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'
HUSHED FLIGHT
The
sport of power
l
.
ess
flight
Rising a
i
r
i
s
the pot of gold a soaring pilot searches for
.
The need to
ti
nd
i
t and th
e
exh
ll
ar
a
tlon of be
l
ng
c
aught
I
n
l
t
Is
what dr
i
ves us
I
n this sport. Many pllot
s s
pend
more than ten hours o
f
their day o
n
an airtield to be able to fly just a few hours. One
may wonder what
i
t is obout soaring thot coptivotes these pilot
s
so
.
RACl.Nû TO THE SKY
Pat!ently and concenuated the pUot sits waitinq 10be1aun<hed. The cockp&1. feels likc ll greenhouse wit" tht> canopy dosed a.nd lhP. ~un nlat1n9 on ll. A kilr>metl'f! long s;eel cab!e bas bee-n attache:d to the sali-plane with at the other end a 380 ~orse· po~vcr t:ngînc oo idle. The pilot glanccs to lh~ Jt>ft 10 fhf" r.«;>rson lteeping the v/ings level and ralse thelr hand. A slgn has been given to the aitheld operations leader th<Jt 1hc pilot is.lcád)• lQ9G\ A ti_ghl &sht>s sisi:nalltng the wlnchmati to pu1l 1he (able
tauL The parachute connected to the ca-bh! in rro.nt of the ~tlpla.nc slowly moves a\Ya)' from thf" plan(' Md the pilot he~r~ a dlckas the connector plece t.e1vlng as the Wt>akes; Onk in the cabJe soaps tight. The
pilot brüt~ kim~l:f. tl;is is thee.alm befOlt'! \h~ ~rotm.
Af.
m"
plant" mo-"t!~ fmward ever ~ s.11ghdy the pers.on at the wlngtlp dtops. their hand and yells ·"right!' The flashlng li9h1 now .$hines conlinuously, 1-rlli.ng (i'\c.wln(hman know 10 hir 1~9a$. In the
rno-ment tt takes. the •Hlnchman to react. the
pilot antkipates. the b'a.ze of evena to fOl~ low A kilornctre û'Wüt, out of ~ight cf the. p1101, the 11An(hm1u'l 9lvf!S" ht'allhy d06f' of po•..ver. The.n, In less than three seconds. neatfy l'la.Jr a ton of plane and pilot ls ac
-lctonardo Tim.ts St?TCMBLR 2012
c~~rated ro cwer-1ookn\lh.. Ae1ndynami<1> kick In and the sallpJ.me lifts off, qulckly but smootlily lkr: pilo! pittht's tht'.ólitc:raft up. The pilot briefly looks to the horizon
and SttS-fot the first time Ofll}• a blwr
be--t11n:'!n °"">'and t.1nd; 1oom .l!IUl\11'.ft.. Ad.!"-cWon point has been reached. from now on any abon in the tuln?·otr mC.1.flS Ayln9
i). low f~V~ (lr<:uH bac:k rouf'ld 1n.s.1~d of
t,rytng 10 land strafght ahead. !kil the air·
sr~ed 1~ $la hit: and lht" plllnf!' 1s:1till elin 'b-lng qulddy as the pi:lo.l oondnuowly puOs bt>ck l"ttQfC iand fnOft' on lhe-stit.k to m<1in· taln lhe pitch atdtude.
The Wlnchman \\lillches a.s the sailpl.ane dimbs over'1cad i'ltld lhcn C1Jt.s lhc pO"o\'er aty11ptl}' lt111n9 1h' heavys1~el c:.a-t:ilto ~g. ltnml?dlately notking lhe drop In P<1wer, 1h~pllo1 de~chf!S l~c:ah~.The: pllo1 pel· form.sa brief cheddist ;;ftersuch an e.xplo-si11e slart pitch norm.al! Clble di<:t<1chcdî Alrbrakes. lockedr Alrspced ok? The lë nd-!ng gear is then retracted. Calm settJes Qv'r 1he pUot "nd plant, c;ool .'llt hlQ.wS if"I frcm the ventilation s.ystem maklng the cockpit comfo1t.:1bl~ M lhc p11ot Oes biKlot. Gbding· qule-t!y anct smoothly th1oogh the atr the wïlplane begif'IS lts .search for tis.• 1n9a1r ••.
HIGH PERFORMANCE
lf'l .a ~U!hk> ~tmo~phere Wilh no wind the tJme a saîlplane coold Oy wltl be deter· mined by its altitude, veloóty and glide perfQtf'Nln~. As milrty an ûcrospace f!T'I• 9ir1t:er
wm
ilriQ·N 1ht-ltft·drag refo1Jr1on 1$ hatdl>• IJneat for regu:la! ëltcrah and thf:s Is no different fo! s.allplanes. However pilotsp1efe'f not to think in l:Jfi ~nd (1taq CC)Cffi. denu but tather wtsh these coefflclents had been expressed in air~peed. Only lwo poinls m \he vclotity potar a-rc fe• all}' oflntl!f'f"$t: th' afr{>~ for minimum rare af des.cent and 1he altspeed fot bes.t glide ratio{hO'H rara planewllf tty forward pe-r incrcmcnt alliludt: drop), A sailph1.nc
manufnCT11tf!:r wi!I dUtlfully prnvldf' Ûlt' polar for thelr alrcrafr and may even save
yo.u tlw effott ot dra ... ~.ng the tangents. in· dical.ing 1he two kty aitSJ)c::ecl!>. Ho-Never, .sint;e durft1g 1ht-bet ter pan of <tffYdayth~
a1mosphere can hardty be called s.table (i.e. there isah\'ays at tea.si a wisp of wind)
a pilot rnlJY tind th<it the g!ide ralio is far f1om wha1 th~ m1lnual $a.Y~ il is.
In ~~bit;' atmo$ph~re! i!'I chf!:ap modt:rn gflder wil! have a ratio or around t:lo and an expensive performance modet around 1;60. In Qthr.1 words;, high pcrlor!Tltln<C couk:I ~11~ Delft at 1 lim ahît11de ($1111 ~o be-low the clouds on a nlce day) and land
l
somcwf'l~t<!'in Amslcrdam! Fa<lorfn ;t tail•
wind to lhis :;ttnario ancf. lhc ptanemighl
tov'1' re ach Vn!f'ndam In one qn, A ~tlhy
lllil bt~.?~ impl'(M's rh"! 9-ude 101110 sinr.e
rhe .-.a{lpl~nt: t:i!n l'ló\\l travtol fu1the1 wHh à q~all;i111dediffercnce. /t:(~iffhP.ad•Nlnd of coutl>P. l'NI~ ihti e,onVf!f'Sl! f!"ffi>C'I. In 1hf'.' ;ieroj;l)aC~ w0tld mlJt:h 1r;>vl3M!~ arf;(.1nd ~d~1<ll"i9 \\'-eight and 1rs<1eed Il 1:. 11 lttiy f;}ao1 tn the d~:-;ign l)f s\'lllplane$ ;,i~ ....n?n. 11 may lhus be a surprise tNat many exper:enced $a!lp!ane p!lo1s fill the wings
of 1hel1 alrcrah wlth •11atet for reasons
01her th;;n to posltlon the centre of grav·
11y prope1ly! Po1en!lal eoergy fs the an· swer. Gfven the same altltude difference, a he.avier .s.arlplane has more potentialen·
ergy to 'spe-nd' on veJocity. Of course the heavier sailplane wifl have a higher sin.k r\ltt 100 bu' lhi.S is out.-.vcighed (pardon tht' pun} by the imptoytci 91iclC11'opc tholl is achi~d Fo1 pr3c.llc:<1I 1t.nons. this is
onl)' u.:ally donc whcn " long flighl is t°J(·
pN'u:d.
USING THE ElEMENTS
on hot (f.ay~ one ·ean somei1imeir; f;Ce the
air shJmmer just above lhe ground te.g.
abovea parldng lot). Theson Is healing up the ground and In rum lhe ground heats
the air above lt creatfng a pocket of hot air. lf nothlng happens lhls pocket's1!00' to the gro.und. But. if the temperature of
the surrounding air Is Ier.ver a'ld tllere is some J,Orl of disturbance (e.g. someone
W<llkin9 to lheir car on lhc pa1kin9 lot), ltlis l)t'll:'i<ct o( hot air rcle<JSCS and Slolrts to
rf:s.e. SU<:h a poóu':t cl tising ai1 is c.tal1ed D lhe1mal.
Il woutd make ä sailpl.tanc pilol's lire 1hlJt
mU(b e~c1 il the shimmcr c>(holai1 vll!rc
lO 1P.m1Jin dislioguiW.ble as il gafns al~ iltude. Unfottun~tely 1his i~ n(l.I Û'll" casf.:
;iind to iht-nak;M t-yt: 1~ hoi ~11 Is lnv1$·
lble.01h~t(lues to the presenc;e0f a 1h~r· mal mu:M be used.
Sinc;e OUI pilOI b Stl11 flylng .IJl only 40011"!, seard'tlng fo1 an e:l<panSt: of ~.:cphah or ;.,ny large da1k sutface could )'lekl a thermal. Then agaln a pocket of hot all may not yet have relea.\ed from these surfaces. The doods are aJso a g'ood marker, a dark nat underslde and nuffy wtiite top indicates
an active thermaJ c.ould be pi:esent under the doud. As it rises lhcthrurrnil COQls duc
to the c:ooter su,roonding air .;ind at somc point thl? cxtrn moistufl? conlaintd by 1hc
ho~er air c:ond~l'l$l!S form1n9 a <lotid. ln iht: ab:.ence Of 01~' ~fgn~ n)•lf'tQ 10\V.Vd\ sucha doud Isa saltplane pdlot's best bet. Tht' pilot als1> looks l!round f()f othef ~ll· plane$,. not only 41$ a mattH
o
r
S(lfety bi.11;;lso toseetf others h.;llt! managed to r1nd a 1hermal, though In this scenario a bet· ter alternative appears. U.nder a darken· ing doud a nock of YNallows fly aroun-d, the birdsarein fac-t dinlngon the i:nvisible swami
o
r
insects caught ln thls tl~mal. Il is highly lik.t-ly that the pilot wilJ (ind a thermo! al lhi;t, dinner party, bul utllfting the thermal efff!<tJv«y is anorher YMtt'!rap.1n.
PIECING IT All TOGETiiER
~lng ahleo 10 u1ili1' 1he1m11I$ efft-<:tM./y IS an e:xnt-mf!ly 1mpo1ran1 sl(lll for 11ny-r.all.plaf'\t' pilot 10 ha·1~. b111 lt 1$ $imply a means to an end. The real goal U belng
able 10 soar greal distarn:e.s in as short a time as possible. On days wheo hal'! 1he skyis blucánd the ot~r hall col/<? red wilh the <1fo1·ementionc:d cloud~ il is no1 un•
r:ornmon for e.xpct'ic:nced pilr;ts to fly
o
w
:r
35()1\.m In tl'W:' sp;<l(t: <')f tl r~ hóurs.. \l/hcn ftytn9 cro»·count1y " 9re<1tcr un· dr:1.s1<1ndfngo
r
wiod, cloud ünd thC"fmül bfoh;iv1ou1 at1t.I thr:ir 1rne'31:1lon [S. re·qurttd. The pilot wor1cloa(i lnC-1'.ll\t!S rot·
tht>r dl1e 10 naVigatlnn tasks bl'!l.n~ i'ddl"d. These tasks may be 1educ:Ed thtough the use of {advanced) com.pu1ers but IB the end an ofd·fash.loned aeronautlcal na'lf· gallon chart aften works best.
•
-Pflots of varylng skltls compete ag.alnst each other in crowcountr)' llying i:n the various championships held throug'hout
the country durin.g the summer moriths. Assign«t routes scmetimes c:ovr:r SOOk1T•
in licngth. lhe pilols svi~ 10 fly th~ di.s· 1.'.lncc as qulddy <s.s lhcycan. Comp<:tition class~ are u5'd 10 sort dlfferen1 glider l'y'J)es into <:ompt":ti1ive groups bas.kJ fór example on spans .and the presence of flaps. orten competlt!Ofls take plac.e over several da)'S placlng both physical .and me-ntal stralns oo p!Jots.
.Soarlng ls che an and sport of n)'l11g, whe1e pllot and machine synduon12e to achleve lncred!bfe reats of alrmanship. Saitplane pilots us'ing the lm!ather to their advaotage wilh the abillty to find and lty thcrm.tals tfr«:l?vtty b. llic bdsis or~,..,. !hing, The cNllcngc:, lhrîlf 1lnd bre.a.lh· 1aki.n9 sighls of soafing to new p!3(es .tart? wha1 dt1v'!'! 1he~t! pilo(.~ Jn 1hei1 queo:;1 for
tl~ing "1r. ~
