UFO 19

Flying Hangar Door

The 1983 “Flying Hangar Door” was home-designed and home-made by a very quiet and talented NASA engineer from Dryden Flight Research Center and weighed as much as a Vespa moped. The all-wing airframe was made of corrugated paper and the wheels were from child’s bicycles (plastic rims). It was powered by a lawnmower engine.

Despite its seemingly bulky shape, the “Flying Hangar Door” was an “excellent flyer”. It is possible that the aircraft never received a proper designation or even a registration.

UFO 22

Aya-7 – unknown manufacturer

Built in Russia, the Aya-7 is a single-seat, high wing monoplane. 30 hp pusher engine. Tricycle landing gear. Length 12’, wing span 17’, wing area 63.6 sq/ft. Empty weight 173 lbs and gross weight 360 lbs. Top speed 69 mph and stall speed 44 mph. Rate of climb 600 fpm. Wing and tail made from wood and fabric. Tail is metal.

UFO 23

Atgimimas – unknown manufacturer

The Lithuania Atgimimas single-seat, high wing monoplane. 22hp pusher engine. Tricycle landing gear. Length 16.6’, wing span 27’, wing area 116.6 sq/ft. Empty weight 215 lbs and gross weight of 415 lbs. Top speed 72 mph and stall speed 28 mph. Fuselage is tubing while wing is wood and composite. Tail is tubing and fabric.

UFO 24

Antoshka – unknown manufacturer

The Russian Antoshka single-seat biplane. 40 hp pusher engine. Tricycle landing gear. Length 16.2’, wing span 31.2’, wing area 111 sq/ft. Empty weight 297 lbs. Gross weight 475 lbs. Top speed 62 mph, stall speed 37 mph. Wing is metal and fabric with tubing and fabric tail. Fuselage metal.

Shenyang FC-31 Gyrfalcon / J-35

Shenyang FC-31

The Shenyang FC-31 Gyrfalcon (also referred to as the J-35 in its naval variant) represents China’s second stealth fighter program and its first carrier-capable fifth-generation aircraft.

The FC-31 features a conventional twin-engine layout with canted vertical stabilisers similar to the F-22.
The aircraft incorporates internal weapons bays to preserve stealth characteristics and uses advanced composite materials to reduce weight and radar signature.

Powered by Russian-designed RD-93 derivatives (the Chinese WS-13 engines), production variants are expected to receive the more powerful WS-19 engines currently under development. These will enable the FC-31 to reach speeds of Mach 1.8 (2,205 km/h) and achieve supercruise capability.

With an estimated unit cost of $70 million, the FC-31/J-35 represents China’s strategic push to modernise its naval air arm. Initial operational capability on China’s newest carriers is expected by 2026, potentially altering the balance of power in the Western Pacific.

Cirrus Vision Jet

Cirrus first began development of the Vision Jet in the early 2000s. The Cirrus founders, the Klapmeier brothers, started the program in their offsite Duluth, Minnesota, facility. It was officially revealed to the public in June 2006 at the Cirrus Owners and Pilots Association meeting.

The first prototype of the Cirrus Vision Jet conducted its maiden flight in July 2008. However, Cirrus ran into difficulties financing the continued testing and development program of the light business jet, especially in 2009 during the height of the Great Recession.

However, after the slow development process in the early 2010s, a new Cirrus investor provided enough financing to complete the development of the aircraft. It was officially certified by the Federal Aviation Administration (FAA) in October 2016. Deliveries of the aircraft began later that same year.

The Vision Jet is a low-wing-configured aircraft with retractable tricycle landing gear. The aircraft’s airframe is also made entirely out of composite materials. It utilizes a single turbofan engine that rests on the top of the fuselage near the rear of the aircraft. Because of the unique engine configuration, the aircraft utilizes a V-tail.

The small cabin can fit up to seven total occupants in three rows. However, the third row is small and typically can only accommodate two adults or three children. Passengers enter the cabin through a clamshell door on the left-hand side of the fuselage.

Additionally, the Vision Jet is powered by the Garmin G3000 avionics suite, including the Garmin Emergency Autoland System. The Vision Jet also features the Cirrus Airframe Parachute System (CAPS).

Vision Jet
Engine: 1 x Williams FJ33 turbofan, 1,850 lb thrust
Wingspan: 38 feet 9 inches
Length: 30 feet 11 inches
Height: 10 feet 11 inches
Gross weight: 6,000 lb
Maximum speed: 311 knots (358 mph)
Range: 600 nm (690 miles)
Service ceiling: 31,000 feet

Akaflieg Braunschweig SB 8 & 8V2

SB-8

The Akaflieg Braunschweig SB-8 is an experimental, single-seat, high performance glider built in Germany in the 1960s, constructed largely from glass fibre skin over built up balsa wood structure. Two were built; the second of which was later fitted with a high aspect ratio (30:1) wing, becoming the Akaflieg Braunschweig SB-9 Stratus.

The Akaflieg Braunschweig or Akademische Fliegergruppe Braunschweig (English: The Brunswick Academic Flying Group) is one of fourteen German undergraduate student flying groups sponsored by their home technical university. Several have designed and built aircraft, often technically advanced and leading the development of gliders in particular. The Brunswick students had been exploring the use of GRP in a series of related gliders, beginning with the SB-6. From the SB-8 to the SB-10, wingspan and aspect ratio were progressively increased. The aspect ratio was increased from 23 to 36.6, resulting in aeroelastic problems.

The SB-8 is similar to the SB-7, which also had an aspect ratio of 23. It performed well but had difficult handling characteristics, attributed to its Eppler aerofoil section. The SB-8 has an 18 m (59 ft 1 in) wingspan, a two-piece wing of Wortmann FX 62 profile with an unswept leading edge, a slightly tapered center section, and more strongly tapered outer sections. It is built around a box beam, with balsa ribs and a torsion shell of glass fibre laid over balsa. The wing is shoulder mounted at 1.5° dihedral, with Schempp-Hirth airbrakes at mid-chord midway along the center section and ailerons on the outer panels. Both SB-8 built have camber flaps on the inboard wing panel and ailerons which are coupled to the flaps (flaperons) on the outboard panels.

The fuselage of the SB-8 is built with a fibreglass skin, over a balsa shell, with balsa vertical frames and two pine plywood main formers in the region between the wings. The nose is pointed and slightly drooped, with a short, single piece, canopy just ahead of the wings, tapering gently aft to a straight tapered balsa/GRP T-tail unit. The tailplane carries a conventional single-piece elevator and the rudder is fabric covered. On the ground the SB-8 is supported by a retractable, unsprang monowheel undercarriage, assisted by a tail bumper.

The first flight was made from Brunswick airport on 25 April 1967; testing confirmed that the glass fibre structure was too flexible and at high speeds the SB-8 exhibited wing flutter, limiting its maximum permitted speed to 170 km/h (105.6 mph; 91.8 kn). The low wing loading also limited its smooth air cross country speed as there was no provision for ballast. Later, removable steel tubes filled with lead pellets were added to the wing roots of the SB-8 V1 to increase wing loading. A second aircraft, SB-8 V2, was therefore built with a stiffened, heavier wing and provision for water ballast, which addressed both aero-elasticity and wing loading problems, allowing the glider to fly safely, without flutter, at 200 km/h (124.3 mph; 108.0 kn).

The SB-8 V2 had shown that glass-fibre wings could be made stiff enough to avoid aeroelastic flutter problems and that the higher aspect ratio produced the expected improvement in glide angle. It was natural for the next Akaflieg Braunschweig design to have a wing of greater span, replacing the wing of the SB-8 V2 airframe with a four-panel wing of similar construction but 22 m (72 ft 2 in) span. At the time of its first flight in January 1969 the SB-9 had probably the greatest span of any glider then flying, though the 22 m (72 ft 2 in)-span Holighaus Nimbus 1 flew only three days later. The increase in aspect ratio over the SB-8 increased the measured best glide ratio from 40:1 to 46:1 and decreased the measured minimum sink rate from 0.61 m/s (120.08 ft/min) to 0.51 m/s (100.39 ft/min). The new wing took advantage of the flexibility of glass fibre to implement elastic flaps. The intention was to avoid the interruption to the wing profile at the hinge, particularly on the critical upper surface, and leakage through it by bending the upper surface instead. This method had been used earlier in the wooden-winged HKS-1 glider of 1953.

Both SB-8s competed at the German National Championships of 1968, Wolfgang Beduhn finishing fifth in the V1 and Helmut Treiber seventh in the V2. The V2 went on to become the SB-9, but the V1 remained in regular use at Brunswick until 1989. It remained airworthy after that, though flown less often, and was still on the German Civil Aircraft register in 2010.

The SB-9 was used by the Akaflieg students in competitions between 1969 and 1971. It also gave them the opportunity to film and study the alarming motions of the wing when fluttering, recording their observations on film in slow motion and in the air. Two antisymmetric, odd, sine-like lateral displacement modes were observed at 90 km/h (55.9 mph; 48.6 kn). The fundamental mode was seen, at a frequency of 3.3 Hz but at 140 km/h (87.0 mph; 75.6 kn) the wing oscillated at 5.8 Hz in a second harmonic mode. During these largely vertical excursions, the wing also twisted and its overall motion excited vibrations in the rear fuselage and tail unit. The flutter problems were addressed by mass-balancing, the ailerons, and by a span reduction to 21 m (68 ft 11 in).

Neil Armstrong was given the opportunity to fly the SB-8 large sailplane, innovative for its use of structural composite materials.

The career of the SB-9 ended in 1972, when it was decided to use its wing on the SB-10 two-seater, a new design with a very different fuselage and the span increased still further with an 8.7 m (28t ft 7 in) centre section.

Variants

SB-8 V1
Original aircraft, empty weight of 260 kg (570 lb) and a maximum take-off weight of 365 kg (805 lb).[3] Flutter restricted maximum permitted speed to 170 km/h (110 mph; 92 kn).
SB-8 V2
Stiffened wing, weights increased by 40 kg (88 lb). Provision for water ballast, maximum permitted speed increased to 200 km/h (120 mph; 110 kn)
SB-9 Stratus
The SB-8V2 was modified with a four-part wing of 22 m (72 ft 2 in) span, fitted with elastic flaps. SB-9 Stratus was first flown in January 1969. It is Empty weight, 325 kg (717 lb), maximum in flight weight, ballasted, 421 kg (928 lb). Flutter problems were tackled with a span reduction to 21 m (68 ft 11 in) and mass-balancing the ailerons.

Crew: 1
Length: 7.505 m (24 ft 7 in)
Wingspan: 18 m (59 ft 1 in)
Wing area: 14.1 sq.m (152 sq ft)
Aspect ratio: 23
Airfoil: root:Wortmann FX 62-K-153, mid:Wortmann FX 62-K-131, tip:Wortmann FX 60-126
Empty weight: 301 kg (664 lb)
Gross weight: 403 kg (888 lb)
Max takeoff weight: 451 kg (994 lb)
Never exceed speed: 200 km/h (120 mph, 110 kn)
Maximum glide ratio: 41.6 at 85 km/h (53 mph; 46 kn)
Rate of sink: 0.61 m/s (120 ft/min) at 88 km/h (55 mph; 48 kn) at 27.7 kg/m2 (5.7 lb/sq ft) and 385 kg (849 lb)
Wing loading: 28.6 kg/m2 (5.9 lb/sq ft)