AERONAUTICS ELEVENTH ANNUAL REPORT OF THE NATIONALADVISORY COMMITTEE FOR AERONAUTICS 1’925 INCLUDING TECHNICAL REPORTS lNOS.210 to 232 ADDITIONALCOPIES WTEMFU-TIOM MAY BE ~D YMK TEEmmEnmmDIxYw~ G~MBR? PBIMIUG ~ WASEIHOTOH, D. C. $LM PERCOfY(LWIHomTs) LETTER OF SUBMITTAL To THE CmxmESs OF THE UmTED STATES: h compliance with the provisions of the act of Msroh 3, 1915, establishing the National — Advisory Committee for Aeronautics, I submit herewith the eleventh annrud report of the . wmmittee for the tical yesr ended June 30, 1925. The statament of the present status of aviation, se outlined in Psrt V of, the committee’s report, should dispel theIimpression that Americs is lagging in the tech&cal development of “ .— airoraft for military purposes. ScientMc reseuoh on the fundamental problems of @t and the ..— colkxtion of resuh of research oonduoted in other progrtive nations em oificid duties of the -...& -... committee. Their opinion that AmericrJis at Iesst abreest of other natiom in the teohnical -. -. development of aircraft is commended tu Lhe Congws ss the most authoritative that can be ,,.---- _— had. I sgree with the committee that substantial progrem in aeronautioe is dependent largely upon soientifLcrmemch. I believe that the work of the oommittee is the most fundamental sotivity of the Government in connection with the development of aeronautic and that its continuance is eesentisl if Amerioa is to maintsin its present admnced position in aircmft . — development. The condition of the sircrsft industry and the prospects for the development of commercial ——— . aviation on, a sound bssis have matarisly improved during the past year. To encourage the .— development of oommemial aviation I wish espeoidly to indorse the recommendation of the .— committee for the oreation cd a Bureau of Air Navigation in the Department of, Commerce. .— CALVINCOO-GE. THE ~BlT13 fiUSE, Decender 10, lJM. ‘ m .— ● m LETTEE OF TRANSMITTAL NATTONALAOVISOEYCowrrTEE FOB kSiROXAUTICS, Tf’dhgto-n, D. C., Mnsmder W, 1925. hill. PRESIDENT: In compliance&h the provisions of the ad of &mgrees approved Maroh 2, 1915 (Publio h’o. 2711 63d Cong.), I have the honor to transmit herewith the EIeventh Annusl Report of - —- the National Advisory Oommittee for Aarcmautim for the &al yem ended June 30, 1026. During the past year gratifying prograra has been made in improving the p.erfornmmie and reliability of airoraft, and the committee’s program of continuous aoientih research gives “ ‘-— — promise of maintaining Amarioa’s advsnoed position among progressive nations in the tech- . —. nioal development of airoraft for nditary purposw. Publio inter~t in aeronautic has greatiy inoreased; and ootidenoe in the ultimate suocese . of oommeroial aviation in Amerioa on a sound basis is warranted. A beginning has been made .— by the letting of oontraota by the Post OfE.oeDepartment for air transportation of the mails. In order, however, to hasten the development of commercial aviation on a broad scale, a — bureau of air navigation should be oreated in the Department of Commerce with broad powers. The condition of the aimraft industry has been substantially improved by the greater ..— volume of Govermwmt orders. W%h sustained Goveruumnt busineae and with the prospect of a growing oomrnereial demand for aircraft, the oondition of the airoraft industry may be -- regarded as no Iongcxmute. While th=e faotors are encouraging and indioate progress toward a healthy development .-. of omnmercid aviation on a sound basis, the oommittee desires to emphasize the importance of .-— the sciemtio work of this oommittee as the most hmdamenfaI aotivity of he ~~~ent ~ ._ -.— connection with the development of aeronautics, from both a oommeroialand a military stand- point. Rsspsctitiy submitted. ChmJZs D. N%wwm, Chairman. The Prwsmnwr, The White EIXM, Mr81iington,D. (.7. r . ● , CONTENTS .— Page . Miter of submMeL.-.-m----- ------- -. —------- --. —--- ------- .--—--- - m Iatterof ~w---------------------------------------------------------------- v Eleventhannualreport—-.-----_- —- —-—------- .------- ———--------— - 1 PAET L ORGANIZATION Funationeof thaW--—--. ----—.------——-----—----——W —— -—. — a Organi%donof theaoromittee__––– -—— ---————- —- 3 — Meetfngeof theentfreaommfttee.—_-—_——— —-—-——— ---—------—---—----- 8 Theemoutivead- .----- .--—- ——------ .-- ——---—- ---—-—- -----—-—-—— 4 flnhdtia..---—-----—-------------—-——-----————— ——- 4. Oommftteeon govemmental *tea------—-—_—----—__----—_--—______ 5 Oommftteeon publfedkmed h-M---. ------——---—--——--–_------—------- 6 Committeeon pereonn4 ~ [email protected]—---—---— -— - . ----------- —---- 6 ~ for O-tk--—---——---.-—---–———-—------—— 6 ThehX@y MenmrtalAm’cmautiaalLeboratmy________ -——-- --------- 6 The 050e of -Utical h-a------------—— ------- —----— —----—- --- 6 — Fllmletalmmti.————----—---——-——— -— ------ .— ------—- --- .-.-— —- 7 PART IL GRNEUAL A(X’MTIW Revfaiond nomenclaturefor aeron8 ..- --- ———-------- —- —- —-- —---—-—- 8 The Wrteenth WilbtIr ‘imght=“~------------------------- --------- 8 Condderatfonofaeronautkwlhmtim---.-------—--.-—---—_—----------.:------ 8 Adoptionof etendmd atmmpheu’e-—-— --—— ——---- -——-———- --— -- ----—- 9 Adoption of altimeter dibratfon *M-. --—__________________ 9 Standard method for determktion of hfgh+l~de performance---- —----- ---------------- 9 U-of nongovernmemtld egenakll-.-------- . ------------- --------— 10 Standardlzatfonof wind-tunneldti--.--———-———---------—-----____—___ 10 - Cooperationof Jkly and N8vy___ —- —--- —- —------ ——— ——--—-— ----—--—-. 10 InvedigatfoM undertaken for the Army and the Nab------------------------------- 11 s- 00mmftteeon &d@ of @ mmirig!d&lbip ~1...___ ————. 11 AmerfcetnAeronautlaalSafety Oode-.-----------—--— -------- ——— ---— 12 PART IIL REPORT9 OF TRCHNICAL COMMITTEE -ofti*on ~-------------------- —--— ------— 14 .- Report of aommittee on powexphknfilfor tit...---—_-------—_—___—----- !26 Reportofaommfttm on materiah for *t------------------- —---- —--- --—- a PART IV. TRCHNICAL PUBIJCATIONS OF TEE COMW’JTEE Summarkaof taahrdadreportE------—-----—------------——--— ——.---—— 40 I&t of tedded notes hued duringthe past yam_______—__ —------ ---------- 46 &t of tsabniad memorandum fssued duringthe plld ywr - - .------- —----- —— -------------- 47 ~PhY of ~utim-.-——_-------—----— _____ —---- 49 PART V. THE PRRSRNT STATUS OF AVIATION . Thepresent~tateof teohnieal&m~_L-----___-------__- ------- ___ 60 Awonemtieel~h in the United Statea-—__________________ 64 Relation of aeronautiad remerobto Mtional defense _________ ——-—---—----- The generalproblemof aemnmtiad ~tion..--.-----___-—__-—_-—___---—__ : Pro@’wafn aommeraMavilbtion----- ——------------------- --—-—-------—---- --------- 67 The problemof the airaraftbd~--------------------------------- -- —--- 68 .—. The simhip problem _________ -—- ——------—--—------ —-- 66 .— s~- ------—-—-———-----—--------—------ --———---——-———— 68 Oonchldon-------- ---—- ------.----- -----__A--- ------ —------ -------— 69 Vn . TECHNICAL REPORTS Pmo No. 210. “InertiaFadamof EIUpacddafor uaein Aitihip Deai&, ” by L. B. Tuckernmn. ..- 61 ..---- No. 211, “Water Model Teati for SemMgMAirahtpa,”by L. B. fick~-. --. 69. ... .. No. 212. “Stahflity Equatfonafor AiraMpHulk;’ by A, F. Zahm----------- --------- —-. -.—-- ..- 88 No. 218. ‘(AR&um6of the Advanowin TheoreticalAemmautfesmade by ?&x M. Xfunk,”by JosephS. hH------------—— ---------------------------- —-.-.~--.----------------..---c. 89 ~~ No. 214. “WW SparSiiiwmChari!aand %g”lhm Pr6portl~;” by EdwardP. Warner---------- 186 No. 215. “AfrForoEs,Momentsand Dampingon Modelof Fleet AirshipShenandoah,”by A. F. Za.hm, IL H. Smtth, and F. A. hula--_-_-._-----. -.--.. ->---------------------------------- 168 No. 216. “!l%eReduotion of AirpIaueFlfght Tmt Data to—-----Standard.Atmcmhra. - ...—.- - .wtl?nsl” by... WalterS. DiebJand E. P. ~yi------____-.--____-_.— =--------- . ..-.----.-.---..----<-- l&s” ‘“ ‘“ .. --- No. 217. “&kdnar y WingModeITda fn the VariableDen&y WindTunnelof the NationalAdvisory committee for Aaroneutios,”by Max M. Munk-------. -—----------------------------------- 208 —-. — No. 218. “StandardA$moaphere-TabIw and Data,” by WalterS. DIehl----- -------- ----— 219 ..-,.— —._ No. 219. “Some Aapeotgaf the Compariaanof ModeIand Full&aIe Twt+,” by D. W. Taylor-------- 247 No. 220. “Co@mfuon of Tda on Air Propellers h Flight,~h WM TunnelMwiel Teataon Similar l?OlTll13;’by W. F. Durand and E. P. tiy--.--.---------:-------.--.----__---------.---_.I 271 . No. 221. “Model Tti with a Syatematio Series of 27 Wiug Seotionaat FuIIRaynolds Number,” by Max M. Munkand Elton W. ~m-.----.-_------_--— —---- ---------------------- -. 801 .- - No. 222. “Spray Penetrationwith a SimpIeFuel lhjeotion No&.le~ by HaroldE. Millerand EdwardG. Beardaley---——------ --_ A--" ---. -.. -Am-w .k - A -- A-.-. +-:&*-.--- 4-:--&---- --,. 81Q ,... - -F. No. 223. “Rwaure Didrfbutfon on the C-7 &ahip,;’ by”J. ‘W~wlqy, jr., &d & J. [email protected] ~ No. 224. “An Investigation of the co~oient of Dfao@ga of Liquids ThroughSmall R&md Oriilceafl by W, F. JWW---,--..----...-. -.-_-.._ ~-~~=-s-.-=-.s--> AA.: -----.--.---.T: 869 . :- . .. ., ... No. 225. “The Air Formaon a Model of the SperryMwaenger”&rPlanewithout Propeller,”by Max M. Munkand WalterS. Dtahl-. ----- —----- ..--. .--- —------ ----------------- ------— --- 879 -A- No. 226. “Characbrietfcaof a Boat Type SeapI~e DuringTa@@f~, by ~. .W.,,,~w.e~, jr., and K. M...... _.. “. _ .—— mu-. -_:_: _::-__-.-–__-.Q—.-..-zz . ----.--a. --h---~.::~a:<a–<--”=--. 891 . No.