Decenber, 1949 AEROMODELLER 76I

A ONE, INCH TO THE NG SCALE MODEL

DESIGNED BY RAY BOOTH

Ray Boolh . . . 30-y€ata of 6gF. . . maried.., ono daugbter . . . m€mb€! .rf th€ D€ligr Oficc A. Y' Ro€ & Co- Ltd. . . . srileots.ro- rnodetter 19* veare , . . hol'ler of Britigh Inioir Taiue€a R€cord E.L.) . . . iDt€rcated ir tsille'8 iowd era flyine ecate' lud Psrslol ivpe... served ir Royd Sigmle ;i rranc€. nckiru' Akeria' Tunigia and lraly. M€Eher of Marchertcr M.A.C.&ftAYRO"M.A.S.

AY EO 504r(

al URILY no orl_.r r\.De o| 3ircraft $rrls so much responsiblL country $ for tnc ,tcrctnpmc-ni ot ' airmind.dness.".in Lhic ; t[e AVRO 50i K. originauy produced in 1915to traitr toti lor thc R.I.C.gl*.:?1.1s$1::-".t"';:":l' t]re 5Ci appe-a"riain severa"lversions, the iil:,:'.:._*:^11ii " tlpe tcing tfre From I;i""'"*'ir932.to 1938lB3 aor"n- 'oi rr't""" olll -ostAvro -eil'kttot"t: s " -as lhFv ter^ afleclion-ately kEown-rour^cl the i ounlrt Siving joyrnl's nL 5/- a flI3ht' Probilblv mlre p, ople had tbcir first experien'e ol nyrng rn end the 504 j( than lo ;nl' othe! type of aeroplane up to the o( 1C38,at $hi"h lime +besPSrrnd old machine' $cre no less it'a" zi y"ar. ot 3Bc. Our c;ver pajnting depicts--a tyPical example Iormatitrg with other mactftres oI AiaE Ltlobrra-n s Jamous circus. Jt is said lhat Lhestabilitv charactPrisiic5 Ncre oI such hiBh o'der tbal in the evenl oi ditEculties itr fliRht it was onll' neccssdrv for rhe pilot to removc his hands and fn't from the controls' and thd machine would automaticallJ' returtr to straisht and level flight. What better macbine thelr could cne chooie a.s the subjecl Jor a flting scale model ? The performance of the model has lar exceedcd luy most con.ervative estimates. and aLthougb it fas only be-etrentered in thrce compclitions, this model ha' so tar Ioll'cted tDA Aeromodeller Chdmpioa of tle Exhibition Tropby (Northertr i[odels Exhibjtiotr, :lilanchcster), lst Prizc in th" FIving Sca]c .qLction af the sarqc exhibition; 2nd Prize in the Model Ait AEROMODELLER December, 7919

cra{t Section at the Manohesterr and l)istricts Society oflNlodel and Experimental Engineers' Exhibition, and lilallv . thc Replica presented by Direc- beautifui Silver Trophfand ^the tors oI Messrs. A. V. Iioe & Co., f-ta., for the bcst flyingscale model ol any Avro aeroplane built b1' a memb-er o{ the staff' For this latter competition the rnachine bad to be flown, points beins arvard6d for talie-off, stability in fliglrt and ianding. T[e of6cial report ot this occasion stated that t]rtr model 504 K "was a-perfcction of both appearance and flvins abilitv ". fc date the rncdel has about 20 minutes nj'in[ to iticretlit, including two flights of ov^er 4 minutes' -Afihougb the prototyre has always been.flou-n rvith an auy luotor o.[ simiiar porver and " Arlrco "*'78 c.cl Mk,-I, - weight shoull bc satisfactory. l'hroughout thc clesign my aim has"been strengtb an<1 durability, and cor-rs.'quently at firs1: glance it may ieem rather heavy. Lct rne. hastt'n to assure i'eaders, how-ever, that the {tying ancl gliding speeds are probablv onlv about lralf tltat of normal pot'er duration inoilcls bf sini.ilar span, due to its rclativcly large sing area. knock-off in the cvent of a crash, 1'he rvings are arraigecl-being to all braciig " rvires " | 132 in' squarc rubber.. lfhe inter- plane strits are attacheii tir ttre wings-by.passirrg I/16-in' iouare rubbcr through the 18 G. alurn. tubos in the u'iugs, then tliroueh the hollow-built-up . The rnain undercarriage is fulli sprung witLr two sh6rtoncrl cigarcLte lightcr spr'ings on each s"idi of t[e . Thc tail skid is also shockabsorbing. Flying. Extretne car:tion stxuld bt: taken until experience trai bJeo gainecl rvith the rnodel, ancl .under no circumstances should thd initial tests be carned out in anYthing but absolute calm conditions. Chc'ch that the complcte rnodel balances on its cor-rect C.G. point (shown on the plan) then test glide ovc-r long grass if at;l1 poisible' I{ lorrg grass-cannot be lound' gltd"e"irs ncar as ooisitrle to tllt' grouod. Should thc lnodel itatl. uack up thc' of the tailplan'' rvith a strip of I /32n-'tlsheet halsa ; i1 it div;s pack up the trailingcdgt'olthc tailolane similarlv. Continue in this wa1' until a fairl5' fl61 giidi is c'btained, bcaring in rnind, o{ course,.that biplarres ivi[ NOT glide with the flat angle of a, conventional tluration tnonoplane, clue to the extra dra[ oI wing struts, rvires, t-tc. i'ill the fucl tank sulficicntly full to cnsurt about ilO sccs' rnotor run, and throttlc the <'ilgil,}e figlrt back*-evtrn at the fxDense tt.[ uneven nLnninq ! Lct the rnachinc attempt to It.b.C. at Lhesesettiugs. It rvjll, in all probability, only-ta-xi stowly along tho groun-d, sq Sraclually iucr-casc the.revs c{ the rnotoi'until] aftel: a long run (about-? to t0 r'ards) the model iust becomes airborne, Observe tho turrt uncler power, which, with the set straight and the correct alnount 'fhese view$ of the of side thrust, should be gcnth to the right. Wren the rnotor m0del in full flight wiltr cuts out the nose should cirop slightly ancl the rnachiqe g<' into- warftr the hearts of all trrnr on^the"gli6i. 111houg): DOWN I} scntle right hand -NO {hose who relnefiber i'.frRUSf"*ot r'vtr rtsed orr thelrotot'ype, should the model r|re €lcgant E04 K, an