CIBA-GEIGY

technical notesAerolite glues in

11 1974 Caley glider replicas

AeroIite° glues inCayley glider replicas

There la e legend In the Yorkshirevillage of Brompton that their one-tlrneequlre frightened the wlte out of hlacoachrnan by launching hlm lnto the alrln a prlmltive flylng machine. haIf-e-century before the Wrlght brothers flretflew at Kitty Hawk.

The equlre wee Slr George Cayley.When Anglla Televlslon produced a docu-mentary about Slr George. they set outto prove hle theorlea wlth the ald ofreplicas created from hle notes andsketches. They succeeded in re-enectlngthat legendary flight. with a remarkablemachine which surpeeeed the moat ean-guine expectations of its performance.CIBA-GEIGY wood glues were used In theconstruction of all the repllces

"A prophet is not without honour. save in

his own country," There can be few men lorwhom that statement is more appropriate thanit is for Sir George Cayley (1773-1857). Thisscholarly Yorkshire baronat presaged our eraol flight at a time when his contemporarieswere exploiting the newly created canaltransport system-their eclipse by the railwayshad barely begun when he died.

Perhaps it is because his ideas were so farahead of his time that they were almosttotally ignored, and his achievements re-mained unrecognised for nearly a century afterhis death. Evan now. when almost everyschoolboy knows the achievements ol Orvilleand Wilbur Wright few even know the nameof Sir George Cayley.

Thankfully. the bulk ol his manuscriptssurvived to be discovered by the late J. E.

Hodgson. who was perhaps the first torecognise his true stature in aeronauticalhistory and to make it more widely appre-ciated. He was instrumental in having theCayley papers deposited in the Royal Aero~

nautical Society's Library, where they are nowaccessible for serious study.

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Among those who have devoted such studyto them are his noted champion and bio-grapher, Charles H. Gibbs-Smith. and Com-mander John Sprcule who has for manyyears made exhaustive studies of Cayley'sideas and has successfully proved theirvalidity with the aid of flying models.

Cdr Sproule‘s interest in Sir George wassparked by that legend ol the frightenedcoachman, with which he first becamefamiliar ar a young employee of SlingsbySailplanes at Kirbymoorsida in 1936. As sooften happens, that interest lay dormant forseveral decades until it was adequately re~

stimulated by acquaintance with the writingsof Gibbs»Smith‘ and Capt J. LaurencePritchard who, in 1961, published the firstbiography of Sir George Cayley',

In a paper' recently published in the Aero-nautical Joumal. Cdr Sproule writes: "Beingvery familiar with the Cayley country aroundBrompton and his Scarborough birthplace, it

was fascinating to speculate where Sir George'sinspiration had come from. _ . I am quitecenain that the happy chance that Sir Georgewas born cn the north Yorkshire coast playeda great part in directing his thoughts to thepossibilities of human winged flight. Anyonewho has visited the windy resort of Scar-borough will be familiar with the squadrons oigulls which glide so elegantly on motionlesswings along the steep cliffs only a few feetaway from the spectator. l have watched theScarborough gulls wheel and soar for hoursmyself-they lock at you and wink as if to say'what fun this is'-and I am convinced thattheir ancestors were the spark which set theyoung and imaginative Cayley olf on his fifty

years cl aeronautical experiment."One other happy circumstance ol CayIey‘s

binh and youth at Scarborough I am also quitesure ol, and this was the presence of theseaport, which in Sir George's time wouldabound with sailing ships of all kinds. Herewas the only technology. apart from the wind-

mrll, whrch derrved power and force lromthe wand. How natural to turn thrngs around90', so to speak, and thus create the sarl-wrngfthe basrs, long belore Flogallo_ ol all the Cayleyllyrng machrnes

“Ourte early rn my study ol Srr GeorgeCayley. rt occurred to me to make a replicaol one ol hrs machrnes to see rl rt llew, and rl rt

drd, to lly rt lrom the orrgrnal place rn BromptonDale. From all accounts no one had ever donethis belore. It was not untrl the summer ol1971, however, that I began to put thoughtrnto practrce, spurred by the lact that nowI had lunchtrme access to Sir George'sorrgrnal papers and sketches rn the Socrety'ssplendrd lthrary-a prlceless opponunrty

"The machtne I had selected to burld fromthe start was the so-called Rrdrng Rudderglrder ol 1852, a large unprloted sarlwrngmodel ol remarkably modern contrguratron ltwas lascrnating to pore over Srr Georgesorlglnal sketches ol thrs machine to try andglean every scrap ol detarl as to how he hadmade the vanous components.

"Alter consrderable ellon to keep thewerght down to the stated 16 lbs, the machrnewas lrnrshed rn Aprrl and tested on the SouthDowns near my home at Shoreham-by-Sea.As all drmensions, CG and materrals etc, arequrte authentrc_ rt lollows that rt must be a truelacsrmrle ol the orrgrnal Prelrmrnary testsshowed that the machrne llew astonrshrnglywell, so on the next avarlable holrday a lamrlyerrpedrtron was mounted to Vorkshrre to lly rt

rn the Brompton Dale"On the evenlng ol the 18th August, 1971, I

heaved the ‘I6 Ib Cayley glrder oll the hugh

eastern slope ol the beautrlul lrttle Yorkshrrevalley and rt sarled away rn stable gracefulll|ght_ exactly as rts ancestor must have doneabout 120 years belore A qurte unreueatableerrperrence, even my wrle, who rs somewhathard»borled as lar as my pro|ects are concerned.was thrrlled. We all remarked on the currousprrvacy and calm ol Srr George's llyrngground, even though the dale rs srtuated rrghtrn the ntrddle ol Brompton vrlIage_ |ust oppo-srte the Hall where Sur George Cayley hadlrved

"Here agarn was a happy chance rn theCayley saga For only a lew mrnutes away lrornhrs workshopfcumfstudy rn the Law Gardenat the Hall, was an rdeal testrng ground lor hrsmodels Anyone who has ever made llyrngmodels wrll know that there rs a knack rn

makrng thlngs lly whrch rs only acqurred bylong practlce l am sure Str George had thusknack Wrth the greatest ol convenrence_ hecould try model alter model rn the nearby daleand learn how to achreve lateral stabrlrty wrtha hrgh mounted wrng or drhedral angle, and tobalance nose heavrness agarnst negatrve tarlrncldence. And how natural to make bugger andbugger models so that one day a ten year oldboy could be lloated oll hrs prrvate hrll-andlater a lull grown man,"

Cdr Sproule subsequently constructed a

COVER FHOYOGRAPH The veplrca man cnrryrngcayrsy grram ,rr run rr-gm .mass Brompton marere anaerrrrg me aaaenrrrarrs lr-qarraary rrrgrrr rarram-gran

1 Cnr semure launches me nramq mama. reprrcaAcross me nate maart .15 cavrev rrrmgerr musr havenone 120 years ur-ram

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replrca ol what he consrders to he one ol StrGeorges rnost rmponant Ilyers Thrs rs thekrte~l\ke "skrmmer" whrch he deprcted anddescrrbed rn 1818. over 30 years belore theother The layout ol thrs one rs based on thetradrtronal Chrnese bow»krte, wrth a smallerone behrnd rt set at a slughtly negatrve angle ol

rncrdence to counteract a suspended werghtat the nose Thrs us the lrrst known example rn

the hrstnry ol aernnautrcs ol the use ol wrngdrhedral to enhance lateral stahrlrtyl one ol themany "lrtsts" whlch Charles Grbbs-Smrthattrrhutes to Cayley

The Cayley papers rrtclude a rough sketchwhrch shows a man "between the shalts"under a long tore-and-alt pole wrth a smalllute~l»ke tarl at the rear Wrth the rrrsrght ot anessentrally practrcal man rnto the 'sketch~book shorthand" ol the eng|neer's hastyattempts to deprct an rdea prctcrlally ratherthan d|agramat|calIy_ Sproule rnterprets thrs asa representatrun, wtth the ohscurrng wrngsurface omltled lor clanty, ol an enlarged`sk|mmer" adapted as a prlmrtrve hang~gl|der

lt thrs was ever put Into etlect. rt wouldcertarnly make thrs srmple devrce one ol the

most srgnrlrcant ol all Cayley‘s desrgns It

would have antrcrpated L|I|enthal's srmrlarachrevements by the better part ol a centurySproule rs cenvrnced that the "sk|mmcr" wascapable ol belng progressrvely "scaledeup to

rnan-carryrng hang glrder proportrons, as rt rs

so easy to make tn any srze Cenarnly there ls

mentran rn the notes ol loads up to 90 Ib havrrrg

been carrred rn thrs krnd ol mnchrne"As a result ol these actrvrtres. Cdr Sproule

was approached late rn 1972 to assrst rn thernakrng of a televrsrcn documentary about thelrle ol Sxr George and hrs aeronautrcal achrex/e»

nrents "I was asked rl would assrst wrth my

extstrng Cayley glrder and any other models I

had, and rrr partrcular, rl would care to

recreate a replrca ol one el the large man-carrrers " The Idea was to re-enact, rl possrblethe legendary llrght ol the coachman rn

Brompton DaleBecause ot programme trmrng, rt was

necessary to research, desrgn burld and testthrs devrce rn under 8 months a consrderabletmderlakrrtg

It rs not recorded whrch ol the manypotentral nran~carry|ng glrtlers deprcted rn the

Cayley papers was the one reported to havecarrred the trmorous coachman Alter somedelrberatuon, rt was decrded to reconstruct thelarge monoplane "governahle parachute" out-lrned rn the Mechanrcs Magazrne ol 1852

2 Car Spraula wrrn me summer mourn me earnestknown neslgn ro rn¢aronr.rw ammrsl lor lateralsranrlm

3 Fs¢;lm.|u ar me rrrusrmrrem as may appeared .rr meMecnanrcs Maqaxma at 1552 used as me nam lor medawn at me man narryrng repllca

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Thrs rncluded a very carelully draughted planol the sarl-wrng wnh a clear rndrcatron olCayleys rntended method ol consrructrng rr

From the outset, Cdr Soroule set hrmsell meob|ect|ve ol brnldrng the machrne rn themanner rn whrch Cayley hrmsell nught havedone rt, usrng matenals that were avarlable tohrm and constructronal technrques known tobe rn use at the trnre or to have been descnbedby Cayley hrmsell He had. rndeed. shown at

remarkable rnventrveness rn descrrbrng Irght-werght constructronal methods rn wood andwrre and canvas, eschewrng metal as lar as wasoossrble There were no lrght alloys rn Sur

Georges trmeOne rnventron whrch demonstrates the

bnllrance ol hrs thrnkrng along these lrnes washrs tensron-spoked wheel lor arrcralt under-carnages now lamrlrar to all ol us rn theeveryday hrcycle wheel Bur to Sur Georgescontemnorres rt was a complete reversal ol alltherr thrnkrng and tradrtron rn wheel confstructron, as represented by the waggon andcan wheel Sur George also demonstrated akeen aporecratron ol the need lor stream-lrnrng, even though the word rtsell could nothave been known to hrm And he knew thevalue ol dragonal bracrng as "the secret ol alrght and ngrd structure"

All ol thrs was rmportant to Cdr Sproule rn

desrgnrng the reolrca He realrsed that the con~structron team would have to "pay partrcularattentron to wergnt, as Srr George had quoteda hgure ol 160 Ib lor a machrne ol 460 sq lt oltwrng) area and 40 lt length "

The team selected to hutld the machrnewere Southdown Aero Sennces at Lasnam

4 Mr ken map uerrr me me or rn; rarnr .rr u.pan~num L.rsrr.»n» Jagrsrung mv r~r.~»r»~r1 :rr rar me reprrarrnan c..nr.~.

5 A (rad up or am- ur rr~.- r»mr~n ,prwfr Mt-.>r§ anrrn- L_., rrr.< .rm Mr mar, rrt mrfrr-a .rn »_a2 er sr", ar.rsh (Dat-:tl wrtll A|<rnd.1l

Thrs organrsatron, under the drrectron ol MrKen Frrpp rs normally devoted to the reparr olgrrders and rs wrdery expenenced rn an

technnques ol lrghtwerght constructron. andthe rngenurty requrred to "make and mend" rn

order to Solve awkward problemsIn order to meet the lrlmrng deadlrnes the

team .rrrawed rnenrserves one ma|or rrbeny rn

the constructron ol the rnachrne They usedCIBA-GEIGY Aerolrte' and Aeroduk' gluesUndoubtedly Str George hrmsell would havewelcomed them had they been avarlable In hrsday ' not only lor the greater strength anddurabrlrty they would have grven hrs creatronsbut lor the complete relrahrlrty and speed wrthwhrch they could be put together Thrs was olcrrtrcal rmnortance to the Lasham team whoneeded the conlrdent assurance that a com'ponent or assembly glued together one daycould be salely taken out ol the clamps andworked on the next And the work could bespeeded up strll lurlher by the rudrcrous use olchernrcal accelerators or the applrcatron olnear to the |ornrs

These glues were, rn lact used very extensrvely rn the constructron ol the machmeThe mann structural elen\ents comprrsed twon\asts_ the long longrtudrnal boom on whrch

A vrew conlrrmed by Cdr Suroule "As hementrons the use ol ‘manne' glue rn hrs notesI used Aerolrte wrthout hesrtatron as amsure a sensrble chap luke Sur George Cayleywould have used rt as ‘manne glue' had rt

been avarlahle rn hrs day" Readers olTechnrcal Notes are, ol course well aware olAerolrte`s establrshed reputatron as ar mostexcellent rnarrne glue

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the sall wlng was supported, and a number olsmaller booms and soars to shape and supportthe wlng Many ol these were ol hollow boxconstructlon, and ol streamlmed secuon wherethe alrllow was around them and not alongthen length Spruce and ash were the nmhersused selected accordrng to the characterlstlcsmost approorlale to tho partlcular appllcatron

The accontmodatlon lor the hapless coach-man ol legend was a slnlple three-wheeled carol boatellke lorm and constructlon agarnburlt as llght as uosslble wlth planklng olspruce a mere 0 1 ln thrck The whole con~tru/ance was well stlllened by a conslderablenumber ol wrres and cords

The repllca was completed and "rolled out"on the 10th ol July lt was as Cdr Sproulesays "a good deal heavler than the 160 lbouoted by Slr George ln mltugatlon all I cansay ls that lor a lllrnrng |ob such as thus. we hadto make a repeatably usable artlcle whlch wasnot llkely to collapse about our latter-daycoachman's ears We dld. however manage tokeep the wlng Ioadmg adequately below theone pound per square loot whrch Slr GeorgeCayley dnd not lrke to exceed "

It had orlglnally been lntended to carry outlnrtlal lllght tesung ol the devnce "ln ballast"to avold exposlng a pllot to the rlsk ol anaccudent ln such an unusual arrcralt HoweverDerek Prggort the Chlel Flyrng Instructor atLashant and a hlghly expenenced pnlot olunusual aeroplanes (he dld much ol thellylng ln "Those Magnllrcent Men ln thenFlylng Machrnes") expressed h|s wlllungnessto act as human ballast lrom the stan As themachrne was lnherently stable, very lrghtlyloaded and apparently robust, thus wasagreed to

It was llrst necessary to balance themachlne so that rts centre ol gravlty was ln thenght place Smce Cay|ey's notes dld notdellne thrs Cdr Sproule had bullt a 1 6 scalellymg model to determme the best posrtlon lorlr Thus proved to be |ust alt ol the lorward sparoosltlon, wlth Derek Prggott nn the p|lol'sposnlon as lar lorward as was practlcablemore ballast was s\|I| needed, whlch furtherworsened the excessnve welghl problem

Nevertheless, a lew ad|uslments drctated bythe results ol early tests w|th the cralt towedbehlnd a car at Lasham made nt posslble to gellt alrborne at about 28 mph And ln one notable

s :ewmlllmg me sal Mtg ~uu»onma 1r..ma»~an“alan lm, .. ramrktllll. "roam .\ppu.\r.m<s ln weaemlr at as aeslgn

7 Roll our In lr» ann Mt _.ln-asm .»~ rattan; as nurol Concorde

A Pramlrng var rllnrmq sr aluwpralr o..l,.

9 the on the qllaar wp. an .mass me mr--

6

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test run, a misunderstanding with the towingcrew resulted in the replica reaching analtitude of 50 ft or so. fonunately withoutmishap. Derek Piggott reported it as "quitethrilling".

With these successful trials accomplishedall was set for the expedition to Yorkshire forthe week of filming. The remainder of thestory cannot be told better than in CdrSprouIe's own account:

"Needless to say. this coincided with a weekof the nastiest and wettest weather ol thewhole summer.

"Our preliminary sojoum at Holme-on~Spalding, by great courtesy ol Hawker $idde~lay, to try to obtain some really long sustainedtows for filming purposes. was en epic of longtrundles at walking pace to find new take-offruns into shifting winds. Here were alsohurried sail furlings in pelting rain to save themachine from being blown away. In duecourse. however. we moved to Brompton forthe final episodes and re-rigged the machinein clearing weather in the shelter of the trees atthe southern and of the little dale. On the lastavailable filming day, Sir George must haveused his great influence in high places-andthe sun shone and a breeze blew right up thesouth eastern slope which village legend hasit to this day is the 'coachman's hiII'_

"We had decided to launch for filmingpurposes with an elastic rope engaged on anopen hook on the nose of the car. in nonnalglider launching fashion. Sir George'a largemachines no doubt were launched quitesimilarly, but using ordinary ropes pulled byvolunteer helpers to roll them down the hillinto the wind; his machines were very lightindeed so they must have become airbornevery easily. So, after some preliminary filming

of a professional actor in coachman costumefor the purposes of the documentary, DerekPiggott took his place with 'influencer' inleft-hand. Our six farmhend volunteers-three on each side ol the rope laid out like a'V' with the hook at the apex-took up theirappointed launching stations. On the com-mand 'run', away they went down the hill andthe car was released by three helpers holdingit beck.

"The replica leapt forward and in e fewyards once again a Cayley-type glider carryinga man became airborne in the Brompton Dalefor the first time for over 120 years. The firstflight was. it is tnie, only for e few yards at amaximum height of five feet or so. but themachine looked magnificent. It was quite amoment for us all, and this time three pro-fessional cameraman were recording thescene.

"Two more repeat flights were made; forthe last one it was decided to stretch theelastic cord by means of a car-out of cameraof course-as our willing Brompton famthandhelpers had to go back to their duties, Accord-ingly the machine, with Derek Piggott again atthe helm, was positioned as far as possible upthe east slope with the tail in the hedge. As allhad seemed well in the previous flights, andDerek had by this time proved to himself thatthe influencer could indeed influence (atHolme-on-Spalding he had successfully avoi-ded an errant cameraman by its use), it wasdecided to go for a somewhat strongerlaunch.

"There is no denying that in the event it wasfor the car sped off down the hill and. withrope stretched to the limit. the Cayley wasairborne immediately. At an altitude of 30 ft orso the machine sailed across the Dale to thewestem side in Cayley's words like a 'noblewhite bird'. Across the valley towards therising ground, the nose dropped. there was aloud bang as the front axle broke, and the tailfell off. All very dramatic, but our |attar~daycoachman was quite unhurl and was heard tooburve on his recording transmitter the words‘Oh dear'. So that was that.

"However, everyone was pleased that theflying in the Dale was so successful and thateverything that we had set out to do had beenaccomplished and filmed."

It has not been proved that the legendaryflight of the coachman actually did happen.but it has been shown that it could havehappened. More importantly, it has been amplydemonstrated that Sir George Cayley. half-a-century before the Wright Brothers, had all theessential understanding of aerodynamic princi~ples. and ol lightweight constructional tech-niques, to have achieved his dream of sustainedflight, It was as he said in 1852: "But for thelack of a light and powerful prime mover,

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\1 Il Sl! Gempv ~ ulvlhl gllll fmurtls lrw shell nl Ni nlll.tatmtun att "tea have mt wmv lw<.a.»a ~.ut§1.t¢|.mttr me |~ ttftacmtertt ar nt." rltem Mtlrt ~¢>.ttl¢-a nl.-.tgafta .wen ptavttltta we ,au ntnts, trttpan atam ttutxt ut »t~ Manton vor nw .t ft-mutt

sustalnezl mechamcal lllqht would be atnand" Sadly the lnvenuon ol the mternalcambustuon englne was several decades awayand could not be rushed

Sur George Cayley dled peacelully atBrompton Hall on 15th December 1857Shortly before hls elghlyflourth blrthday alterwhat must have been a Me ol almost totallullllmenl Few men have achreved more. andlt ls sad that he recenved so ||ttle recogmuonlrom hlslory unlul recent nmes He has well

been called the Father ol Aerlal NavlgahonWe are nndebted to Anglla Televlslon Ltd and

Southdown Aero Servuces tor then help ln

oreparmg and llluslraung thus amcle, and toCdr Sproule and the Royal AeronautlcalSocuety lor permrssuon to draw lrom lnlorfmatlon publlshed ln the Aeronautlcal JournalAnd we are honoured that through the use

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ol CIBA-GEIGY glues. we have been enabledto play some small parl m establlshmg Slr

George Cayley ln hrs nghtlul place as 'thcvemable mvenlor ol the aeroplane"

References1 Charles H G|bbsfSm|ll'\ `S|r George

Cayley, Father ul Aenal Navlganon (17731857)"-lecture glven to the Hustorucal

Group ol the Royal Aeronautucal Socnety, ref

prmled ln Aeronaullcal Journal, Apnl 1974also "Sur George Cayley‘s Aeronauncs"Sclence Museum. 1962

2 Capt J Laurence Prutchard "Sur GeorgeCayley the Inventor ol the Aeroplane",1951

3 Lt Cdr J Snroule “Maklng and FlymgRepllcas ol Snr George Cayley`s Glnders",Aerorlaullcal Journal, July 1974

Posrscvuw w~ me puma to team nt." str Gamgv may rms |o~ned uma atsltaqtttsrtea pmmmltttas who areforever enshrlmsd In the Interniluonal Aerospace Nall ul Fame at San Dmga Calvlnrnla Mus puonecrlrlg conlrlhullorlla the nuronnutlcal sclences and man S Drnqress |r\ lllghl ls thus acknowledged

Publilhld by Pllltlcl Dlviliorl

CIBA-GEIGV (UK) Limltld

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