THE INDIA RUBBER WORLD 



[December 1, 1918. 



Rubber in Airplane Construction. 



By Edgar H. Wilson. 



SOME of the most essential accessories for airplanes are made 

 of rubber for the reason that they are aflfected neither by 

 high altitudes nor by sea-level conditions, and, moreover, if 

 the plane meets with a mishap, rubber parts are the last ruptured. 

 Airplane parts that are now made of certain other materials could 

 just as well be made of something different, but this is not so with 

 parts made of rubber, the importance of which in the field of 

 ■aerodynamics is being admitted to an increasing extent. The 

 -lives of aviators depend on the action of each part; a fact that 

 iratist be borne in mind in the construction and manufacture of 

 all parts and accessories. 



TIRES AND TUBES. 

 Pneumatic fabric tires were the first rubber equipment to be 



RUBBER PADS, RADIATOR CAPS AND INSULATED WIRES. 



Many rubber pads are used throughout an airplane between 

 the axle and its bed, between the tail skid and the adjoining 

 cross member, to reduce motor vibration. These have all proved 

 their ability to assimilate punishment, and to save more impor- 

 tant members from excessive wear. Hard-rubber radiator caps 

 are of much the same construction as those used on automobiles ; 

 they are used on many types of airplanes. Insulated wires per- 

 form the same duty as on an automobile, except that they must be 

 better protected and of greater efficiency. 



RUBBER STREAM LININGS. 



Fiubber is a very efficient stream-lining material. On some 

 types of machines the axles and spreader tubes running parallel 

 to them are completely covered by a rubber tube which expands 



used on airplanes. The original type has now been superseded during the landing of a machine, and contracts as it leaves the 

 by efficient cord casings with thin treads and completely ex- ground, so that the head resistance of this member is at a mini- 

 posed side walls. Weight and cross-section at this point must mum. Possibly the most efficient stream lining is accomplished 

 be cut to the mini 



■mum, because it 

 forms parasite 

 head resistance. 

 The inner tubes 

 are of very light, 

 yeX strong con- 

 istruction, and are 



1 s e ( 



that 



ISO enc 



'pinching is re- 

 Iduced to a mini- 

 jmum. The tubes 

 jare equipped with 

 jspecial valves 



Eh i c h protrude 

 rough the rub- 

 r covering that 

 (.surrounds the 



/Rubber Grommefs 



Gun Recoil Pads 

 Control Handle 

 Rubber Pedal BarCbnfrols 

 iYire Protectors 

 Oxygen Helmet and Tubing 

 Matting for Pedal 



v~ 



fuselage 

 ■■; "'Tank Cover 

 'Foot Hole Rubber 



er Tires and Tubes 



Rubber and \ Modern Biplane. 



at the tail skid, 

 where a rubber 

 bib is attached so 

 that the opening 

 in the fusilage is 

 closed to air cur- 

 rents while in 

 flight and stones 

 and foreign mat- 

 ter are kept out 

 while taxi tig 

 across a field. The 

 inner-plane wires 

 have also been 

 stream-lined, when 

 they are parallel, 

 by a specially con- 

 structed rubber 



fepokes of the wheel. The openings of'diese valves will fit both tube which encloses them. Wind-tunnel tests show that two 

 ' merican and French air pumps by merely reversing the cap. wires thus covered offer less resistance to the air than single 



I GRIP HANDLES AND GROMMETS. 



' Rubber grip handles used on all light fighting planes, are 

 [light and of efficient construction. Heavy day or night bombers 

 use the "Dep" or wheel control, made of vulcanite or hard rub- 

 ber. Grip handles are made in three types. One is used in 

 -connection with Liberty-motor-equipped planes and the other 

 two in connection with the lighter rotary motors, where parts 

 of the switch control are necessary in the end of the stick or 

 "joy" control. Rubber grommets, or escutcheons, are used in 

 many places for protecting wires passing through the cowl and 

 to protect the tachometer and speedmeter shaft. They are pro- 

 vided in various sizes, of round and oblong shape, and designed 

 to hug the hole in which they are placed. 



SPECIAL HOSE. 



A special line of aircraft hose has also been developed. .A.ir 

 liose is not used to any extent, but hot oil and gasoline hose are 

 TUtilized in many places in the construction of standard aviation 

 motors. Performance must never fail or serious accidents will 

 •occur. The specifications for the hose used by the Government 

 have been drawn up by the Signal Corps after competitive tests 

 with various kinds of hose. Recently a molded and braided 

 type has made its appearance, which has been found more 

 efficient than the other types of hose. There has also been con- 

 siderable improvement in radiator hose, which must be light 

 .and yet resist high temperatures for long periods. 



wire uncovered, which results in largely reducing head resist- 

 ance, which means a considerable increase in the number of miles 

 per hour, as well as a diminution in gasoline consumption. It 

 also eliminates the harsh vibration peculiar to wires that are 

 not stream-lined. There are also irregular rubber parts which 

 cover control-surface regulators for changing the balance of the 

 plane while flying and disposing of its load of bombs. 

 FUSELAGE-WIRE PROTECTORS. 



Fuselage-wire protectors are an adaptation of the idea of the 

 ball-and-socket fastener applied to a rubber washer. Both "ball" 

 and "socket" have a groove across the flat surface, along which 

 lies the fuselage wire. The little device is put at the exact 

 point where the wires cross and the tension of the wires them- 

 selves holds it indefinitely in place, while at the same time it in 

 turn holds the wires together, yet leaves them free to move with 

 itself as the axis. It thus provides a solution for what was a 

 serious problem — how to fasten the fuselage wires together flex- 

 ibly and prevent them from wearing each other by friction, 

 particularly when the planes struck the ground and the longerons 

 straightened out, thereby changing the angles of the fuselage 

 wires relatively to each other. 



SHOCK ABSORBERS. 



Many types of shock absorbers have been tried and found 

 wanting, but the rubber cord is in favor at the present time. 

 Originally, when rubber was first adopted, a series of rubber 



