JET-DRIVEN AEROPLANES

New Zealand Herald, Volume 82, Issue 25293, 29 August 1945, Page 5

JET-DRIVEN AEROPLANES

USE IN CIVIL AIR TRAVEL GREAT POSSIBILITIES PRESENTLY

From an address by H, L. HIBBARI Corpo Jet propulsion is unquestionably one of the greatest advances to come out of the intensive research and development of the war years. I think that jet propulsion has placed man in the entrance to the final phase of his efforts to propel himself through space. Jet propulsion is just coming out of the laboratory. We have learned a lot about this new technique in the last few years. But we have barely made a beginning. Not much can be said for war. It is destructive, and cruel, and wrong. But under war's impetus scientists do move ahead. The basic necessity to save our lives, to win victory, has stirred the whole nation. Scientific research possibly has advanced farther during the war years than any other phase of our life. To win the war we needed faster aeroplanes, the fastest aeroplanes in the world. But the conventional propeller-driven aeroplane had just about reached its top speed. The urgency of the need brought the answer, which was jet propulsion, far sooner than it would have come except for the awful haste of war. This ageold —yet at the same time brand new — idea had been stalled in the laboratory for years before the threat of superior enemy planes forced it out. In June, 1943, we were asked at Lockheed to develop a fighter aeroplane around the Whittle jet engine that had been de-. signed by the British. , Only 143 days after the Army made its request, my colleague, Clarence Johnson, chief research engineer at Lockheed, had designed and supervised the construction of a jet fighter, our P-80 Shooting Star. This design period customarily requires from 12 to 18 months. In just 143 days after Johnson made his first design on paper, the Shooting Star was ready to fly. It would be foolish, of course, to suggest that these 143 days represent the solution to problems of jet propulsion from beginning to end. We have many problems, big ones, yet to solve. Supercharger Research Researchers for years—even centuries —have been studying gas and the metallurgical problems connected with these turbines. At General Electric, for example, the turbo-super-charger has been in development ever since 1918. This gas turbine is the father of the powerful jet engine of today. The persistent efforts of General Electric to design—on their own initiative —a good supercharger, during the years between the first and second world wars when American appropriations for military research were cut to a bare minimum, enabled the United States to put our heavy bombers out of reach of enemy guns and fighters early in this war. This work on turbosuperchargers was also the basis for General Electric's later work on the new engines which power our jet aeroplanes today. There are three basic types of jet engines First the ultimate form is the rocket, which carries all the elements for combustion within itself. With the perfection of rocket motors, in a very few yars, we shall be able, if we wish, to fly above the earth's atmosphere and attain speeds without limit. The second typo is the pure jet engine, which depends on air drawn from the atmosphere, mixed with fuel, and ignited in the combustion chamber. The Shooting Star is a pure jet aeroplane. Although it can fly very fast and very high, it can never fly outside the atmosphere, and it'can never attain the maximum speeds that a rocket can reach. The V2 Rocket Finally, we have a compromise between the jet engine and the present arrangement. This will be a gas turbine that revolves a shaft to which a conventional propeller is attached. Understand that I am not prophesying when L talk about rockets. The Germans developed an amazingly ingenious application of this principle in their V-2 rocket bomb. The people of England can tell you that the V-2 was a very real threat in this war.. Had the war continued some months longer our own east coast cities would have been subjected to attack by even larger rocket bombs. The German V-2 reached a speed of 2500 miles an hour and an altitude of more than 60 miles. By some struct tural changes—the substitution of a pilot for the war head, and devices for steering, slowing down and landing—it is interesting to note that one could convert the V-2 into a rocket fighter. The V-2 carried a warhead of 22001b of high explosive. Substitute more fuel for the warhead and you reach a top speed of 3200 miles an hour and altitude of 175 miles. And if hydrogen were used instead of alcohol the V-2 rocket would travel 250 miles above the earth at a speed of 4000 miles an hour. Think what that means in terms of the next war —if we are ever foolish enough to permit a war to begin. Jet Engine Described A pure jet engine powers the Lockheed P-80 Shooting Star today. The air enters at the front and is compressed by a blower turning at high velocity. From the blower the air enters the combustion chamber, where it is mixed with fuel injected at high pressure., This mixture is burned in a continuous explosion, heating the gases and expanding them violently. There is no complicated ignition system in this engine. A spark plug sets off the initial explosion. Once the engine has started a small glow plug heats whitehot and ignites the mixture. From the combustion chamber the gases blast to the rear, where the jet nozzle permits them to escape. But first they rush through blades of a gas turbine wheel, driving it at high velocity. This turbine is connected by a shaft with the compressor blower, supplying the power necessary for the initial compression of the air. finally we come to the combustion engine that uses the power generated by a gas turbine to rotate a conventional propeller. This uses the same basic ciigino as the P-80, except that the shaft is extended forward and drives a conventional aeroplane propeller through proper gearing. This is a simple, efficient arrangement. ft can be adapted to all types and sizes of aeroplanes designed for any speed below 500 miles an hour. 1 predict that our conventional reciprocating type aeroplane engine will be replaced by engines of this type in a very few years. Future Air Transports The future transport will be of the pure jet type. It can be as large as is necessary to meet the demands of the travelling public, for there will be plenty of power available to fly this ship. The cabin will be pressurised for flight above 50,000 feet. The luxurious comfort of this aeroplane will surpass anything you have known in the field of transportation. In the jet transport, travelling above the speed of sound, 10 miles above the earth, there will be no noise, no vibration, no sense of speed. Weather will make no difference at all, since you will fly over storms. Uadio navigational

D, Chief Engineer, Lockheed Aircraft >ration. aids, already well developed, will permit you to land with perfect confidence 011 an airport that is obscured by fog, snow or anything else. If you are an airline operator, you will find that this aeroplane is much easier and more economical to maintain and operate than your ships of today. Yoi! know what easy maintenance means. Jt means less expensive operation, and that means lower fares for you, the passenger. Let us get back to our transport. The cockpit will be enough to make an airline pilot of 1945 blink his eyes and start an inventory of missing instruments. There will be the conventional flight instruments, air speed indicator, altimeter, bank and turn indicator and so on, but most of the complicated engine instruments 011 the control panel of a modern transport will be gone. There are 110 complicated fuel-setting adjustments to be watched or manifold pressures to be maintained. Little the pilot can do affects the efficiency of the engine's operation. This transport we have described will be able to use any airport that is large enough to handle our big bombers today. It is likely that current research 011 wing flaps and other high-lilt devices will permit even lower landing speeds than today's ships possess. The chances are that each of its power units will supply as much as 10,000 horsepower. This aeroplane will not be built immediately. The industry needs a few years to get acquainted with jet propulsion. The aeroplane 1 1 have just described is 10 to 15 years away. Jet-propelled Helicopter In the meantime you have something to look ahead to almost at once. The new high-speed, pressurised transport aeroplanes, developed since the start of the war, will go into airline operation within a year. These ships are fast, they are the last word in comfort and luxury, their pressurised cabins make over-weather, year-around flight possible at sea-level comfort. Their cruising speeds will be in the neighbourhood of 300 miles an hour at 20,000 feet. There is one other project I want to discuss—a jet-propelled helicopter. I believe that with ten to fifteen years of development this will become the standard form of family travel for all Americans. The turbine engine is located at the middle of the plane. The blast from its combustion chamber is led up through the rotor rather than out through the tail as in the P-SO. Passing through the rotor blades, the hot gases are exhausted through the backswept nozzles at the rotor blade tips. The same condition of unopposed forces that we have seen before exists here. The reaction • of' the pressures causes the rotor to revolve, just a§ your rotating lawn sprinkler is driven by the force of the water jets. The movement of the rotor blades will provide the lift and the forward thrust for this ship. Control will be insured by an auxiliary adjustable jet nozzle in the rear of the plane. High Speeds Predicted This helicopter can be operated simply and safely. Cruising speed will be in the neighbourhood'of 200 miles an hour. Its range will be roughly 500 miles. It will land and take off with no forward motion whatsoever. Should an engine failure occur, the ship can be brought gently to a landing with no power. It will be sold for the price of an automobile Do not look for this helicopter this year or five years from now. In my estimation it will be at least ten years before the problems are worked outf, but it is coming. We have been dealing in pretty high speeds today, but we have not reached the limit yet by any means. As a matter of fact, I am not so sure that there is a limit. On flying outside the earth's atmosphere there is theoretically none to the speeds that can be attained. If we have somewhere to go fast, there is no reason why we shall not be able to travel at 10,000, even 100,000, miles an hour. We shall have to have some reason for going so fast, but I know of nothing now that will prevent our doing so if we choose. Germany has already developed an aeroplane that could fly outside the earth's atmosphere. Their Messerschmitt IG3-B rocket fighter is limited only by the amount of fuel carried in 'the plane and the pressure protection afforded the pilot at high altitudes. The ME-163 theoretically could lly 100 miles high. There is nothing from the medical standpoint that will prevent our travelling at these high speeds. Every minute of our lives we are spinning with til™ earth at about 1000 miles an hour. And our earth and the rest of the sun ; s planetary system is whirling through space at the breathless speed of 500,000 miles an hour.