Aviation To-Day, and the Necessity for a National Aerodynamic Laboratory

By Captain W. Irving Chambers, U.S. Navy

Those who are engaged in the development of aviation for war purposes do not pretend that it is going to revolutionize warfare, but it has been fully demonstrated that of two opposing forces, the one which possesses superiority in aerial equipment and skill will surely hold a very great advantage.

Contemplated Uses of Aeroplanes in Naval Warfare

A. They can be carried, stowed, and used by all large ships.

  1. To reconnoiter an enemy's port, or to search out his advanced bases and to assist in the operations of a blockaded or a blockading force.
  2. To locate and destroy submarine mines, submarines and dirigibles, and to assist in the operations of submarines and torpedo boats.
  3. To damage an enemy's docks, magazines, ships in repairer under construction, dirigible sheds and other resources.
  4. To provide means of rapid confidential communicator between a fleet commander and the commanding officer of a cooperating force on shore, or of the commander of another fleet or division.

B. They can be carried by all scouts and large cruisers.

  1. To extend the "eyes of the fleet" in naval scouting.

C. They can be carried, with ample supplies and camp out on board any naval supply auxiliary,

  1. For scouting at advanced bases and for extensive use and expeditionary forces.

What Is Being Done Elsewhere

France leads the world in aviation and all that she does worth noting. A short time ago, in response to an inquiry by & Minister of War, over 3000 officers signified their desire to lea-" aerial navigation. Germany leads in aerostation, but is making great progress in aviation also. France has eight dirigibles, Germany thirty. The number of aeroplanes actually possessed In each is a rapidly increasing quantity, but France will probably possess about 350 before the end of the year, the ultimate aim being to possess 1000 as soon as the requisite number of pilots can be taught to use them.

The following statement, while it does not include all large sums that are being spent, will suffice to compare our own activity with that of some of the principal powers:

 

 

Government appropriation

Popular subscription

Total

France

$6,400,000

$1,000,000

$7,400,000

Germany

$1,500,000

$750,000

$2,250,000

Russia

$5,000,000

(?)

$5,000,000

Great Britain

$2,100,000

(?)

$2,100,000

Italy

$2,000,000

$100,000

$2,100,000

Japan

$600,000

(?)

$600,000

United States

$140,000

$140,000

As Italy is the first to have had extensive experience with aircraft in actual war so far, some observations on her establishment and her experience will be of special interest.

In 1911 there were no public or private aeroplane factories of any importance-in Italy, but this year the Aeronautic League has been formed, privately, to present to the government as many aeroplanes as possible. Funds have thus been raised to donate 100 aeroplanes, and now there are about 10 factories expecting to profit by this popular interest in the military use of aeroplanes.

There are now four squads of aviators serving in Tripoli and Cyrenaica, with 40 aeroplanes, mostly of French make, and there are 30 more in Italy.

These aeroplanes have been effectively used in scouting and they were the first to practice bomb throwing. Bomb throwing from Italian aeroplanes has been abandoned in Tripoli, however, because of its inaccuracy, and the inability to carry a sufficient number of the size required, and the attendant risk to the aviator. The Italian aviators prefer to fly without passengers. It is probable that the Italian machines, being hastily purchased, were not weight carriers, and did not have much range between high and low speeds,

For bomb dropping the dirigibles have proved greatly superior.

The captains of all dirigibles are naval officers, and the semi-rigid type is now preferred.

Under the existing conditions in Tripoli, and with no enemy in the air, and hangars available on shore, the net results have been all in favor of dirigibles for observation purposes, for taking photographs and for dropping bombs.

Bombs have dropped with good effect over Turkish camps, and good bombs have been supplied which can be timed to burst in air, as well as others which are incendiary. An apparatus has been devised by which bombs can be thrown horizontally as well as with a certain angle of inclination.

Weather conditions being equal, the Italian dirigibles, which, owing to their reversible propellers, are able to remain stationary in air, can furnish more reliable reports than aeroplanes.

The aeroplane as used at Tripoli cannot fly at night when the best weather conditions obtain; the dirigible prefers to do so, as it then loses no gas.

Aeroplanes are found to be quite safe from musketry fire at 3000 feet height. They have been hit on several occasions at lower altitudes, but without serious damage resulting.

The best aeroplane flights have been from Tripoli to Gharian and back, about 90 miles each way, and to Homs and back, 70 miles each way. The aeroplanes used can easily reconnoiter at 100 km. (62 ¼ miles) per hour.

The best dirigible flight was from Tripoli to Sidi Sidi and back. a distance of about 125 km. (77.6 miles), during which two of the small type left Tripoli in the early morning and explored all the coast, including the Turko-Arab positions at Zuara, where they dropped bombs effectively, the whole time being 9 hours 55 minutes. Off Zuara they replenished their fuel tanks from the boats of the fleet at sea.

Late Note.—The latest German dirigible recently made a flight of 1300 miles, but it is much larger than those used by the Italians.

On one occasion one of the dirigibles was struck a number of times in the after part by rifle bullets (volley fire), and returned to the hangar down by the stern.

Messages have been dropped from dirigibles in small sand bag with parachutes to which colored pennants were attached, and communication by flag or semaphore has been used, but wireless has not been used on account of the danger and incomplete development.

The Italian doctors claim that aeroplane pilots, of the machines used in Tripoli, will last effectually but six months, after which they require two years of rest, but that the dirigible pilots last indefinitely.

This result will be modified by the introduction of automatic control, mentioned later.

Foreign Naval Aviation

Italy.—Last year 15 naval officers were detailed for aeronautical service, at which time six Farman, three Bleriot, one Nieuport and one Etrich machine were available.

Two hydroaeroplanes, original designs by Italian naval officers, have been building for some time at the naval dock yard, Spezzia, and at Bracciano, the chief aeronautic station.

France.—In February of this year, a foreign periodical, referring to the purchase of a Curtiss hydroaeroplane by Paulhan, the French aviator, made the following statement:

It is probable that the American Curtiss hydroaeroplane will soon find its way in large quantities into the French Navy, which at present owns officially one aeroplane only, an old pattern Maurice Farman.

I am not sure that this was authentic, but I have noted in the French press frequent expression of regret that they had allowed the Americans to precede them in the naval development of aviation However, since then they have made up for lost time by providing a systematic organization, and the appropriation of ample funds for naval aviation. Their establishment includes a naval aviation center on the coast of Frejus, about half way between Toulon and Nice.

The cruiser Foudre, formerly used as a mine ship, has been fitted out as an aviation ship, located at Frejus. The first hydroaeroplane accepted, a Voisin, has been hoisted in and out in three minutes. The Foudre does not permit of housing machines in sufficient numbers, and hangars are erected on shore to accommodate other machines that have been acquired.

During the recent maneuvers of the French fleet in the Gulf of Juan, near Frejus, where one squadron was blockaded by another, the commanding officer of the Foudre visited the flagship of the blockaded forces in a torpedo destroyer, and informed the admiral that one of his aeroplanes, during a reconnaissance of the Gulf, had obtained exact information concerning the disposition and movements of the blockading squadrons. Submarines had been observed navigating on the surface with evident intention of attacking the blockading force. At no time had the blockading squadron, located 15 miles off shore, perceived or heard the aeroplanes. One Nieuport (100 h. p.), three place, monoplane, one Farman and one Voisin biplane were used.

England.—Last year public indignation was aroused in England because a few naval officers had been obliged to learn the art of flying entirely on their own responsibility, and at their own expense, and because the first naval aeroplanes, two Valkyrie machines have been privately donated by a public spirited citizen.

On January 11, 1912, Acting Commander C. R. Samson, R. N., made the first flight from an English battleship over a rail platform erected over the bows of H. B. M. S. Africa, in much the same manner as Eugene Ely flew from the U. S. S. Birmingham, and the U. S. S. Pennsylvania in 1910.

An official reply to a query in Parliament, noted March 6, 1912, concerning England's preparedness in naval aviation, follows:

One hydroaeroplane is now under construction at Eastchurch and two others are on order. Experiments with this type are being continued at Sheerness, Lake Windemere and Barrow.

The Royal Flying Corps has been established, and the naval wing of this corps has its headquarters at the Naval Flying School at Eastchurch. The memorandum to Parliament states:

It is impossible to forecast what its ultimate organization will be, as this depends to a great extent upon the results of experiments which are about to be commenced with hydroaeroplanes. The present organization must, therefore, be regarded as provisional.

Germany.—It is significant of German foresight that one of the first steps undertaken, when it .was decided to construct a large aeroplane fleet, was to found an aerodynamic laboratory. This is at Gottingen, where the best known course of instruction aeronautics is ably conducted by Professor Prandtl.

The Berlin Aero Exposition of this year showed a surprising development in domestic aeroplane progress. There were 176 exhibitors. Twenty-two aeroplane firms were represented by 40 aeroplanes of which not more than three were freaks, and three showed defective construction. There were 18 motor firms represented by 41 different types of motors, 41 firms for accessories, 5 tool firms and 6 steel firms.

Several German naval officers have perfected themselves in aviation, and several types of machines have been used for naval work, of both foreign and domestic make. Our Curtiss hydroaeroplane has been procured.

A competitive test for hydroaeroplanes, arranged jointly by the German Flying League, and the Imperial Navy Office, took place at Heiligendamm, from August 29 to September 5. Competitors were required to be German subjects, and every part of the machines competing, except the motor, was made in Germany. Competitors were required, after ascent from a given spot on land, to remain in the air for one hour, to alight on the water within a square of 150 meter sides, marked by buoys, to stop the motor and, after resting on the water for not more than 20 minutes, re-ascend to a height of 500 meters and return to the starting place entirely unassisted.

It is astonishing to learn how nearly the characteristics required of the machines in this competition correspond to our own "requirements," independently conceived.

These machines must have sufficient inherent stability to resist sudden squalls and must be so readily guided that the pilot will not be exhausted by the longest flight.

When the motor stops in air the machine must commence to glide automatically.

The gas throttle and all levers for regulation of motor must be large and substantial and situated on the right of the pilot's seat, about 20 inches in advance of the back of the seat.

Seats arranged for two persons must be arranged so that clear view forward, each side and downward is provided for both occupants and the latter must be protected from the draft of air. Elastic leather belts 3 inches wide must be attached to each scat and arranged to be cast adrift quid.' by either the right or the left hand.

It must be possible to control from both seats and the pilot must be able to cut off the control from the passenger scat.

The motor and the pilot seats must be protected against the splashing d water.

The propeller must be protected against coming in contact with water by a special arrangement. Preventative measures against short circuit, in consequence of the moisture, must be provided and the machine must have a speed of at least 80 km. (49.7 miles) per hour.

Late Note.—There were seven entries in this contest, only one of which succeeded entirely.

Other Countries.—Exact details are lacking of the progress m many other countries, but all progressive powers are bent on keeping abreast of the times, especially the British Colonies, Russia, Japan and Austria. The latter country has produced one of the very best aeroplanes in existence, the Etrich, and is also developing the hydroaeroplane.

Development in the United States Navy

When Congress appropriated $25,000 for the development of naval aviation last year, three officers had been ordered to aeroplane factories for instruction, in anticipation of three machines which were finally purchased, two Curtiss and one Wright.

At that time a land aerodrome was necessary for practice, and a hangar was accordingly built on Greenbury Point, Annapolis Md., where a sufficient area of flat land was prepared for an aerodrome by the leveling of some trees and the partial filling of a swamp. This served its purpose until the navy machines had all been provided with hydroplanes, and we had demonstrated the practicability of carrying on instruction entirely over water. The aerodrome is now held in reserve for the housing of spare machines, for the exercise of the land attachment of the hydroaeroplanes and for any other emergency use.

It was originally contemplated to establish an aviation school in conjunction with the Naval Engineering Experiment Station, where experiments could be expedited, but it soon became apparent that the desired number of officers and men could not be spared away from their regular duties for a sufficient period, and that the progress of instruction would be seriously delayed until the machines had been suitably developed and equipped for issuing to ships of the fleet, where practical instruction could proceed, with ample resources, in a systematic routine way. Incidentally, it was recognized that to get good service from these machines in the fleet, constant practice would be required, and the personnel be made as familiar with them as with other articles of equipment.

This was the first object in favoring the hydroaeroplane attachment.

To-day it is recognized the world over that hydro-aviation offers one of the most promising fields of development, for the reason that a water aerodrome is nearly always available, is safer in landing, is less obstructed, and the aerial currents over water are less treacherous than over land. A ship provided with aeroplanes will thus become the hangar and will be surrounded usually by an ideal aerodrome, i.e., by water sufficiently smooth for practice.

Last December the three machines, with their aviators, were transferred to San Diego, Cal., where a camp was formed with small tents from the U. S. S. Iris, and hangar tents, of the army pattern, which had been prepared at the Mare Island Navy Yard.

Experience with these tents demonstrated certain defects, and that they were not conducive to efficient progress with a small force of men. Better tents, designed by the Bureau of Construction and Repair, have been made to replace them.

After a season of winter work at San Diego, the camp was transferred again to Annapolis, and located nearer the Engineering Experiment Station, on the north shore of the Severn River. This experience with tents has demonstrated that they not only facilitate the removal of a camp from one place to another, but that it is cheaper to use them than to provide permanent sheds of more durable material at all places where a camp may be established. The use of tents also enables us to be prepared, with the advantage of experience, to transport, at short notice, all the material that may be required at an advanced base.

Instructions and Tests

Many officers, interested in this work, have applied for instruction, but, as before mentioned, it has not been possible to detach from their regular duties, even temporarily, all who desire the experience. Eight officers have qualified.

At the end of August, 1912, a total of 593 flights had been made by the four instruction aviators in the three machines. The record stands as follows:

 

In the Curtiss Machines

 

Flights

Total time

Distance

Hrs.

Min.

Miles

Lieutenant Ellyson

200

40

30

2227

Lieutenant Towers

202

37

2

2035

In the Wright Machine

Lieutenant Rodgers

132

33

54

1530

Ensign Herbster

59

14

54

630

Total

593

126

20

6422

During flights over water the aviator can usually count safe place to land. For this reason most of our hydro-flying been done at an altitude of about 500 feet. But, as scouting reconnaissance work will require flying at an altitude of about 3000 feet, Lieutenant Ellyson has demonstrated that there will be no difficulty in flying the hydroaeroplane at 3000 feet or over. On one occasion he ascended to 2850 feet in 23 minutes and 23 seconds. On another occasion, he ascended 3200 feet, but it required 44 minutes to reach the first 2500 feet. Investigation of the different grades of gap line shows that the difference in efficiency is considerable.

The longest flight yet made with passenger anywhere, in the hydroaeroplane, is that made by Lieutenants Ellyson and Towers jointly, from Annapolis, Md., to Hampton Roads, Va., and return and this flight amply demonstrated three things: (1) the suitability of the "hydro" as a type for long flights; (2) the practicability and utility of the dual system of control, and (3) the necessity for greater improvement in motors. The return flight was enlivened, in very cold weather, by a series of minor mishaps: the motor. In making such flights it is still advisable to follow a shore line convenient for landing in case of motor trouble.

Lieutenant J. H. Towers, U. S. Navy has recently made a flight of 6 hours, 10 minutes and 20 seconds, with the standard navy Curtiss hydroaeroplane. This was made in due course of a regular work, but it stands as a world's record for flight in a hydroaeroplane. A performance of five hours only would have been satisfactory.

As a part of the instruction and a fruitful means of informing us concerning necessary improvements, many repairs have been made by the aviators themselves, and the enlisted mechanics detailed for the purpose have received instruction in this way. A new Wright machine has also been built in this way from spare parts purchased from the company.

It has not been possible, under the circumstances of a meager appropriation and few officers, combining instruction with experimental work, to establish a thoroughly satisfactory system of instruction as yet. The ideal would require each aviator student to obtain a course of study in aerodynamics and meteorology up to date, of about four months, such as that recently established at the Massachusetts Institute of Technology, the theory preceding the practical work, if possible. Such a course would be best attained by the establishment of a school for aviators in connection with the lectures at a national aerodynamic laboratory.

Experimental work.—The work of instruction has been handicapped by a practically continuous series of experiments, with the result that long delays in repairing have rendered work in both particulars slower than was anticipated. On the whole, this method of experimentation for the solution of problems other than the improvement of minor structural details and the test of navigating instruments is very unsatisfactory. Important experiments involving physical research should be relegated to an aerodynamic laboratory and its aerodrome annex. Other important experiments, such as the development of wireless, requiring frequent changes, should be made at an aircraft factory where extensive repairs and reconstruction are facilitated. Special facilities already exist for doing such work at the Washington navy yard.

Some experimental work has been done on different methods of installing the wireless plant, but intermittently, owing to the enforced absence of the expert officer whose suggestions were being followed. Although the work is unfinished, it has given promise of realizing a range of 50 miles at a sacrifice of 50 pounds only in weight.

Most of the experiments have been devoted to improving mechanical details of the motors and to trying different models of hydroplanes, the result of laboratory investigation at the Model Basin.

Much useful information has been gained thus about hydroplanes, and many uncertain but alluring ideas have been eliminated.

There are seven different types of hydroaeroplanes now in France, but our efforts have been confined chiefly to two distinct American types, the single boat with balancing pontoons, and the catamaran type with two pontoons. Both types have given great satisfaction, but the single boat, which has been used on both the Wright and the Curtiss machines, seems best for our purposes. It is superior in rough water, and it is the father of the flying boat, towards which our ideas have always been inclined.

The Flying Boat was discussed in the early days, about 1905, between Mr. Glenn H. Curtiss, and representatives of the Bureau of Equipment. The first real flying boat was made and tested at Hammondsport, N. Y., a year ago last summer, and flown last winter at San Diego, Cal. After several alterations in the location of the motive power, the Curtiss flying boat tested this summer, with great satisfaction, by Lieutenants Ellyson and Towers, is regarded as a decided advance in hydroaeroplane design, and gives promise of extended usefulness in rough water.

The practicability of sending aeroplanes in flight from a suitable platform on board ship was early demonstrated by Eugene Ely in flights from the U. S. S. Birmingham and the U. S. S. Pennsylvania. We have frequently demonstrated the practicability of sending them in flight from water alongside of a ship, and both Mr. Glenn H. Curtiss and Lieutenant John Rodgers have flown alongside of a ship, have been hoisted on board and hoisted out again in a hydroaeroplane. Lieutenant Ellyson has successfully performed the daring experiment of showing the possibility and facility with which a hydroaeroplane can be sent in flight from a ship in smooth water over an improvised single wire cable, but I would not recommend the use of this device on a ship with rolling motion. Lieutenant Ellyson eagerly subjected himself in a hydroaeroplane to the extreme shock of the first catapult device in order test the effect of such a shock, not only on the aviator but on the motor attachments and other fittings. This crucial test was entirely satisfactory in its revelations, although the aviator and the machine got a ducking, and it will probably never be required again.

There is no risk that these zealous aviators will not cheerfully undertake in the interest of adapting the art of aviation to naval purposes, and it is worthy of note that the work has progressed thus far without serious accident, although it has been arduous, dangerous and replete with temptations for the aviators to rival many of the sensational performances that have resulted disastrously to contemporary pioneers in civil aviation.

A simple and convenient self-starter is a practical necessity to the hydroaeroplane before issuing it for ship use. Several mechanical devices have been tried with varying success, but other more promising devices are about to be tried, and there is reason to believe that the very best will soon lie in use on all of our machines.

The navy aeroplane catapult is a simple device for getting aeroplanes away from a ship in the quickest manner, and over the shortest track, the object being to avoid carrying on board ship any more paraphernalia than necessary to accomplish the object.

It has been demonstrated several times that an aeroplane can leave a ship by its own power over a suitable platform that is long enough, and can even alight on such a platform, under favorable circumstances, but it is desired to avoid the encumbrance of a platform.

The catapult is so small that it occupies little space, it can even be mounted for use on top of a turret, it can be transported to any location on the ship, and it can be readily dismounted and stowed away clear of the guns.

Compressed air is used for the power, as all ships carrying torpedoes are supplied with air compressors. When preparing the apparatus for use the air is pumped, to a suitable pressure, into a receiver which is connected with a small cylinder conveniently located on deck. The piston of the cylinder has a stroke of about 40 inches, and the piston rod is connected with a small wooden car by means of a wire rope purchase which multiplies the travel of the piston to any desired extent, or to any limit fixed by the travel of the car on its tracks.

The aeroplane, of course, rests upon the car and, when a flight takes place, both are projected from the tracks together in about 1 ½ seconds, the pressure being automatically and gradually accelerated throughout the stroke. The car drops into the water when free from the tracks, and is hauled on board by a rope attached to it.

The device, as used at the Washington navy yard, November 12, 1912, was mounted on a float (see Fig. 1), so that the bottom of the hydroplane was not more than two feet above the water. When discharged, the hydroaeroplane gradually arose in a steady, beautiful flight, as soon as it left the tracks, without any tendency to seek the water. (See Fig. 2, in which the car is seen just dropping clear of the hydroplane.)

During a previous trial, at Annapolis, the device was mounted rigidly on a wharf. The car and machine were both free to lift from the tracks during any part of the stroke, and after the aeroplane motor had been started full speed, the full pressure of 300 pounds was turned on at once. On this occasion the machine reared at about mid-stroke and, as a cross wind was blowing, the right wing was thrown up, and a corkscrew dive into the water resulted. Lieutenant Ellyson, the aviator who managed the

machine on both occasions, and whose iron nerves were relied on to stand the shock, was fully satisfied, by this extreme test, that the shock ought not to deter any good aviator. It was also gratifying to note that no part of the machinery or fittings was ruptured or showed any signs of weakness.

When tried at the Washington navy yard, November 12, the float enabled the apparatus to be pointed towards the wind, which, however, was nearly calm at the time. The car was held down to the tracks by reverse flanges and extra wheels, and the balanced valve of the cylinder was arranged to be gradually opened to full power by a simple wedge shaped cam attached to the travelling block on the piston head. The aeroplane was also held down to the car by an iron strap, the ends of which were tripped automatically at the end of the stroke by studs on the tracks.

Several preliminary tests of the device, with sand bags to represent the weight of the aeroplane, were made before the final test of November 12, and curves of speed and pressure were obtained in each case. These curves are reassuring and demonstrate the possibility of getting, by this method, the curve of velocity to follow any trajectory desirable within practicable limits.

Figure 3 represents the car weighted with sandbags for a test at the Navy Yard, and Figure 4 shows the car with its sandbag burden just leaving the tracks. It is interesting to note in this picture some of the heavy sand bags and the block to which the holding down strap was attached suspended in mid air, while the comparatively light car is dropping away from them.

This picture (Fig. 4) also shows the air-flask, the cylinder, the piston rod and the cam.

Instruments.—Aviators and manufacturers have been slow in making use of instruments which not only make flying safer, but which may be made to relieve the aviator of much of the nervous tension and strain of long flights and flying in uncertain weather. A constant increase in the number of disasters has disturbed the people of France for some time, with the result that special attention has been given to the problem of safety; special efforts have been made not only to improve inherent stability and structural strength, but to provide means for controlling the equilibrium automatically.

One cannot blame those who are already skilled in flying for being conservative in this matter, in view of the many defective devices that have been exploited to effect the object. There is a good reason for going slowly and carefully in the test of anything that presumes to take the place of the aviator's skill, but manufacturers and aviators are beginning to realize that progress in aviation is greatly dependent upon the perfection of instruments for safe guidance and automatic control, that there is something more than acrobatic skill required to place aviation on a practical footing in the navy, that the elimination of man as a factor of chief importance by the supply of mechanism which will perform the things that he is prone to do indifferently, especially under the strain of fatigue, is a practical necessity to his success as a real aerial navigator.

Simple and reliable automatic control devices which may be added without sacrifice of too much weight are now being eagerly sought, and some that may be rigged to work automatically, semi-automatically, or not at all, at the will of the aviator, are being made.

The Air Compass.—Much important work for which the aeroplane will be useful in the navy will not necessarily require the air pilot to navigate in a fog, or at night, or out of sight of his base, but in sea scouting, which I think is destined to be one of his principal spheres of usefulness, the pilot may be caught in a fog, he may be obliged to navigate at night and will have to lose sight of his base frequently. It must be possible, therefore, to navigate as accurately in air as it is to navigate a ship by dead reckoning at sea.

Motors.—Improvements have been confined principally to the correction of small defects, which have been made as soon as discovered. Much more could be said about what is still needed. When anything goes wrong, or when trouble begins in a flight that promises well, some trifling detail of the motor is usually at fault, a small pin here, a pump connection there, but nearly always something new and unexpected. It was so with the early motors of automobiles, and this thought inspires confidence in the perfection of aviation motors, although the demand is still greater for increased power or speed rather than reliability and durability.

Rangeof Speed.—A weight carrying aeroplane such as a hydroaeroplane necessarily needs a motor with considerable range of speed, and the same kind of motor is needed to reduce the danger of alighting. This is not the kind of motor and combination of motor and surfaces that now wins the speed contests such as that for the Gordon Bennett Cup. I think aviation would be improved if the terms of future speed contests were arranged so as to require each contestant to go over the course twice, the second time at an average speed 20 per cent lower than his highest average.

Requirements.—A year ago our manufacturers requested specific information as to the conditions to be satisfied in adapting the aeroplane for naval use. The answers at that time were necessarily indefinite, but with the benefit of a year's experience we have been able to issue a set of "general requirements," sufficiently broad m scope, to permit a wide latitude for ingenuity and improvement.

These requirements cover not only the peculiar conditions to be satisfied in naval aviation, but, for the first time, require our builders to show that their machines are designed in accordance with up-to-date practice. Builders are required to prove technical data, which will eliminate from competition all who depend on haphazard methods. Complete stress diagrams under different conditions of load and all fundamental characteristics, a knowledge of which is indispensable to an intelligent comparison of designs, are demanded. The stamp of approval is given to the introduction of improved methods for the automatic control of equilibrium and our builders are encouraged to attain a high degree of efficiency, to improve the factors which govern safety, and nothing is demanded that may not be readily accomplished under the limitations of the art as it is generally understood at present.

Unsatisfactory Limits in Appropriations

In accordance with the policy of the Department, as mentioned in the last annual report of the Secretary of the Navy, aeroplanes are now placed in the same category as other articles of a ship's equipment, and are appropriated for accordingly, the general architecture and constructional features being provided by the Bureau of Construction and Repair under its general appropriation "construction and repair of vessels," and the motive power, including radio apparatus, being provided by the Bureau of Steam Engineering under the appropriation for "steam machinery," it being intended that all Bureaus will do their share in providing the specific parts which naturally come under their cognizance in the Department organization.

It seems unnecessary to place a limit on aeroplanes under these appropriations when expenditure on boats, steam steerers, windlasses, boilers and "all other auxiliaries" costing much more, is unlimited. No economy is effected by placing a limit on any one of the numerous items under these appropriations, and no extravagance can occur by removing the limits on aeroplanes because, regardless of limits, the amount of each appropriation remains the same, and expenditures on each item will be jealously guarded, by the Bureau concerned, to carry on current work as necessities arise.

It is particularly unfortunate that the small limit of $20,000 is placed on aeroplane machinery under the Bureau of Steam Engineering, because our experience shows that each aeroplane used for instruction requires two motors to carry on the work effectively. This, of course, will be impossible under the present limit, as the expense of repairs is also comparatively great. The limit of $35,000 under Construction and Repair is unsatisfactory also.

Influence of Foreign Laboratories

Little more than a year ago our knowledge of the effect of air currents upon aeroplane surfaces was almost entirely a matter of theory. The exact information available was so meager that aeroplanes were built either as copies, slightly modified, of other machines, or else by way of haphazard experiment. This state of affairs obtains to some extent in the United States to-day, although in Europe aeroplane construction is now largely based on scientific data obtained at notable aerodynamic laboratories.

The intuitive, hasty and crude methods of the pioneer cannot succeed in competition with the accurate and systematic methods of the scientific engineer, and it is beginning to dawn upon our perceptions that, through lack of preparation for the work of the scientific engineer, i. c., through delay in establishing an aerodynamic laboratory, a waste of time and money, a decline of prestige and an unnecessary sacrifice of human life has already resulted.

Students of aviation do not need to be informed of the practical necessity of aerodynamic laboratories. They have repeatedly pointed out, in aeronautical publications, the immense commercial advantages to be anticipated from the establishment of at least one in this country, and they have naturally expected that some philanthropic patriot, of wealth and scientific interest, would come to the rescue with a suitable endowment fund that would enable such work to be started in short order without government aid. The fact that no patriot has responded is disappointing, in view of the large private donations that have done so much for aviation in France, but in my opinion, it simply indicates something lacking in the manner of disseminating information concerning the importance of the subject. I am not willing to believe that our people will refuse to establish one when they are fully acquainted with the advantages to humanity, and to sane industrial progress, and when a reasonable concrete proposition is advanced for their consideration. I have submitted such a proposition which follows, in general outline, the ideas advanced in an address to the Fifth International Aeronautic Congress by one of the greatest authorities in the world, the Commandant Paul Renard, President of the International Aeronautic Commission.

A National Aerodynamic Laboratory

Before considering the character of the work to be clone, and some details of the needed plant, it will facilitate matters to show what should not he done at such a laboratory.

There are those who dream of supplying the laboratory with all the instruments known to mechanics, to physics, and even to chemistry, in order to have a creditable and complete national institution. They would concentrate in one locality all the scientific instruments and acumen available with the false idea that economy would result. This would be a grave error.

The financial resources, however great, are sure to be limited, and a too ambitious or a superfluous installation would squander the sources of power and indirectly menace the initiative of other industries. The character of the new work to be done demands that everything should be rejected that can be dispensed with readily, in order that appliances specially needed in the new work may be provided, and that these appliances be of the latest and most efficient types.

For the sake of economy, not only of money but of time and intellectual energy, tests and experiments that can be executed as well or better elsewhere by existing establishments, should be avoided. For example, it is unnecessary to install a complete set of instruments and implements for testing the tensile strength of materials or their bending and crushing strength. Many other establishments permit of such work. If the laboratory be located in Washington, where certain advantages exist, such work could be readily done at the navy yard, where other facilities exist, such, for instance, as the testing of models for hydroaeroplanes, and flying boats. The Bureau of Standards and Measures, and other government branches in Washington, also offer facilities which it would not be wise to duplicate in such a laboratory.

I do not think that such an institution should be burdened with measuring the power of motors, or preoccupied with the details of their performances. This may be done at various other government establishments, and it is understood that the Automobile Club of America is also equipped for this work.

Nor is it necessary to have a complete chemical laboratory under the pretext of studying questions relating to the chemistry of fuel, or the permeability of balloon envelopes.

I do not wish to convey the idea that an aerodynamic laboratory should be deprived entirely of such facilities, and that it should be obliged to seek minor information from other establishments when that information may be more economically obtained by a duplicate plant on a small scale. Such duplicate conveniences, however, should be regarded as strictly accessory, hut it should be well understood that, whenever important researches can be prosecuted as well or better elsewhere, dependence should be placed on those other establishments where such work is a specialty.

Two Distinct Classes of Work

An aerodynamic laboratory should be devoted to (1) experimental verification; (2) experimental research. The first is concerned with testing the qualities of existing appliances, propellers, sustaining surfaces, control mechanism, etc. Usually these tests are made at the request of interested parties (as is now the case with the water models at the navy yard model basin). A constructor or designer will bring, for example, a propeller, and will wish to know its power or thrust at a given speed on the block, or on a moving appliance under the conditions of flight, or he may bring several propellers to compare their performances and to ascertain what power they absorb at different speeds.

One of the very successful appliances devoted to this work at St. Cyr is a movable car in which an aeroplane may be mounted and tested at speeds, in perfect safety, as to its strength, its efficiency, and the suitability of its control mechanism. This device is specially adapted to make actual service tests of sustaining surfaces—in other words, to try out, in perfect safety, the relative efficiencies of finished aeroplanes. It is a most important adjunct, as it supplements and rounds out the important research work on models in the closed laboratory.

Tests of this character, i. e., verification tests, constitute, so to speak, standard work. They are performed at the request of manufacturers, clubs, independent investigators, and other interested parties on condition of payment for the actual cost of the work. They, therefore, contribute to the support of the establishment.

The tests of verification, however, notwithstanding their great utility, do not constitute either the most important or the most interesting work of the laboratory. The research work, which prosecutes continuously and patiently systematic, thorough and precise investigation of new ideas, or of old ideas with new applications, with the specific intention of discovering laws and formulae for advancing progress of aerial navigation, is of greater importance, because it is the short cut to substantial efficiency, economy, improvement and prestige.

This work is concerned with developing adequate methods research in all branches of aerial navigation, and in reliable information to all students, engineers, inventors, manufacturers, pilots, navigators, strategists and statesmen, knowledge thus gained should be disseminated regularly through publications, lectures, open-air demonstrations, and by exhibitions of apparatus, instruments, materials and models—in fact, by all the facilities of the aerodrome, the showroom, the library and the lecture room.

An exact knowledge of aerodynamics can be best acquired in such a laboratory by experimentation with standard scale models in air tunnels, such as those used by M. Eiffel, and others. In this way reliable data is obtained of the air resistance to be encountered, and the efficiency at various velocities, the amount of lift, the effect of varying impact at different angles of attack on the stability, in fact all the exact data which, reduced to curves and diagrams, enables the engineer to design a machine in a scientific manner. From such data the performance of a new machine can be closely predicated. The performance of the finished product can be verified, later, as before described.

Much of the research work will be prosecuted at the request of technical men outside of the institution to whom the laboratory should offer, gratuitously as far as possible, its material and personal resources.

The Council and Organization

To obtain benefit from these researches it will be necessary to know that they are worth the time and expense, and a body of men—a council or a board of governors—should be authorized to accept or reject requests for this work. This will be a delicate task, but the principal duty of the council should be to establish and to correct, from time to time, a program of the research work to be executed by the director and his staff, and to co-ordinate the work to the best advantages within the limits of the money available. The disbursement of the government funds, however. and the responsibility therefore should be entirely under the director.

With the actual state of aerial navigation and its deficiencies as a guide, it will be the policy of the council to concentrate effort upon such points as seem most important, promising and interesting for the time being.

I do not think there would be any doubt, if we had the laboratory in working order now, but that all questions relating to improvement in stability, automatic control, and safety in general would have the right of way.

The council or board, which in England is called the "advisory committee," should be representative of other government departments than that employing the director, and should be independent of the director and his administrative staff. It might be possible for the director to act as a member of the council, and if so, it would conduce to harmony and expedition.

The council should not be a large body, but should be composed mostly of specialists of unquestioned ability, men interested in the sane development of aerial navigation in various branches of the government, and in its useful and safe adaptation to commerce and sport.

Whatever the ability of this council, it should not be allowed to pretend that it has a monopoly of aeronautic acumen. Many brilliant and worthy ideas may originate outside of the establishment which it will be wise to investigate. And to avoid any possibility of the council being charged with narrow prejudice, it is indispensible that it be not composed entirely of specialists. In a few words, it should comprise representative men, who are also learned and technical men, with broad vision and reputation, whose presence will guarantee to industrial investigators that their ideas will be treated in an unpartisan or unbiased spirit. I will not attempt to suggest the composition of this council or board, but it is evident that the army and the navy should each be adequately represented on it.

Endowments, Prizes, and Rewards

If the laboratory should obtain, in addition to the funds required for prosecuting researches by its staff, any endowments of financial aid in excess of immediate needs (and I am confident it will eventually), it would accomplish useful work by offering prizes and granting rewards for important results achieved outside of the institution. The division of rewards would be one of the functions of the council, and it is possible that this would be one of the best uses of such resources, after the success of the laboratory is assured.

The complete role of an ideal aerodynamic laboratory can be summed up now in a few words in the natural order of establishment: (1) Execution of verification tests by means of nominal fees; (2) Facilities to technical men for prosecuting original researches; (3) Execution of researches in accordance with a program arranged by the council; and (4) Reward of commendable results accomplished outside of the laboratory.

Nature of the Plant

Researches and tests can be made on either a large or a small scale, preferably on both.

The use of small models can be made prolific in results because of the comparatively small cost, provided we understand the laws governing transformation into the full sized products. For model work a large plant is unnecessary. M. Eiffel has done very valuable work in a very small establishment.

Certain classes of tests with large models, such for example as the block test of propellers, do not require much space. But the conditions are altered when such tests are made on a machine in motion. These more difficult tests are absolutely indispensable, and very important to the usefulness of an official laboratory.

Experiments and tests with small models being comparatively inexpensive, private establishments often undertake their execution, but when we attempt to draw conclusions from their results, we are obliged to admit that the laws of comparison with full-sized machines are debatable the world over. Comparisons are sensibly true between small surfaces and larger surfaces that have been extended proportionately to the square of the linear dimensions, even to surfaces five or ten times larger, but when we pass to much larger surfaces, as we are obliged to, we are forced to adopt formulae with empirical coefficients about which there is indefinite dispute.

The difficulty can be overcome only by precise experiments upon large surfaces, and such experiments, whatever the manner in which they are performed, will be costly. If privately executed, the financial returns would not cover the cost.

The laboratory should comprise, therefore, two distinct parts, one devoted to experiments on small scale models, and the other to experiments on surfaces of large dimensions. But in both parts, precise and thorough work is necessary.

When we have studied separately each element, of an aeroplane, for example, it will be necessary to test the complete apparatus. An aerodrome annex is, therefore, necessary, or, at least, laboratory should be located in proximity to an aerodrome of which it can make use. In order that the observations may not only be qualitative but quantitative, it will be necessary to follow all the movements of the complete machine, to know at each instant the speed, the inclination, the thrust of the propellers, the effective horsepower, and, in fact, to conduct a true open air laboratory for aircraft, after the manner of certain tests that have been prolific of results in France.

The English have established close relations between the Royal Aircraft Factory and their laboratory, the function of the former being that of the reconstruction and repair of aeroplanes, the test of motors, and the instruction of mechanics.

Location of the Laboratory

The location of the model testing plant, the headquarters of the administration staff, requires comparatively small space, and there is no reason why it should be remote from, a city, or from intellectual and material resources. It is advantageous to have it easy of access to many interested people who are not attached to it.

The location of the open-air laboratory should obviously be at an aerodrome, as near as may be convenient to the model testing plant or headquarters. Close proximity of the two parts is desirable but not necessary. The high price of land near a large city obliges the aerodrome annex of foreign plants to be located at a distance, but we are fortunate in having here, at Washington, ideal conditions for the location of both parts. The model laboratory should obviously be located on the site of Langley's notable work at the Smithsonian Institution where the nucleus, an extensive library of records, and certain collection of instruments are still available. The National Museum is also an ideal location for the historical collection of models that will result.

No more ideal location for the annex, the open-air laboratory or aerodrome, exists in all the world than that afforded by the, as yet undeveloped, extension of Potomac Park. This is government property, which is of doubtful utility as a park only, but which would be of immense utility and interest as a park combined with a scientific plant of the character under consideration.

There is no reason why the public should be excluded from such a practice field, but there is much to recommend that it be open to the public under proper regulations as to the traffic, especially on occasion of certain tests or flights of an educational value. It is of sufficient area, about one square mile. It is about two miles long, is almost entirely surrounded by broad expanses of water, and while convenient of access, is so situated that the public may be readily excluded when tests of a dangerous character are in process of execution. The fine driveways that will be required as a park will offer excellent facilities for the practice work of the aerodrome and for the moving test cars that should be supplied.

One of the most attractive features of this location is the advantage it offers as an ideal aerodrome for both the army and the navy, for both land and water flying, and the opportunity it affords for co-operation in all branches of the work of instruction and experimentation. Furthermore, it is near to the shop facilities of the navy yard, the accommodations of the Washington Barracks, the conveniences of the various government hospitals, and it would doubtless add to the information and interest of the nearby War College Staff and the General Board of the Navy. Its location would enable our statesmen in Congress, and a great number of the officials in all departments to keep in touch at first hand with the progress of aeronautics, with the quality of the work done, and with the manner in which the money appropriated was being expended. The educational facilities offered by the work and by the lectures would be invaluable to the course of instruction for army, navy and civil students of aeronautics.

As Washington is a mecca for business people of all parts of the country, a laboratory located here would be convenient in a commercial sense, especially in view of its southerly location, which renders the open aerodrome available for use throughout the greater part of the year. The only objection that I can see to the Potomac Park extension is that the ground will require a considerable clearing, but the trees on the harbor site of the location would not necessarily require removal.

The Apparatus Needed

It is useless to discuss here the various instruments and methods which have been subjects of some dispute abroad. All have some good feature, but time has shown where some of the cumbersome and unnecessary installations may be eliminated to advantage and where others may be improved. The new plant of M. Eiffel, at Anteuil, may be regarded as a model for the wind tunnel and the aerodynamic balance. A duplicate of that plant alone would be of inestimable value. The last volume published by M. Eiffel is a forcible example of the value of his discoveries, by this method, with respect to the angle of incidence and the displacements of the center of pressure. It seems to merit the utmost confidence, although the details of his installation differ from those at Chalais, at Koutchino, at the Italian laboratory, and others. This method permits of testing the resistance of body structures, the sustaining power of surfaces, the tractive power of propellers, and the influence of transverse or oblique currents. If a "free drop" apparatus at uniform speed be regarded as indispensable to obtaining the coefficients of air resistance to solid bodies of different shapes, it is possible that the interior of the Washington Monument could he used to advantage, as was the Eiffel tower, without disturbance of the main function of that noble structure. This would be an excellent place from which to observe the stability or action of falling models cast adrift at an altitude of 500 feet, under varying atmospheric conditions. The free drop of full-sized model would, of course, require the use of kites or captive balloons.

The moving car, previously referred to for tests of verification would be the most useful open-air plant and would soon repay the outlay required by the value of the information obtained from its use. A miniature duplicate of this method for preliminary tests on models with a wire trolley would be of value in a hall of dimensions. It would be useful in winter work, but not invaluable.

The track of the open-air vehicle at St. Cyr is too restricted to give the best results. The car cannot circulate continuously at high speed and maintain the speed for a sufficient length of time. An ideal endless track may readily be arranged at the Potomac Park extension, preferably of rectangular form with rounded corners. A railway track would be preferable, but excellent results could be obtained from autotrucks run on macadamized road-beds. Good results could be obtained by the use of suitable hydroaeroplanes or flying boats suitably equipped with instruments.

At the aerodrome annex ample facilities should be provided for measuring the wind velocity at various heights and at different points. The convenient installation of recording anemometers and the employment of kites or captive balloons should be considered.

A branch of the U. S. Weather Bureau could readily be established at the aerodrome here in connection with the investigation of meteorological phenomena affecting the movements of aeroplanes in flight, and as an adjunct to the national laboratory.

Exactly measured bases and posts of observation are also required, as well as instruments of vision or photographic apparatus, to permit of following machines in their flights and of preserving the records for study.

One of the most useful installations for recording advanced information is an actual aeroplane itself equipped with instruments adapted to record, while in flight, much of the information that is desired. Such a machine is already in use in France and in England.

It will be in perfect harmony and convenient to the laboratory to obtain all the services of an aircraft factory for the Washington navy yard, where facilities already exist for the reconstruction and repair of aeroplanes, the test of motors, and the instruction of mechanics. But this should not be allowed to interfere with our policy of relying upon private industry for the purchase of new machines for the sake of encouraging the art among private builders.

It will suffice to merely mention the hangers or sheds required, or the local accessories, such as drafting rooms, offices, and minor repair shops. The character and location of these present no difficulties, but they should not be made the principal part of the institution as they are in several elaborately equipped foreign laboratories. The power plant, however, is a subject for careful consideration, and the economy effected by M. Eiffel in his new installation at Anteuil is worthy of study.

Cost

I have seen estimates varying from $250,000 to $500,000 for such a plant, but inasmuch as $100,000, with an annuity of $3000, donated by M. Henry Deutsch de la Meurthe, to the University of Paris, for the establishment of the aeronautical laboratory at St. Cyr, seems to have been sufficient for a very creditable though somewhat deficient plant, I will venture an opinion that $200,000 would be sufficient in our case. Although the same plant would cost more in this country, I assume that some of the buildings required are already available at the Smithsonian Institution. If located elsewhere, the cost would be considerably more than the sum named.

A Commission Recommended

Inasmuch as more definite information regarding the actual cost of a dignified and creditable, but modest and sufficient installation should be obtained, and as the details of the plan, the scope, the organization and the location of such an important undertaking should not be left to the recommendations of one man, a commission or board should be appointed to consider and report to the President, for recommendation to Congress, on the necessity or desirability for the establishment of a national aerodynamic laboratory and on its scope, its organization, the most suitable location for it, and the cost of its installation.

 

 
 

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