The Stal-8 (In Russian: Бартини Сталь-8) (I-240 in the VVS designation ) was a more practical development of the Stal-6 as a fighter.
It was longer than its predecessor, by the use of a an M-100A (licence-built Hispano Suiza 12YBR) 860 hp engine and was characterized by the presence of a protruding cabin in the upper fuselage, to maintain aerodynamic cleanliness. Unlike the Stal-6 the pilot’s seat was fixed in its upper position.
The Stal-8 construction was mainly the aluminum-magnesium alloy Altmag. The joints were made by spot welding. The cooling system and landing system were very similar to those of the Stal-6. Two 7.62mm ShKAS machine-guns were to be fitted in the top decking over the engine, synchronised to fire through the propeller.
Structurally, the Stal-8 featured a monocoque fuselage formed from metal slats with a C-type profile. The wing was built around two spars with stamped steel ribs. Altmag’s wing coating, 0.5mm thick on the top and 0.8mm thick on the bottom.
The forward part of the wing included the evaporative cooling system. The ‘enerzh’ double skinned surface-evaporation radiators formed the leading edge skin, back to the main-spars. The 4-section ailerons were located on the trailing edge, which could be used as flaps during takeoff, landing and turns. Like the Stal-6, it maintained the system for varying the angle of incidence of the elevator rudders as a function of flight speed.
The 175-liter fuel capacity was achieved through two tanks located near the wing root. The oil tank upper part formed part of the surface of the fuselage in front of the cockpit. In this way, at high speeds, the oil was cooled by the air flow itself.
Construction of the Stal-8 was started in the ships of Factory No.240. Work on the prototype was suspended in late 1934, when work was at approximately 60%. The reasons were various, among them because the GVF, in whose institute Bartini’s brigade worked, was not very in favor of generating military devices in its facilities that did not contribute to their needs. On the other hand, the State Directorate for the Aeronautical Industry (GUAP) did not pay much attention to the project either, considering it “foreign” as it was a responsibility of the GVF. The new Polikarpov fighters I-15 and I-16s were being produced and although the Stal-8 was superior in many respects, there were great doubts about the vulnerability of the cooling system.
Stal-8 Engine: Mikulin M-100, 860 hp (licensed Hispano-Suiza Ybrs) Wingspan: 9.60 m Wing area: 15.30 m² Length: 8.22 m Height: 2.23 m Empty weight: 1100 kg Maximum takeoff weight: 1740 kg Fuel capacity: 250 kg Wing loading: 100 kg / m² Power load: 1.75 kg / hp Maximum speed at sea level: 550 km / h Maximum speed at 3000 m: 630 km / h ROC: 20 m / sec Practical range: 180 km Practical ceiling: 9500 m Endurance: 2.4 hours Range: 800 km Take-off run: 190 m Accommodation: 1
The work started by AI Putilov in the OOS of the NII GVF on the use of steel in aeronautical construction was followed by other groups of engineers. On April 30, 1930, Bartini proposed to the management of the Central Construction Bureau (TsKB) the creation of a fast airplane with a totally clean aerodynamically airframe. The project was analysed and approved, but its realization was very far away.
First of all, Roberto Bartini , despite being a communist, was Italian and therefore could not be allowed to have access to the secrets of the Soviet aeronautical industry. Second, most airplane builders at that time did not believe in the “wonderful foreign engineer” and therefore did not wish to share their experience with him.
Fortunately, help came from the VVS chief Pyotr Ivanovich Baranov and the RKKA chief of armaments Mikhail Nicolaevich Tukhachevsky. They succeeded in starting in 1932 the fast plane project works at the CNII (Factory No. 240).
The Stal-6 was originally conceived by Bartini as a fighter under the name EI ( Э кспериментальный И стребитель – Experimental Fighter). As it was developed within the structure of a civilian research institute, no weapons were installed.
Structurally, it was conceived as a low-wing single-seater monoplane, with a wing area of 14.3 sq.m. The tail unit was of the monoplane type. One of the most unusual features of the new aircraft was the presence of a single 800 x 200 mm wheel on the front centre portion of the fuselage with two stabilization skis on the underside of the wings. Both the wheel and the skis were fully retractable. The retraction system was manual using a rope system.
The structure was made of chromium – moly steel tubes (hence the name Stal – Steel) and the skin was an aluminum-magnesium alloy (AltMag, Electron) on the entire front and Bakelite on the tail. The wings featured a steel tube structure with a stainless-steel coating. The wing ribs were made of U-type steel profiles. The fuselage was noted for its aerodynamic cleanliness with the cockpit deck flush with the top of the fuselage. The weight of the aircraft with the 660 hp engine was only 850 kg.
Stal-6 structural drawing
The aircraft used an evaporative water-cooling system inside the wings. The engine’s cooling water was heated to steam. The steam was circulated through the double wing cladding made of ‘enerzh-6’ (stainless) steel. There it condensed to become a liquid state again and cooled to return to the engine. This configuration avoided the use of external radiators, improving the aerodynamics.
The control of the elevators could be adjusted so that the pilot could vary the pressure to exert on the control stick depending on the flight regime and speed.
To minimize air resistance, the cockpit was inserted into the fuselage, without protruding. Visibility of the runway during takeoff and landing operations was ensured by moving the pilot’s seat upward, with the pilot’s head protruding above the level of the fuselage. During the flight the seat was returned to its normal position.
In 1933, under the direction of Bartini, the construction of the single-seat Stal-6 (Russian Сталь-6) began.
The first flights began on October 7, 1933. In one of the first flights 400 km / h were reached. Pilots A.B.Yumashiev and P.M.Stefanovsky demonstrated that take-off and landing operations with a single centre wheel were as safe and easy as with conventional gear.
The speed reached at sea level was 420 km / h, almost 100 km / h higher than that of contemporary fighters and was a new world speed mark for aircraft in its class. It is noteworthy that the main RKKA fighter at the time was the Polikarpov I-5 that reached only 280 km / h and the new fighter also devised by Nikolai Polikarpov that was preparing to be tested at that time, the I-16 with an M-22 engine, only reached 359 km / h.
The reaction that the Stal-6 provoked was not what was expected. VVS authorities immediately ordered its builders to work on increasing the speed of their fighters. The builders began to protest, claiming that increases in speed were impossible to achieve in such a short time. The GVF (Civil Aviation Fleet) was ordered to build a fighter based on the Stal-6. This fighter was named Stal-8.
Important discussions centred on the vulnerability of the use of the vaporization cooling system. All water-cooled systems are generally more vulnerable than air-cooled systems, unless they are specially armored as in the Ilyushin Il-2. However, the increased area of the cooling surface in the vaporization system, which increases the risk of impact, is offset by the less impact of a hole in the entire system.
During the Stal-6 flight tests, the pilot ABYumashiev carried out several flights with the cooling system switched off to mimic damage to the cooling system. Each flight lasted more than 30 minutes. Taking into account that the autonomy of the majority of Soviet fighters of the time did not exceed one hour, it follows that the damaged fighter could not only return to its base satisfactorily, but could also finish its combat without problems. The Stal-6 used a single cooling unit and this could have been a development point as well, as segmented systems tend to be less vulnerable.
Engine: 1 × V-1570 Curtiss Conqueror, 469.8 kW (630 hp) Wingspan: 9.0 m (29 ft in) Wing area: 14.3 sq.m (154 sq.ft) Length: 6.88 m (22 ft 6-3/4 in) Height: 7.316 ft / 2.23 m Empty weight: 850 kg (1,874 lb) Gross weight: 1,080 kg (2,381 lb) Fuel capacity: 135 kg Maximum speed at height: 420 km/h (261 mph) Maximum speed at sea level: 350 km / h Landing speed: 110 km / h Ceiling: 8000 m Rate of climb: 21 m/s (4,135 ft/min) Climb to 1000m: 0.8min Climb to 2000m: 2.0min Climb to 3000m: 3.0min Endurance: 1.5 hours Practical range: 180 km Take-off run: 150 m in 10 seconds Landing roll: 280 m in 20 seconds Crew: 1
The Bartel BM-1 Maryla was a fighter aircraft design for the Polish military that did not advance beyond the design stage. It was designed in response to a Polish War Ministry competition in 1925 and was placed third, netting Bartel a zł 1,000 prize. Maryla was the name of Bartel’s wife. The design was a single-seat parasol-wing monoplane. A distinctive feature were Y-shaped struts joining wing with an undercarriage. It was not built.
Engine: 1 × Lorraine 12E Courlis or Hispano-Suiza 12 cylinder liquid-cooled 340 kW (450 hp) Wingspan: 11 m (36 ft 1 in) Wing area: 22 m2 (240 sq ft) Airfoil: Bartel 37/IIa Length: 7 m (23 ft 0 in) Height: 3 m (9 ft 10 in) Empty weight: 1,020 kg (2,249 lb) Gross weight: 1,500 kg (3,307 lb) Maximum speed: 285 km/h (177 mph; 154 kn) Crew: 1 Armament: 2 × fixed, forward-firing 7.7 mm (0.303 in) Vickers machine guns in the fuselage 2 × fixed, forward-firing 7.5 mm (0.295 in) Darne machine guns in wings
The prototype Bearhawk LSA N289EH had a Continental A65/75 engine, with an empty weight of 728 lb, with an aluminum prop and no electrics. Barrows estimates that 750 pounds is a realistic empty weight for a builder who works hard to keep the airplane light. With the LSA maximum gross weight of 1320 lbs. (in the utility category), this 2-place LSA has a very respectable useful load. Barrows has said that the airplane is really designed for a max gross weight of 1500 lbs (in utility category), so there is a built-in margin of safety for those who do not have to fly under the LSA rules. The Bearhawk LSA utilizes 4130 Chromalloy tube and fabric along with all-aluminum, flush riveted wings.
The Bearhawk LSA can take off in as little as 200 feet and climb at 1500 ft. per minute and then level off and cruise at 120 mph sipping only 5 gph. Barrows reports an economy cruise speed of about 110 mph sipping only 4 GPH with the Continental C-85 engine. With a 30 gallon tank that gives you over 7 hours in the air. Not many vehicles can do 110 mph only consuming 25 miles per gallon. If you want to get there a bit faster, you can push it up in cruise to 120 mph burning about 5 GPH.
The cabin width is a spacious 31” wide and 97” long. The Bearhawk LSA can be flown with the windows open for taking those perfect aerial photos.
Prices and contents of the Bearhawk LSA kits and components (2014): Standard QB Kit – $30,000 (requires some welding) Includes: Quick-build Wing Kit Standard Fuselage
Deluxe QB Kit – $36,000 (no welding required) Includes: Quick-build Wing Kit and Deluxe Fuselage Kit
Quick-build Wing Kit $15,500 These Wings are sold in an advanced level of completion. The top skin is fully riveted. Fuel tanks are included as are the ailerons.
Standard Fuselage Kit – $15,500 – Some welding is required but the fuselage frame comes fully welded with all of the major attachment fittings welded – unpainted (includes landing gear and motor mounts) Also includes Horizontal Stabilizer, Rudder and elevators as well as control sticks and rudder pedals. Deluxe Fuselage Kit – $21,500 – The same as Standard Fuselage but has all the tbs and the frame is primed and painted. Includes all pre-cut sheet metal, doors, and frames, fiberglass nose bowl, tail spring, seat frames, instrument panel blank, etc.
The prices and contents of the kits and components (2014): QUICK BUILD KIT $40,500 The Quick-Build Kit is on the FAA 51% approved kit list. Because the airframe is largely fabric covered and because of the way the FAA constructs its definition of the 51% rule, there is no actual structural fabrication to be done other than completing the riveting of the top skin. This is left partially open so the builder can access and install certain components. Although all of the wing control surfaces are almost ready to be installed, the builder must install the hinges first and then install them, which is part of the 51% program. The same thing is true of the tail, landing gear, control system, etc: the components are finished but must be installed. Assembly and installation not fabrication. The Quick-Build does not include windshield, tires and brakes, covering/painting materials, seats, upholstery kits, cables, pulleys and hardware.
Bearhawk LSA
For 2013 – included with the Quick Build Kit Complete set of plans, with serial number (Note: If you have purchased plans separately, the kit price will be reduced by $295.) Fuselage completely finish welded, no welding required. Ready for stringers, cover and systems installation. Landing gear and tail, completely finished, ready for cover and installation. Control system completely fabricated, ready to install. Wings finished, interior primed, with only the top skin which is already drilled and dimpled and ready to be riveted. Control surfaces assembled, ready to be installed/covered. Wing Struts with end fittings ready for drilling/installation. Fuel tanks ready to be installed (aux tanks optional). Motor mount ready to be installed. Choices are Lycoming 0-320/360, 0-540 and Continental 0-470. Firewall and boot cowl, ready for trimmimg and assembly (not drilled). Utility door and float attachment points standard. The frames for all seats are included. Builder will fabricate seat pans and upholstery. Wing tips fuel caps trim wheel w/chain aileron cable guards Flap/Aileron rod end bearings (10) gascolator clear windshield (tinted or UV block extra) Gerdes brake master cylinders (one set) Wing tie down rings Aileron bellcrank bearings (4)
Builders of the Bearhawk LSA can purchase the plans and can purchase some sub-kits or components.
Bearhawk LSA Engine: Continental, 65-100 hp Wingspan: 34 ft Length: 22 ft 3 in Wing area: 170 sq.ft Gross weight: 1200-1500 lb Height 3 point: 75 in Empty weight: 750+ lb Fuel capacity: 30 USG Vne: 140 mph Landing speed: 30 mph Cruise speed: 100-125 mph Takeoff roll: 200-400 ft Fuel burn: 4-6 USG/hr Range w/res: 650 miles Cabin width: 31 in Seats: 2 tandem Cabin length: 97 in
Designed and built by F.S.Barnwell at Whitchurch in 1938, the Barnwell BSW Mk.1 was a single-seat, low wing monoplane of all wood construction, powered by a Scott Squirrel engine. The designation BSW standing for Barnwll (the constructor), Squirrel (the engine) and Whitchurch (the place).
Originally, Barnwell had meant to build the machine himself, but the vast activity of the Bristol Aeroplane Co. in connection with the R.A.F. expansion naturally meant an ever-increasing load of work on Barnwell’s shoulders, and he therefore decided to entrust the construction of the machine to a firm in Bristol.
First registered [C of R 8560] on 20.6.38 as G-AFID c/n 1 to Frank Sowter Barnwell, Alveston, near Bristol (aircraft based at Bristol (Whitchurch) Aerodrome, Bristol, Gloucestershire) it first flew on 17 July 1938.
It was written off on 2 August 1938. Shortly after taking off from Whitchurch, the engine, a Scott Squirrel, failed. Barnwell attempted to turn and return to the aerodrome. The machine stalled, crashed and killed Barnwell.
