Motorgliding Apr .-May 197 6 50 Cents Rf-5B Sperber

MOTORGLIDING APR .-MAY 197 6 50 CENTS RF-5B SPERBER

WORLD LEADER IN MOTOR SAILING An associate of. the 1/FW-FOKKER"Group

THE INDEPENDENT SAILPLANE THAT WILL TAK E YOU SOARING JUST BY TURNING A SWITCH !

SPECIFICATIONS : PERFORMANCE (motorflight )

Engine : LIMBACH SL-1700-E Max (level) speed : 118 MP H (68 HP at 3600 RPM) Rated cruise speed : 112 MP H Hoffman Vari-Pitch II I Propeller : 640 FT . (Climb, Cruise, Full Feath .) Take-off roll : Landing roll : 550 FT . Seating : Aerodynamic TANDEM (2 ) Wing span : 56 FT (36 .8 FOLDED) Climb rate : 690 FP M Wing area : 204.50 SQ. FT . Stall speed : 39 MPH Wing loading : 7.3 LB/FT . SQ. Fuel consumption : 2.9 GAL/H R Fuselage length : 25 .3 FT . at 106 MP H Maximum height : 6.43 FT . Range : 300SM/480K M Empty weight : 1000 LB. Useful load : 500 LB. Ceiling : 17000 FT . Gross weight : 1500 LB.

Fuel capacity : 10 GAL . SOARING PERFORMANC E Standard cost Wooster, Ohio, $29,500 Max speed : 140 MP H Stall speed : 42 MPH Min sink rate : (48MPH) 174FP M Glide ratio : 29 :1 SPORT- AVIATI AF /NC. 401 HOLMES BLVD. WOOSTER, OH/O44801 12181 202-8301

MOTORGLIDING Donald P . Monroe, Edito r

Vol . 6, No . 2 Published by The Soaring Society of America, Inc . Apr .-May 1976

Contents Page

RARA AVIS (of sorts), by Doug Terman 2

THOUGHTS I BROUGHT HOME FROM BURG FEUERSTEI N by Tasso Proppe 5

FOREIGN SCENE, by S . O . Jenko 7

EULOGY OF THE CROW, by Tasso Proppe 9

BETTER PROSPECTS OF USE OF MOTORGLIDERS FOR SPORTING PURPOSES, by Per Weishaupt 1 0

LETTERS 1 2

POSTFLIGHT NOTES 1 2

Cover : RF-4D, by Don Monro e

MotorgZiding is published bimonthly by The Soaring Society of America, Inc ., whos e offices are at 3200 Airport Avenue, Room 25, Santa Monica, California 90405 . The mailing address is Box 66071, Los Angeles, California 90066 . Subscrintion to Motor- gZiding is $5 .00 ($6 .00 outside of U .S .) for 12 issues (two years), beginning wit h the current issue . Back issues are available at 50¢ each . Second-class postage paid at Santa Monica, California . Reproduction of any of the material printed i n Motorgliding, unless specifically excluded, is encouraged . Readers may wish to cor- respond directly with Harry N . Perl, Chairman, Powered Sailplane Committee, 390 7 California Way, Livermore, California 95440 ; or Richard Schreder, Chairman, Air- worthiness and Certification Committee, Box 488, Bryan, Ohio 43506 .

The National Soaring Museum is an affiliate of The Soaring Society of America, Inc .

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Circulation of the Feb .-Mar . 1976 issue was 1250 . This issue was mailed in Aug . 1976 .

RARA AVIS (of sorts ) One evening at the Wiki-Up, Earl the Squirrel and I are lofting Tuborgs . (Ear l by Doug Terman flys twins for the local pea patch air- line .) Earl firmly believes that man wa s Spring is the cruelest season in the not meant to fly without his right han d tropics . At least for a New Englander . firmly connected to a throttle . So I lav- The beaches are still flour white, the ish words of L/D, minimum sink and gree n sea still an incredible blue and the air upon his Lycoming-deafened ears . palms still flopping in the Trades . But Earl is a West Indian and his expo- one knows that the Green Mountains o f sure to soaring is limited to an instruc- Vermont are shrugging off their snow cover tor, some years ago, pulling off power i n and the valley floors are bursting wit h a simulated engine failure . But his fac e color and the Mad River is roaring it s registers his appreciation for my enthu- song . And if I have a home, it is Vermont . siasm. He finally tells me of a strange Access to Vermont is only a matter aircraft he has seen lurking in a hangar of signing on a BWIA flight and five hour s in Martinique . Not really a glider be- of boredom . But this passage between th e cause it has an engine . Not really a States and the West Indies is a very spe- powered aircraft because it is used for cial thing to me . I have made the tri p soaring . No idea of the manufacturer . five times in small boats and once befor e Now Martinique is the Atlantic out- in a light plane . And as an additiona l post of Gaul . It is French . Therefore , factor, the acquisition of a small plane they speak French . I do not speak French . has been lurking in my bank balance . So But Earl speaks French with a patois over- the stack of Trade-A-Planes keeps growing . lay . Earl also has access to an airplane . And I look for an ad which I can never We exchange money and promises and at dawn , find . . . we lift off from Vigie Field, St . Lucia for TWO PLACE aircraft for sale by Martinique . This is how I was introduce d reluctant owner . Aerobatic, low- to FOGEK . wing with long-range tanks . Low FOGEK is a Fournier Sportavia RF- 5 fuel costs, retractable gear an d powered by a VW engine out of Limbach . soars like a bird . Reasonabl e Two-place, low wing and aerobatic wit h offers considered . . . . some restraints of g-loading on her 47- foot wings . She consumes about 2 .8 gallons per hour . This process can go on for about five and one-half hours at a startling 97 mph . She is fashioned o f wood and fabric, metal and love . The cockpits are tandem . No sitting to the left of centerline . Everything snuggles around you and is comfortable . The panel speaks metric-meters per second , kilograms per square centimeter, degree s in Celsius, and kilometers per hour . And , a short stick with buttons on it! Man y the bloody Fokker I've caught streaking for the lines from behind a towering cu a t sundown . A short burst on 123 .5 and he' s a flamer . The back cockpit is decently remove d from my sight and hearing . Some soul s have ballasted this area but its general function serves as luggage area for a sleeping bag, tools, a life raft and a spare set of shorts . But to be fair, it s fun to fly with mutual FOGEK fans . Soaring? No, not a Nimbus, but still great fun . I guess that well over half of my total time has been thumping around in thermals over Vermont, ridge-running the Alleghenies and riding wave in Maine . 2 and cross-countries are an adventure . search and rescue . Beyond this, I mus t Hang the ETAs . If the vario goes wel l go at 13 :15 hours for this is the appointed into the green the power comes off and time . There may not be any alteration i n FOGEK and I renew our love affair . the time . The airport manager is unhapp y But then there's something even more as the registration has already been can- about an aircraft like FOGEK . It is th e celled due to the sale of the aircraft ou t great joy of being one with an aircraft . of French registration and the FAA has no t That great joy of response and precision replied to my requests for temporary regis- and even of mutual trust and sometimes of tration for a ferry flight . And how els e mutual disbelief in what we can attemp t may an aircraft fly unless it is registered ? and accomplish together . She constantl y This is the first law of aerodynamics . teaches me the art of aviating . A poor So, as they say, be it . At 13 :1 4 flare, not enough spoiler and her gear FOGEK and I sit quivering at the end o f kicks me skywards in a series of mushy Lamintine Airport's runway 08 . The stick hops . We blush together . And lack o f is sweaty in my hand . The cockpit over- sufficient airspeed for entry must b e poweringly hot and cramped . Rpms to 280 0 avoided for the engine will not generat e and we are rolling . No airspeed indica- enough ponies to drag you over the top . tion . The tail is up and still no airspeed . But back to Martinique . Rpms to 3100 now, oil pressure good an d FOGEK was owned by the Beech dealer , the engine sounds fine . But no airspeed ! Amedee Rambeau . No one was intereste d The variometer is showing signs of lif e in learning to fly her . But for what ? and I consider aborting the flight an d Certainly not to export fish in, or t o all the while FOGEK is happy and alive an d fly to Venezuela with the family and ove r climbing out in the afternoon sunlight . water--out of the question . It only ha s I pull the gear up . Snick-thunk . We're one magneto . It is made of wood! It i s clean and climbing a't 2 .6 meters per sec . powered by a VW!!! So Amedee and I als o The cockpit cools to a pleasant tempera- exchange money and promises and bits o f ture and the needles have settled int o paper . No check ride as the owner befor e familiar places . I clear the pattern and Amedee is somewhere down island sprayin g notice that the crash trucks are return- crops . Amedee has not been checked out . ing to their positions near the tower . I The mechanic shrugs, starts the engine , level off at 3000 meters and explore th e points to the oil pressure gauge, hold s up his finger implying the number "one, " wags his finger to imply "no," pats me on the back and walks away . I shut down the engine, go back t o the hotel and hire an interpreter t o translate the manual . The manual is hand- copied in French from the German factory- prepared manual . My translation of German into French into English reads : "On proceeding to break the groun d sometimes observe some things of note . The speed of air when not sufficient will fall the aircraft only . " I resolve to implement a test pro- envelope of flight . I nudge the stick an d gram and neatly lay out a schedule o f something happens . Immediately . The rud- taxi runs, high-speed taxi runs, a gear der seems to require pedal application t o retraction test, dynamic and pitot syste m turn properly . I try them together and w e check, liftoff and immediate landing o n turn immediately with lots of pressure o n Martinique's massive runway, a whole NASA the seat of my Levis and the ball cosil y type program . nestled in its doghouse . The following morning Amedee cheer- Trade wind cu are aligned in street s fully tells me that I have a one-tim e below me and I can see islands well to the ferry flight permission from Paris . I t north . Dominica there . Guadeloupe perhap s must be done this afternoon at 13 :15 hour s that smudge beyond . To the south the whit e There must be a chase plane to mark m y sand beaches of St . Lucia ringing the gree n position in the sea when I ditch . I may mountains . And beneath is the sea patterne d have to post bond to cover the cost of by the wind and burnished by the sun . 3 The pucker factor is easing consider- buzzer making discordant noises from some- ably now . The alien stick is now cool and where within the recesses of the cockpit . easy in my touch . No longer a sweat y Instant pucker . grasp but light beneath my thumb and inde x My engine has stopped . All airplane s finger . Tentatively, I pull back power . have engines . Engines keep airplanes fro m The rpms sink smoothly to 800 and the onl y falling out of the sky . Therefore, my sound now is my breathing and the wind . airplane will fall out of the sky . For- Approach to stall, power off, decaying air- get about soaring . That's just for fun . speed, slight burble and she breaks cleanl y This is for real . That's the dark, deep , and without fuss . Lots of aileron contro l rotten Caribbean Sea down there ! left right up to the break and rudde r Training . Selective Response . Right . enough to fan a sultan . Stick eased for- That's what I paid those guys $8 an hou r ward, some rudder and recovery . The sea' s for . Checklist . Proper airspeed and con- horizon again parallels the canopy sill . trol of the aircraft . I am nattering t o Canopy! I can look not only to the lef t myself and FOGEK is happily continuing on but equally well to the right . And up and her way . I recheck the vario . The sink even back . I can see all of the world from is still slightly above one meter per sec . up here! The cockpit is not some replic a Let's see--1500 meters altitude divide d of an instrumented boudoir with brocaded by 1 .2, ah-well let's plan 1 .5 equals-- bench seats and color-coordinated instru- al 1000 seconds- ah divided by 60 equals-- ments . It is leather and stark dials an d al-sixteen minutes . Death, it would seem , a gull's-eye view . is still sixteen minutes away . The cock- I try a departure stall and then a pit is now stuffier with the lowering al- spin entry . FOGEK's manners are impeccable . titude and trade wind cumulus are brushing Spoilers out and back with no noticeabl e by the wingtips . It's getting bumpy and change in pitch . A gear cycle and clean up . every few seconds FOGEK has a tendency t o I sit there happily in the sure knowledge raise a wingtip . I glance down at the that this is a once-in-a-lifetime airplane . vario and it flickers to 4 meters pe r The trim and stick feel familiar beneath second up . The powered airplane drive r my touch . My hand falls naturally to the leaves the controls and the soaring pilo t spoilers . The lifeless air speed indica- takes over . We spiral up in green air at tor seems nothing more than a poor reflec- 45 degrees of bank, the altimeter singin g

tion of the sound of wind flowing past my a song . We lose the thermal and bus t canopy and the firmness of the controls . through sink into another bubble of lift . FOGEK and I have made our peace . FOGEK swims upward through a sea of risin g St . Lucia is now less than ten mile s air . We play and soar and sink and soa r away and with all of my playing around, I again . St . Lucia is straight below . I try still have 2000 meters of altitude in my the area over Mont Jeaulouise and the vari o hip pocket . I pull the throttle back t o indicates massive up . With all the engine its stop and try to find the attitude- controls rechecked I touch the starter an d airspeed-wind whistle to give me my mini- the 62 ponies start cantering again . Just mum power-off sink . The vario stabilizes a throttle stop adjustment . at a little over one meter/sec . The laz y But there are still two hours unti l disc of the propeller also becomes sta- sundown and perhaps the ponies can rest tionary . There also seems to be a warning for just a bit while FOGEK and I play . 4

THOUGHTS I BROUGHT HOME FROM BURG lowest 600 x fuel consumption + FEUERSTEIN 1975 this airplane's consumptio n

by Tasso Proppe 400 x best time this pilot's time My employer, General Dynamics Con- vair, finally put me out on the pasture that is : the contest today is loaded i n for being over-age ; company policy doe s favor of low fuel consumption . Tomorrow , not allow employment of people over 65 . the point system may be in reverse and a So, the first order of business for factor of 700 maybe attached to time (speed ) me was a vacation trip that I had pu t and the best fuel useage is only valued 30 0 off for years . One of those$400 charte r points . There is also an evaluation o f flights to Germany to visit friends and start reliability (stop watch from the sig- relatives--and, of course, snoop around nal "go" to actual engine start) and nois e gliding activities and manufacturers to pollution (sophisticated gear to record maybe come up with new ideas for something the noise profile around the airplane com- I could afford to do back home (in San ing and going at specified altitude . ) Diego) . The task of the day and it's evalua- It was quite convenient that the Feuer- tion are discussed at night after suppe r stein Motorglider Meet coincided with my with an exchange of ideas : where are we vacation schedule (or vice versa)--but I going, where should we be going, what's th e only had two days to spare to attend it and order of our priorities ? one evening to give them a little presen- There is bickering, too, about details . tation on what we do here, what problem s Fuel consumption is measured by taxiing up we face, and what I think the direction to the gas pump and filling up to the brim . of the development effort should be . After the task accomplishment, the glider This is what I found noteworthy- pulls up to the pump again, is filled up keep in mind, though, that my interest is to the top, and that amount is measured . oriented towards flying and soaring as a The two-cycle people have to mix addition- popular sport, for fun, for the experi- al oil into the gas--five percent . They ence to master the air and what it has to feel disadvantaged, because the oil con- offer, and not to establish distance or sumption of the four-cycles is ignored . speed records by developing costly mach- On a miserable day with no wind and ines, too expensive for ordinary people no lift anywhere, the task was simply : to own and operate : "stay airborne for a fixed time" (thre e The Burg Feuerstein Meet is not a hrs, I believe) . This is representativ e competition to push a singled-out one- of a typical motorglider operation, loit- sided feature like "penetration",'fue l ering in search for thermals) . The ensu- consumption", "speed" . It's objectiv e ing results were somewhat of a surprise . is to compare the existing designs in The minimum power requirement to stay up their ability to respond to a variety is just a little above engine idle, an d of salient requirements--"economy" , some engines cannot be operated in tha t "soarability", "utility", or "nois e range--unless you keep your teeth togethe r pollution" . by a brace, and that does not solve the There is no victor and no champion . problem of reading the instrument pane l The comparison is sometimes loaded with all dials fuzzy and what this does in favor of "minimum engine time", some- to instrument survival . Some of thos e times in favor of "speed", or "minimum "all-attitude" carburetors (which I hate , fuel consumption" . And the result is a as you may remember-Motorgliding, Augus t better idea for what the characteristic s 1973) increase fuel consumption in that of a motorglider really are and what com- range rather than decrease, and they foul promise to shoot for in design and devel- up plugs that way . The thing that caused opment for general utility . a few chuckles was the seating comfort : The meet no longer tries to imitate some pilots volunteered quite derogator y the one-sided (distance and speed) cham- remarks about that aspect of the man- pionship competitions of high-performance machine interface they had to sit on and sailplanes . It is geared to everyday endure for three hours . Imagine an in- soaring usefulness . The evaluation for- structor having to spend six to eight hr s mula for 1000 possible points on a pre- a day that way . scribed course may be : Yes, in real life, the 800 or so 5

licensed motorgliders in Germany are pri- the Austrian FAA which is recognized b y marily dualseaters used for training in all western countries (except USA) an d soaring schools and clubs . The studen t costs short of $1000 . learns to handle the airplane under the Rotax also produces a 27-hp unit , power with enough time between takeof f not. .ATC'd, with ripcord starter and sin- and landing to get the feel for the con- gle ignition that should be worthwhil e trols . Then he advances to power-of f investigating for the type of desert- (propeller stopped) approach and landing , fun motorglider that I keep dreaming of . and he needs only two or three dual winch With cooling blower and again with muf- launches under supervision for the transi- fler, it weighs 60 pounds at a cost o f tion to a normal sailplane . You hardly $275 . On my request for information mater - see an aerotow in a club operation-the y ial, Rotax promised me more details, whe n just cannot afford them . available, which I will pass on to Motor- The Feuerstein objective seemed t o gliding . The Crow also has a dual seate r be primarily tailored to that utilit y tandem sistership, the HB-21, powered b y requirement . It so happens that it coin- a V .W . conversion with 65 hp, more span , cides with good soarability in the medium and generally better performance than th e performance class . old Crow. Hans Zacher told me-with his usua l The Scheibe FaZkens (side-by-side emotional involvement-that, for the firs t and tandems) are dominating the scene ; time in the history of the motorglider and they dominate the market, too . They meets, he got close to his goal of sep- are slower than the RF-5's but they soar arating the design and achievement para- instead . With a fixed rather than retract- meters of motorgliders from those of th e able landing gear and a tubular steel fram e purist glass ships and coming up with a fuselage, they represent sturdiness, main- direction towards soaring utility and tainability, no-nonsense operability . I fun . found one operating out of a godforsake n Was there any sensational new devel- hinterland village gliding site with no opment? That depends on your viewpoint . visible shop support-just putting in a There was something like a Motor Nimbus , day's work, no fuss, no hassle . I believe, but I haven't seen it fly . I t Whenever I talked to the enthusiasts , had engine start trouble, I was told, and a few major differences came to light be- it seemed out of place a little, in a crow d tween what we can and cannot do over here , of workhorses, a highly-bred glass ship , compared with their problems . They are probably built for eccentrics who like th e jealous of our "Experimental"-Category . Churchill Downs Steeplechase . Too fickle Whatever they do has to be done to licens- and delicate for my taste . ing requirements-sailplane requirements , There was an interesting engine in- that is . A design, once approved, canno t stallation : the engine buried in the win g be modified without re-running it through on one side, the propeller swinging in a the licensing process . They design to a slot at 60% chord, the thrust vector about new category="Motorglider", generall y five feet right of the airplane centerline . single wheel landing gear, sailplane char- The off-center propulsion works fine but acteristics-no dual ignition . They cran k the propeller in the slot makes a terribl e out commercial machines for commercial use . noise generator . When these machines turn up in the U .S . , The successor of my Crow, the HB-3 , they lose their license and become "Experi- has a Cessna-type landing gear, the pro- mentals" because the European category "Mo- peller. swings around the upper fuselag e torglider" is not recognized by the U .S . boom-and it is powered by what appear s FAA . That prohibits any commercial us e to me to be an exciting new engine, a two - by gliding schools . It makes them toy s cylinder, two-stroke 40 hp Rotax, completely for the rich rather than tools to pro- self-contained with its own cooling blower, mote soaring amongst the younger gener- baffling, alternator, electric starter, dual ation . And the insurance premium doubles . solid-state ignition and muffler'. All of In the light of that paralyzing proposition , it weighing just about 100 pounds . It the Europeans would rather not enjoy an sounds like a four-stroke, even idling experimental category and retain the use- and displayed a start reliability that fulness of their motorgliders . To them , was amazing That, to me, was a sensa- the motorglider has infused a new leas e tion . This unit has a type certificat e on the survival of the sport of soaring . as an aircraft engine (motorglider) fro m 6

FOREIGN SCENE interest was again the Nimbus IIM (See June 1974 MotorgZiding) which is now i n by S . O . Jenko, Dipl . Ing . ETH production flight test stage . It feature s AMTECH SERVICE S electrically retractable outriggers whic h can be separately actuated and is supposedl y 1975 Burg Feuerstein APS Contes t an advantage for hangar storage as well a s The last year's contest took place movement on the ground . from September 8-12 . Because the Soarin g The Hirth 0 28 engine (no longer i n Division of the German Aero Club decided production) was modified by W . Collee wh o not to sponsor this year's event, and i n was one of the originators of this APS de- order to carry on this traditional APS sign . The modifications include a dua l meet, Messrs . Jan Eilers, Gerd Stolle an d ignition and fuel supply . The maximum Hans Zacher took on this task (see Augus t power is 55 hp, while the takeoff power 1974 MotorgZiding) . The November 1975 is 50 hp . There are two main tanks o f German Aerokurier carried a rather brief 7 .9 gallons each in wings and two auxil- account of this international event , iary tanks of 0 .8 gallons each, providin g presented here in translation . enough fuel for a powered flight of 3 .5 t o The purpose of this yearly contest 4 .5 hours . Also, a new muffler was de- is not only to make it international in veloped (67 dB(A)) which is below the re- scope but also to provide opportunities quired level of 68 dB(A) . for demonstration, test and evaluatio n At a gross weight of 1275 pounds the flights . There were some twenty contest takeoff roll on grass is 1310 feet ; the participants who also took part with other s cruising speed is 93 mph and the rate o f in various technical sessions ranging fro m climb is 394 fpm at 59 mph . the elementary task of trying to defin e During the next few months extensiv e anew the auxiliary-powered sailplane to the test flying will be done in South Afric a problems of the traveling flight with an and some new records may be forthcoming . . . . APS (see last issue of MotorgZiding), the Two other auxiliary-powered sailplane s usage of an APS as a sport, the noise re- of interest were the Austrian HB-3 and HB-21 L duction, etc . manufactured by Brditschka (see May 1974 Mo- The flying part of the contest con- torgZiding) . The fabric cover gave way t o sisted of the following tasks : a fiberglass skin . The two-place HB-21L ha s a new aircraft engine, based on the VW en- Date Tas k Winner AP S gine and developing 65 hp . The redesign (Sept . ) was done by the helicopter designer West- ermayer . Comparison testing with othe r 8 115-km tri . C . Gad SF-25 E conventional auxiliary-powered sailplane s showed these two designs to be on the sam e 9 130-km 0 R C . Gad SF-25 E level .

10 Endurance - 2 . 6 New Developments at Scheibe Aircraft Co . gal . fuel allow E . Heppt AS-K 14 The November 1975 German Luftsport has two very interesting articles about 11 0 $ R - leas t Gad/ new development work at Scheibe Aircraft fuel consumpt . Wiesbauer SF-25E Company . They are presented here i n translation . 1 1 200-km tri . E . Heppt AS-K 1 4 Auxiliary-Powered Sailplane SF-3 2 12 100-km 0 R Gad/ There is a new single-place auxil- Laumann SF-25E iary-powered sailplane prototype bein g * Castle Pommersfelden built by Scheibe . It features a retract- The first three daily contestants flew able pylon-mounted engine with propeller . SF-25CS, SF-25E, SF-28A, AS-K 14, RF-5B , The basis for this development was th e Nimbus IIM and HB-21 . experience gained from their SF-27M o f From a technical view no entirely new which some 30 are still flying since it s designs participated . Instead, some im- birth in 1967 . Its steel tubing fuselag e provements were noticeable . The point of 7

provided good service ; it is being used is about 2 .6 to 3 .1 gallons per hour . A with some modifications, also for cos t 5 .3 gallon fuel tank would be sufficien t reasons, in the new SF-32 . Instead of for a two-hour powered flight . fabric cover fiberglass skin will b e The test flight was scheduled for las t used . January . The best part is the projecte d The wing is not new either : it comes price : 35,000 DM to 40,000 DM . from the Swiss Elfe AN-17 sailplane of the Albert Neukom sailplane plant . The span Auxiliary-PoweredBergfaZke IV is 17m and features a surface comparabl e As reported here occasionally some in quality to fiberglass ships . builders have converted a few BergfaZk e The Elfe AN-17A has a rate of sink of sailplanes into auxiliary-powered sail- 1 .8 fps at 46 .5 mph, a gross weight of 81 5 planes . From the first flight in 196 9 pounds and a glide ratio of 40 . there are still some 50 flying . Thus i t The two panel wing consists of an is of no surprise that Scheibe Aircraft aluminum spar, the shell (skin) is 0 .236 Co . is developing its own auxiliary-powere d inch thick made of plywood and plasti c version whereby the two-place capabilit y honeycomb . The Schempp-Hirth type div e is being retained . brakes are on the top wing surface only . The engine used in this modificatio n The outriggers are removable . is a Hirth 0 28 (52 hp), provided by th e There is a retractable wheel (380 x known APS enthusiast W . Collee . The re- 150 mm) ; a swivel tail wheel is couple d tractable power package is positioned be- to the rudder cables . Thus the SF-3 2 hind the second seat ; it takes about 2 0 should be quite maneuverable on the ground seconds for retraction or extension . This The horizontal tail consists of a auxiliary-powered sailplane is now in fligh t fixed stabilizer and an elevator . test stage . The power plant is a two-cycle, two- cylinder engine Rotax 642 which also powers Some technical data : the Austrian HB-3 (mentioned earlier) . The Austrian engine manufacturer Rotax APS model SF-32 BergfaZke IV is primarily a snowmobile engine factory . Number of seats 1 1 + 1 A small portion of the production is mod- Wing span ft 55 .8 56 . 6 ified into "aircraft engines" : among Wing area sq . ft 143 188 other items an electric starter, dual ig- Aspect ratio 21 .73 16 .9 8 nition and a larger, quieter muffler ar e Empty weight lb 747 880 added . Gross weight lb 990 1320 The engine is about to be certificated Wing loading psf 6 .9 7 in Austria and Scheibe Aircraft Company Best glide ratio 37 31 expects to receive it in Germany . at mph 56 57 (We hope to receive complete infor- Min . rate of sink fps 2 .1 2 . 6 mation on this engine for a future article .) at mph 50 The propeller is driven by a belt, Stalling speed mph 43 .5 43 . 5 the reduction ratio is 1/1 .95 . Rate of climb fpm 394 296 The retractable power package is Engine Rotax 642 Hirth 0 2 8 driven electrically . The fuel consumption 40 hp 52 hp

Latest News-Stop the Presses ! The airmail just brought the latest issue of the Chinese Humming Dragon, containing an article on a revolutionary new engine , specifically designed and developed fo r auxiliary-powered sailplanes, about 40 h p at 3200 rpm, having a weight of only 20 k g (44 lb) including aZZ accessories with a 50 dB(A) muffler . Certificated productio n models to be available at $150 fob Wes t Coast . We'll try to have additional information and a few illustrations in the next issue . . . .

SF 32 8 EULOGY OF THE CRO W in the canopy to see where it is, and beep- ing the engine starter button just briefl y by Tasso Proppe enough to keep it from going over the nex t compression . The starter only works wit h The Crow is dead, at least, it seems the ignition on--which shows on the "en- so, and we are waiting for a report from gine-on" trace on the barogram. its last owner, Bob West, on what might With the gliding angle of 18 :1, thi s have happened . altitude is only good for 18 miles from I test-hopped it July 1975, after base-theoretically, that is . If you con- landing gear repair, still without canopy , sider a decent, non-emergency pattern ap- and it flew the way it always flew-so I proach and some possible sink you may run handed it back to Bob with the usual father- into, it will be more like 10 miles safe . ly advice, and he flew it to my and hi s However, if you have an engine that start s satisfaction . A few months later, a frien d reliably when you need it, 5000 feet amount s of his flew it and spun it in-all I kno w to a beautiful altitude for soaring out in- so far is : at climb-out in a strong breeze , to the country (Wolf Hirth called it "luft- making a turn into downwind . He and th e wandern" -air hiking) . Crow did not survive . The barogram shows that at aroun d I am still emotionally attached t o 14 :40, I went down to 2500 feet, but tha t the clumsy but lovely little bird ; so, I was no reason yet to re-light the engine . feel I owe it a eulogy and I couldn' t Sure enough, I ran into another therma l think of anything more appropriate than that carried me up to 6000 and eventuall y to indulge in the memory of "My Neatest another to 7320 feet, a net gain of 612 0 Flight . " feet over engine shut-down altitude . By By the time this is printed, it wil l that time, I had travelled over Ed Fletcher' s be more than two years ago, April 6, 1974 . little Sky Ranch air strip, the Borrego The AGCSC (San Diego Gliders) had an outing commercial airport, to Clark Dry Lake, a t scheduled in the desert - a good reason fo r the northern end of the Salton Sea basin . me to join them . A dip at 15 :40 on the barogram wa s I trailered her to Ocotillo Wells, an man-made : There was a Japanese twin je t air strip on a dry lake in the Borreg o trainer downed in the rugged desert a fe w Desert, some 120 miles east of San Diego , weeks ago . They were dismantling it t o stuck her together with the help of vol- get it out in pieces . There used to be an unteers-that's nearly two hours of work old rule amongst aviators that "one cras h -and got airborne shortly after 13 :00 . attracts another ." So, spiralling down After four minutes of powered flight at to take a look, I wanted to make sure m y 900 ft above ground, I found a thermal, engine is available when I need it . That' s killed the engine, tried to work it-an d the pip on the engine-on trace at 15 :40 . missed . Getting uncomfortably close to th e I started it up and ran it for 10 - 1 5 ground, I re-lit the engine three minute s seconds before I glided down to wave a t later and climbed back to 1000 feet . At the dismantling crew-and to run smack in- around 13 :28, I found another thermal . to a thermal which proved to be good fo r This time, I kept the engine idling for 6000 MSL, slowly drifting out of an are a two minutes to make sure I could stay in it , that is marked on the map as The Borreg o gained 200 feet, and shut the engine dow n Badlands . That was one of the sweetes t for good . thermals I ever encountered to bolster m y From then on, it was soaring. The ego . The dismantlers watched me in dis- early afternoon thermals carried me onl y belief pulling away with a dead propelle r to 2500 feet and by 14 :00, I made it to a back towards Ocotillo Wells . They followe d comfortable altitude of 5500 feet or so-- me later in their jeep to ask questions , which allows me to devote some attention still with a baffled look in their eyes . to the procedure of hiding my propelle r I made my way back in two hours in slowly behind the fuselage pod knife edge . That decreasing thermal activity but without involves a hand-held mirror through a hole using the engine . The engine-on trace

9 shows the taxi run after touchdown and covered by a plastic canvas . Everytime I another low-level flight from one end of wanted to fly, I had to build me an airplane the dry lake to the tie-down area . with the help of volunteer onlookers, a The punch line of this story is : A 4½- nearly two-hour task-but that doesn' t hour flight on less than one quart of gaso- change the fact that she was truly the firs t line--a purist fiberglass ship would have workable and operational motorglider back i n used five times that much to get started . 1963 and still good in 1974 ! It probably would have also covered fiv e There is a little addendum for the times the distance, yes . But it would no t barograph : Since I am not competition- have dared to spiral down that low over the minded anymore, I don't have it calibrated . Badlands . I don't think this is a matter I carry it for my after-the-flight evalua- of operating costs . To me, it seems more tion, and the altitude figures are take n a matter of taste . At my age, I enjoy th e from flight instrument readings which I leisurely drifting around on a Saturday read into a tape recorder together with afternoon, poking my nose into the wilder, time, location, and other pertinent data . ness and the wonders of nature with the I use smoked mylar sheet instead of alum- engine for independence of takeoff and in- inum foil . After fixing the record, I us e flight freedom of decision without the it like a photographic negative and do m y hazard of running into a point-of-no-retur n evaluation (like the typewritten entries ) situation . on copies thereof . The engine-on trac k The Crow provided just that. The only is an improvisation I added with the hel p misgivings I had was that she was designe d of a cheap 12-volt relay, the pen attache d for being kept in a hangar . I had her on to the armature . a trailer at home alongside the house,

BETTER PROSPECTS OF USE OF MOTORGLIDERS year and the more competition-minded pilot s FOR SPORTING PURPOSES may have been absent, we had a very interesting discussion over three evenings . by Per Weishaup t After that, I sent the Bureau of the CIVV an interim report for their Novem- After having been appointed President ber meeting about my impressions of the of the FAI/CIVV Motorgliding Sub-Committee situation . last spring, I in June 1975 sent an Ope n I told them that many pilots wer e Letter to a number of international avia- quite satisfied with the present FAI rule s tion and soaring magazines asking motor- for motorgliders and thought new and bette r glider pilots a number of questions under motorgliders would result in more sport- the title "Why don't we use motorgliders ing flights . more for sporting purposes? " With regard to the nearly empty FAI A number of the magazines published record list for motorgliders we found ou t the letter, and the committee got quite that the FAI originally by error homolo- a number of interesting answers from mo- gated some German records which had bee n torglider pilots all over the world . flown before the records were inaugurate d Based on these answers the committe e on January 1, 1971, and for that reaso n arranged a discussion on the occasion of they had been cancelled again . the Burg Feuerstein meeting in Germany Another reason for the few records last September . Although it was not a might have been the minimum requirement s full-scale championships competition that in the 1971 Sporting Code . They seem t o

10 have been too hard, and with the publish- out to a starting place somewhere, stop ing of the 1975 Code they have been deleted . your engine and cross your starting line , So we are now allowed to start with smal l perform, say a triangle, pass your finish records and improve upon them ; this in line and after that restart your engine an d itself may stimulate the battle of records . motor back to base . With regard to badge flights quite a This brings us to the question of docu- number of Silver and Gold Badges as wel l mentation which was eagerly discussed a t as some Diamonds have been flown with mo- Burg Feuerstein . Apart from some system torgliders, but as they are not registered with recognition time interval and sit e separately their number is unfortunatel y clocks to make sure that you have not pho- unknown . tographed your turning points before passin g Competitions have been few owing t o the start line it would be nice with som e the fact that in most countries there are more advanced systems combining clock , too few motorgliders and they are too scat- barograph and camera, and some interest- tered . There have been some informal meet s ing projects were shown at Burg Feuer- and some motorgliders have taken part i n stein . regular gliding competitions, but the only We ought to get somebody to put out real development with regard to competi- a prize for the best system . It would b e tions has been the German competitions of interest not only to motorgliding bu t which during the later years have taken to all performance soaring which could b e place at Burg Feuerstein . made easier and cheaper that way . Until further experience with regard The above points were all taken ad to competitions and competition rules has notam by the CIVV at its meeting in Marc h been gathered the committee find that any 1976 . The CIVV has no idea to force th e competitions at present should be run ac- motorgliding people to do something the y cording to the German rules . do not want, even if there still are mem- That the engine should be used as part bers of the committee that think that at of the sporting performance was strongl y some date some kind of sporting competi- rejected by nearly everybody . And even i f tion including some use of the engine wil l there still are people in the CIVV that appear . Well, let us wait and see . On e like this idea I think that the gliding possibility is what the Germans call Wan- committee of the FAI ought to appreciat e dersegelflug-competitions where the com- that the motorglider pilots really want t o petitors during say a week fly a sort o f make gliding and soaring performances and combined tourist-and-soaring course, usin g not motor flying performances . the engine where necessary to reach th e However, it was very much stressed by day's goal, and soaring as much as possi- the motorglider pilots that they wanted t o ble on days when there are the thermal s be able to use the engine not only to ge t enough . into the air but also to fly, e .g . away from The first thing to do, however, i n a control zone or otherwise away from thei r my opinion is to fill out the empty--the base to an area better suited for soaring . many empty :--places in both FAI's and th e And after having performed a soaring per- National Aero Clubs' record lists for mo- formance they wanted to be able to restart torgliders . Let us show them that we are their engine and fly back under power t o interested, and let us show them what th e their base . They wanted to improve safety , motorgliders we already have are able t o cost and frustration by eliminating ou t make of performances-with time we can im- landings . prove upon them, not necessarily with th e This was not possible according to th e Nimbus M but with the newer and not quit e old code which prescribed a flight afte r as expensive types as the new SF-32 an d passing a starting line to a landing . PIK 20E and what else are coming . And However, in the 1975 Sporting Code do not forget our two-seaters . They may the word landing has been replaced with not be so high-performance as we coul d Finish Point which is defined as "The Fin- wish, but they are certainly able to mak e ish Line OR the Landing Place ." This mean s impressive soaring flights nevertheless . that if only you can arrange your cours e And when we show we are doing this wit h with official observers in a way acceptabl e them the manufacturers will understan d to your National Aero Club you can motor we want something to beat them .

1 1 LETTERS RECORDS

Editor : Three world motorglider records hav e Interesting changes in motorsegle r been claimed in Germany . On April 19 , certification are forecast for Germany 1976, Friedrich Kensche flew an SF-25E in the near future . Max allowable gros s at 45 .9 mph over a 100-km triangula r weight of 1000 kg vs . the present 750 kg , course for a multiplace record . On Apri l and minimum allowable L/D of maybe 25/ 1 28, Kurt Heimann flew an SF-27M on a 373- are likely soon . mile out-and-return flight, and on the A recent short visit in Europe brough same day, Gunther Jakobs flew an SF-25E not only the foregoing to my notice but with passenger for a 402-mile goal . These also that Italy has just adopted rulemak- are all subject to approval by the German ing allowing experimental certification . Aero Club and the FAI . Homebuilding (and flying of such) is now legal there : And furthermore, puttin g the U .S . even further behind, Italia n POSTFLIGHT NOTE S certification procedures for motorgliders are expected to be completed soon, possi- We hope you have enjoyed this issue . bly by year-end . The next one will tentatively feature Bob Bernald Smith Tawse's paper, "Motorgliders : State o f Fremont, California the Art ;" Bill Budachs' article on deliv- ering a Falke; an'article exploring th e possibilities of a tailless powered sailplane, by M . A . Zimmerman ; and S . O . Jenko's "Foreign Scene ." After that , Editor : well, it depends on you . If you are i n Fournier RF-4D based at Compton Air- a position to contribute an article or port, California. Over 600 hours on it now . photographs, please do so . If we are t o Most soaring flights under the LAX TCA in maintain a regular schedule we need con- thermals kicked off by the oil refinerie s tributions from those participating in th e of Wilmington oil fields . Up to the 5000- activity . foot floor of the TCA when the marine in- version lifts . Up to 8500 feet in conver- gence zone lift in the hole in the TCA north of Long Beach Airport . Up to 11,500 fee t CLASSIFIED AD S in wave lift directly over San Fernando Airport . Three-hour flight in wave lift DESIGNING & BUILDING your own aux- over Malibu Beach during Santa Ana wind iliary-powered sailplane and in need o f condition at 3500 feet . Most flights dur- sound engineering advice? For free de- ing weekday lunch hours . Gave up motorin g tailed information send a self-addresse d to Elsinore-lift is better over the cit y stamped envelope to : Amtech Services-mg , most times . Flown to airshows in Canada , RD 8, Mansfield, Ohio 44904 . Mexico, points east as far as Oshkosh, Wis- consin and all over California . Wouldn' t part with the little Fournier for anything . RF-5B, 600 hrs . Excellent condition . Mike Bittner $18,500 . R . C . Graham, 1432 Sand Run Rd . , Manhattan Beach, California Akron, Ohio 44313 .

1 2 Contest winning performance at a reasonabl e The Tandem Falke's outrigger wheels an d price, plus docile handling characteristics and a steerable tailwheel allow completely independen t worthwhile range under power (about 280 miles ) operation . With its outrigger wheels removed th e mark the Tandem Falke as today's best value i n Tandem Falke may be conveniently hangared self-launching sailplanes . The 60 hp Limbac h with other sailplanes . engine with a Hoffman feathering propelle r provides plenty of power to operate from regular A side-by-side version is available for pilots wh o airfields . prefer this arrangement . Similar performance , but slightly lower rate of climb and glide ratio . Order the SF-25CS "Falke. " Engine-on Performance Prices include flight test, German certificate of Takeoff run 500/650 ft . airworthiness, flight and engine instruments , Rate of climb (sea level) 430 ft./min . electric starter, feathering propeller, cabi n Maximum speed (sea level) 106 mp h heater, upholstered cockpit, two-tone paint , Cruising speed 81-93 mp h packing in container, and shipping to the port of Endurance (cruise) 3 hours Hamburg : Fuel capacity 10 gallon s Scheibe SF-25E Super Falke DM 55,50 0 (First place, 1974 Burg Feuerstein ) Gliding Performanc e Scheibe SF-28A Tandem Falke DM 49,800 Scheibe SF-25CS Falke DM 49,000 Maximum glide ratio 26/27 to 1 at 53 mp h Minimum sinking speed 2.95 ft . /sec. at 43 mph All prices FOB Hamburg GRAHAM THOMSON LTD 3200 AIRPORT AVENUE SANTA MONICA, CALIFORNIA 9040 5 [213) 398-4714 Sole distributors of Scheibe powered sailplane s in North Americ a Motorgliding Second Class Postage Pai d c/o The Soaring Society of America, Inc . At Santa Monica, Calif . P .O . Box 66071 Los Angeles, California 9006 6

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