PARACHUTE IN THE SKY

The first thing we found out for yourself, the Tang is that the use of standard parachutes as wings for paralta ineffective. The Tang that had to be developed the soft wing of his own design.

 

Preliminary calculations and numerous experiments have shown that we need an aircraft which can hover in one place and take off almost vertically. Optimum unit load on the wing of the glider should be around 4.6 kg per 1 sq m, power capacity is 80 L. E., and static thrust of the propeller is around 240 kgs. Our “Karlsson” became a kind of attempt to approach these ideal parameters.

 

Wing-parachute (paracrine) of our aircraft is an elongated Pentagon with an area of 31 sq m; it consists of nine tubes with a width of 870 mm, each of which is in turn separated by a rib into two sections. The air intake pipes have a height of 190 mm. This design provides a relatively small drag paracril and relatively high aerodynamic quality.

The top panel is cut from mantle material type “anorak” (Czech Republic), although it could be used and domestic plamennoi type “Bologna” (art. 52087 or 52188), from which most often are sewn serial gliders. Bottom panel — painted calendered fabrics (art. 56005 56005 Krpk or PKK). From the same material cut the front gusset plate, the side ribs and the stabilizing of the cloth. The main ribs are cut from a nylon cloth (Ref. 56011 AP). The top panel, ribs, stabilizers, and scarves are reinforced by strips (art. LTK-15-185), creating a sort of power structure. Less loaded zones are enhanced with ribbons of art. LTK-13-70.

 

It should be noted that the wing of the motor glider is not experiencing in-flight loads, kotorye usually occur when opening the parachutes. This means that made in the image and likeness of the standard parachute, it is obviously strong.

 

Profile paracril quite thick — the maximum height is 500 mm In front of the ribs forming the air intakes, sewn ten laderman width of 8 mm, into which is inserted a bamboo battens (slats of the Korean curtains), to prevent the “caking” of the air intakes, which contributes to the rapid filling of the wing and increase its rigidity.

 

Slings (60 PCs.) made from it is made, and two toggles.

 

Suspension system is assembled from strips of LTK-44-1600 with locks AXIS (it is possible to use lighter locks OSK-D or three rings). The free ends of harness — ribbon LTK-44-1600, with four semicircles at the top and two buckles at the bottom. On the rear free end has a ring for lanyard control, used for towing flights. For powered flight the toggles are attached to the camera via extension files. The top free ends are connected peremychnoy.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The end portions are fixed paracril two files of cord SK-200 for the top “mustache”. The latter, incidentally, perform on our parapet more than ten functions, and their presence on this kind of aircraft is quite reasonable. These elements are made of duralumin tubes — we, in particular, used the sports spears, joining several workpieces by means of plugs-adapters constructively to the required length — 5100 mm To trike parapet they are attached at four points with the help of textolite and steel adapters. Installation and dismantling of the “whiskers” takes only a few minutes.

 

Worth, NAC seems to mention that large-scale RC flying model of the parapet, equipped with “moustache”, perfectly flying, performing stunts, including the loop, and it was all captured on film.

 

We found in particular that “mustache” guarantee the preservation of the work form paracril if open intakes. In addition, “whiskers” prevent the ingress paracril in the zone of rotation of the propeller, as between cords strung in a grid. “Whiskers” prevent lanyard twisting, prevent folding of the wing in its transverse cross section, enhance safety while nosing apparatus during takeoff or mileage due to the fact that it will automatically sets the optimal angle of attack paracril. And finally, the “whiskers” give the opportunity to start without assistants, just need to add “gas” and the dome paracril over my head.

 

Trike parapet is a spatial truss structure assembled mostly from duralumin (D16T) pipes with a diameter of 40 mm, connected with dural well plates 2 mm thick textolite adapters. Power frame rectangular for its production we used the wing spar decommissioned aircraft An-2.

 

The chassis of the four-wheeled trike, with two front steering wheels. This scheme has a high resistance compared to three-wheeled and vividly this advantage is revealed in the landings in a crosswind — PGS. Trehalase however, as a rule, Capoterra, turning the front and one of the side wheels.

 

Each of the front wheels and has independent suspension on the basis of the motorcycle shock absorber is a telescopic pen from the front fork of the motorcycle IZH-15K (you can also use the same nodes from the motorcycle IZH-Planeta-Sport). The feathers are installed (separately each) to your upper^ and lower the bridge, fastened in the front of the trike on the spar by means of steel angles. When mounting feathers should take into account the progress of the shock absorber is at full compression should be a safe distance from the ends of the propellers to the ground (not less than 200 mm).

 

The steering knuckles of the front wheels connected by a transverse rod (tube D16T with a diameter of 28 mm), forming a steering trapeze. The control of the front wheels is made with pedal connected cable wired with swivel front wheels. The rear wheels chassis—easily removable, creates the certain convenience at the transport of the parapet.

 

Wheel chassis designed on the basis of hubs from a moped “Riga”, turned to

 

relief. Bus — type 300×125, with lightweight tires and tubes from tire children’s bike. Fixing the tire on the hub — dural disks. The bearings are the same as in the base hubs — No. 201. Chassis showed itself to be surprisingly strong over the parapet even the hard landing could not take him down. The wheel hubs are fixed secrets and mandatory spletayutsya.

 

The power plant of the parapet twin — engined: its basis is formed by two type of engine IZH-15K (you can also use the motors from the motorcycle IZH-Planeta-Sport that practically the same thing). The engine is extremely lightweight — they cropped the gearbox, leaving only the mounts. The cylinders, together with the heads located on Motte-Lejeune Bonhomme n incoming will sink, therefore to improve the cooling needed to cut the jumper on the center of the cylinder, between the ribs, and Tangier. drill holes in all the ribs of the cylinder heads. Modified engine (excluding ignition system, carb, mufflers and driven sprocket) has a mass of 18.5 kg, packaged — kg. 22 the Carburetors on our power plant — Japanese, such as “Mikuni”, although it would be more affordable from 43-350. The silencer is home-made, welded of sheet steel — one-to-two engine. Ignition contactless, elektronnoe, like KAT-1A —Kahn on a motorcycle “Rising”. Generator — G-427 (7 In, 60 W) ignition coil — B-50M. Candles — And-23, their tips additionally fixed with springs.

 

The force engines were not exposed. On the carburetors mounted light Vozduhoflotsky — basically to create resistance in the inlet which improves the engine acceleration. The fuel in the carburetor flows by gravity (in principle, it would be possible to use the pump outboard motor).

Throttle control of the carburetor — foot: the sector of “gas” is set to one of the pedals (on our parapet on the right). The “stop” button remote stop the engines are located on the right and left brake control parakram. Near each of the cylinders are mounted ejectors of a thin sheet of aluminum, which improves the cooling of the engine.

 

Each of the engines is fixed at five points using a hard rubber cushion. The scheme of the power plant is somewhat similar to what is used on trikes “Search-5” (see No. 3, 1988), only on our parapet used chain transmission. The gear shaft shall

 

to have angular contact ball bearing, since the thrust creates a significant axial load. Sprocket chain gear has 19 teeth; by welding mounted on a leading helical worn-gear engine-IZH-Planeta-Sport. On the slave — 42 teeth, borrowed it from the rear wheels of the same motorcycle.

 

Engine start is performed using the developed by us the inertia starter, which is based on the micro KMD-2,5. The mass of the device is only half a kilogram (it is basically mass flywheel). The relay requires a fuel mixture,

 

consisting of 31% ether, 45% kerosene, 8% castor oil and 16% oil MS-20. KMD-2,5 and easily starts (it is necessary only to sharply turn the flywheel by hand), and develops a 10 to 12 thousand rpm. Launch engines paralite is carried out alternately by means of friction nozzle on the flywheel: it ensures contact of the rotating flywheel to the secondary shaft chain gear.

 

The power plant has two screws: the first — with a diameter of 1500 mm, with a pitch of 700 mm; and the second is of the same diameter, but with a step of 600mm. the Reduce step of the second screw relative to the first is caused by the effect of tightening the first screw thread. They are both made from a dry pine billet, glued together with epoxy glue up of four boards. After the final surface treatment papered fiberglass epoxy resin. To the Central hub (flange), each of the screws are fixed by bolts with nuts and washers, with mandatory locking nuts according to the methods described in No. 12 of 1988.

 

The fuel tank is transparent(from two-gallon plastic Jerry cans), it is located in front of the pilot, on rubber shock absorbers; fuel flows to the carburetor by gravity. If you intend to use a fuel pump,it makes sense to install the tank in the back.

 

The instrument panel is spring loaded — it protects it from vibration. On the dashboard mounted indicator climb rate, altimeter and temperature gauge the cylinder head (two TTT-47). Receiver air pressure (LDPE) made “whiskers”.

 

The pilot’s seat cut and sewn from avisenta with a foam gasket. Mounted it on the trike ribbons type Ltcr P-813-800 and are equipped with safety belts. Depending on the growth of the pilot the position of the seat can be adjusted in height. In the cold season before the pilot set the visor from

organic glass.

 

When debugging a machine, special attention should be given to its alignment. Indicative of the point of toe-hooks the trike to krylo shown in the diagram. But more accurately the position of points is determined after the experimental approach to a height 2…3 meters: the unit in this case is guided tan to avoid jerking paracril “mustache” — otherwise the wing can izmeniti the installation angle to negative. Characteristically, the alignment Paralela significantly affects the propeller thrust, since the trike is suspended from paracril at two points, and when Tightening the brake alignment is moved relative to the focus wing. However, a well-regulated system “paracril-trike” is quite stable and if any adverse effects quickly returns to a state of stable equilibrium.

 

Adjustment of the lengths of the sling is possible within certain limits to alter the wing profile. In this case the wider spaced free ends, the higher lateral stability Paralela. And adjustment of the lateral stabilizers, it is possible to make paracril resistant to stalling, and also to change the turning speed. Note that when adjusting, it is recommended to increase the length of certain rafter not more than 50 mm, checking the impact of changes in approach at a height of 1.5…2 m. Slings two front rows paracril should be strictly the same: the maximum deviation of their length — not more than 10 mm.

 

Adjustment of the lengths of the first row of the Central sling starts with a size of 2800 mm. With decreasing the length increases the vertical component of velocity planning, and already at a length of 2500 mm side intakes have not been filled. The side straps must be 200 mm longer main — depends on the stability of the parachute system. The sling length should be measured from the buckle half-rings to the bottom of the cloth paracril, including the length of the stabilizing sheets and kerchiefs. Correctly adjusted when planning wing has a negative angle of attack and tilted the intakes down. The difference of the lengths of the sling first and the last (sixth) row is 1 250 mm.

 

In the motor mode of flight (with traction) angle of attack paracril is 7…10 degrees. During takeoff and landing, this angle some more.

 

Adjustment of the lengths of the sling is serial outbreak of the attachment straps on the buckles of the half-rings the free ends of the harness. After verifying the length of nodes on the sling again tie a simple five-eighth-mishegoyim “Stina”, Nan is shown on one of the drawings. Further, when the length of the slings is determined, the end of it is sewn with nylon thread No. 9-13, which fully guarantees against the outbreak of such a node.

 

In the production of approach it must be borne in mind that the pitch control (up or down) by means of adjustment of the engine speed, and a turn — pulling the appropriate brake control.