Thanks to Hurricane91 and Tomas for the data and translations.
Avia Av-57
The fuselage was all-metal construction. Eight main longerons were shape as first picture in the text. Main longerons carried loads from wings and undercariage. The others longerons were shape as second picture in the text. Eleven bulkheads were riveted, the others were made from profiles of shape in third picture.
Tail surfaces were all-metal costruction. The frame was made from opened dural profiles. Stabilizer was adjustable during flight. Control surfaces were equiped by flettners and fitted with ball bearings.
Pilot's cabin was enterable thru the door from passenger's cabin.
The windshild was made of shatter-proof glass. Side windows were opened.
Yippee! Wind sound!
Left pilot's seat was adjustable up-down.
Oops!
Pilot on the right seat operated radio station.
Jack-of-all-trades...does he play harmonica on longow tripow? (sounds...!)
There was an emergency exit on the cabin ceiling.
Reserved!...If Matt's flying - I'm outta here!
Wheel controls were dual. Pedal controls were adjustable.
Now I can pretend I'm actually flying.
Compressed air brakes was controlled by lever on the steering wheel together with pedal controls (see the photo of A-204, which I sent you earlier - it's the same system).
Psussssssh! (New brake wav...just like the Antonov An-2)
Stabilizer was controlled by stabilizer control wheel. Two flettner control wheels were placed on rear wall of the cab.
Throttle levers and setting of fuel mixture were under dashboard.
Flaps lever was under throttle levers.
Lever for retracting undercarriage was on the left side of the pilot. Emergency control of undercarriage extension was between pilot seats.
Had me worried there for a sec.
Main undercarriage had oleo-pneumatic shock absorber. Rectraction was operated by hydraulic hoist.
Undercarriage has been extended by its own weight and pushed by air pistons and cables.
Psssffuuussssh! (More cockpit sounds)
Size of main Wheels were 1500 x 300 mm. Tail weel was size 600 x 200 mm.
Tail wheel was also oleo-pneumatic shock absorber and full castoring.
Soft, gentle skid sounds.
The passenger cab was upholstered by waterproof fabric. The upholstery was added by some polished material in upper and lower parts.
The sounds could be embarressing...Milton?
Windows had a dimension 27 x 41 cm.
Passenger's seats had armrests and seat belts. There were twelve padded chairs and two folding seats in the cabin.
Air vent and heating were providing to each seat.
Gentle interior air flow sound, scarcely perceptable, but there.
Over the passenger's seats there were nets for in-cabin baggage.
Some instruments were mounted in the passenger cabin. (They may have been indicators altimeter, airspeed indicator and real-time clock as in Aero A-204 - see the photo)
Dimension of the cabin was: 1,78 m height, 1,75 m width, 6 m lenght.
Entrance door was situated on the port side behind the wing.
Barely audible from the cockpit.
Toilet with washroom was behind the passenger's cabin.
There were two emergency exits - the first was on the starboard in the rear and the second on the port side forward.
The 'third' (mine) already mentioned above...I think!
Baggage spaces there were placed under the pilot's cabin, behind the toilet and in the wing.
Capacity of rear baggage compartment was 2,3 m3, total capacity of all compartment was 4,14 m3.
Other equipment: navigation lights, two accumulators, radio station, hand-held fire extinguisher, first-ait treatment box, tool kit.
Engine assembly consisted of three Hispano Suiza 9V engines (license of Wright Cyclone 1820-1).
Now yer talkin 'turkey' Milton, Sir!!!
Airscrews Hamilton were in-flight adjustable.
Engine beds were welded of steel tubes and attached via four bolts.
The engines were covered with aerodynamic NACA cowlings and equipped by extinguishing system.
Not enough to drown out the din from those big radials...Heh, heh.
The overall volume of four fuel tanks was 1600 litres.
Each of the three oil tanks was volume 58 litres.
The fuel and oil tanks were welded of aluminium.
Dimensions:
Aircraft lenght...........................15,90 m
Aircraft height.............................4,45 m
Wing span................................22,50 m
Maximum width of the fuselage....1,90 m
Wing surface............................81,50 m2
Engines:
3 engines 575 KS.......................1725 KS (KS = HP)
NOISE x 3...Heaven!
Drive.........................................direct (without reducer)
Weight of engine with accessory..430 kg
Cargo capacity:
Crew (1 person and radio operator)...160 kg
12 passengers................................960 kg
Mail and baggage...........................300 kg
In-cabin baggage............................180 kg
Total............................................1600 kg
Fueling:
Petrol..........................1130 kg
Oil................................135 kg
General characteristics
Crew: 2
Capacity: 14
Length: 15.90 m (52 ft 2 in)
Wingspan: 22.50 m (73 ft 10 in)
Wing area: 81.5 m2 (877 sq ft)
Powerplant: 3 × Hispano-Suiza 9Vd radial piston engine, 429 kW (575 hp) each
R-1820-1
Yeaaaaaah! (lads in the engine 'shop reckon they can squeeze a couple o' hundred horses from each if you want a souped up version...
...alright Sir, you don't want a _ _ _ _ _ _ _ _souped up version, just thought I'd mention it (sorry).
Performance
Maximum speed: 300 km/h (190 mph; 160 kn); 330km/h (205mph at 5000')
Catch - me - if - you can!
Cruising speed: 270 km/h (178 mph; 150 kn)
Range: 1,200 km (746 mi; 648 nmi)
Service ceiling: 4,000 m (13,123 ft)
Special accessories:
Battery, radio................85 kg
Weights:
Weight of aircraft (with instruments, seats, wiring)......5600 kg
Cargo.....................................................................3000 kg
Take-off weight........................................................8600 kg
Minimal performances:
For standard air density CINA 1,225 kg/m3 and full load (CINA was precursor ICAO)
Maximum speed near ground........................330 km/h
Cruise speed near ground.............................280 km/h
Initial climbing.................................................6 m/s
(Dingbat!)
Maximum ceiling........................................5600 m
Operative ceiling.........................................5000 m
Operative ceiling with two engines................2000 m
Flying range...............................................1200 km (745miles)
Climbing from 0 to 500 m...............................1' 8 min
Climbing from 500 to 1000 m..........................2' 2 min
Climbing from 1000 to 2000 m........................5' 2 min
Gliding when two engines are stopped................1:25
Take-off.......................................................200 m
Landing.......................................................200 m
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