By  Terry (The Tiger) Baxter
.....Terry has submitted some new ideas about his concept that has gone to land based plane called the "SS" Catch 22.  Click here to read and see more about what Terry is up to now.  He still hasn't done any building, but he is sure trying to come up with an aircraft that will meet his needs in the Australian outback.....
(The following is a series of letters from Terry Baxter of Darwin, Australia, who is trying to design and build a three-place, amphibious flying wing for use in moving his family between homes in the vast expanses of the Australian Outback.  He has gone through several iterations, having settled on what you will see a little later.  If you have any ideas that might help Terry in achieving his goal, please correspond with him at the following address (unfortunately he is not online):  Terry Baxter, c/o Darwin Butterfly Sanctuary, 79 Mueller Road, Malak, Darwin, Northern Territory 0812, AUSTRALIA.  Phone:  (08) 8927 6019). TWITT would appreciate a copy of whatever you send to Terry so we can keep this record up to date, which might help others in their analysis or prevent duplicate thoughts.

November 18, 1999

     Having come across No. 149 TWITT Newsletter 1998, I wish to become a member and request lots of information.  I am a senior citizen, hold a degree in horticulture and am a qualified lepidopterist, breeding butterflies and operating the Darwin Butterfly Sanctuary.  I am a member of the Australian Society of WW I Aero Historians and am trying to procure the original plans to build a “Sopwith Pup” before I die.  If any of your members have any information I would appreciate it.  I am a member of the Top End Ultralight Club and do training in a “Drifter”, a “Thruster” and other aircraft, as I need an ultralight license even to fly the minimum aircraft “Scout” in Australia; not like in America where no license is required if certain rules are adhered to.
     Now to the main reason for joining TWITT.  As by the address you can see I Iive at the top of Australia, but when Cyclone Tracy blew me out of Darwin in 1974, I bought a farm in Victoria to house my family.  The commute between Darwin and Victoria is 4200 km each way over roads that are not always the best.  There has to be a better way to make this trip.
     In conjunction with a Frenchmen, we have been trying to design a “FACET” similar to Barnaby Wainfan’s who I believe is one of your members (ed. - he is not, but we stay in touch).  An Australian designed a “FACET OPAL” in which he died and I have repeated dreams about it.  My main concern is designing and building a “Long Distance FACET” or flying wing to commute between the top and bottom of Australia so I can manage both of my properties.  I believe commuting by plane is safer than the long distance by road and it will be much easier on my wife and little girl than the long ride.  So with my family on board it needs to be safe and I have heard it is hard to stall a FACET or flying wing and they just mush down; is this correct?
     I have in mind twin engines for safety; small four strokes in-line or opposed or twin small radials.  I am no aero engineer, only an old plumber, so need a presentation of different models for selection.  I have been playing around with an old 1930’s concept where the designer quoted a 4-wheel pusher would probably be the future plane.  I have a 5-wheel sketch as below.  In my dreams Scott Winton keeps telling me that the wing should be the cockpit.  Scott designed the ‘Facet Opal” which he used to break 4 records, including climbing to over 30,000’ on 40 hp, before a fatal accident with the aircraft.  If you have any photos of the Facet Opal I would appreciate one.
     I have been making balsa models and have duplicated the ply sandwich idea with a trangle shape front to a square where the passengers sit in a triangle at the rear with twin pushers and a tri landing gear, conventional 3-axis control.  The 
passengers are recessed into the main spar of the wing putting them at the CG, which still allows the plane to fly solo with the pilot up front to balance the weight of the engines aft.
     The engines would have to be close together for one engine to still keep the aircraft in flight if one failed.  Do you have a concept in your files as a facet or flying wing?  Ply/foam fuselage with 18” deep wing at the center to 6” outboard, approximately 20’ wing span, 12’ chord at the fuselage and as a guess twin 60 hp motors.
     As I have built many ply boats I think the ply/foam combination would be the easy way to build as all you need to do is order custom length ply, mark out the shape and cut with a jigsaw.  You can then trace it onto another sheet giving you a right and left hand side, then joining them with bulkheads for seats, etc.
     Using two light weight engines in the wings of about 60-80 hp which could easily be unbolted, the whole plane could be dismantled and housed in the family garage.  If the motors weighed about 80 lbs. each - say a F30 Hirth 95 hp at 38 kgs - two motors would be about 170 lbs., the same weight as a pilot and then most of the balance problem would already be solved if the passengers sat at the CG.  Little ballast would be required for balance and if the pilot’s seat is moveable fore and aft to correct most balance problems.  An 8” aluminum tube sub spar at the CG could be welded up as the fuel tank with an equalizing transfer pump to port or starboard to balance it laterally.  Fuel used at the CG point would not affect stability.
     I believe that I could build a Facet or wing using the ply/foam system obtaining a craft that would float if forced down on water.  It could be very cheap as I would recycle auto main leaf springs for the main wheels traversed across the fuselage with one forward trailing castor wheel and individual brakes on the main wheels.  These would be operated by a lever moved either side for differential braking or pulled up vertical to operate both brakes.  A simple drum bolted to the wheel with external brake bands operated by cables.
      I would use foam ribs with 1” wide ply cappings and cover the leading edge to a “D” shape with 8mm ply and folded aluminum sheet for rudders, elevators and ailerons.
     A complete main wheel bolt on external brake system is marketed in Australia for $80.00, 12” castor wheels $95.00 each, and 16” wheels complete $82.00.  Springs at no cost; recycled from wrecks.  As I have also been in charge of  large sheet metal works, folding the control surfaces from single sheet aluminum would be a breeze.  The fixed fins at the end of the wings with rudders only operating outwards individually for yaw and both together as air brakes would be great.  The castor front wheel with individual main wheel braking would give good steerage and if flaps are incorporated with a over-center locking lever, you could have a S.T.O.L. effect.
     Having done a rough calculation on materials in Australia, I could build a 14’ fuselage for about $1,000 complete and the full de-mountable 20’ wings for $1,000 also, using recycled gear.  What the engines would cost I do not know, but a rough estimate using Subaru as an example would be another $3,000 for the two.  This looks like $5,000 for a three seater, 300 hp aircraft, with a 200 kph cruise speed, 60 kph stall and 65 kph liftoff in about 25 metres.  This is all guess work so can your members tell me how close I am.  I know that Subaru’s can produce about 150 hp each and with pusher propellers 4 blades should be very efficient if the airflow is undisturbed and directed without turbulence to them.  Deep airfoils would give a lot of lift, say 18” at the root and 6” at the tips, keeping the trailing edge straight for each manufacture.  This plane should be able to fly on only one motor.

December 1999

     Further to my previous letter, $30 US is included for membership, info. and postage.  As I noted in my previous letter, I need to build a 3-seat powered “Facet” or “Flying Wing” to fly from the top end of Australia to the bottom, as it is 4000 km between my properties and a lot of it over tiger country.  I would intend on landing in some of it for camping, fishing and shooting, so I can live off the land enroute.
     I have one son who is out in the remote coastal mangrove areas catching mud crabs as his living.  Generally he brings in a load of crabs about once a week, but sometimes he doesn’t come in for a week or more and I become very worried about him because of the dangerous waters, rip tides and threat of crocodiles as he is always alone.
     This brings me to my added request in relation to my Facet or Flying Wing, which I want to build for commuting between my properties.  Is there any amphibious flying wings in America as I could use the same plane  to scout his areas of work, deliver supplies and transport some of the crabs back to Darwin.  Fishing in the same area for fresh fish would also be a benefit for my family, which loves seafood.

     I already have a set of floats with spring loaded retractable wheels from a previous crashed plane, or I could use ply/foam construction to make a flying boat, or adopt an aluminum dingy or boat under the wing to land on the water.  I believe the cheapest way for me at the moment is to use the floats I already have. 
     It could be a single stabilizer, twin engine tracker and with no passengers should be able to carry at least 100 kgs of supplies, fuel, food, etc.  I need two engines for safety in the remote areas.  The wing could be attached to a standard outboard motor boat hull, which could carry the crabs back to Darwin and would also be a good fishing platform.
     A twin pusher could be another version and with a trampoline between the floats would also make for good fishing and a stable platform for shooting crocodiles.  A ply/foam flying boat which would be ideal and not expensive to build, but it would require two motors capable of take off singularly.
     Has anybody in America done something like this; I know there is a trike with an inflatable boat on the market in your country.
     I enclose a further $30 US for postage, information, etc.  The photo I enclose shows the internal wheels in the floats with the doors which close and seal when the wheels are raised by a control wire and the springs which are internal return the wheels to the up position and retract the doors.  The floats are very wide and should support at least 750 kgs each; both wheels fold backwards in a over-center position in the landing mode for airstrips land and grass.
     Porpoising the floats should allow the plane to unstick from the water on take off when loaded and you could taxi around to make a wake to get air under the floats.  I also have a trailer which the floats can roll straight onto with the wheels extended.
     I also enclose a photo of the Mk III Scout which I am resurrecting; one of the first ultralights - 1970, which I am donating to the Darwin Aviation Museum after I modify it to a tri-retractable landing gear with floats and make it a bi-plane, combing the modifications other Aussie’s have done!!!

March 14th & 18th, 2000

Further to my previous concepts which you have published, I now submit the concept I want to proceed with.  It was triggered by the “Choucas” by Noin Aeronautiques (two seater, Vmax 170, Vc 130, Vmin 60 kph, 503 Rotax & 260 kgs empty weight).  The wing and rudder assembly I believe seemed suited to adapt to water operation with the large parallel center wing section with tapered tips, although it was a mid-wing.  The side-by-side seating made it a wide fuselage which lent itself to development of the hull form and raising the wings to a high position to clear the water as a seaplane.  The large rudder also appealed to me for good control when water taxiing in conjunction with throttle control of twin engines. 
    Although the Choucas could be flown without power because it had a large wing span, the caption was that flying wings were hard to pilot.  I have doubted the wing width, but reduced the wing span to about half.  I want a slow landing speed so have made the wings deeper for more lift.

     The configuration to me, seems eye pleasing, but I need input from experts in relation to wing span as against power, etc.  I believe the Liberty Subaru auto engines would be the way to go, but would like to develop a 5 cylinder diesel manufactured from VW barrels as a radial.  If the Great Plains aircraft 2600 VW can produce 96 hp, I am sure a 5 cylinder radial could be made to produce at least 100 hp in a direct drive diesel.  The Subaru engines should give about 120hp, would use standard auto engine mountings cantilevered off the wings main spar at the CG for balance purposes, with extended shaft to the VW Kombi final drives secured on the leading edge.  Donut couplings on the drive shaft extension should reduce vibration within the wings.  This combination should give about 100hp at the propellers.
     I have selected twin engines for safety and opted for a full width bench seat at the CG for passengers and camping gear.  An aircushion seat pressstudded (ed. – I imagine he is referring to Velcro) to the bench for comfort, easily removed to pack gear using the same seat belts to secure loads.
     Using the ply foam construction and fiber glassing the complete external surfaces, I could produce a very strong hull.  Using the throttles of the engines at different revs, and a large rudder, water steering would be simple.
     The proposed hull width is 4’6” and approximately 12’ long.  I believe a plank wing would be suitable.  Using aluminum tubing main spars could also be used as fuel tanks which would be at the CG and, would not give any balance problems as fuel is used up.
     I have to keep under 614 kgs maximum takeoff weight to be registered under experimental ultralight in Australia.  I would like to keep the engines, batteries, etc. to 214 kgs which give me 400 kgs for the complete airframe, wheels, etc.  I have previously built a 12’ sailing boat for two people that only weighed 52 kgs, so I should be able to produce a 15’ hull for 100 kgs, pilot 80 kgs, crew 80-100 kgs, thus allowing me approximately 120 kgs for the wings, wheels, etc.
     I want to build this to a very basic design using the most simple ideas.  These include using lever operated,  torsion sprung (VW rear suspension of the “Kombi Vans) retract for the wheels.  Differential, lever operated cable braking system with external brake drums.  It must have adequate wild terrain clearances as the prime purpose of the design is a long distance commuter over Tiger country.   I will use strut braced wings of foam ply with aluminum 6’ tube main spar or even larger, and; a deep airfoil section in the center, tapering to the ends in depth only.  I have no idea of the span  or chord and hope members may assist me in the wing design.
     Would you copy some of the sketches and dissect enough information out of this letter to distribute to the members.  I want as much criticism and help to finalize plans for presentation to the Australian Ultralight Federation and the Sports Aircraft Association of Australia. 
     Many locals are interested in my Ornithopter which I mentioned in my previous correspondence, but expressed disapproval of the gull wings.  I have read the articles of the Raven Wing in the TWITT newsletters and I believe my gull wings will work and, using the wing warps should have adequate control.  Because I am 70 years of age, I have added a trike base for power assisted self launching with a comfortable air seat and go-kart steering.  Using the soft cover book on sailplanes which I procured through the TWITT newsletter, I believe 25 hp should be adequate to get me airborne and only need about 5 hp to maintain flight seeking thermals.
     I still fly every Sunday morning at the Top End Ultralight Club where many self-built aircraft have arrived lately, but as yet no flying wings.  But trikes, especially the Australian Edge with the Streak wing capable of over 100 mph are arriving weekly and all these are basic flying wings.
     The main thing is I want to achieve all my aims before my “used by date” expires and enjoy flying in craft I have built myself.  I cannot think of anything more satisfying in life.
     Thank you for printing my concepts in the newletter as by distributing your newsletter at the Top End Ultralight Club, my concepts have created that much interest that two people also want to build the same plane.  May the wind be always in your hair.
Hull Length                               15’
Total Length (nose of tail)         19’
Hull Width                                 5’
Tail Height at Trailing Edge        6’
Wing Span                         No Value
Center Chord                           7’6”
Engine Center Lines                  84”
Prop Diameter                          54”
Elevators  Chord                      2’
Width                                      7’
Flaperons                               10’

February 4, 2001

     Having found a February 1996 Pacific Ultralights magazine with a tribute to the Horten brothers, written by Rob Germon of New Zealand, it featured the fabulous H.P. 1.  The H.P. 1 was a side-by-side two-seater with a baggage load of 90 lbs., a range of 615 nm., and a top cruise speed of 165 kts., on 90 hp.  It had flaps with a stall speed of 38 kts, rate of climb of 1050 fpm at gross load.

   Apparently a Rotax version had also been flown with a 532, cruising at 130 kts, and a single seater with a 447 Rotax with a cruise speed of 110 kts.  I believe that there is a video covering all these aircraft flying; would it be possible through TWITT or its members for me to obtain same.

      I believe that the H.P. 1 could be developed from its original all aluminum construction to a modern composite ultralight aircraft much cheaper than the normal 3-axis trainers like the Drifter and Thursters in a much more economical operating costs in the ultralight field.  Just looking at its drag free shape even with fixed undercarriage it must be better than all other ultralights.  Are there any plans available?


Terry (The Tiger) Baxter

(ed. – From the drawing you included this looks very much like the PUL-10 that is currently being developed in Germany.  We have presented material on this in past newsletters and as far as we know there are no homebuilder plans available at this time.  I think the plan was for kits to be made once all the bugs were worked out, but the program is behind schedule.
     I put your question to Reinhold Stadler who has some involvement with the PUL-10 project.  He returned the following:
 “Never heard of a HP1.  It really looks similar to the PUL 10. I would bet, it refers to the first project ideas discussed by Reimar Horten and Siegfried Panek.  That would fit to the HP abbreviation.  The original layout was with metallic tubular frame, so it could fit.  This must have been done in the 80ties in Argentina?  The wing shape is similar to the PUL 10, but with a little Horten-tail (a feature introduced with the H IV).  Anyway, I cannot remember either Reimar Horten nor Siegfried Panek mention a HP 1 to me. 
     What is puzzling me is the reference in the drawing "H.P.I. 1936 Walter and Reimar Horten".  If the design is really from 1936, it would have been a H ?, but surely no HP.  Even the later airplanes, built by someone else had the original H for Horten, nothing else (e.g. the Go 229 was a Ho 229, even GWF used the Ho abbreviation).  As far as I could find out, Walter was not involved in the PUL 10 project.  The layout does not fit to the layout used by the Hortens in 1936.  Maybe the idea started at that time, but the lookalike would have been different, I guess.  The big single-piece windshield was not possible for the Hortens at the time and, no tricycle landing gear was common.  The big fuselage was used on the H XII first, if I remember right.  At least the text is not done by Reimar or Walter, the number one is written different in Germany. Maybe that is a sketch done by somebody else who got a secondhand description of that project?  I have to admit that there are -of course- Horten projects that are unknown to me, so why not?  But for the moment I have nothing at hand to verify this.  If you find out anything else it could be interesting!  Sorry, that I can not say more about this nice-looking little project.”)

February 4, 2001

Having in my possession a drawing of French inventor Pernaud’s first model aeroplane which he built and flew in 1871, I was further intrigued by his twin-propellered monoplane, patented in 1876.  This remarkable machine of single control column, retractable undercarriage and amphibious into the bargain must have been the forerunner offer of the later Facets.  It also shows the elevator, fin and rudder. 
     In the attached drawing notice the fixed rear wheel acting as a help to directional steering below the hull and the main part of the wheel retracting into a center case, the balanced rudder effect with guys from the aft end of the swivel point of the rudder to the straight part of the wings trailing edge.  Also note that the four bladed paddle props operate in opposite directions counteracting prop torque.  It must be admitted if this concept had been built in the 1800’s, it would have flown???

     It is my intention to build a rubber powered model of this design using the complete transverse spars as shown with thin bamboo strips crossing the spars as ribs and papering the whole wing with the elevators attached to the trailing edge as shown in the drawing with the fin in situation to the wing also.  Notice the aerofoil shape of both the rudder and elevators.  I do not believe the landing wires are necessary in the model.  Although this concept only had yaw and pitch control, the low CG due to the hull shape and wheel weight it should have been stable in perfect conditions for flying related to the power source which I would surmise would be a belt driven by a light weight steam engine of those days.  Even the spring tail skid for rudder protection for land takeoff was a good thought as the aerofoil shape would have kept the craft in ground effect for some time.
     I intend to make my model approximately 30” in wing span, and as the aspect ratio is only about 3:1, I would only have about 10” of rubber for each prop, but with the high ground clearance into the wind I should get lift off.  There will be only fixed undercarriage.
     Has anyone ever carried out this exercise before and does any member who has input please write to me.  It can be seen from the drawing that side movement of the stick moved the rudder left or right and forward movement or back operated the elevators so control attachment to the trailing edge could have accounted in the concept, but washout is noted at the rear of the wing at the fuselage, and to the wing tips.  Let’s face it, early inventors did have the concepts for flight.

 Terry (The Tiger) Baxter
 79 Mueller Road, Malak
 Darwin, Northern Territory 0812
  (08) 8927 6019

(ed. – Some very interesting drawings.  We would be interested to see pictures of your completed model, hopefully in successful flight.  Keep us informed of your progress.
     If any other members out there have tried this project, we would like to hear from you.  If anyone has any more information on this particular aircraft, we would be interested to hear what you know.)

March 8, 2001

As a matter of interest I came across a very basic self launching slope soarer called ether “Assassin” in a May 1999 Airbourne magazine of delta concepts.  It was stated that a 48” model was extremely aerobatic and would fly in 40 kt wind without ballast.  If this is the case, why has not a similar man-carrying ultralight been built, or maybe one has, but living in such a remote area I had not come across one in the magazines and EAA does not seem to feature the flying wing concept.  It appears to have separate elevators, ailerons and rudder, but I believe “elevons” would be enough with the rudder input for adverse yaw and the elevators could become flaps of the center blended wing area.

     From my readings, it appears less power is needed by the flying wing concept due to the low drag.  But I would love to see someone use the simple 2-cycle, air-cooled, direct drive 60 hp engines now on the market to design a 2-seater tandem or side-by-side ultralight with fixed tri-landing gear for the ultralight people of Australia.
     It would be a plyfoam composite covered with fiberglass and even foam wing tips could be added to the cutoff shape of the wing tips.  This would suit the tropical areas of Australia.  A large market is awaiting.  Push-rod controls would lower maintenance and if the center body was moly chrome with each wing slotting into the sides, say of 10’ span each, it would be easy to trailer in the remote areas.
     I enclose pictures of interest from one of our fly-ins that Andre Maertens of Q.Land Australia sent me of a bush hanger and a U.F.O.  My workshop is a mowed area under a red-flame tree in the front of my house adjacent to the road with a fire hydrant close by.


    Another concept I came across was the five-pointed star like the instrument used by the Ninja’s of Japan.  A simple concept that would be made of three lengths of aluminum tube for the leading edges and aluminum channel for affixing the ailerons and elevators.  I don’t think rudders would be necessary, just the fins for stability or a single fin and rudder for better control.  Once again, the twin opposed air-cooled 4-stroke direct drive power comes to mind for simplicity and I believe 60 hp would make this a 150 kt speed machine in the ultralights.

     I would like to thank the members of TWITT for sending me all the literature on the history of flying wing development, having no computer and living in such a remote area makes it hard to get any info.  Please forward anything of interest and I wish to thank those members that made the effort to phone me from America.

Yours Sincerely,

Terry Baxter
c/o Darwin Butterfly Sanctuary
.........................................................79 Mueller Road, MALAK
.........................................................Darwin, Northern Territory
.........................................................Australia  0812

(ed. – Thanks for the pictures.  I have included the two of the UFO.  The magazine article of the UFO (Useless Flying Object) says it was designed and built by David Rowe and, represented his third attempt at getting a round aircraft to fly properly.  In the article he commented it was much slower than it looked and, that after designing and flying round wings had been interested and novel, but they did appear to be quite inefficient.
     I am glad that you have heard from our members in answer to some of your previous questions on flying wings and your attempts to build something for your private use.)

March 25, 2001

Having come across many large type models which have successfully flown, I cannot understand that a 2-seater flying wing ultralight has as yet never been successfully launched in homebuilt plans or kits.  Take the following sketch, although there were no actual measurements; a tandem say with 60 hp could follow, or even 100 hp.  It appears to be a standard 3-axis control and would certainly lend itself to a full composite construction.  I still think this could be classed as a flying wing!!!

      Another was Teledyne 262 of about 7’ wing span using a rotoduct.  I could not find any details of this model but it was all fiberglass.  This would suit a belt reduction, flat 4-cylinder Subaru.

     Then there is the AMR XD110 Research scale model for a two seat Bensen Nova training aircraft.  First flight was 1969 on a Ross 4 hp driving a multiblade shrouded propeller.  Wing span of 7’, chord 10’, max payload of 80 lbs, max level speed of 300 mph and a stall speed of 10 mph.

     The third prototype was a scale test model in 1976 as a two seat STOL advanced trainer, non-stalling, double wing delta with sealed control surfaces.  Radio controlled command guidance.  Conventional take-off and landing using retract tricycle landing gear.  A later version with twin rotoducts buried in the aft fuselage was scheduled after 1976.
     It appears that the rotoduct is a very efficient means of propulsion.  I take it is a number of multiblade props, one behind the other like axial flow turbine flood pumps.  Can you send me any information on them?



(ed. – Thanks for the follow-on letter showing us more of what you have found in the way of models that, like many other things, never made it into a production stage.  This seems to be typical of many commercial projects when it is found there is really no market either in the private or public sectors.
     As for information on rotoducts, we don’t really have anything that would be of help.  Ducted fans, which they are commonly called here, have not proved to be as efficient in homebuilt applications as might be expected.  Rohr Aircraft tried one on a delta wing in an attempt to take on Cessna’s 150 training aircraft, but it also never got beyond the prototype stage for various reasons.
     Bob also noted that I had not included the correct picture to go with the text material you provided.  I did have it in the newsletter at one point, but in the process of doing the editing took it out without re-inserting it.  That has now been corrected.)

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