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September 15, 1924   AVIATION   987

application that has been made of the famous Liberty engine which is continually receiving new laurels and greater respect as America's World Fliers rapidly approach their goal.
It is specified in the regulations for this contest that the planes must have an air speed of greater than 90 mi./hr. and in order to eliminate planes which might be considered more or less of a two place pursuit type, a restriction has been placed on the wing area making it necessary for planes to have greater than 360 sq. ft. of area. It is also specified that cockpits must be left open. However the ingenuity of the pilots and mechanics will be brought forth by the regulation which permits of other forms of streamlining.
Fillers may be placed between the cables, streamline wires may be substituted, wing fittings may have streamlined covers attached. Wherever constructionally possible, nose radiators may be replaced by free air radiators, which undoubtedly present less head resistance, and provide more effective cooling with a given area.
All planes are required to carry a contest load in addition to a pilot and passenger whose total weight must average 340 lb. This contest load will be determined by using a formula based on the cubic inch displacement of the 400 hp. Liberty engine as follows:
400/1649 X cu. in. displacement of motor used X 0.85 = Contest Load.
This load may consist of shot bags which will be furnished by the contest committee. Fire extinguishers, and parachutes may be included in the contest load. This has been done, in view of the military machines which are designed for seat packs and in order to overcome the desire of some pilots to remove the fire extinguishers and thereby a slight bit of weight. Fixed instruments, gas, oil and water are excluded. Bomb racks, guns and mounts may be removed. 
This contest which is probably one of the most interesting and instructive, will start at 2:30 p. m. on Thursday, Oct. 2 and will be for a distance of 180 mi. twelve laps around a 15 mi. course. Here too, standing starts have been used. However, groups not to exceed seven planes each will be sent away simultaneously.

            Mulvihill Model Trophy

This in an age of flight. If the youth of today is enlightened in the so-called mysteries of aeronautics, the problems will no longer be mysteries. In order to encourage the knowledge of aviation, the Mulvihill Model Trophy contest, which is a duration race for model airplanes, takes its place in the program of events. Together with this trophy go prizes totaling $500. This very interesting contest will start at 9:30 a. m. on Friday, Oct. 3. Already a number of cities have held elimination contests and civic organizations have arranged to send the winning boys to Dayton and pay all of their expenses. The ingenuity of the young men taking part in this contest excites the admiration of our so-called ease hardened aviation experts. 

It is predicted that new records for duration of model airplanes will be established during the races. Boys throughout the country are preparing to match their skill against the winner's of last year's contest, who will participate in the contest this year in an endeavor to win the trophy.

Efficiency races, as a general thing, are to be avoided during a gathering such as the International Air Races. This is not because of any fault of the officials in failing to recognize the desirability of such contests, but through their desire to conduct races which may be handled practically on the flying field during the turmoil and excitement of the meet. They wish to have the races conducted in such a manner that the results may be clearly and distinctly followed by the public. It is always possible to conduct efficiency trials, wherein the results do not necessarily need to be known for some time. As is the case abroad, where efficiency contests are conducted, in most cases they extend over a period of several days. 

Aviation Town and Country Club Race

The regulations for the Aviation Town and Country Club of Detroit Trophy race which forms event No. 6, have been drawn in such a manner that the results of the speed portion of the contest may be clearly followed by the public and the final results of the entire event may be announced as quickly as the speed race has been run. The race is divided into two parts, one known as speed, and the other as efficiency. The contest is open to airplanes having engines of a piston displacement not to exceed 800 cu. in. Planes must show an average air speed of greater than 80 mi./hr. in the race, and must be constructed to seat comfortably a pilot and at least two passengers. The contest is for a distance of 120 mi., eight laps of a 15 mi. course and as in the majority of the other events, the planes will be sent away from a standing start. The speed portion of the contest which carries total prizes of $2,000, divided over three places, goes into the airplanes showing the greatest speed in the race. 

The efficiency portion of the race is based on the following formula and carries a like amount in prizes. 

W/Hp. X Mi./hr. = Figure of Merit
W = Weight of load passengers
Hp. Horsepower credited contestants = cu. in. displacement/4

Mi./hr. = Average speed of completing race in miles per hour (must not be less than 80 mi./hr.)

From a glance at the above there will be three things which the average engineer will find objectionable. First, that the contest should be based upon the load that the plane can carry irrespective of passengers. Second, that horsepower should not be used as a basis of comparison, but that the actual fuel consumed should be given consideration. Third, that if the horsepower is to be used the actual horsepower rating of the engine should be taken into consideration rather than a fictitious horsepower obtained from a formula.

Now let us consider these objections from the standpoint of conducting the race in a practical manner on the field. First of all if weight, rather than passengers for which seating accommodations are provided, should be taken as a basis for consideration, we would find that our over zealous pilots would insist upon loading their planes to the limit; perhaps not what they might consider the limit, but which in all probability would cause an accident on the course during the race, particularly if two or three of the ships should happen to strike a turn at the same instant, making it necessary to maneuver one of the planes more or less violently. Therefore, for reasons of safety, it has been necessary to require pilots to carry their load in passengers or ballast equivalent.

How may horsepower be determined? We immediately say by proper dynamometer test. What does that mean in a contest? It means that a dynamometer test has been run on a given engine. The engine is placed in the race. Perhaps a new valve action has been added. Perhaps a different carburetor setting has been made. The spark may have been advanced slightly, or a hundred and one minor changes may have been made in the engine which no longer makes the dynamometer test applicable. This very question has arisen in past contests and it was in order to eliminate questions and arguments, and questionable winnings, that horsepower was based upon a constant. This was obtained after careful investigation of the better airplane engines. It was found after this research had been made that an average of 4 cu. in. per horsepower could be assumed. True some engines will be penalized and others will be favored, but it was necessary to strike some workable average.

The Aviation Town and Country Club of Detroit trophy will be awarded to the aero club or to the chapter of the N.A.A. represented by the pilot of the airplane receiving the highest total awards for speed and efficiency. In case of a tie the trophy will be awarded for the first position in the efficiency portion of the race. This contest will start at 10:45 a.m. on Friday, Oct. 3.

Dayton Chamber of Commerce Trophy

One of the most interesting events is for the Dayton Chamber of Commerce Trophy. This is open to civilian and military contestants flying large capacity airplanes. By this is meant airplanes capable of carrying a pay load of 2,000 lb. or more. Four thousand dollars in Liberty Bonds, distributed

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