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Ultraflight Manufacturing Lazair

uf-lazair


The Lazair is a single-seat twin-engined high-wing monoplane with conventional three-axis control (unconventional three-axis optional). Wing has unswept leading edge, swept forward trailing edge and tapering chord; inverted V-tail. Pitch/yaw control by elevon; roll control by 40% span ailerons; control inputs through stick for pitch/yaw and pedals for yaw (stick for pitch/yaw/roll optional). Wing braced from below by struts; wing profile double-surface. Undercarriage has four wheels in double taildragger formation; no suspension on any wheels. Push-right go-right ground steering by differential braking (also differential engine output). Brakes on main wheels. Aluminium-tube framework, without pod. Engines mounted at wing height driving tractor propellers. Aluminium-alloy grades: tubing 6061T6, sheet 2024T3, plate 7075T6. Ribs made from high-density plastic foam. Wing covering 2 mm Tedlar.

By ultralight standards the Lazair could now be considered an old design, having been created by Dale Kramer in 1978, but continuous evolution since then has ensured that it is still a popular and highly competitive aircraft, especially with pilots who appreciate soaring ability rather than sheer power.

The concept, however, has never changed: an inverted V-tail machine with high wing with foam ribs and aluminium-alloy leading edge, plus of course the distinctive transparent covering which makes the Lazair look like no other aircraft. Though it still looks the same, that covering has been the subject one change, with Mylar being replaced by Tedlar in the interests of ultra-violet light resistance.

The more obvious alterations concern the control arrangements, the engines and the undercarriage. Originally the Lazair had a single top-mounted stick with a mixer to apportion movement between the elevons and ailerons; separate rudder pedals were optional and, if ordered, could be easily disconnected in flight to bring the aircraft back to stick-only control. Now the position is reversed: latest Lazairs have a conventional bottom-mounted stick and rudder pedals as standard, with stick-only control available to special order.


It has full three axis control. The control stick controls the ailerons and elevators, and separate rudder pedals control the rudders. The rudders and elevators are combined (ruddervators) in the turned down tail which makes the Lazair very controllable in slow flight and taxi because the air blast of the engines is directed into them.

One unique feature of this Lazair is the ability to lock the rudders and ailerons together to fly it using the stick only if you are not used to using rudders or you prefer to fly that way. You can unlock them with the flip of a knob to use rudders separately.

The wings come off easily with just a few bolts making it ready to transport.


Units delivered by June 1981 300.

Pioneer engines of 100 cc and 5.5 hp each were normal fitment in 1981, but for 1981 these were replaced by the Rotax engines, each mated to an unusual 'biplane' propeller. This in turn was discarded for 1983 in favour of an injection-moulded composite propeller with centre spinner and - most important - provision for the pitch to be adjusted on the ground.

 

lazair-1
 

The 1982 model came 6th in that year's London-Paris, with the non-swivelling tailwheels, narrow track and additional nosewheel.

This progressive increase in thrust has made drag less critical than before, allowing Ultraflight Sales to fit a more stable, wide-track undercarriage without hurting the performance too much. En route, the additional nosewheel has been discarded and the aircraft turned into a true taildragger. Ground handling has been further improved by making the tailwheels castor and by fitting an independent disc brake on each main wheel; wheel spats are now standard equipment.

 

lazair-2
 

Options include floats and skis made from glass-fibre reinforced polyester with a pigmented gelcoat.

The 1983 price: kit requiring 150h to complete C$6450; ready-to-fly C$8190.

In 1983 the Lazair II was still under development. In concept the aircraft is likely to be similar to the single-seat model, again using two direct-drive engines mounted on the leading edges of the wings. The engine type chosen was the WAM WAE 342, a horizontally opposed twin which is particularly powerful for its weight. The engine manufacturer's design to certify the unit for motor glider operation had delayed deliveries and caused the postponement of the Lazair II launch from 1982.

uf-lazair-2


The Lazair III is a high wing strut braced monoplane with twin engines, an inverted V tail and three axis controls. The wing has a constant tapper with upswept wing tips. Tedlar plastic covering gives the wing and tail surfaces its transparant Gossamer look which enables the operator to pre-flight nearly every nut and bolt. Engine off soaring is another feature. The latest model features a cockpit pod. Centre mounted joy stick, rudder pedals, tail wheel steerable through independent braking.

The Lazair Elite features a centre mounted joy stick, rudder pedals, tail wheel steerable through independent braking.

 

 

LAZAIR 4 Engine on Floats


Engines: 2 x AB Partner 185cc, 6 hp
Static thrust, 40 lb
Max pilot wt: 230 lbs
Wingspan, 36 ft 4 in
Wing area, 142 sq.ft
Aspect ratio, 9.3
Overall length, 14 ft
Empty weight, 183 lbs
Usable payload (include fuel), 250 lbs
Wing loading, 2.8
L/D power-off glide ratio, 13:1
Cruise speed, 35 mph
Stall speed, 17 mph
Approach speed, 25mph
Flair speed, 20 mph
Liftoff speed, 20 mph
Takeoff roll distance, less than 100 ft
Rate of climb, 400
Fuel capacity, 2.5 USG

Engines: 2 x Rotax 185, 9.5hp each at 5800rpm
Propeller diameter 35 inch, 0.89 m
No reduction. Max static thrust 140 lb, 64 kg
Power per unit area 0.13 hp/sq.ft, 1.4 hp/sq.m
Fuel capacity 5.0 US gal, 4.2 Imp gal, 18.9 litre
Length overall 14. 0 ft, 4.27 m
Height overall 6.3ft, 1.93m
Wing span 36.3ft, 11.07m
Chord at root 4.8 ft, 1.47 m
Chord at tip 3.1ft, 0.94m
Dihedral 2 deg
Sweepback 0 deg
Tailplane span 6.67 ft, 2.03 m
Total wing area 142 sq.ft, 13.2 sq.m
Total aileron area 4.8 sq.ft, 0.45 sq.m
Total elevon area 8.6 sq.ft, 0.80 sq.m
Wing aspect ratio 9.34
Wheel track 3.9 ft, 1.18 m
Wheelbase 10.0 ft, 3.05 m
Tailwheels diameter overall 4 inch, 10 cm
Main wheels diameter overall 16 inch, 41 cm
Optional floats: length 10.0 ft, 3.05 m; width 25 inch, 0.65 m; height 14 inch, 0.36 in
Weight of pair including mounts 60 lb, 27 kg
Optional skis: length 68 inch, 1.72 m; width 13.5 inch, 0.34 m
Weight each 13 lb, 5.9 kg
Empty weight 2101b, 95kg
Max take-off weight 530lb, 240kg
Payload 3201b, 145kg
Max wing loading 3.73lb/sq.ft, 18.2 kg/sq.m
Max power loading 27.9lb/hp, 12.6kg/hp
Load factors +4.0, -2.0 design
Max level speed 50 mph, 80 kph
Never exceed speed 55 mph, 88 kph
Max cruising speed 45 mph, 72 kph
Economic cruising speed 40 mph, 64 kph
Stalling speed 20 mph, 32 kph
Max climb rate at sea level 400 ft/min, 2.0 m/s
Min sink rate 200 ft/min at 23mph, 1.0m/s at 37kph
Best glide ratio with power off 12/1
Take-off distance 100ft, 30m
Landing distance 75-100ft, 23-30m
Range at average cruising speed 165 mile, 265 km

Lazair III
Empty wt: 220 lbs
Wing span: 36’4”
Wing area: 144 sq.ft
Height: 6’4”
Length: 14’
Fuel cap; 5 USG
Construction: Aluminium, Tedlar
Engine: 2 x Rotax 185 (370 cc) 38 hp
Prop: 71 cm composite
Max wt: 490 lbs
Stall: 22 mph
Max speed: 60 mph
Vne: 65 mph
Cruise speed: 26 kts, 50% power
Climb rate: 400 fpm @ 30 mph
Design limit: +4, -2g
Glide ratio: 13-1
Wing loading: 3.4 lbs/sq.ft
Power loading: 12.89 lbs/hp

Lazair Elite
Empty wt: 254 lbs
Wing span: 36’4”
Wing area: 142 sq.ft
Height: 6’4”
Length: 14’
Fuel cap; 5 USG
Construction: Aluminium, Tedlar
Engine: 2 x JPX PUL 425 (425 cc) 40 hp
Static thrust: 190 lbs
Max wt: 464 lbs
Stall: 23.8 mph
Max speed: 62 mph
Vne: 70 mph
Climb rate: 700 fpm @ 30 mph
Design limit: +6.6, -2.8g
Glide ratio: 10-1
Wing loading: 3.27 lbs/sq.ft
Power loading: 11.6 lbs/hp

Ultraflight Sales Lazair
Stall: 22 kt / 25 mph / 40 kmh
Cruise: 35 kt / 40 mph / 64 kmh
VNE: 56 kt / 65 mph / 105 kmh
Empty Weight: 95 kg / 210 lbs
MTOW Weight: 240 kg / 530 lbs

 

 


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