SCHOOL OF AIRCRAFT (PART 4)AIRPLANE FOR TWO. Use of a low powered engine in a two-seater suggests several options of its aerodynamic layout. If not enough power, you can increase the load-bearing properties of the wing, increasing its area (and in the first place – scope). As an example, this approach can cause a plane to the ATL (the company “Robin”) and a series of French double units of the company, “Fournier”. These machines are made entirely of plastic and is fitted with lightweight motors air cooling capacity from 60 to 70 HP wing Area from 10 m2 and a span of about 10 m.

Of course, such aircraft lower flight performance (except range which is substantially higher due to low power and therefore more economical engine). Accordingly, in operation, such devices are cheaper.
However, aircraft enthusiasts should remember that these machines have serious limitations for crosswinds on takeoff and landing – no more than 3-4 m/s. This somewhat complicates the use of such aircraft-especially when the need for regular flights (e.g. for training purposes).
Another option is a low-power double unit assumes a dense layout of the cockpit, which allows to reduce the size of the twin plane to the single parameters, as well as significantly to reduce its weight.
A very successful version of the light twin aircraft with a “tight” layout of the cab – high MFI-9 “Junior” Swedish Amateur aircraft B. Anderson, who worked at the time in the United States. The aircraft had a double cabin with the pilots on-road – side-by-side. A high-wing had a small reverse sweep to maintain the desired alignment. The wing was mounted behind the cab, so is not blocked browse both up and down.
French double planes with the wing of the big lengthening
French double planes with a wing of large aspect ratio:
And — ATL (“Robin”): the location of the pilots — side by side; the engine power to 60 HP.; empty weight – 250 kg; takeoff weight of -470 kg; maximum speed – 180 km/h; ceiling 4,100 m; range – 800 km
B — RF-5 (“Fournier”): the location of the pilots — one after the other; the engine “limbs” with a capacity of 63 HP; wing area — 15,16 m2; wing profile – NACA-23015 at the root and NACA 23012 at the end of the wing; empty weight -418 kg; maximum takeoff weight — 660 kg; take-off weight when performing aerobatics — 605 kg; maximum speed level flight of — 200 km/h; maximum flying speed is 270 km/h; rate of climb at ground – 3 m/s; ceiling – 6,000 m; the run – 216 m; take off distance is 522 m; landing distance—250 ft; run 120 ft; range – 760 km

Double plane
Double plane Chibis:
engine power 45 HP; frequency of rotation of the crankshaft of the engine -4600 rpm; the rotational speed of the propeller is 2000 rpm; the propeller diameter — 1700 mm; screw pitch — 1400 mm, static thrust – 105 kg; wing area – 13.4 m2; empty weight — 220 kg; takeoff weight – 400 kg; maximum speed – 120 km/h stall speed 70 km/h; rate of climb at ground level – 1.5 m/s

Light twin training aircraft-vysokopilya
Light twin training aircraft-vysokopilya “automobile” pilots:
And – МFI-9 “Junior” (Sweden): engine power – 100 HP; wing area is 8.7 m2; empty weight – 340 kg; takeoff weight 575 kg; maximum speed – 240 km/h; rate of climb: 4.8 m/s; ceiling – 4500 m; flying range – 800 km
B – training aircraft АRV Super-2 (England) engine 3 – cylinder, two-stroke capacity of 77 HP; wing area—of 8.55 m2; empty weight -288 kg; takeoff weight 474 kg; maximum speed – 160 km/h

In the US, however, the plane did not appreciate. Anderson returned to Sweden and organized the firm, which started production of the MFI-9 “Junior”. Soon cars began to be exported, and in Germany it was organized the production of the device under license. Light aircraft operated in educational, sporting and even military options.
In 1985 in the UK for this scheme, specially for the pilots of Amateur built aircraft АRV “Super-2” with the “tight” layout of the cockpit. This car even with two pilots on the takeoff weight was inferior to single aircraft only 100 – 110 kg, and therefore had excellent flight characteristics. And with a more powerful motor it easy to perform complex aerobatics.
There is another direction of creating low-powered twin aircraft, which can be called “minimal concept of the plane” – which has no elements that are functionally secondary to the flight cockpit, fuselage, cowlings, fairings, etc.
A somewhat different concept – the plane Chibis, built Kalotay and V. A. Sukhov from Yekaterinburg. Its powerplant is a four-stroke motorcycle engine, boosted to 45 HP power, which is inadequate for normal twin plane. So the designers have equipped the “Chibis” wing is larger and has a very small specific load. Aircraft design -solid wood hollow and therefore very light.
Double the twin-engine plane
Double the twin-engine plane
Double twin-engine aircraft “swallowtail”:
the total capacity of the power plant – 44 HP; wing area -11m2; empty weight – 195 kg; takeoff weight of 346 kg; maximum velocity of -90 km/h; stall speed: 50 km/h

In the “Chibis” even with the same motor still flies with two pilots, while providing a minimum acceptable rate of climb of 1.5 m/s. of Course, in a strong wind, snow or rain up in the air on such devices is not recommended.
Still it was about single-double vehicles. When a sufficiently powerful and reliable engine, this concept is probably the most rational. However, if a powerful motor you have, you can benefit from the experience of the Amateur designer N. Prokopto from the city of Zhukovsky, has created a double plane “yegorych” with two 33-horsepower engine RMZ-640, equipped with silencers. A good layout made it possible to fully realize the effect of blowing the wing propellers and minimize the deploying time when failure of one motor.
Double the twin-engine plane
Double the twin-engine plane
Double twin-engine aircraft “yegorych”:
engines – RMZ-640 with capacity for 33 HP; wing area – 11.4 m2; wing profile – R-IIIA”; the empty weight is 311 kg; takeoff weight with two pilots 450 kg; maximum speed – 130 km/h; stall speed 55 – 60 km/h (depending on load); a rate of climb of 2.5 -4 m/s; run — 50 – 60 m. mileage – 70 – 100 m

The pilots are comfortable enough in the cockpit are for-car – side-by-side. Large glass area provides excellent visibility. At takeoff weight with two pilots 450 kg airplane is easily torn during the run, and the failure of one engine, steadily continues. Flaps during takeoff is rejected at 20 and landing -25 degrees.
One of the most simple twin-engine aircraft – twin “swallowtail”, built in the city of Saransk club S. Chunayev. The aircraft is equipped with a pair of upgraded outboard motors. Instead of the traditional fuselage the aircraft has a farm of duralumin tubes, and wooden wings and tail covered with transparent Mylar film.
“Swallowtail” belongs to the class of “heavenly snail”, which is not like all Amateur aircraft designers, especially those who have not built one plane.
Double the twin-engine plane
Double the twin-engine plane “Impulse”-2:
engines – RMZ-640 with a capacity of 35 HP with V-belt reduction gears with a ratio of 0.5; chassis-retractable; wing area-of 7.48 m2; take-off weight of 600 kg; the maximum horizontal flight speed of 180 km/h; stall speed – 105 km/h 1 – wooden wing spar; 2 – wing (fiberglass); 3 – Aileron; 4 – flap; 5 – door cab (left and right); a 6 – connector of the fuselage; 7 – fuselage (fiberglass); 8 – land at Park compression chassis

The layout of the aircraft, “Pulse”-2:
1 – front landing gear; 2 – air receiver pressure; 3 – electromechanism MP-100 for cleaning of the nose landing gear; 4 – instrument panel; 5 – door ; 6 – a connector of the fuselage; 7 — fuselage (fiberglass); 8 – rear part of the fuselage, made integral with the keel (fiberglass); 9 — pull Elevator control; 10 radio; 11 — main landing gear; 12 — niobate position landing gear; 13 – land at Park compression of the shock absorbers of the chassis; 14 — fold the front landing gear

Different layouts of cabins double light training aircraft and gliders
Different layouts of cabins double light training aircraft and gliders:
A – plane “Microjet-200” (France) – cabin with a stepped arrangement of the members of the crew
B – plane “Fantrainer” (Germany) – classic layout “tandem”;
In – plane SAAB Safari (Sweden”) – cabin location crew members side-by-side
G – glider KAI-12 Primorets (CIS) – playback Czechoslovak glider LF-109 pioneer – tight tandem arrangement

The layout of the cockpit of the Yak-52
The layout of the cockpit of the Yak-52
The recommended size of the cabin two-seater aircraft with car-located members of the crew
Recommended cabin size two-seater aircraft with car-stay crew members
The layout of the cockpit of the Yak-20
The layout of the cockpit of the Yak-20
The layout of the cockpit of the Yak-20:
1 – handle trimmer; 2 – line of sight; 3 — Gaza strip; 4 – crane control flaps; 5 – fire hydrant; 6 – switch magneto; 7 – button start; 8 – filler-syringe; 9 – altimeter; 10 watches; 11 – speed indicator; 12 – compass; 13 – the turn-and-slide; 14 – variometer; 15 – attitude indicator; 16 – motor tehstroy indicator; 17 – temperature gauge cylinder head; 18 is a tachometer; 19 — a niche for cards; 20 – ignition switch

Very beautiful fast car modern shape, designed for initial training, managed to construct a V. Golovu from the city of Samara. The aircraft with increased specific load on the wing, called And-2 “Pulse”, has a minimal double plane sizes, retractable tricycle landing gear and an extremely smooth covering. The design of the aircraft is made mostly of plastic with small “patches” of parts of the wood.
“Impulse” is equipped with a pair of engine RMZ-640 and V-belt drives. Experts have expressed doubts about the ability of the aircraft to deploy to fend off the moment when failure of one motor, but the test machine showed that “tame” the plane in such a situation is still possible. Were test pilots claim to “Momentum” in terms of its stability and controllability and cockpit layout.
Amateur aircraft designers need to keep in mind that the success of the two-seater aircraft depends on how well arranged its cabin.
On the plane with a dense arrangement of the instructor and the student each other, only one set at hog – at the front pilot. The “classic” layout double cabin (Yak-52) Amateur aircraft is rarely used, however it should be noted that in this case, the novice pilot subsequently rapidly adapts to single machines, including aerobatic.
Note that when “automobile” pilots for training novice consumes approximately 30 percent less flight time, and the piloting skills of the students to be more sustainable. Moreover, with this arrangement, the instrument panel is also enough to have one set of instrumentation – usually it is located on the left front of the cadet.

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