalls, gauging his height so that the last dip coincides with the last few feet of usable height! Not, perhaps, a recommended method – but one which proves that the new Drone is virtually foolproof.
B.A.C. SUPER DRONE
750 C.C. (28 H.P.) DOUGLAS HORIZONTALLY OPPOSED TWIN-CYLINDER ENGINE
TARE WEIGHT WITH ALL EQUIPMENT ... 390 lb.
FUEL, 6 1/2 GALLONS ... 50 ,,
OIL, 1 GALLON ... 10 „
PILOT ... 160 „
LUGGAGE ... 30 „
ALL-UP WEIGHT ... 640 lb.
Areas and Loadings
SPAN ... 39ft. 8in.
SPAN (WINGS FOLDED) ... 10ft.
WING AREA ... 172 sq.ft.
LENGTH ... 21ft. 10in.
LENGTH (WINDS FOLDED) ... 27ft. 10in.
HEIGHT ... 7ft.
WING LOADING ... 3.7 lb./sq. ft.
MAXIMUM SPEED ... 70 m.p.h.
CRUISING SPEED ... 60 m.p.h.
LANDING SPEED ... 22 m.p.h.
RATE OF CLIMB AT SEA LEVEL ... 380 ft./min.
SERVICE CEILING ... 12,500 ft.
FUEL CONSUMPTION ... 1.25 gall./hour.
RANGE AT CRUISING SPEED ... 300 miles.
TAKE-OFF ... 45 yards.
LANDING RUN ... 45 yards.
PRICE (with A.S.I., Altimeter, oil pressure gauge, compass, logbook and registration fee), ?275 ex works.
MAKERS B.A.C. (1935). Ltd., London Air Park, Feltham, Middlesex.
Flight, April 1936
MODERN LIGHT AIRCRAFT REVIEWED
FOR a number of years certain private owners and club pilots have been asking for a pusher type, and those among them who have had a chance of flying the Drone or the Super Drone - the newest version - must have stepped out of this little machine feeling all the more certain that pusher flying is real flying.
Nowadays, the Super Drone is something a good deal more than a glider with an engine, and Lord Sempill's flight to Berlin and back has shown that it can do a heavy job of work so long as the pilot is not too impatient. With a cruising speed of 60 m.p.h. it is not always possible to make a journey according to plan, though the five-hour endurance is very useful when head winds are encountered. Nevertheless, its ability to fly safely at something under 25 m.p.h. means that the Drone pilot can be out and about when others are eating their heads off on the tarmac. The machine was originally developed by the late Mr. Lowe-Wylde in 1932, and the new company was formed last year.
Certainly, the Super Drone is one of the most intriguing machines in the air that it is possible to imagine and, furthermore, it is just about as safe as anything could be. The pilot has a complete range of forward visibility and, with no slipstream to bother him, he can fly naked and unashamed without discomfort. The landing is simplicity itself, and the stall produces nothing worse than a momentary dip of the nose; full rudder with the stick back involves a steep spiral which corrects itself as soon as the stick is eased forward again. Even to the pilot who is accustomed to the vitality of the normal machine the controls are not unduly sloppy, though there is, at low speeds, a certain tendency for the Super Drone to take its own time over entering turns and stopping gentle yawing movements.
Various people on the Continent have interested themselves in the machine, and building licences have been granted to firms in France, Belgium, and Holland. A 750 c.c. Douglas engine is the standard power unit.
The specification of the Super Drone is as follows: Span folded, 10ft.; length, 27ft. 10in.; weight empty, 390lb.; disposable load, 250 lb.; maximum speed, 70 m.p.h.; cruising speed, 60 m.p.h.; landing speed, 22 m.p.h.; initial rate of climb, 380 ft./min.; cruising range, 300 miles. Price, ?275. Makers: B.A.C. (1935), Ltd., Hanworth Aerodrome, Feltham, Mddx.
STARTING UP: By pulling a wire wound round a drum behind the engine.
THE LATEST TREND: Mr. Lowe-Wylde - as usual pioneering - with his latest venture. He has, for experimental purposes only, added a motor-cycle engine to his B.A.C. VII two-seater and has already done a considerable amount of successful flying with this combination.
THE POWER UNIT: A close-up showing the little Douglas on its mounting and the petrol tank above it.
THE "AIR BABIES" IN FLIGHT: On the left, the two "in formation," and on the right Capt. Ayre in the air.
BABY TALK: From left to right, Capt. E. D. Ayre, the Master of Sempill, Mr. Lowe-Wylde, and Mr. Gordon England.
THE B.A.C. "DRONE" IN BELGIUM: Here is a snap of the first "Drone" to be built in Belgium.
Drone G-AEAN was short lived. Registered in January 1936, it flew with C.W.A. Scott's circus that season but crashed at Southend on July 22, 1936.
PRACTICAL PROOF: On December 20 Mr. Robert Kronfeld delivered a B.A.C. Super Drone to Holland and flew well over 200 miles non-stop in the process. He left Hanworth at 10.30, cleared Customs at Croydon and landed eventually at Zierikzee, some twenty miles from Rotterdam. The weather was foggy and cold, but, with the new exhaust-warmed induction system, no trouble was experienced. In this photograph the Super Drone is being demonstrated by Mr. Kronfeld at Schiphol, Amsterdam.
Mr. E. D. Ayre sets off, pipe in mouth, to give a demonstration of the impossible - with the B.A.C. "Drone."
A number of modifications, together with the use of a 750 c.c. Douglas engine, result in a considerably enhanced performance and improved control for the Super Drone. Mr. Kronfeld demonstrates its controllability at Hanworth.
"If we are to sit in front of the wing, why not put the engine behind, Drone-fashion?"
FOR "SPORT-FLYING": Under the management of Mr. R. Kronfeld, production of the "Drone," an ultra-light aeroplane (600 c.c, 14 h.p. Douglas engine) has been resumed at Hanworth by B.A.C. Ltd. The machine was first designed by the late Mr. C. H. Lowe-Wylde. Mr. Kronfeld shortly hopes to make some long flights with the "Drone," which is a machine that should be most suitable for recreational flying and will be seen at most flying clubs during the coming season.
The B.A.C. Super Drone is an ultra light pusher type, in which the pilot has a very excellent view.
Drone G-AEKT was registered to the parent company in November 1936 and survived until the war.
FRESH FROM THE HIVE. A greatly improved version of the B.A.C. Drone has been produced and is seen here in a spirited zoom at Hanworth. The wings are now arranged to fold and there is tankage for 5 1/2 hours' fuel. Cruising and maximum speeds are respectively 60 m.p.h. and 70 m.p.h.
A striking "angle" on the B.A.C. Super Drone which cruises at 60 m.p.h. with a 750 c.c. engine.
The Rolls-Royce Heinkel (four passengers and two pilots), which is credited with a speed of 240 m.p.h. from the Kestrel engine. In the air is the B.A.C. Super Drone.
An impression from the inside of the London Club's hangar while the four Drones (two of them to be seen) shoot-up the surrounding landscape. A part of the Club fleet stands without.
The enclosures were decorated with the flags of all nations whose countries are linked to our own by the routes of British Airways Ltd. In the air is Mr. Kronfeld's Drone.
M. Manchoulas coming in to land at Le Bourget after his flight from Ghent in the Scorpion-engined power glider.
"- nothing up my sleeve." Mr. Idwal Jones demonstrates the docility of the B. A. C. Drone.
The Belgian B.A.C. "Drone" on a sharp turn.
A number of different engines have been fitted to the various Drone developments. This particular model has a flat-four two-stroke Ava.
Самолет Drone представлял собой планер, оснащенный мотоциклетным двигателем Douglas.
Makers of light plane history. The first attempt to revive interest in the "ultra light" was the Lowe-Wylde (now Kronfeld) Drone, seen here.
IT COULDN'T BEAT THE "DRONE.'' Rain and generally dirty weather failed to prevent Mr. Kronfeld reaching Paris in the "Drone." Here the tiny machine is seen just prior to starting from Croydon.
A section of the long line of machines on exhibition. In the foreground is the B.A.C. "Drone," then a Spartan "Cruiser," a Railway Air Services D.H.86, the K.L.M. Douglas D.C.2, and others.
The Fleet: Miss Joan Meakin's Wolf glider, the Airspeed Ferry, and the B.A.C. Drone are in the foreground.
LULL IN THE STORM: Varied fauna at the Bristol club's garden party last Saturday, which suffered severely from the weather. Seen here are one of the Club Swallows, the Bristol 143, an Autogiro, a Drone, and three Harts of No. 501 (City of Bristol) Squadron. The human element is mainly seeking solace in the clubhouse, which, with the Airwork hangar, can be seen in the background.
Not quite so startling as it appears - merely the Super Drone with its wings folded, thus reducing the width for housing purposes to 10 ft. Note the wide undercarriage.
The 750 c.c. Douglas engine of the type used in the Drone.
DRONE-DRIVER: The installation of the 30 h.p. water-cooled Carden in a new version of the Kronfeld Super Drone.
NEW POWER FOR THE DRONE: How the flat-four Ava two-stroke engine is arranged in Lord Sempill's new Drone. The airscrew is well clear of the cut-away trailing edge and the engine turns over at only 2,100 r.p.m., so the familiar noise is no longer heard; this machine has, in fact, that quality of quietude which should add greatly to the pleasure of what is now rather more than "Drone-floating." The price of this model has been fixed at ?325 with full equipment.
PROOF: Lord Sempill's flight to Berlin (11 hours) and back (9 hours) in a B.A.C. Super Drone must have given a jolt to those who habitually scoff at ultra-light aircraft. Lord Sempill is seen at Croydon with Mr. Kronfeld (right).
ONE OF THE LADS: A familiar overalled figure at Hanworth these days is the Baroness Rudoleine von Simolin, 17-year-old daughter of one of Germany's biggest chemical manufacturers. She is now serving a hard-working apprenticeship at the Kronfeld factory at Hanworth, and is seen here in front of the Carden-engined Drone.
Mr. Robert Kronfeld, managing director of B.A.C. (1935) Ltd., in the cockpit of the Super Drone. With him are Mr. E. C. Gordon England (director) and on the left, the latter's brother, Sqn. Ldr. T. H. England.
ULTRA-LIGHT LUXURY: A totally enclosed and exhaust-heated cockpit has been designed for a special Kronfeld Drone recently produced to the order of a private owner, Mr. R. Dimock. It will be noticed that this machine also has a rubber-sprung split-axle undercarriage and the latest exhaust system. Mr. Dimock will not be likely to lose his hat again, (as once happened, with catastrophic results) while flying this machine.
UNDERGRADUATION: Mr Kronfeld taxies his new "flying" ground trainer at Hanworth while the latest type of Carden-engined Drone De Luxe flies overhead. The standard De Luxe model costs L325, while the ground trainer is priced at L195. The Country Flying Club, of Leicester, charge 9s. an hour for instruction on the normal ground trainer which they have been using successfully for the past month or two.
"DIVINE WIND'S" crew see something of British aviation: Messrs. Iinuma and Tsukagoshi, famed for their 100-hour flight from Tokio, recently enjoyed the hospitality of that section of the Industry which centres on Hanworth. They are seen greatly intrigued by Mr. Kronfeld's exposition of his ground trainer.
Front to rear. Lord Sempill’s special 35 h.p. Ava-powered Drone, the Kronfeld Monoplane, Kronfeld ground trainer and two Carden-Ford powered Drones. The way in which the Monoplane’s engine was moved rearwards to clear the wing can be compared with the large trailing edge cutout in the Drone.
The Kronfeld Monoplane makes its public debut at the RAeS Heathrow Garden Party on May 9, 1937.
The Kronfeld Monoplane is seen there, serving as a makeshift rain shelter.
A rare picture of the Monoplane in flight, taken once again at the 1937 Garden Party.
Cockpit and sparse instrument panel of a Kronfeld Drone.
Pilot's view of the Super Drone. On the left are the controls, the very full array of instruments and the cockpit layout.
The Drone pilot has an excellent view and is free of airscrew slipstream.