Evening Star Newspaper, January 20, 1929, Page 66

S | 5 THE SUNDAY STAR. WASHINGTON, -D.- C. ANTARY 20, ALTTUDE FILRE G CONPARSON Indicated Recording Barom- eter Method May Be : Inaccurate. Indications that the recording barom- eter method employed by the Federation Aeronautique Internationale in deter- mining official world's altitude records may be inaccurate by as much as 3 per cent below the altitude actually attained are found in a calculation by photo- graphic methods of the remarkable alti- tude fiight made October 10 by Capt St. Clair Streett and Capt. Albert W. Stevens of the Army Air Corps. One of the main purposes of the flight, which missed a new world record by a small margin, was to test photo- graphic equipment and to obtain a com- parison of altitude figures as calibrated from the recording barometers by the Bureau of Standards and the interna- tional federation methods and those calculated mathematically from the photographs. g The method of determining altitude by photography is simple in principle, #ccording to the Army officials in charge uf the flight. If the distance between ground points shown in the photograph taken from the plane is known, then, by easuring the distance of the image separations on the negative and know- ing the distance from the negative to the optical center of the lens, or the focal length, the problem becomes a geometric one of similar triangles and | can be figured to within one-tenth of | one per cent mathematical accuracy. Comparison of Results Made. A comparison of results made through | eamera calculations with those obtained | from the barograph formula has been | decidedly illuminating, according to an ! announcement just received from Wright Field, Dayton, Ohio, where the test was made. The highest altitude reached by Capts. Streett and Stevens, according to the Federation Aeronau- tique Internationale calibration, was 37,854 feet. According to the Bureau of Standards method it was 39,606 feet and, according to the photographic method, 39,050 feet. In order to obtain accurate calcula- tions from the photographic method, the Engineer Corps at Wright Field sent a detachment to make six closed traverses aggregating 188,987.92 feet in length of the area of ground photo- graphed by the highest shots of the camera. Capt. Stevens describes this work as follows: “These traverses were run with tran- sit and tape and had an average error of closure of one part in 10,700. Fol- lowing this survey, the altitude was calculated by four different methods, as a result of which one photograph shows an altitude of 37,920 feet above ground, or 38.890 feet above sea level, and a photograph made several minutes later in flight shows an altitude of 38,- 080 feet above the ground or 39,050 feet above sea level. The ground ele- vation of 970 was determined from the Tecords of survey of the C. C. C. & St. L. R. R, which passes Rushville, Ind. (the point of landing). It is believed that these values for elevation, as de- termined through weeks of careful cal- culations, are correct to within 40 feet plus or minus, Tables Off 3 Per Cent. “It will be observed that the figure of 39,050 feet is much higher than the figure of 37,854 feet obtained from the Federation Aeronautique Internationale tables, for a barometer pressure of 152 mm. of mercury. A conclusion may be drawn that the Federation Aeronautique Internationale tables are off about 3 per cent and too low for this altitude. It is also of interest to note that the Bureau of Standards has computed, from the tables of the National Ad- visory Committee for Aeronautics, and using tables of temperatures obtained on the fiight, that the elevation by ba- rometer was 39,606 feet. Again as- suming that the camera method is the most accurate, the N. A. C. A. formula 2 approximately 1'2 per cent off and %00 high. g “The methods of calculation used by the Corps of Engineers are four: The purely mathematical method requires 12 hours’ computation for a single photograph; the Bagley method re- quires 4 hours; the pyramid graphical method requires 4 hours, and a second mathematical method requires 8 hours. ‘The results by the four methods check within 50 feet and average of the vale ues was taken.” AIRPORTS TO BE RATED. ‘Work to Be Started This Month by Commerce Department. ‘The rating of airports on the basis of their adequacy and facilities will get under way late this month. The De- partment of Commerce is charged with this activity under the air commerce act. ‘The highest type airport is to be de- signated as “AlA,” and will be so marked for the benefit of aviators fly- ing across the country. Designations have been provided for lower types of airports, 5o that pilots will know exactly the type of field and facilities they can expect. Extend Canadian Air Service. Plans for establishment of airplane passenger and mail service lini Halifax with ths air transportation systems of Canada and the United States are being made by Maritime Airways and a group of Halifax busi- ness men. Application has been made to the Canadian department of marine and fisheries for the purchase of five Fokker planes used in the recent Hud- son Bay expedition. 4-WHEEL Hudson—bendix Featuring: one year drilled and countersunk by son Co. Cars Called fo No Association Disc 3360 M Street N Phone West 2378 | on truss members. BRAKES For Relining Until Feb. 1, 1929 BUICK—Mechanical Chrysler—Hydraulic;$ 1 4.00 guarantee, AMBLER AUTOBESTOS BRAKE LINING, the highest grade brake lining in the world, and brake inspection certificate with every job. Prices Cover Future Adjustment Service Auto Brake Service Co. 711.G Street Phone Lincoln 9703 Movie Film Shows Sensations Felt by Parachute Jumpers Sensations experienced by para- chute jumpers are said to be well illustrated in a motion picture of a multiple parachute jump made on the way down by the last jumper. Charles E. Planck, who car- ried the camera in his jump, was the fourth man to leave a plane in a multiple jump over Lunken Afrport, Cincinnati. He wokxh:- tures of the three preceding jumpers and then turned the crank while he leaped into space after them. Even the sensation of the ground rushing up to meet the Jjumper as he nears the earth is embodied in the film, which will be used in the instruction of ground school students. WORLD’S BIGGEST HANGAR CONSTRUCTION IS BEGUN Goodyear-Zeppelin Corporation Is Filling Government Con- tract for Navy. | Construction of the largest hangar in | the world has been begun at Akron, Ohio, by the Goodyear-Zeppelin Cor- poration as the first step in the filling of a Government contract for the con- struction of two 6,500,000-cubic-foot dirigibles for the Navy. The Akron hangar, in which the aerial morsters are to be constructed, will be 200 feet high, 1,175 feet long | and 325 feet wide. The floor area of 389,000 square feet will be entirely un- obstructed, the roof being supported, despite its tremendous width and length, More than 6,000 tons of steel are to be ussd in the hangar framework. The vast structure will be supported by 1,300 concrete piles. More than 7,000 cubic yards of concrete will be used in the foundations and flooring. MAIL PLANES WILL GET ICE-WARNING EQUIPMENT Instruments to Aid Pilots in Fly- ing Through Cold by Show- ing Temperature. By the Associated Press. SALT LAKE CITY.—Eleven air mail planes operated by the Varney Air Lines with an eastern terminus here soon will be equipped with new ice-warning in- struments to aid pilots in flying through cold, wet skies. Ice is a great hazard to airplanes, often forcing them down when heavy coatings form on the wings and cut down the aerodynamic efficiency. The pilot’s only aid is to know the tempera- ture and atmospheric conditions along the wing surfaces of his plane so that he may avoid areas that are likely to increase the ice hazard. The new instrument was developed by the Moto Meter Co. of New York and exhibited at the Chicago air show for the first time. With it the pilot can, when warned, seek a new air level. FLYERS ORGANIZE. “Early Birds” Are Incorporated Under District Laws. The Early Birds, an organization of pioneer American airmen who flew prior to the World War, has been in- corporated under the laws of the Dis- trict of Columbia. The Early Birds or- ganized at Chicago last month in con- nection with the international aero- nautical exposition. The cbject of the society, according to the incorporation papers, is the de- velopment of aeronautics. Trustees named in the papers are P. J. B. Mol riss, Brig. Gen. Benjamin Foulois, as- sistant chief of the Army Air Corps, and Maj. Ernest Jones of the Bureau of Aerantuics, Department of Com- merce. * NEW SEARCHLIGHT RULE. Private Equipment to Be Governed by Department of Commerce. The Department of Commerce is to rocertify all private aeronautical lights in order that equipment may be installed which will meet the requirements soon to be put into effect. All beacons or searchlights not on airports, according to the new regulations, will provide a 24-inch searchlight, which will throw a beam in the direction of the nearest airport. The beam will be required to be sufficiently elevated so that it will clear all intervening obstructions and have a very small angle of divergence, not to exceed four degrees. BASES ARE. PLANNED. Survey Party Goes Over England- India Air Route. A survey party from Imperial Air- ways of England has set out for the Mediterranean to lay out bases for the Mediterranean section of the proposed England-India air route, a total of 5,000 miles. Passengers to India will travel by airplane from London to Basle, where they will take a night train, arriving at Genoa for breakfast. Flying boats will travel along the coast from Genoa, stopping at Rome and Naples and either Brindisi, Taranto or Gallipoli be- fore flying along the Greek Islands and on to Suda Bay, Crete. The route then will be laid to Tobruk, Italian Libya, and along the -coast to Alexan- dria, where the line will link up with the present service to India. 'assen- gers and mail will be taken from Lon- don to Karachi within seven days. SPECIALS aluminum rivets machine, Keasby and Matti- r and Delivered ounts on These Prices 427 K Street Phone !‘r‘nnll.ln 8208 UST ARRIVED ¥ ntroducing to youth and progressive Americans._. «n ENTIRELY NEW LINE of AIR-COOLED FRANKIINS with the Drivii B Feel of an Airplane RE—for the first time in years—is a new motoring thrill fortheyouth of America. A challenging new experience for the man who has owned 20 or more automobiles.... With these new cars, Franklin steps far into the lead—intro- ducing a revolutionary, new type of performance, known only to air-cooled motoring. Surging power—rocket acceleration —zooming road speed—soaring smoothness—cushion-like riding comfort . . . . The whole demonstration affords the sure, swift driving feel of an airplane. EW 1OW PRICES SENSATIONAL N The One-Thirty A spacious car of traditional Franklin quality; powered bya high compression, six-cylinder, (314" x 43{") air-cooled motor, famed for roac and hill records. The Sedan priced at $2180 2180 PRICES F. 2185 2 FRANKLIN‘S great Expansion Program pro- duces astonishing new standards in fine car values—the smart, new models with the mar- velous driving feel of an airplane, present 0. B. FACTORY The One-Thirty-Five Longer wheelbase; larger bodies; added luxuries; new, silent transmission; new, more powerful, six-cylinder, air- cooled motor (314" x 434%). The Sedan priced at $2485 . quality features never before combined in one automobile. Style-setting body designs; broadcloth uphol- stery of newest mode; clear-vision corner pillars; non-shatter windshield; full-elliptic springs; hydraulic spring controls; counter- FIRANKIIN 2773 The One-Thirty-Seven Seven-passenger bodies—un- usually commodi on wheelbase and wide trea new, nt transmission; S balanced, case-hardened, seven-bearing crankshaft; automatic valve-oiling; silent transmission; hydraulic four-wheel brakes; non-tarnish chromium plating— All these emphasize this fact—the luxury of air-cooled motoring has reached a new high point—and at prices as much as $600 less than any former prices of corresponding Franklin types. See the beauty and learn the airplane feel of the Franklin today. (THE NEW AIR~-COOLED CAR WITH THE AIRPLANE FEEL ALSO ON DISPLAY AT THE AUTO SHOW JAN. 26th—FEB. 2nd FRANKLIN MOTOR CAR CO. HARRY W. BURR Salesroom—1517 Conn. Ave. N.W. Service—1909 M St. N.W.