ENDURANCE IN THE AIR

Sun (Auckland), Volume II, Issue 374, 7 June 1928, Page 11

ENDURANCE IN THE AIR

Secrets ol Flying Success nothing to chance in pacific venture Exclusive to THE SUN (By C. T. P. ULM, co-pilot to Kingsford Smith in Southern Cross) NO. 11. EVERY ounce counts when an airplane is laden for a long flight. There are two factors which must be taken into account in deciding upon the carrying capacity of a machine. These are lift and speed power. One machine may lift a huge load but its lower speed cancels the benefit of the extra fuel carried. How can men be sure that they can endure the physical strain of many hours flying? Fitness of nerve and mind of the crew must be as certain as the efficiency of the machine.

ON the question of “heavy load flying,** there are two main factors to be studied, and they are cared for in the main in the design of the plane, j They are: (a) wing-loading (being the | amount of load to be carried to a j square foot of available lifting surface). and (b) power-loading (being j the gross load to be carried per avail- j able horse-power —the sum of these j being usually referred to as “composite loading.” Everyone realises that there is a limit to which a plane can be “composite loaded? and then flown, and we now know something of this subject, aa. after many “building up load tests,” we eventually established a n ew world’s record for “composite loading.” To give an idea of the amount of research work required on this subject alone, I will point out that when Kingsford-Smith and the writer broke the round-Australia flight record, in July, 1927, our plane was overloaded and our wing loading was about 7.81 b a square foot, and our power loading about 14.21 b a horsepower, giving a composite loading of 221 b. We have now established a world’s record with a composite loading of 49.21 b. The plane was, of course, overloaded, but it flew, and, with this gross load (15,8071 b) created a world’s record for sustained flight in multiengined, heavier-thun-air craft by staying aloft for 50 hours 7 minutes. Let me say here, that one of the many reasons for us deciding on a Fokker plane was the fact that the the:i world’s record for composite loading was established by a Fokker plane (Kelly and McCready's U.S.A. transcontinental flight, with composite loading of 471 b). For, naturally, one of the very first essentials in choosing a plane for a long non-stop flight is its capacity to lift and efliliently fly with a load of petrol sufficient to enable it to reach its destination, plus a margin. Every airplane that has ever embarked on long non-stop flights of 2,000 miles or over has been “overloaded”—overloaded meaning the carrying of a load greater than that which it was designed to carry with tho required normal safety factors. I know of r.o plane in the world to-day that is designed and constructed to carry a petrol load sufficient to give it a non-stop range of 2,900 miles without overloading. Safety Margin Sacrificed And our first problem was, Irrespective of the remainder of our route, to secure a plane that would do this. In any type of plane chosen we bad to sacrifice some proportion of the factors of safety designed for it. It Is all a matter of compromise and the nature of the compromise

must be decided by the type of flight the plane is to be used for. Some prefer a high ‘‘power loading,” and j comparatively lower “wing loading,” the result being a plane with a large lifting surface (wing) and relatively smaller power plant, which, as a whole, results in a slow air speed, a good range in hours, but a poor range in 1 miles. On our trans-Pacific flight we need range in miles, not range in hours. We had to determine (and have done ! so after many careful tests) the most economical speed at which to run our engines to enable us to fly the greatest number of miles, not hours. The third factor in heavy-load flying is controllability—for it has been proved that it is possible to “take off” with a plane, so heavily loaded that it will not tty. This may sound an Irishman’s way of expressing myself, but the facts are as given in the following instance: Given a long enough runway, it might be possible to take off with our plane loaded to, say, 17,5001 b. The plane would, for instance, rise off the ground and be flying. but while so heavily loaded would not be able to gain an altitude greater than approximately the span of its wing (in this case 72 feet), and the slightest roughness of the air causing a “bump” would throw the plane out of control, and, being so close to the earth, a crash would be inevitable. Sheer flying skill could not avert a s crafeh in a case such as this. Of course, the pilot’s skill is all- ■ important in those heavy-load takeoffs, and the first few hours flying thereafter until the load is lightened , by the consumption of petrol. In > our case our pilots have proved themselves to be capable. On six separate occasions they have taken off the Southern Cross with loads l,ooolh greater than we will require on any stage of our flight home. Not to mention innumerable building up load , tests, when many flights were made carrying 50 per cent., 60 per cent.. 70 per cent., 80 per cent., 90 per cent., and 100 per cent, of the ultimate gross load. Drastic Tests As an instance of the thought and care to be exercised in organising these test flights alone, I will mention that before the third 100 per cent, test flight was made we had to redesign ; the rudder, strengthen the whole tail end of fuselage, fit extra vertical members at points of great stress in the > fuselage, install secial flexible petrol pipes which were immune against vibration, redesign and make stronger axles, and have specially strong \vheels and tyres designed and built, etc., and over 3.400 gallons of petrol was “dumped” in the air so that the plane ' would not be subjected to undue strains when landing heavily loaded. The result was that we never had even a minor accident in all these tests, in which the equipment was, throughout, overloaded. And on one of these flights the petrol

alone weighed the equivalent of 57 men each of 1601 b. The foregoing is intended to demonstrate, in words, that we have the right plane to fly efficiently with sufficient fuel and oil to carry us over the three long non-stop stages we have to make, and that our pilots have the experience and ability to fly these loads of petrol, supplies etc., off the ground. No fixed hours of “on and off duty” will be kept by the pilots—one will hand over control to the other when he feels that he needs a rest. The navigators are, so far as comfort is concerned, much better off than the pilots. The navigators’ cabin being six feet high by five feet six inches wide by eight feet three inches long—therefore, although we have a large charttable installed and the radio equipment takes up quite some space, the main area ol! the floor is available for the navigator “off duty” to lie down full length, and rest in this position is valuable. Of course the navigators’ duties demand that often they must be both on duty together and one at least will always be on duty. Proved Ourselves . And we have proved to ourselves that I we can remain “on duty” and alertly I efficient for more than the required 36 I hours without a spell. Kingsford Smith has, as most Australians well know, over 3,300 actual flying hours to his credit on practically all types of planes, under practic- ' ally all types of conditions. His recent experience flying the Tri-mptor Fokker (with Lieut. Pond as co-pilot) on nonstop flights of 49 hours 27 minutes and 50 hours 7 minutes has given him not only a thorough knowledge of this type of plane (and he handles the big plane now just as well as he handled the old “Bristol Tourer” in our Round Australia Flight days), but a supreme confidence in her capacity to fly heavily loaded and in his own ability to “stay on the job” efficiently for a greater length of time than we require at any stage of our trans-Pacific flight. j For my own part, I know that I have the endurance for the job ahead. I well remember having worked and flown for thirteen days (in connection with and during our Round Australia Flight), averaging only two or three hours’ sleep a night—on one occasion (Port Darwin to Minilaya Station) having been forced to keep awake and efficiently on the job for 39 hours without sleep and under far more trying conditions than we will experience on this flight. In addition to our previous and present experience (technical, physical and mental) we are now both in strict training—and occasionally test ourselves out by driving an automobile for some 12 or 15 hours, then flying for 3 or 4 hours, then running for an hour or two, then flying some more and then more automobile driving, etc., for a total of 35 or 40 hours on end, until now we know that the “human element” <■ will not “let us down.” Other members of our crew will also, prior to the actital start of the flight, undergo similar training, all of which will be finally followed by several test flights with the plane equipped and manned exactly as she will be on our trans-Pacific flight. During the next two weeks our complete radio equipment and the balance of our navigation and flying instruments will be installed and tested. The engines have only to-day (April 27) come out of the shop after a complete overhaul and rechecking, and they will be “run in” in test flights covering about 25 hours’ flying time. We will then be O.K. for the start and hope to take off from San Francisco on our 7,300-mile flight to Brisbane, on the 30th or 31st of May. While the chances of being forced down at sea are, in our case, very remote, we have done practically everything possible to ensure our safety should this occur. The whole of the 72 foot wing is of entirely wooden construction, and in itself is sufficient to keep the craft afloat. In addition to this, a special dump valve has been fitted to the main tank (807 gallons capacity), and the whole of the contents of this tank can be dumped in 50 seconds and the dump valve resealed, giving extra flotation. Steel

and wood saws are carried, and if we are forced down at sea we will cut off the out-board motors and the whole of the fuselage, which is of steel construction, and use the wing alone for our flotation. Rations and Water Emergency rations are carried in the wing and we have a special still made with which we can condense more than sufficient water to keep us alive. Our navigation instruments and nautical tables would be kept with us and we could, while floating on the wing, determine our position from time to time. Our biggest safety factor is a special emergency ratio transmitter, which is completely watertight. The aerial for this transmitter will be lifted by means of a kite or gas balloons, three or four of these being carried. This emergency transmitter is battery actuated, the rest of our radio equipment being operated from two air-driven generators of 50 watts each. While on this question of being forced down at sea, let me explain that if one of our engines was to “cut out” completely at any stage of our flight, we can reach inhabited land

be the finest ever installed in air- ' craft. We can send and receive on both long and short wave lengths. The short wave equipment will be used mostly for communication with shore stations and the long wave for the reception of the radio beacon signals and communication with vessels at sea, securing radio bearings, etc. The foregoing very briefly endeav- i ors to illustrate that we have the right I plane and equipment to start with; that our pilots have the ability and experience successfully to fly the plane off the ground and thereafter handle her during the hazardous (heavilyloaded) period for the first few hours of the flight: that our navigators have the necessary equipment and experience competently to navigate the craft over the whole of the route; and that every possible precaution has been taken to ensure general safety. The next question, therefore, is “Can the crew efficiently fly the plane for 35 or 36 hours’ non-stop?” We say the answer is “Yes.” It is largely a matter of physical and mental endurance, and can be answered in two sections, i.e., for the pilots and for the navigators.

with the remaining two engines only running. Should two engines fail completely, we can stay in the air for from 10 to 12 hours and fly a distance of from 500 to 700 miles. Statistics covering the operations of three-engine aircraft such as ours show that a forced landing is occasioned by engine trouble once in every 1,600,000 miles flown (average). Also let me say here that although we are using a land plane, we would not for a moment say that a land plane is the ideal type to be used in flying over long stretches of water. The ideal type is fin amphibian, powered with either three or four engines. < There is no good ship of this type in i production in America, although one , or two are on the way. The main , reason that we are not using an am- ( phibian plane is the question of cost. 1 A plane of the type just mentioned , would probably cost in the vicinity of * £■ 20,000. i Finest Radio Equipment 1 Our radio equipment has been £ praised by every expert on the West £ Coast of America and is declared to I

The pilots are seated in comfortable seats side by side, and their cockpit will be totally enclosed during the j flight. Complete dual control is fitted, and although they cannot (when off duty), lie down full length, they can : “stretch out” horizontally, and get quite a fair amount of rest —also the pilot off duty can stand up to his full height. ' which is a great relief, a “change being often as good as a rest.” Since the Ross and Keith Smith flight in 1919, Australians have pioneered no new air routes connecting our country with other lands. We have, certainly, the honour of Bert Hinkler’s wonderful flying dash from the Motherland over Ross Smith’s old route, and still more recently our good friend George Hubert Wilkins’s really splendid scientific flight over 2,200 miles of the Arctic wastes, both requiring skill of the highest order, courage and endurance, and we now believe that our trans-Pacific flight will put Australians up with the world’s leaders in aviation as it is known to-day, and open a new route giving quicker communication with our American neighbours on the i other side of the Pacific. *