75 CENTS
~ROUND S
NDVEMBER, 1974
IMMER
SERVING ULTRALIGHT FLIGHT ENTHUSIASTS SINCE MAY, 1972
ISSUE NO. 22 NOVEMBER, 1874
GROUND
SKIMMER
CONTENTS
MAGAZINE STAFF Editor I Carol Boenish Price Consulting Editor I Lloyd Licher Art Director I Dave Meyers USHGA BOARD OF DIRECTORS PRESIDENT Lloyd Licher
8 SAVE OUR SITES~ Larry Talb~~aak Schroder and Carol Velderrain
VICE-PRESIDENT Kas De Lisse
12 ON MY WAY DOWNWIND
SECRETARY Carol Velderrain
18 HANG GLIDER AERODYNAMICS AND FLIGHT DYNAMICS
TREASURER Carol D. Price FLIGHT DIRECTOR John Lake
Chris Price
Irv Culver
28 THE SAI LFEATHER-A LIFESAVER John Lake
30 KITING KROSSWORD PUZZLE OFFICE STAFF Carol Velderrain, Mgr. Chon Aranda Kristy Hale Viola Smith
Suzette Lowrey & helper
32 SSA/MIT/AIAA SYMPOSIUM Dr. Paul MaaCready
35 HANG GLIDING AROUND THE WORLD &ACROSS THE NATION THE COVER: Bill Frary soars the northwest face of Green Mountain in Denver, Colorado, in a Pliable Moose Thermal Shark.
47 GUIDELINES FOR THE POTENTIAL BUYER
All rights reserved. Anyone desiring to reprint any part of GROUND SKIMMER must write for permission to the United States Hang Gliding Association, Inc.
DEPARTMENTS 2 President's Report 4 Ultralight Conversation 6 Flight Director's Report 27 Tech Tip - Jeffrey Johnson 48 Photo Gallery 50 Classified Advertising 52 Calendar of Events
Total paid circulation for Issue #20 was 10,282.
Gerry Ross
CONSUMER ADVISORY: GROUND SKIMMER and USHGA, Inc., do not endorse or take any responsibility for the products advertised or mentioned editorially within these pages. Persons considering purchase of such equipment are urged to consult hang glider pilots and dealers in their area and refer to the Hanglider Manufacturers Assn. Category I Specifications for Rogallo-type hang gliders.
Tony Koleriah
puhli
conf.i rnl()d. nominations 17, 1975. Each many members tions should 65306, post member
/,)
... a:sse1mble in
ITV
II WIL
F
L
1D
nto 16 in.
Wi
MM
40 in
with
Ul
INC MACHIN California 950'14
Phone: (408)
ft. for
ID
rudder
know how
l)y handlebars
the same
I want that
ti Oll in complicatocl and
If
the he wil
gliding'
pleasant and A major ample, i compete women only, or whether open Until
wil 1
low him to make the I'll keep posted .Tim M. Foreman
Amarillo,
hang 1berately ,;equently compli would be to
Villa Park,
a
three
OR STANDARDS
I
he Nationals They wi 11 bt1 interesting the well as Chris Wills, Boh Dart, Rich Jack Schroder, Dave Muehl,and form the committee. There wj 11 he an instruction seminar at the meet schools or instructors who can't it are requested to send in their thoughts on curriculum, technique, and safety. So far, "Widow-maker" hi 11 near Provo, Utah, front :runner for the next Nationals, A movie called On Any of it. If you have other , please contact me through
A time flying quired between Hang as between Hang and 4. for will be flown tive Personally, l hate logbooks, has been proven to me that they will be in the instruction phase. I was the time between ratings, hut Dart pointed out that will reduce the
714-586-7964
6
OUR VANISHING
BY LARRY TALBOT
finding more and more
our own halfway ple the
often l literally
maklng his own trail ! Where man goes, so more than our share that :remained at Sylma:r was suppl trash , but there away f:rom them! In order to nr'c!ser,ve
50-,gal Jon even ten
some
that
for your record hurts you hurts the
When insurance protection to part of the 1/SI!GA membershlp or on an individual , 8URSC/UTJI,: '.
You
flight doll
the sport with
environment:
4
don'
hundred (lollars on
Ii
H<clp control
un-
acceptabl
multitude of
area ing when Pt, Fermin can even enced pilot and has proven reali hls own imitotJ has to he done about the abiliti
and
they should understand and
who will can
about the
1y
C:/\RO L Vli Lll!rnR/\ IN
machine.
climbed by summer. HANG GLIDTlR com·· slope every Decembor, fame. Jockey' Ridge the most popular sites in ,w,f>tlJLH), the inventor Rogallo glider here p. J threatened by
dune one mil lion dol-
dollars' turned
and "People" are currently selling land to donors for $5 per square foot. few owning thousands of dol will own will:' be
N
10
and one-half mi is not so very half-mi short of the tance to the top of Saddleback Mountain parents' house
the distance The only d1 stance absolutely the distance sure that 1 one can in Southern California. The trouble air is too go down a val looked like it would take minutes to and sti 11 have an hour of left to reach the mountains that looked ago. After ince four in up and down such valleys at SO miles dirt roads in the blue VW vils every direction the I was to kind with or without When lo and behold the road started the was a thousand feet tall. halt on the fi vils by
after Carol and I be the
12
turned the wind than 15 minutes upon this, what 1
and then
14
\ II 11~/,l 111 < A I )I I\:; ! 1 k)( )I I I I (\l If. c 1111) I I I< ) 11
IN
offers 16' to 20' Ro1,u:i1110 co1mpetition and endorsed National Meets.
are built to withstand the stresses and sometimes demand of their kites. dia. 6063 T832 aluminum with hardware and all AN duty and sails are wrinkle··free and hold their oz. dacron sewn by a problerTI. All in fixed 1nsta11at1on components are iim~-ern,urina a proper fit every time.
D Prices are right in there, too. $510
$595 for the five models now offered. r~11,mr,,,,1,, line of accessories and plenty of raw m1::rt<>ri::il and hardware on hand if you wish to and build your own Aircraft meet or exceed CATEGORY ONE Standard
H<>nn11,r1,,. Manufacturers Assn.
are
once dered then I do now, I really landed of me that me understand kite the hawk the molecule of ai or like the more
if
OT
up over the atop the rock that has For what could be than
the 28 Mill Street Connecticut USA 06033 n<>,AIAr!':lhin<:: and Flight School franchises now
Inquiries invited.
16
I
('714)
we to
l•n
we have and must bui This principle aerodynamics, can be seen in some fabric-covered where fabric some affected to not that of the the shape Fortunately and airnot The point that one must consider the materials and processes that to be used for the construction of the vehicle and blend these limitations wjth of the desired aerodynamic in oTder to achieve the best results. c!e-
pressure
more than that changes in magnitude distance in some direction. Now our little cube of air at snme will pressure side than it sees on the side and will thus be curved direction of the :low pressure FIGURU 1
stop streamline outboard but near the in Figure , this
PR1i/S81;1IE WWER '.t'HAN AVE7RA(!E
have large rib the weight no matter how spanwise i will between the ribs i the ribs have curvature in the area of the fabric, So there are only a few an
1110
the airfoil so erage useful flight shape the fab1'ie, wi l1 1 oads wi 11 conform rib shape and have slope at the and the is well to have a physical feel the basic we are to make of hang would like to 18
It
obvious the~ the closer the airfoil, the higher the nrA~<:11>'<' gradient, Our Ii ttle hlock turned path and accel
on
20)
FIGURE
I Jl l \ \ FIGURE moral
this story
the effective span of our machines couped but instead continual swept up by the p:ressure field goes back to form part of the
usually the machine made up bric. Since threads running at right ,,ach other and usually """"'"noAd that one group of threads runs tia1ly spanwise and the other group runs essenti chordwise, we can write the form T +
where AP the local pressure difference across the membrane, T tension p{n' unit width, R is radius of curvature, c denotes chordwise direction, and b denotes spanwise direction. We can also write an but adequate equation for the membrane above the supports by using the angle theory: large is held to
b
It Tb
low value. Wlth these considerations and nmny look at our problem of the
in
our
ly
what to do to
improve the the safety at the same improve the nr,r1:01·mance. Of course we must examine the negative aspects of the Rogallo-wing
around the aerodynamic center necesto st:ahle machine obtained
has
own
builders all and use their exercise strict expertise in constru,cti,:rn. detailed specifications on HA 20 or I-IP sorlos stanand 11 sail $LOO to cover handling, Dealer inquiries
\321 CalleValle(11nit Fl
Clemente · ·California
11·74
pilot. Reviewing the basic faults the Rogallo hang 1 . Low perfc1rmam:e pitch adverse conditions. these faults result from loose
Second, motion at machine can
arrangement where one-third of the fabric very with the battens it down, the forward tw·o-thir,ct, slightly At positive the wing like rigid and at the forward the battens and
I Gliller system has been th,u·n,11u,f1lv de11el'oved to insure the best in reliable hairidl'ing am:ro~tengm1o/e~andumnh~F.i~h
the ultimate in wants to get with it, we a coirny,rete cmrnp,etit'ion Solo aml accessories are dealers may write the address below
Member of
Glider Manufacturers Association
930 West Hoover Avenue Ill , """''"'
orc:ALERSHIP INQUIRES INVITED
II
*Patent in progress
P 0. BOX 6044 • CONCORD, CALIFORNIA
• 415 798·7350
1
In recent months terrible toll has been taken from the ranks of A few have ''""'''•'·'"''"' folly. However, most of them were fate with blatant mostly went existent in cliff,.like cle describes
happens, Later, when the accident one comments will be that really flapping. That the most common denominator in the acchlents to pilots these this, we must not to way to an illusion of unto the prin-, ciples. don't some our cher at hand is not must experiment. the proof in the death. usually said that controlled. This we are careful to understand the meaning of For most of us, the term to false deas because we've not thought through the and implications of the word. It better to look at control as stemming from the "force" our body mass exerts the lift of the wing as our from the and/ or ce:u c, LLui,<u Just as your body to pull against, so
32
or, more lower at tack, the center of remaining moves forward and lifts the nose. But that characteristic of airfoil of In
ike :it, it'
a tendency to drop steep turns. i yaws into dive whose proxJmates that of and that' that turn goes away, but the helpless to from the the reasons above. Panic dives out of
u11 questions .John Lake, Box
91409. A
34
n
4,
LL
40,
47.
instructor
tion, tifl
this can sponsoring second time of enthusiasm and mont towards tho ultralights, tho of conventional gliders. In fact, the was Glen only "sold out" Developments Brown' "New Trends in Hang Gliders. 11 The hang gliding portion of the the was character! zed tomont and controversy frontier knowl odgoab lo eager, speakers developments and in tho realm of flight No gained profess i in this this tho that: "Analysis of the Control
36
WITH POCKETS
, , .DEALERS
an annual event in tmg .t:ctm1, the first ultralight wide, "!ti-foot long, 20-foot into the ocean brine.
FOR PRICE SHEET
CIRCLE YOUR CHOICE
virtually ft was in sea
entered the wi done by me was to The next in an r carus II
L, XL orange, tan
blue, 1 4
6
BY TOM MILKrn
9,
and
ADDRESS AND CASH CHECK ORDER TO
NORRIS WHITE P,O,BOX LONG BEACH, CAL, 90815
Wind·
Mountain Com-Symposium on attract
around tho storm front
morning,
winds hlew directly
Mountain /\rea in Londonderry, v,,rm,mr, making for great
(Contfnued on page
40
comrnen:ial Aircraft COMPANY must have the proper
and
UARANTEE HIS
to be lowed the other.
on This of the
equal chance glider. This determining factor in wing loadings.
the competi··
42
one Carolina.
at or or· dealers for only
BY DARYL TOMBERLIN
Aspen, Colorado 81611
The Bell Soaring Heltnet is distributed worldwide by Eipper.forrnance, Inc., Torra nee, CA
44
I I
long which will
some
buy a coming summer ca:n write to me, . , Anchorage, Alaska competition, soaring, and
Col
WRITE OR CALL FOR INFORMATION ON THE DEALERS IN YOUR STATE 243 MATHEWSON WICHITA, KANSAS 67214 316 262-2664
46
low.
D
I
I
IN FULL COLOR @AN
DEAL GIFT
TY COLOR LITHOGRAPHS ARE YOUR ORDER WITH PAYFOR HANDLING TO: $11.
<>••i••"'~"" in
come to
us. You may expect prompt service and low but do not expect
Visit our store or write
2.010 LINCOLN BLVD, VENICE. CALIF, 90291 Phone (213)
50
52
B N A L O V
U W A F p
R !
N T
s
I
L
A G
L F
NEW •Fully controllabl
CONSUMER ADVISORY:
ders al before and i ·-bent shi
Used
gli
should be disassembled for the first time carefully for dented bol
loose thi es, cables, tangs with non-circular holes, and on Rogallos, sail torn or torn loose from their an chor points front and back on the keel and leading l doubt many wi 11
MANTA -
PLIABLE blue and $375. Must sell. (714) nings. PLIABLE MOOSES Good condition.
5/8"
.. Gliders (714)
0436.
SURPLUS TUBING. 6061 T
.049"
Best buy to money on near-new Introduction of new models to our 74/75 line finds us with several beautiful, nearly new std. Rogallo demos to sell at outstanding ! All are complete, ready-to-fly offer wide selection of sail colors. We also have several tow kite demos available. Don't miss this once-a-year close out Call now to Bill Bennett' Delta Wing Kj R Gliders. (213)
BENNETT DELTA
17'6". Soaring and Annodized black, col Custom -made . Mo,., ! (21:'i) 792-3809
WILLS WING
condition.
4
, Mich. 1 ine inclu··
Northwestern .049" Gliders Assn., lnc., 1215 Washing- ALUMINUM TUBING 18' 606:5 T : 85¢/ft. Dynamic Tool· ton . South, Minneapolis, Minn. ing, Mariposa Ave. , Torrance, 5541 . (612) CA 90502. (213) , 860-0612.
. Properly bull ICARUS II kit Will demonstrate in San Diego for . $800. 461-o:,s6.
EIPPER-FORMANCE 16' Flexi-Fl . Multi-colored sail, convertibar with harness and seat. Good condition. Make offer. Call (213) EIPPER-FORMANCE 17'. White sail. $175. Materials for 4 kites, $450. (213) 866-4976. sail, tuned,
Custom color . $400. Ken.
(213) 433-5504.
EIPPER-FORMANCE - 19'. Flown 9 times. Custom sail, case. $395 or trade for motorcycle, guns, . (213) -8608 (evenings).
QUICKS1LVER-B, Like Must sell . $500. Greg DeSmith, (714) , Escondido, Calif.
54
glider plans . Com .. include Dan Handbook Wri foI' free u. .. (616) 343-1480 Easy . Burdick, Kalamazoo,
WEST WIND SCHOOL OF HANG GLIDING. Start your hang gliding with consci export Box Beach, (213)
GET HIGH, INC. school, kite dis tributor and warehouse for the Rocky Mountain Featuring Seagull Eipper and Be 11 Helmets Box 4551, Aspen, Colorado
. (714)
TOWING KITE, 17'6" standard lo, folds to 7' pkg , includes trol with floats and bar $325. Without bar Rich Rallison (213) 644-5244 evenings, 534-2121 ext. 186 days.
99701 .
DETROIT ··CHICAGO
ICARUS v. Has foam ribs, Needs lower , :rib braces, and covering . #235 Eric. (213) 943-4447
FLEX I -FLOATER - 19' standard. Sail forms sail. 5 foot wide control bar FREE-FLIGHT 18'. condition with bag and harness. $350. (805) 4987215 (mornings).
S/IILl3IRD OF ALASKA Todd Davis, 1738
m.I ton, Fairbanks,
13'-30' lengths: 60¢/ 5/8"
SAILBIRD OF CHICAGO. . Wright, Napervil
.090 11, 95¢/ft. THE HANG GLIDING Air
' 60S40.
Ki ts and
11 .. 74
l'alnl
havi
Boh.
902:rn.
S/IY YOU SAW
IN CROUN/J DKJMML'U!
I