TO MEASURE THE STAGGER of an aeroplane, a plumb-line is dropped over the leading edge of the upper plane. The stagger is the distance from the plumb-line to the leading edge of the lower plane. The object of stagger is to prevent the airflow over the lower surface of the tope plane from interfering with the airflow over the upper surface of the bottom plane. Generally, it also provides the pilot with a better view.
Elaborate ground organizations, depending largely on radio, for ensuring the safety of air travel.
This chapter is by Major Charles C Turner, the aeronautical correspondent of The Daily Telegraph and Morning Post. Air traffic control has a wide appeal among our readers and little seems to be known about it among the general public. Air traffic depends more and more on efficient radio services, and in Great Britain, because of the frequency of poor visibility, this dependence is great. The control of air traffic is not longer a localized problem. There is now an Inspector of Air Traffic Control. He supervises the traffic side of the Air Ministry's staffs at all the principal airports -Croydon, Heston, Manchester and Portsmouth.
The Radio Room at Croydon Airport
TO GUIDE AIR LINERS DURING FOG radio apparatus is installed at Croydon Airport. The radio room of the control tower is show above. In this room is the directional radio installation. During fog the control officer announces by code a “controlled zone” system. The radio officer sends messages to incoming air liners, telling them how to proceed on arrival in the controlled zone.
Air Traffic Control
AERIAL DIRECTION POST at Schiphol Aerodrome, near Amsterdam, Holland. It shows the direction of airports in Europe and the East, and was built for the interest of passengers. A pilot, before he starts, calculates a compass course, taking into account the speed and direction of the wind and the normal cruising speed of his machine. If the wind changes in direction or speed and landmarks are obscured, he may require the help of directional radio. At Croydon, Lympne (Kent) and Pulham (Norfolk), as well as at many aerodromes abroad, there are instruments capable of telling a pilot his position.
Air Traffic Control : Photogravure Supplement
AT LE BOURGET AIRPORT, near Paris. The Imperial Airways liner Horatius is a biplane, one of several flying between London and Paris. It has four Bristol Jupiter air-cooled radial engines, three of which can be see. The total horse-power is 2,200. The maximum speed is about 120 miles an hour and the cruising speed 95-105 miles an hour. The new Le Bourget Airport was opened by M. Albert Lebrun, President of the French republic, in November 1937. The imposing control tower is on the right, behind the nose of the air liner.
Air Traffic Control:
ALL CLEAR FOR THE START at Tempelhof Airport, Berlin. The aircraft is a Junkers Ju 160. This is a fast cabin monoplane, with a maximum speed at 3,000 feet of 211 miles an hour and a cruising speed of 199 miles an hour. The nine-cylinder radial air-cooled BMW 132A engine develops 750 horse-power. The signal to leave the vicinity of the aerodrome buildings and to taxi across the field, in preparation for the take-off, is given by a panel or disk, such as that held in the official’s right hand.
Waiting for the Starter’s Flag
WAITING FOR THE STARTER’S FLAG in the King’s Cup Air Race in 1937. The King’s Cup Air Races are arranged on handicap lines. In the foreground is the Short Scion Senior four-engined liner, with its engines running ready to start. The aircraft which compete in these races are of all types and sizes, ranging down to the smallest of single-seater machines.
How competitive flying has advanced the design of civil and military aircraft. Air racing has had a long and strange career, despite many arguments about its utility value. It was more appealing when it began in the pioneer days of Hendon, when aeroplanes were slow enough to be flown round a course of pylons within full view of the public. Those were the great days when hundreds of thousands of people went by wheel and on foot to London’s flying centre to see such pilots as Hamel, Porte, Lee Temple, Verrier, Grahame-White, Hucks and others disport themselves on contraptions many and varied. Aircraft, however, developed so fast that pylon racing died a natural death, and only long-distance racing could survive. Major Oliver Stewart contributes a chapter on this fascinating subject.
The story of the Montgolfier brothers who translated into reality the centuries old dream of flight. They progressed until they saw their balloon ascend with the world’s first aeronauts to make the pioneer voyage into the air. This chapter is written by P R Bird, and is concluded from part 6.
An Avro Training Biplane
AN AVRO TRAINING BIPLANE is a good example from which to illustrate the various items of the rigging of an aeroplane. During the process of rigging, the machine is lifted just clear of the ground on trestles. The height of the trestles is generally such that the machine is held in the same attitude as that in which it flies level. Correctness in the height of the trestles is most important, because, if the aircraft were rigged while in the wrong attitude, the machine would not fly properly.
The story of Sir Alliott Verdon-Roe, whose biplane of 1908 was followed by many famous designs. Of all names associated with the development of aeronautics that of Alliott Verdon-Roe ranks with the highest. He is an essential part of the progress of flight and a founder of British aviation.
Many of us will recall the excitement which was aroused when we first heard the news of his early activities, and some of us, too, will have pleasant memories of our early flights on the 504 Avro biplane which seemed to possess a thousand virtues and no faults. I wonder how many of my readers had their air baptism on this type of machine? Certainly it was responsible for the introduction of flight not only to many pilots but also to thousands of passengers, for after the war of 1914-18 it was extensively used for joy-rides and did much to add to the then limited air-mindedness of the country.
With another pilot and only one machine of this type, your Editor attempted to found a flying club at Hendon as late as about 1924, but, as subsidies were not then easily acquired, our joint attempt could hardly be described as a great success; our machine, however, did admirable work in passenger-carrying on the South Coast. The point is that of the machines available we chose the Avro as the most suitable for instructional work and the carrying of “joyride” passengers. Its record of safety was phenomenal. There could be no disagreement about that.
It was Roe who, in the days of the front elevator (which I personally liked because it could be trimmed conveniently to the horizon), decided to develop the tractor-screw machine without an elevator in front. He thus broke away from the Wright brothers’ policy, and that of other constructors and pilots such as the Farmans and Cody. This chapter provides a full account of the pioneer work of Sir Alliott Verdon-Roe.
TRACTOR TRIPLANE, in which A V Roe made successful flights at Lea Marshes, London, in 1909. This machine was fitted with a nine horse-power JAP motor-cycle engine, and had a wing span of twenty feet. The tail of the machine was also a triplane assembly. It had a span of ten feet and an area equal to half that of the main planes. The angle of the main planes was made adjustable to give the aircraft a wide speed range in level flight.
Vickers Wellesley Monoplane
THE VICKERS WELLESLEY MONOPLANE is a machine built entirely on the geodetic principle. In geodetic wing construction there are no main spars or ribs, all the strength being supplied by outer members which also provide the shape of the wing. This aircraft has a retractable undercarriage. The structure below the wings which look like seaplane floats are streamlined bomb carriers. The Wellesley is the type of machine that was chosen at the end of 1937 for the attack by Great Britain on the world’s distance record in a straight line.
The First Free Man-Carrying Balloon in Flight
THE FIRST FREE MAN-CARRYING BALLOON in flight over Paris in 1783. With two men on board -J F Pilatre de Rozier and the Marquis d’Arlandes - this hot-air balloon rose to over 300 feet and travelled a distance of about five and a half miles. Some twenty-five minutes elapsed during the flight, which provided a thrill for the aeronauts when the fabric was set alight by the fire used to heat the air in the balloon.
Past and present aircraft with unusual features of design. Almost every conceivable arrangement of wings and tail has been tried at some time or another. Almost every form of construction has been used. Yet it is by no means certain that the fixed wing aeroplane, as it is today, is the final pattern to which all future types will conform. This chapter is by Major Oliver Stewart. It is the second article in the series on Unorthodox Aircraft.
Fixed Wing Machines
CIRCULAR WINGS were used on the Tilghman Richards aircraft, a model of which is photographed on the left. Research and experiment were carried out on this type between 1910 and 1914. The chief advantages claimed for the annular wing arrangement was that the span of the aircraft could be about half that of an aircraft with orthodox wings of the same area. The Tilghman Richards machine attained a speed of 83 miles an hour with an engine of 80 horse-power.
A PTERODACTYL tailless in flight in the central picture. The Pterodactyl is a tailless machine designed by Captain G T R Hill, and the first model appeared in 1926. Its aim was to give improved stability in flight and to avoid the dangers of stalling. Several machines of this kind have been built, one of them as a high-powered Service aircraft.
All Types of Aircraft Classified
International Service Markings
Colour plate showing how the service aircraft of some of the leading counties of the world are distinguished. An article on Aircraft Markings appears in part 15.
(Facing page 180)
THE TRICYCLE UNDERCARRIAGE, used on some of the earliest aeroplanes, has recently been revived. The Stearman-Hammond Model “Y” two-seater monoplane is a good example of the application of the tricycle undercarriage to modern machines. This American design has created considerable interest in Holland. The tail remains up when the machine is resting on the ground, and the nose wheel, as well as the two side wheels, plays a part in the landing of the machine. Landings are considerably easier than with the orthodox undercarriage, there being no tendency for the machine to bounce into the air if a bad landing is made.