METHOD AND MECHANISM FOR CHANGING THE WING PLAN THE GEOMETRY OF AIRPLANES SPORTPLANE IN FLIGHT BUILDER (A DESIGN STUDY) By Antoni
8509 Greenflint Lane Austin, Texas 78759
I SELDOM HEAR of homebuilt aircraft activities in I invented a high lift device called "METHOD AND South America so I was pleasantly surprised when I re- MECHANISM FOR CHANGING THE WING PLAN cently received a letter from Brazil describing a beauti- GEOMETRY OF AIRPLANES IN FLIGHT." ful sleek all-metal homebuilt and an invention for a It has a patent pending in Brazil, U.S., Canada, high lift device. England, West Germany, Italy, Japan and France. I knew there were EAA members in South America Of course, I would like to explore it on a commer- because I do get occasional letters and book orders cial level but for this it is necessary to make public from there, primarily from Argentina and Venezuela the device. as well as Brazil. I think it would be a very good idea to permit any I knew too, Brazil was developing a pretty good EAA member to use it free in his own plane, of course aeronautical base and is internationally known for without commercial exploitation. I would give an of- turning out some excellent aircraft designs. As a mat- ficial permission to use it for each interested person. ter of fact, during its rebuilt from a basketcase condi- This device, beyond its principal finality, if used tion, my current Emeraude's English-built Rolls Royce in assymmetry form and automatically moved by aero- 0-200 engine was fitted with new pistons from Brazil. dynamic forces in front of a stall-spin, probably will But allow me to report on another element of avia- give lift to the stalled wing to recover or avoid the tion in Brazil . . . one of greater interest to us. It has spin. This dangerous test, of course, would be better to do with a homebuilder, an EAA member. His letter made by N. A.S. A. follows: The idea of this high lift device came when I was in the final part of building my plane ESQUALO-180, Belo Horizonte, 13 de abril de 1981 very similar to the Italian Falco but mine is all metal Mr. Antoni Bingelis and more slender. 8509 Greenflint Lane I annexed its specifications and some photos for you Austin, TX 78759 to know that here in Brazil also there are friends that (Pardon My Accent) think and work like you in U.S. (in little scale and Dear Bingelis, with more difficulty, of course). I am an EAA membership No. 73160 since 1972 and If you consider that it is a good idea to permit some of course I read your articles every month. Through EAA membership to use the device, I would like to them I learned how much N.A.S.A. studies the stall/ have you help in publishing it in SPORT AVIATION spin that frequently causes mortal accidents. in your articles. Of course stall-spin is a very complex problem, but Sincerely yours, I hope to give some help to this subject and at the same Mauricio Impelizieri P. Moura time to pay back all the help that the EAA gave me P.S. My address is: R. Mangabeira 546 Apt. 301, 30000 through these past nine years by SPORT AVIATION. B. Horizonte - Brazil
SPORT AVIATION 55 Well now, it does look like a good idea so here's a This pivoted leading-edge slat, when swung for- stimulating concept for you experimenters, engineers, ward, increases the wing area in the outer portion of aerodynamicists and theorists. A little something to the wing and at the same time changes the angle of impinge upon those lackadaisical summer thoughts so attack. The resultant benefits claimed are reduced ap- prevalent during the dog days of summer. Let's call proach and landing speeds as well as better control. this report on Mauricio's (I wonder if his friends call The system can be made to be automatically ac- him Maury?) invention, "Method and Mechanism For tuated at pre-selected speeds to obtain a simultaneous Changing the Wing Plan Geometry of Aeroplanes In or optional change in the wing camber, an increased Flight", a design study because, to my knowledge, it wing tip chord and the formation of an adjustable slot has not yet been built or tested on a real airplane. in the leading edge of the wing. The device has to do with leading edge slats. Most of The means and mechanism for doing all this to the us are familiar with leading edge slots and slats. Lead- wing consists of a lengthwise slat nested along the ing edge slats and slots have been around for a long outer third of the wing's leading edge. This slat is pivot- time. Many variations have been built and tested. Per- ally mounted at its inboard end and is contoured to haps the most familiar is the fixed wing slot built into match the shape of the wing leading-edge. the leading edge. These slots were featured on some Actuation of the slat is mechanically through a drive light aircraft like the homebuilt Druine Turbulent and system made up of an electric motor and the components the old U.S. Culver Cadet to name a couple. Then there illustrated in Figures 1 through 5. are the sliding leading edge slats of the type found The key element in the device is the slat guide rail on the French-built Rallyes and on the U.S. built Helio (see Figure 5). This guide rail may have a straight line Couriers. Most of these "pop open" automatically at path or may be provided with a curved path to effect low airspeeds and high angles of attack. the desired change in the airfoil camber for the wing Of course, anyone who has ridden on an airliner in and the degree of tilting to be imparted to the slat. the past decade and has at one time or another sat next These sliding operations are collectively expected to a window is bound to have noticed the large lead- to result in the proper positioning of the slat with ing edge sections which slide forward with grinding respect to the wing and thereby improve aircraft sta- and clunking noises. After that noisy action has ceased, bility at low speeds on take-off and when landing. the airplane's wing will have greatly increased in wing As Mauricio puts it: area and is now reconfigured for landing at a much "All kinds of sweptback wing designs usually have lower speed and with greater controllability than would considerable geometric torsion (twist) from the root be possible with the basic cruise configuration. So you to the tip, to make it possible for the stall to progress see, slats and slots really are not new to aviation. How- from the root to tip. But what is good for landing isn't ever, what is new (and apparently patentable) is Mauri- good to run. I know you have one brilliant staff and cio's design and mechanisms for increasing the wing they, of course, realize this, but I am presenting one area and changing the angle of attack in flight by solution: pivoting a section of the leading edge.
is deployed
Orivl ihoft (Torque lute) Slot pivotolly mounted to «ing
Jot leading edge motclws wing contour
Bearing* SECTION A - A Bioringi SECTION A - A
FIGURE 2. LANDING/APPROACH CONFIGURATION FIGURE I. CRUISE CONFIGURATION (SLAT IS NESTED) (SLAT IS DEPLOYED)
56 SEPTEMBER 1981 Meshing drive gears
Pivot point mechanism
Slat swept forward around pivot point
Forked sliding member attaches to tip end of slat
formed
Universal joint
Jock screw
Shaft Universal joint
FIGURE 3. ACTUATING SYSTEM DRIVES SLAT FORWARD
Preloaded coil spring Aft beam Drive shaft Slat-pivot attachment point Slat
"1 ,Verticol shaft
Spherical bearing
Sbt pivot attach point
Support with slotted guide slotted guide
Coil spring preloaded - pulls Shaft free to rotate 360° pulls shaft backwards to neutral position (slat fully retracted) Spherical bearing
FIGURE 4. SLAT PIVOT POINT MECHANISM
SPORT AVIATION 57 Direction of "The device, when opened, provides as much geo- metric torsion as you need. (When the wing is in cruise configuration it does not need geometric torsion, or at least it is very much reduced.) "Of course, you will get less drag and more speed, putting all sections of the wing near the same better point of polar curve of the wing." As stated earlier, the idea is untested and should Forword sliding oction of skit at be regarded simply as a design study at this point. 0 wing tip (schematic view) - also see Figure 3. Mauricio pointed out that he did not have time and enough money to use his device on the Esqualo-180 because it was already finished. However, as soon as possible after the end of the test flight he intends to M install it in "gloves form" as an add-on modification. r If you are interested in experimenting with the de- vice contact Mauricio directly . . . not me. I've ex- hausted all I know on the subject. r IfiF- Many new ideas, designs and inventions have Cross section detail emerged from the fertile minds of the EAA member- L+M along section M - M ship and these ideas are not unique to the U.S. mem- Slat guide rail bers only. Often one idea leads to another and we all (straight) Direction of benefit from it. In looking back through the prolific movement presentations of material that the EAA makes avail- able to its members through the pages of SPORT AVIATION, it is no wonder at all!
[2.) Sliding movement of slat - both forward and downward with curved slat guide rajl optionally forms angle b with the wing chord
FIGURE 5. SLAT MECHANISM OPTIONS AT WING TIPS
58 SEPTEMBER 1981