USHGA Ground Skimmer November 1974

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