Gasoline Requirements of Commercial Aircraft Engines
THIS paper was prompted by the numerous inquiries received by the Bureau of Standards from airplane owners and airport operators regarding the grades of gasoline that are suitable for aircraft use and the suggestion that the Bureau test all brands of commercial aviation gasoline and publish the results or that the Department of Commerce issue approved type certificates for certain standard grades of aviation gasoline.
The purpose of the author in presenting the paper was to open discussion on the subject, and in this he was very successful.
The problem of a suitable fuel and its general distribution throughout the Country for aviation use is complicated by considerable divergence of opinion among aircraft-engine manufacturers as to the kind of fuel preferred and by wide differences in detonation characteristics of gasolines of like volatility. No chemical or physical test has been found that will serve as a sure criterion of antiknock value, and laboratory tests on the same group of fuels in a variety of engines have given results that are not entirely comparable.
The subject is summed up in the concluding statement that aviation gasoline should have adequate antiknock value and volatility and should not contain an excess of gum or sulphur. It seems to be the engine manufacturer's problem to make knock tests and determine how volatile a fuel is required for his engine. The engine manufacturer's problem would be greatly simplified if more oil companies would adopt the policy that has been adopted by at least two oil companies of marketing all over the Country, under definite trade names, aviation gasolines of essentially constant quality as regards antiknock value and volatility.
Discussers representing oil companies and aircraft and engine manufacturers present their respective difficulties with the problem, and the long-standing dispute over the responsibility of finding a solution is renewed. The oil men assert that it is the task of the engine builders to design engines that will operate satisfactorily on the available fuels, and the engine makers claim that the oil companies should produce and distribute universally a fuel that will not knock in high-compression engines.