ISSUE NO. 20 /..JULY-SEPT,1974
SERVING ULTRALIGHT FLIGHT ENTHUSIASTS SINCE MAY, 1972
GROUND
SKIMMER
MAGAZINE STAFF Editor I Carol Boenish Price Consulting Editor I Lloyd Licher Art Director I Dave Meyers USHGA BOARD OF DIRECTORS PRESIDENT Lloyd Lieber VICE-PRESIDENT Kas De Lisse
10 EVOLUTION OF THE QUICKSILVER Bob ·Lovejoy
1~THE ONCE AND FUTURE WING Richard Miller
22TAKIN IT WITH YA I
Larry Talbot, Gerry Uchytil Bob & Helen MaTaJ11Jr1any
SECRETARY Carol Velderrain TREASURER Carol D. Price FLIGHT DIRECTOR John Lake OFFICE STAFF Carol Velderrain, Mgr . Chon Aranda Kristy Hale Viola Smith
1
26TUBING SIZE? Al"t PoweU
:30HANG GLIDING AROUND THE WORLD &ACROSS THE NATION :34 THE FURTHER MISADVENTURES OF DIX ROPER by Dix Roper
:38 ACC !DENT R&: VIEW BOARD Rober t V. Wi Us
46 PHOTO GALLERY
DEPARTMENTS THE COVER: Dave Cronk in Quicksilver just after launch-assist from Bob Lovejoy. George Uveges snapped this photo at Torrance Beach, California where much of t he Quicksilver's perfection & testing was done. All rights reserved. Anyone desiring to reprint any part of GROUND SKI MMER must write for permission to the United States Hang Gliding Association, Inc . Total paid circulation for Issue #19 was 11,070.
2 4 39 47 48
President's Report Ultralight Conversation Bird's Eye View Classified Advertising Calendar of Events
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11 there that (it i now . Hence the dates were reset that' the way t will be. sponsor of the contest and may but USHGA wi 11 tion Director. d be avail ab"I ve encontest from the 1500' and
time. There has been confusion for the 2nd Annual U.. National shi , which will be sanctioned ems that cl nate te and tual"ly t was Trabuco Canyon . Before ever it became
Bruce
WILBUR WRIGHT AND HANG GLIDING
JUDGING AIRSPEED
Dear Sir: The May, 1974, issue of SOARING contained an articl of al interest to hang glider lots and enthusiasts: and Observatfons in Flight, 11 It i Wi 1bur
Dear r: After readi Kilbourne
Of F n,1; nA<'>'~
sion the complex It was difficult think of a hang gli
the relationshi horizon is att>it,ude definition is the between the wing' the direction of the relative wind, tween the chord line and the fl i defined as the direction of if a wing the W'ing. For downward the re'I wind i ward. of attack i nearly impossible to by visual observatfon. The drawing i 11 us trates my point.
l'OOBAH
agree with Dave Kilbourne arly the most
in
comunder W. H. Wolf Columbus Indiana go
Valle rd Ultra 1 Gl Park, ifornia
very ""'~<:;mi<: t ,, r governs sions of tnr1-n,~trt1 '1,t><:im11~r<: space vehicles, race critical machi champion in hi ice it, when the situation i the very worst b'le can . s are better at realizing all the hazards because of their exence.) You must to el"iminate all ble ha2:ar,js, Whatever risk i 1 "i the risk you are capabl of handling with confidence. Professional stuntmen race drivers a NwnhinA"ti ri take Hang glider Law and experience (p1,em1e tu:r>n
page 6)
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FOR INFORMATION
w·ind. In a canyon turbulent. 5. If put nut on fall Whatever na1:1pe11s cording to pen other
ow down and be bo1 , sooner or later
it wil1
100% Law.
Calendar was 'it in early
ina
FLIGHT REALITIES Adams Avenue, San Diego, CA 16
MOUNT PETE:R SKI AREA,
ROUTE 17A
GREENWOOD LAKE, NEW YORK CALL
WRITE
914-986-4992 OR i:'.U1-01ic-l:lb3t , BOX
ALSO GLIDER SALES, WATER TOW LESSONS
done.
It displeases me to read an article written by someone who uses the article as sa·1 mmick to se hi chievement. Neither do I like read arti that cri icize and slander other e' achievements. So, if this article even hints of either of these ces, pl ease understand that it was not my i on. With thi cl understood, I would like to introduce you to thi and evolution of the e which describes the hi If you are not fami ar with the ,.,,,,,,,,,," can define it for you by simple ng it is best hang glider design in the world and l other designs are mere failures. In the mid··sixti , whi'le a student at San Jose Coll , I deve·1 recurr·ing whi'le drivi from ,lose, iforn'ia, to my home in Los Angel fant'icized myself gliding down the coastal hi1ls·ides in hang glider that looked a lot like an anti biplane. Realizin~J how much fun thi cou'Jd be I to investi bilities of buil such a glider. During the col , however, c and social activities priori I couldn't seem to around to it. , whi'I thi trip with friend, I mentioned thi dream my belief in bility of i becoming realty. moved over to me her hand on my leg and breathed with a the wedding, I in Industr·i Design and journeyed to an autornoti ve designer at Genera ·1 Motors ling. I became nterested in sail anes and soaring. also became friends with an pilot named John Kuhn who was an avid soari pilot. He and his friends were very concerned about rap·idly increasi costs of thinking about little gli n. soaring. I After two a half y1'!ars in chi we returned to Southern Cali forni where I became a i gner for tel, Inc. I became friends with some neers whom soon discovered were lot 1 oracl In ancient oracl thi took the'ir was a person who the answers to ans and once something rel, one of d me my deas were ish, that hundred and buil di Well wal few weeks later and saw a picture homemade , li pi in my friend' , I numbers mentioned in the article and could about thi newborn "movement." I ider design I could find and decided a 1 of room for "i lo the most consistent because of their
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l ·i ke ki
, and were al glider the glider and asked me citement I i ng m<c! awake sleep She my 1 and softly in awoke with the desi I wou·1 cl build a biplane but to ng lems, I would it . It would be completely triangul and have dimensions that would anow it and ·ide my van. Whi'le glid·i broke the tail section . To the aston shment of we 11 without it friends and myself it flew just i was believi and I construction the full glider. frame was 3/4 in. . pine with 1/8 in. 10
, it
was outclassed matter decent campfire'
, "No," and
The Bell
Helmet is distributod worldwide by Eippor,Forrnance, Inc., forrance, CA
nee the very earliest of aviation the flying wing has been an idea in of its time. It has , now in one fcatfon, now in with unquali success. The closest acceptance has been as a sail of i li mi tat ions it has to remain in shadow of aircraft of conventional design. Only now with the of interest in lowvelocity flight, the fly'ing ng finally come home to roost. The of the flying-wing aircraft lies in its simicity poetically ' if the matter can be 1 most cl approx. Of all aircraft and dynami the bird and it appears to offer the performance per unit of airframe. For one reason or another, however thi promise has never been fulfilled. As a the wi i cl inferior to the conventi ab'i 1ity accommodate to a wide ty (CG) 'loadings and thi has uded its consipurposes. Nor has it deration for commercial or mi'li proved e of achieving the speed range required to atta'in the sort of cross-country that would make it competitive in ng appl cations such as modern competition soaring. The flying wing is obvious not a jack-of-all-trades but a rather al of ing machine e of doi one thing superl vely That one thi unsuited to outside i hi ency fli 'in a limi this reason it has become of the ultra-li movement. Sol remains on light ai intended to fly owly narrow the flying wing will continue to the choice. has i ght does 1ow-ve 1oci prob 1ems. Chief among these are rle1ow ai at low rates of sink and ble radius of turn Low zontal velociti , even 'in the case of l i iders, re a high coefficient of lift, and a short us of turn dictates a relatively low aspect ratio in order to avoid an excessive differential in wingtip velocities and the bility of stalling an inner tip duri turns. While there are undeniable aerodynami and to hi coefficient of 1ift and low aspect ratio are cul di ous in terms of what is commonly but erroneously called induaed
a in
sever'i much flying at its flow loss. 14
ironies rearward anti axis te both the
tip more
has
how
abi l to of the most diffi i:,n,··n"'"f<>r,,rl di sci pl ines of the
even expense be-
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Foldablc into
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40 in
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lJ LT R A LI ( ;i IT F LY I N c; MA Cl 11 N ES
P.O. Box 59
California 95014
Phone: {408)
LID
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STEEL ROD
TUBING
ALUMINUM STRIP
ROD
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SHORT LENGTH WOODEN DOWEL
ALUMINUM OR
TUBING
4. LIGHTWEIGHT NYLON LIGHT ALUMINUM
homemade wind work the information along. a1 too 1 ,1nd very
of
be
wi 11 carrier carrier, and sometimes even from ci the same carrier! Remember that airplanes much space and can only so much wei ts in passenger ai have their limi rements are sometimes strict for the mutual the ki who to arrive with him flying and the airlines in bl :
kite to
wfth me and It got
vvh ich
r vvi the smooth you that you
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DET[:RMINING RATIO OF WALL & DIAMETER TO LENGTH
you have a 17-foot kite using x .049-inch num tubi for the You are dent that al this kite is Now you want to produce 18-, 19- and versions thi same kite. If the same size tubing is used for these larger kites, they will be weaker and more prone to fati tural failure. knowi how to scale , the arger can be made as spar l proven . some Photographs of kites in sizeable spar deflections. no vi ibl flections are noticeable elsewhere in the airframe i conthat the leading tubes are the most parts of the ai , and that those are due to bendi We would therefore like to perform the scali such the bendi stresses in the those in the spars of the seal kite are not greater spars of the parent des Let us compare the proven kite (Kite A) with , but the same spar and hypothetical kite of di sail geometry (Kite B). We want to know what size spar tubing is appropriate if Kite Bi to be at least as as Kite A, if wing load"ing i held most basic variables are spar 1 ng weight (W), and bending moment trary point al the spar. Since the same sail , we will assume that, scale, the ai oad stributions are identical. plies that the followi relationship the moment at any fi poi along the to the product of flying wei with the constant proportionali on the relative tion al the i to be eva l Note the not; vary with spar 1 Al cally: i the dimensionl of onal ity.
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Wing loading wing planform
defined
gross
ng wei
divided
w
Since the ki planform area Al cal ly where stant also Substituting
dimensionl cononality, and of
w,
in
w
can be sol for M, giving:
Thi
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I i now convenient to introduce the bending f
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SE'CT./ ON MODUW8
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ki We tu-
TUBING
WRITE OR CALL FOR INFORMATION ON THE DEALERS IN YOUR STATE MATHEWSON WICHITA, KANSAS
STOP DREAMING AND START FLYING!
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WEST WIND School of Hang Gliding P.O. BOX 331, MANHATTAN BEACH, CA 90266 - - - - - - FOf< FURTHER INFORMATION CALL (213) 378-8033 --,-·,----,--.---
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gliding overwhelmed with United States. we cor'resp,inden1:e from abroad. certainly isn't within our borders, new records and shments are pouring foreign continents Southern Hemisphere'. as wel 1 as co1·respcmd,enc:e e whose with other hang gl enthusi is GROUND 01u.M1'"1!,11. Below are a few reports our "foreign correspondents." GROUND S1GMME:R r1"'11ene
NEW ZEALAND P1wn1-1,v- (cousin of Dan Poynter been ng the llJ,i-mi 1e of tahi to Manukau Heads (in Auckl some time when perfect conditions final l (vi from Colorado, what is now the hang iding -l'n,1m·ry,v and-return distance ck flew the cliffs one way and almost al'\ the about a mile. Jeff completed the flight: miles in hours! If you're visiting "Down Under Marett of the New Zealand Gliding to contact him at 62 Ni Road, Westlake, phone number: 497073. CANADA The Canadian Natfonal K'ite cm1mornr1sn10s 6th and 7th at Newson British
. Estimated a·t ing the meet show that The winners were: SOARING: 1. Neil . Dave 360
. Bill I
:
. .Jim Buckl . Dave Dei Portman . And,
found in the Alps but wind canons are often idea 1 1 mountain . The of such high mounta·ins that are usually , ight, and local. Because the mountains are so high, weather from coming over them. Rex Miller and I have in the and have even nirln,•err•d glad to headed
free to ,John Manta P .(L Box 8058 Zurich Airport Switzerland TOURING EUf.':lCIPE The United that best mer ·1 ong th1·ouqh1iut the 1
selected be exhibited 1 sumthe Paris Air Show, i di was re·· and l Robert Boeni , California. by W.A. Allen of
Dan
"IN FULL COLOR "/\N IDEAL GI FT
COLOR LITHOGRAPHS ARE 18" X 22" HIGH SEND YOUR ORDER WITH PAYFOR FRAM I NG. FOR HANDLING TO: MENT IN FULL PLUS •ONLY $3.00 EACH ONLY
Competitiv,1 Analysis plan,
20 to 30 a·11 the way down to 400 . I knew stunt men but they were not even make th'I fl i wi , Dee, watch.ed the vanish into the white voi within two seconds after take-off Within five onds we all i that we had made b'ig mistake .. We a 11 f(" 1t the same rush of anxiety "This might be the timethatwebuythefarm." The of wasn't there anymore only the fear. increased our disorientation grew. When I hit the first turbulence and was thrown off course I imrnedi ·1 ooked at my comWi th sinking ing, I discovered that having a wri and knowing how to navi with ng ki are two di things. , not did doubt comhad the sensation I 11 and mi was blowing As we all became more and more and "which was straight ahead" were tell if white I could no waiting feet in front me or 600 feet below me. 13ut I knew vocally that if I were around to see another foggy day, would never again it from the sw'ing seat of hang glider: Dick flew to the left and came out of the himself in the canyon behind the darn, trees and the Without mi dea 'I of relief, to rnv'"'"'+ course 'in for a safe l flew about one mt,,V't-01" mile to the LZ. He said he fel he looked down and could final the until he l the h1lls1 di no other came into out of the Though of I
March 30, 1974 was the "Grand Fl Park twas ni under your n Vi coul all cl that enshrouded in the top down Using ki an umbre 1'I a works rain. However, with thi day deluge, rain started dripping ng more than our rits, we . At thi point, fli Zi Danny Rogers, and I cided that it would he more fun ng wet while riding under a ki rather than standi under one. 13esides, the wasn't thick top as it looked from landing area! As we started of the Sylmar down with the'ir with an en1::oura,ai the mist a 1111,AY'i'.PY' over 20 Even though we the car the ,;,kcP-,nn· other
in thii
, ated with havin9 about the that our i,v·l-l"<•m" overbalanced our us knew that we had made our but that we could un<fouht1:dlv ng days ahead at the new
B N A L O V U W A
E p R I
N
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s
control •Can be spare time. •Material cost approximately 00 F'OR T, T'i''l•.'RATTll?li'
I A B L
L E
•Fully controllabl
•Easy to build. <11Semi -canti 1
ane
gl·icler.
'
that it st10uldn't you into the nation's Ne)ither should it
RK UR
0
N
SHIRTS WITH POCKETS
A VAi LAlllE rROM YOUR
Ughl weiyh!· (l(m
Minimum drng (3
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tan ORDERING:
oll of the following Information on your order:
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SHIP BY: [::::JPrepnid UPS
MEHIL ENTl:RPRI
UPS 5900 Conrerbory ,Al21
City, Col 90230
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a dozen al in on cine who deal wi all afrcraft accidents one Navy pilot who flies tom and hang gl , the new editor of GROUND MER, expert hang 9l·ider pilots, and one intermedi hang glider pilot. Thi ves an idea of the breadth of viewpoints at meeting. After the various members to each other, your chairman some of the sand of the Board, previously outlined to Board of Di"'"''""'"'' of the USHGA. They include gathering of accident reports and other data on many hang icier accidents as ble (throughout the world), s of the and classification thereof into es of cause ble, publication of findings as trends in causes and recommendations for accident preventfon, and accumulation of accident data to rebut claims of critics and to educated public officials n9 the true record of the new sport. These swill be realized increas "ingly as members of thi:, the bil 1 for submitting information on all serious fi hang glidin9 accidents to the USHGA office Ange·les. Severa 1 arti c·1 , 1etters, and memoranda the committee the chairman. These ·inc "luded statement and projects Chuck fl di who was earl e to stay for the meeting, and newspaper articl critici rate in the new and nting lation and new , and both from and about an associ in San Diego who i actively regulation of the because of record. Thi individual, who states once conducted the lar9est school in the world is corresponding tfcal and and wri publication to prove that the dangerous to be eft unregulated or in control of i own It occurred to the group that it would be a good i to invite thi eman to the next meetof the Board in the he mi be ""''""ti,.,, to some education and some more accurate on the sport than i contained in his various letters and accident summar"ies. from a number of individual vi ta 11 y i rrl·.erPs 11·.Prl of the sport in various were noted and the parts of exr)ressc•d herein for these atlon of time and to communications We hope that functioning wi 11 of the discussed in these letters rman noted that the American Al ub concern with safety to ours in and has a commi which compiles accidents and r causes in North America annually in a fashion we would like to follow if time and sonnel are in the future. One of our immedi needs was to be a simple but comprehensive accident 38
report form to be d·istributed to 1111 hang gliding clubs throughout North America as soon as chairman to ca 11 on hi ng acCi dent for ""'"n""'"H ''"' in the , and by the these minutes in the SKTMM8FI, we hope to an accident form of one in be stributed the in the ate future. The chairman had in his possession various formation on thirty-nine accidents, inc·1 fatalities and two spinal cord i egia. This data was distri for individua1 as a who 1 after Time did not allow oral dents, but have been difficulty of of cause was 1mrnor11 ,,.,, usions will be 1. The accidents involve 1 severe injuries to the Dr. who was kind on ca·1 ·1 the twenty-Fi associates all from or fractures of the and rather than the more in-· There was one of a fifte,rn-year-old para-· that Dr. Jensen treated with a neurosurgeon but not know the circumstances of the crash. were also a few accidents invol wounds resome surgery. Dr. Jensen some of the other nr·rhnnPrii surgeons at the two ta 1 which n:,cei ve Co1,mt:rv cases seem to be ng some data on type of with the aNdAm,+ Or. was very friend"ly meeting The crashes involving fatalities and serious head and cord to involve either intermeor were ther the wrong maneuver or who ran some unexpected wind the most common maneuver i the JolJ-d,eu'ree turn stall and dive without sufficient al recover. If the first thi accidents reviewed any indication, cantoo much attention to the rements turn even for The attitude orientation of the stall and dives much more than and the dives are too often running hill or nearby cliffs or ridges. 7.9174
very un-. i
Gammon in Kirkl boro, New York for that others will Dr. Puskas
formation the injuri
we
I ace
ence
ion JJV'r1ro,rr,ve
worn
on
d
&
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To:
04
I am also
medical
or 787-6600.
instructions on the student into the assistE1d by the instructor.
T
r n , 44
MEETS OR STANDARDS 7.9174
SAY
YOU
SAW
IT
IN
IJROUND SK.i'.MMl'EFi
oaf Mountain Maine. Contact • P.O. Box 142,
Nov. 18, USHGA Membership Meeting. Bell Helmets ..•.... Bennett Del K&G ••••••• IFC ,44 r:i,..,,~,,.,.;. K&G BWB
......... 7
Daedalus .•.......... OSK Aircraft Corp .... 21 ,41
Nov. Country.
, Contact , CA applica·information. Jan , 1975, 2nd Ultralight Fli , CA. Seminar, Prof. Paul , c/o Northrop Insti tute of Technology 1155 W. Arbor V·l ., Ingl , CA 90306.
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