I COVER:
Mark Smith N·o. 1 in durability test after successful hap flights 2 in hiJ 20 pound monoplane hang glider. Remember this name. Watch for MS 5 or 6,
COVIR PHOTO by George Uveges: See L&S display ad sheet for his address. CONTENTS THIS ISSUE *Som comments an a structure using synthetics. LCDR R.H. BOEL TER,USN *A D sign Proposal for a Minimum Weight Glider Dr. P.B.S. Lissaman 1 {,Not a self-soar system, but it can help us create the new generation of self-soar 'monoplane hang gliders.) *ED jfOPALIAN and his full plan for a model flying wing. *MIKE KOMAN'S INTRODUCTION and the problem of professional use of his ideas. *DraJ..ings by Eddie Paul of a wearable and of the encroaching ultralight.
I GET SET: July 1: World; most attended self-soar meet: Congressman aid and self-soar member Victor Powel I hos cal led the giant i · TACTILE FLIGHT MEET Over 200 hang 'gliders will arrive at Jockey Ridge, Nags Head, near Kittyhawk, N.C. Full story and details forthcoming. S-SA invites you to attend the great tech'n-fly. NO COMPETITION,but much flying and hardware exhibition and idea sharing, This will receive more professional 'Come' advertising than all local meets combined. Already five groups from just southern California have committed themselves to attend. I
"WHtT IF..•••• ?"
SAFETY This phrase should be fundamental to every training program.
BUDDY SYSTEM: Guard against help that is not needed. Avoid tempting one another I to competition or exhibition. Buildl right-minded CONFIDENCE by knowing right answers. Otherwise.defines a fool.
Patience and the willingness to stop will improve our good safety record. Sor.1e professionals
i are getting hurt because they fail to stop flying when the stotln arrives. ALL authors, speakers~ and members should consider not using the term 'butt-skimming.' This _is the most dangerous term of our movement. It is unfortunate this term was started. Rig to land standing or on your belly! _Landing on your butt will drastict1lly increase your chances of receiving permanent back injury and leg paralysis. SAFETY Our movement has a problem. The most promoted, ship is not suited for beginners because it' requires speeds and slope angles that bring unnecessary injury from ordinary beginner training programs. That ship is the high wing loaded sharp nosed conical Rogelio • Fortunately, three pioneering companies are· leading the re-definition of the Rogelio standard class. They are now a~le to provide a Class 1 ship for a Class 1 pilot ! We congratulate Kilbourne Sports Speci~lties for their No. 8 ship in this regard, Whitney Enterprises for their Porta-Wing on !his in solution to this question. problehi, and Seagull Aircraft for their Seagull Ill *We invite these three companies to publish their plans in Low & Slaw to quicken the redefini~ion of the standard class Rogollo. So far , Seagull Aircraft has committed complete and unobri~ged plans to the April, 1973, large format L& S. Vj"e invite all companies and individuals to submit their onolysisof the weight-shift-only Rogaqo question for the beginner, especially as regards wing-loadings, nose angles, camber. contrail constructions,. sai I billows, and flight session parameters. Please submit your letters in double spaced typin.g or neat printing. Thank you. Most readers are beginners -potential custortiers- and oreanxio·us to study every available analysis on this matter. S-SA dnd L&S: Our having to self-soar'ingly convert from a booklet series to a professionalized servic~ o~ganization that remains free to serve the special interest areas of pi lot-carriable and w~arable systems rather thon on assistance-needed 'ultralights' (unflikables), is nearing on end. :Your patience wi If be rewarded; when you believe this, please have L&S users sign up L&S 22,23,24 will for thJir own copies of Low & Slow !!! We need their subscription too. be serit just before the 1973 February; IF YOU NOW HOLD THE NEW FORMAT 1973 January L&S, please tell us as you RENEW NOW. We cannot afford to send you twa copies. Thank yau • .Many fiave received the Jonucry large color issue an trust. Copyri'ght . © by Self-Saar Association, Inc., 1973 Each year we p~blish 12 ca,secutive issueJ of Low & Slow.·Each year is a set. Each_ set is $6. Order 197.1, 1972, 1973. The 1973 set is the large.format titled Jan throug~ ~cember, ~nthly.Ask for full informati'.'n package and send all letters·and orders to the .editorial and bus,nes:s address, and keep us informed so we ca+ serve you well. P.O. Box 1860 Santa Monica, CA 90406 BE LIGHT, self-soar ! ' '
I
SOME COMMENTS ON A STRUCTURE USING SYNTHETICS by
LCDR R. H. Belter, USN
I
The layouc of "Le Minimum" is considered "Le Minimum" as regards const~uction manhours. The constant chord surfaces and simple fuselage would pose no problems in construction of wood using modern bonding agents and simplified parts. As an e~ample, each wing rib could be solid styrofoam or consist of a scyrofoam leading edge an~ two caps wich a plywood web for the rear p;,rtion. Conventional truss type ribs are ~ften an assembly of as many as forty individual pieces, and are not superior, or even any bit lighter. Various other simplifying methods can be utilized, so that the aircraft can be readied easier. The next move toward simplified construction is to reduce the number of parts which require individual attention and fitting. The use of glass cloth reinforced polyester resin is proposed as the next st_ep in this direction. Douglas "air- comb honeycomb" core macerials is proposed as a suitable means of stiffening panels. No exotic kesin or cloths are proposed, since the ordinary resin and boat cloth are easy to handlf and wet outside using contact molding techniques. The translucent laminate pennies in spection of the core- to laminate bond which is an absolute necessity for any stiffened panel. The use of glass laminate as a primary suuctural material makes constr~ction of proper molds an immediate hecessity. There are of course manhours expended making these molds and forms, but since they are only construction jigs they can be quike un sophisticated. Wood and masonite are proposed for these items with a suitable "'.acer soluable wax as a parring agent. Care must be exercised in the aircraft design ~o avoid the use of compound curves; so cone frustrums and cylindrical sections predomiqace. The wing proposed would use a channel or C spar with honeycomb web stiffening. The thickness of the caps would be increased by using a suitable glass tape. The number of plies would be varied according to the local loads. The leading edge ribs would be hot wire sliced expanded foam. The rib from the spar aft could be made as· a honeycomb stiffened cylinder top and bottom with a diagonal truss added during the asse~bly. ·These sections could be made up in sheets and then sliced off as r~'i'-uired. All secondary bonds would be N :ith a flexible epoxy and mechanical fastening. The leading edge would be unstiffened laminate laid up in a female form in sections 8 ft. long the joints occuring at the 4 ft. and 12 ft. section on the 'semi span. .This form is made using commercial aluminum which is quire readily bent to shape. It may be feasible to wrap flat laminate to a satisfactory section shape over the ribs. Torsion is rnken by the enclosed cylinder of the leading edge and spar, the spar being considered to carry all bending loads. The configuration of the aircraft is such that it would be difficult to feed the drag loads into the fuselage through the leading edge, so a hard rib at the root with a diagonal drag brace running forward and outward ·to the spar is proposed as the solution. This is considered simpler than attempting to handle drag and torsion forward of the main spar at the fuselage. The fuselage is proposed as a triangular truss utilizing three angle section laminate longero~s. The diagonal truss members would be hot sections laid up in sheets and then sliced as required. They would be lap joined co the longerons using a ,semi-
•..• continued on page 14,low~r...
3
I I
THIS IS NOT A HANG GLIDER: WE PRESENT IT·ONLY AS AN EXERCibE.
AS MANY
THE GOAL
things1. as we
MIGHT
LEAD US TO
DESIGN!I G I
REDRAWN BY COPY RELEASED
A DESIGN PROPOSAL FOR A_ MINIMUM WEIGHT GLIDER
by Dr. P. B. S. Lissaman THOUGHTS ON A LOWSPEED MINIMUM WEIGHT GLIDER !
It is curious that the developement of modem gliding has followed a compferely opposite course ro the closely related sport of sailing. Thirty years ago, sailing · implied large expensive craft and equipment, numerous crew and considerable operational skill and ability. Today thousands of most unnaurical individuals can drive to the nearest water, launch a small craft singlehanded, and disport themselves in a way as pointless as it is pleasurable. This may have been the way it was with gliding 10 · the Wasserkuppe, bur it is certainly not the case today.
For sometime the author has felt that there was a deep latent interest in really simple gliding and that something on the lines of an aerial sailing dinghy would find great public acceptance. This would involve developing a small glider of ra_ther special character. Ar the risk of sounding obvious, some requirements of this type of glider are 4iscussed. First, it would have a performance such that soaring flight were possible and reasonable endurance obtainable from moderate launch heights. This would primarily involve a low sinking speed, certainly below 4 fr./sec. Next it would have to be compact in size and very easily rigged so that it could be transported in a station wagon and handled by one or rwo men. This puts severe limitations on span and calls for simplicity and security in wing attachment. Ir would require docile flying qualities and have to be especially safe for amateur operation. Finally, the structure should be rugged and simple enough for rapid unskilled home construction. One visualizes casually packing this glider in the back of a car, driving to a grassy slope, and spending an afternoon gliding with the minimum of dependence on equipmen: and helpers. Most areas of the U.S. have suitable locations within a very short di,stance (compared for example .with navigable waters) and this little glider could introduce one ::--, many fascinating aspects of low altitude contour gliding, especially when the consequences of misjudgement would bt: nothing more than a broken wing or fracrured fusela_c:c whic!c could be easily repaired over the weekend. There are also many obvious aspcctc. c<' ,·., .. :.; competition. In chis essay the author attempts co show chat chis is realizable without resorting to any untried or exotic approaches, although all aspects of the design must be carefully controlled. Weight reduction is of very major importance and while conventional materials are proposed as an immediate project, there is great promise in the use of more unusal structures with synthetic materials like fiberglas and foamed plastics. These would lend themselves ideally ro mass production and suggest attractive commercial possibilities of selling the glider in kit or completed form.
5
ED
Wade through ,,That you do not get but do not miss that which can be helpful to you in your special interests. OPTIMIZATION OF BASIC PARAMETERS
l
While it has usually been customary to discuss the perfo;mance variables of aircraft in term~ of weight, aspect ratio, and lift arid drag coefficients based on wing area, a more basic apalysis will show that these are not the fundamental parameters and that a natural set of duly independent variables is weight (W), equivalent flat plate drag and spdn loading (W/b). The use of these parameters presents performance envelopes with reritarkable clarity, especially with regard to induced drag, which is in effect eliminated a~ a function of aspect ratio. ·
d11 this basis, optimization and manipulation of the drag equation gives the velocrty for minimum sinking speed (Vms) as I
v,:,,s -
ct rr. ·y rK7,r <w;,f,. J.-f !y.
'fr
where k is the aircraft span effectiveness and the air density: and all terms are eipressed in consistent units. A further manipulation of the performance equations will give the minimum
sfoki g sp=d
.,
t-(l)t+i*f-~T,' t(t-')~~l!/1
T is equation is of very great significance in the glider design and it is of some · nterest to note that it is an exact result and defines completely the min imum sinking speed.of any glider, providing k and cl.are known correctly. The terms in the equation have not been regrouped or simplified because the present expre sion is developed immediately from the basic equations and falls into the arran ement naturally. Obviously the practical realization of this figures for depen s upon being able to fly at Vm, without experiencing major off-design perfor ance defects such as those associated with separation of one form or anoth r. A this point it is interesting to develop the expression for the best glide ratio r L/Dmax which is found to be -¥,
y
L/p1r11b< = at a speed
V
L/D:: 3~
t (~7i) ~ J~
i-
Vms
I
A~ the moment modern sailplane design seems concentrated upon obtaining: the highest possible I/D ratio. If range and peneuation are the objects of the· desigrt this is clearly the important factor; however, if endurance is the main objec~, the significance of L/D is greatly reduced. Examination of equation (c) puts the philosophy of high performance glider desigtl in a nutshell: it will be seen chat span and profile drag are the only imporiant factors, while span is predominant. Weight does not enter into the expre~sion although, of co'."s~, it has its significanc~ from many .practical angles. However, if span 1s fixed, the one means of improvement 1s by re ductidn of d which is of course a well known fact, explicable at many levels, long Jnderst~od by our feathered friends, and the current preoccupation of sailpl~ne designers.
I I
6
However, considering a design required to minimize sinking speed a very different equation occurs which is expressed by (b). This shows that the important parameters are b, W, and d in that order and chat their significance varies greatly, in fact, span is three times more important than weight itself, and weight is twice as important as profile drag. This suggests thac for a glider of a given span, weight should be reduced in every possible way, even at the expense of increased drag. Physically chis may be expressed by the face that at V ms induced drag represents % of the total drag so that reductions in profile drag are of very liccle significance. Thus it appears that if a new structural approach is made, giving importance to weight reduction at the expense of drag (for example, using an externally braced wing and simplifying the fuselage by disposing with non load carrying fairings) very low sinking speeds may be obtained on a relatively small gli • der. Figure 1 shows span loadings against profile drag for two glider weights and for 2 ft./ sec., crossp!otted on this curve are the appropriate spans and V min. It will be seen that 2 ft./ sec. represents a rather difficult target not only in terms of span but more significantly because of the low Vm that is required for optimum performance. Choosing a sinking speed of 3-33 fc./sec. gives a very much more reasonable set of curves which are plotted in figure 2, assuming a conservative set k of .85. This figure is discussed below. .
.
i
One of the more significant details of figure 2 is the low sensitivity to d and che moderate spans required. Evidently the limiting factor is Vm and it appears lower limit on th~s w~.uld be ~b~ut 35 fc./sec.: even this spe~d woul~ in~olve o~erT ation at a very high hft coefficient and a carefully chosen wing secnon is reqwre1 co give a. safe margin between stalling and optimum sinking speeds. !
i
All the parameters in figures 1 and 2 are easily idencifable with the exception of d which may be an unfamiliar means of expressing profile drag. As an aid in esrimaring chis quantity the profile drag figuces for some well known gliders are listed below. These show quite clearly chat the drags discussed in this project ace easi~y realizable.
SPECIFICATIONS AND PERFORMANCE OF A
MINIMUM WEIGHT GLIDER DESIGN
By choosing suitable parameters from the curve discussed in th·e previbus section a simple glider is proposed. The details of the aerodynamic and structut.d concepts are discussed in fucthe_r sections so only basic figures are given here. Levity is always a prime concern to aviators and in this spirit the writer has cho· sen to call the design "Le Minimum." I The glider is of conventional layout with an enclosed cockpit, a Vee tail and excernally wire-braced wing. The flying weight is 290 pounds, wing span and area 34 i:. and 170 sq. ft., and length 17 ft. Minimum sinking speed is 3.02 fc./sec. and max,imum L/D 13.2 at 45.S ft./sec. Stalling speed is 30 ft./sec. and maximum speed is 70ft/sec. The su-uctuce is stressed for 5 g and is primarily wood with the trailing portions t>f the wings and tail fabric covered. Layout and performance are shown in figures 3 and 4.
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3 pound/ 4 1 Tony T-Jones Good practice Ground handle Running Thought leaps Orientation Awareness
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FULL SIZE PLANS by Ed Topalian Step 1: Cut oul wing from 1/16"x 12" sheet balsa fJOOd and sand all the edges. Step 2: Warp nose airfoil and tip reflex in with steam as shown in the sideview. Step 3: Glue ribs in place (hold while drying). Cut solder to lenght, and bend tightly around nose. Do not glue on so you can replace it with a larger one.
Rib Plan
Ribs (2)
cut from
1/16" balsa
Solder Weight
10
11
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It
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Copyright @ by Self-Soar Association, 1973. Copies permitted only for classified ad use. Send II for sample of Low 6 Slow. If interested, also ask for our display ad rtile sheet, Subscription/year 16, 1971, 1972, available.
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... continued from page 3 flexible epoxy resin and niechanicaf f ascenings (machine screws). The fuselage would have a bulkhead at the front spar location, chis could be a honeycomb stiffened section. The forward fuselage would be a stiffened cylinder, most probably using longitudinal stiffeners co save some weight. This could indeed use a single flat laminate and the above hot section laminate combination. This would be sufficiencly flexible to wrap onto che fuselage, and should be lighter than a honeycomb panel. As a point of interest, honeycomb can be bonded to a flat laminate and then can be w.app~-J ooco a surface, at which time ch·e inner laminate can be bonded on. This resulcs in a well stiffened panel. The minimum weight of a~" chick honeycomb panel using one ply of 10 oz. cloth on each side is approximately .45 lbs. per square foot, 2 plie,a one each side being abouc,6 lbs. per square foot. The single ply laminate is not particularly rugged, yet is quite heavy, hence one must decide if a stiffened panel should be used vice a truss system as che lightest and most expedient technique. The no.se of the aircraft would be formed by a fibreglass ogive "flowerpot~" The above techniques are proposed as an attempt co reduce the total man houcs required to build a suitable aircraft. A great deal of attention would have co be paid to design detail and features to avoid excessive weight. Fibreglass is not particularly light, and an excess of resin as seen in most fibreglass boar construction would cause very significant increases in weight. le is doubtful if construction of one aircraft would result in real man hour savings, but subsequent models would be quite rapid. 14
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WEIGHT BREAKDOWN Wing
LB
Mainspar ( spruce) Ribs (styrofoam) Leading Edge Skin (1/32" plywood) Covering (A/C fabric) Fittings (A/C alloy) Flying.wires (streamline steel)
14 12
14 2
2 3,6
47.6 Tail Spruce spar, styrofoam ribs fabric covered
15.0
Fuselage Slides (3/16" & 1/8" plywood) Top (1/8" plywood) Bottom (1/4" plywood) Frames, Longerons, and keel (spruce) Wind screen (plexiglas) Control linkage and seat
25 5 11 4 1
4 50
total 112.6 gravitational gremlins 7.4 pilot 170 TOTAL FLYING WEIGHT: 290
Equivalent Drag Area (ft.l
DRAG BREAKDOWN
2.55 .29
Wing (Cd .015) Tail (Cd .012) Fuselage (Cd .15) Flying wires Wing-Fuselage Interference
.85 ,31 ,30
total viscous gremlins
4.30 .20 4.50
16
ADDITIONAL PERFORMANCE FIGURES Span effectiveness .85 At maximum LID C . 707 At minimum sink C J.17 At stall C 1.60
PERFORMANCE VARIATION . WITH PARAMETERS Near the design conditions the variations for off design configuration has been calculated and is expressed as the variation of sinking speed with the major physical design features. This becomes: Variation with weight: .52 ft./sec. per 10 lbs; Variation with span : .133 ft./ sec. per foot span Variation with drag : .0168 ft./sec. 1/10 ft.2 equivalent drag area ·
DISCUSSION OF ASPECTS OF THE DESIGN PROPOSAL general A few aspects of the different problems are· discussed largely to justify decisions in layout and design. The prime consideration throughout has been to achieve simplicity and it will be appreciated chat many compromises that would be unnecessary in a more sophisticated concept have had .to be made. Obviously it is impo·ssible to discuss all the reasoning and ideas behind each decision and one may say that much thought .and caiculation is dismissed in a few sentences.
aerodynamic The major problem in lift i.s obtaining sufficiently high usable lift coefficients at moderate drag penalties. This calls for a special ~ecrion which is unlikely to be found among modern airfoil families. Physically this section will be characterized by a chick fairing shape ( 14- 18%) with a maximum thickness fairly far forward (20- 30%) and with a large nose radius (2%). It will be highly cambered (5- 7%) with a symmetrical camber having uniform super velocity distribution. In chis spirit the author has sketched a possible section (£ igure 5) made up from existing standards families. No test results are available for this section but the possible characteristics are. shown. Those familiar with highly cambered airfoils at low Reynolds Numbers will appreciate the temerity of the author in attempting co predict its performance. Achieving a C max of the order of I.8- 1.9 presents a very great problem, and it may be necessary to use a section with a fixed full span leading edge slot. This would present no structural difficulties and would solve the high life problem: it is possible chat the drag penalty ( about 50% wing drag increase) would be acceptable. However, chis approach is not pursu·ed at this stage. drag As has been discussed previously, the drag coefficient doe;; not present very great problems, largely because a fairly high drag is acceptable.
17
stability -
In very light weight designs the pilot constitutes the major mass and thus the cockpit location is fairly critical. An earlier layout had considered perhaps a shoulder or midwing configuration with the pilot immediately ahead of the leading edge, but calculations showed that this would involve too far forward c/g position. To avoid breaking the wing leading edge it was necessary to place the pilot underneath the wing. This gives a stick fixed stability margin of about 15%. Another very satisfactory solution aerodynamically would be to sweep the wing forward from a shoulder position. However, this presents problems in the layout of the flying wires.
control There are no real problems anticipated with this aspect. Adequate elevat0r power can readily be achieved and the aileron control would be good. Stick forces would be very light and ,l the control linkage was amplified to reduce weight (by eliminating many pulleys and bearings) ~ 1, conceivable that the forces would be very light and if the control linkage was amplified to reduce weight (by eliminating many pulleys and bearings) it is conceivable that the high friction might almost entirely mask any control feel. This would probably be acceptable, although undesirable. The untapered wing would give good lateral control and have no incipient spin at the stall.
,s
structural The flying wire oucboarded node is located ar the center of life of the wing. This implies that the maximum bending moment occurs at this point and that the main wing loads inboard will be compressive. It is interesting co note chat the main spar is almost 60% overstrength and the size is determined largely by stability and handling considerations. The leading edge skin provides a good contour (necessary at high lift coefficients) a,; well as torsional rigidity anq span wise stability of che main spar. One inch think styrofoam ribs are used. These can easily be cue t0 contour with a hot wire. Lightly loaded struqures of this type are an interesting design challenge, using conventional materials it usually turns out that the simplest structure is lighter than a more sophisticated one, largely because of the weight involved in stabil::,.N 9 the very small sizes required to withstand the loads in a critically stressed design. tail All the remarks appropriate to the wing apply even more markedly here. Loads are virtually negligible and it is not even necessary to maintain any special airfoil section beyound having one roughly of streamline shape.
/use/age -
Great emphasis is placed upon simple construction for the fuselage. Fundamentally it consists of three plywood. frames with a monocogue plywood skin. The cross - section varies from trapezoidal near the cockpit to triangular aft of the wing. This would be builc upside down using the top deck as a datum- jig, the sides being then attached and sprung into the bottom intersections. le may be noted that modem banding agents, for instance epoxy reins, have such excellent properties wich respect co fill and adhesion that there is no necessity to make mitre cues for long joints of compound contact angles. An aluminum alloy compresioo cube takes the wire loads and the wing is at cached by pins at three points. The canopy is· a plane piece of some transparent plastic attached to one side of the cockpit. [c is sprung into shape on closing the cockpit. The seat would be a canvas bucket arrangement and control linkage predominately of aluminum alloy. A very simple stick- rudder mechanism for the Vee- tail has ~<c_en devised. The control cables woll_l_d be p.i"!X)wire with n_ylo_E.. guides.
18
operational The glider will be launched by ground cow or springshock methods. Because of the light weight a relatively small amount of energy is required for chis and a rig could be designed co attach co the jacked- up rear wheel of an automobile and operated by a two man crew. An energy storage launch system could be designed using steel or rubber springs which would be wound up by a pick off from an automobile and released from the glider by a cable. This might make single handed launching possible. The rigging is particularly simple, one extremity of the compresion strut telescopes, so that after the wing-pins and flying wires are attached this can be extended by a lever and locked in place. An incidental .advantage of the wire bracing system is chat dihedral could be adjusted as required. For recovery and transportation the glider could be carried in a station· wagon with the wings on the roof and fuselage in the back with only moderate overhang. The Vee· rail, which is a fragile structure, would be fairly well protected from landing impacts. and the forward fuselage would provide good crash protection for the pilot. In spite of the lightness chis would be a very sturdy air· frame and considering the low landing and stalling speeds it is cleat that it would be very hard, to damage the pilot or structure. A detailed analysis of the spinning behaviour has not been compl~ted but it will be very difficult to spin inadverre ntly because of the wing plan· form. The spin would probably be of the flat variety and the Vee· tail would provide good control power for recovery, by avoiding the rudder shadowing that occurs in a conventional tail.
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DO YOU HAVE ANY PROFESSIONAL INTEREST IN THE Self-soar or skysurf movement? If so, you may want to receive the weekly hot-line newsletter called Hang Glider Business Weekly. Send $12 for HGBW at P.O. Box 1860. your 52 consecutive issues to Santa Monica, CA 90406 Send a self-addressed and stamped envelope of the business size if you wish a free copy. BACK COVER: WAA photo of the Koman l, the cable-bowed leading edge high asped ratio Rogal lo from which Cronk gained ideas for the Cronk 5 after having built the Cronk 3 (pfon in L&S 12 and 14,which see}. KOMAN was certainly the leader in this regard as he tested his ships on beaches of Southern California during visits from Philadelphia. We hope Koman can return to receive some credits from Cronk on these matters. We received word that WAA is working for Cronk now; if you hove any confirming information on this merging, please inform L&S. Koman was also partners with Faust on the Diel Soap ship for which Koman was paid. Koman is coming up with a new generation monoplane hang glider which plan we hope to publish in 1973 . L&S will later produce a full story on Koman which will include plans he drew for L&S use in this story for the Koman l,2,2:«\,2B,2C, and for spoiler controls used in winds and for wider nose Koman ships. Koman now hos coined the company name of SKYSURFING SYSTEMS. He gets the new business publication called HANG GLIDER BUSINESS WEEKLY. The story includesa photograph of Koman instructing Cronk on the innovations Koman had that the Cronk 3 did not have. 19
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