Stratus EA 81

Stratus 2000, Inc specialized in the design and manufacture of engines based on Subaru automotive engines for homebuilt aircraft. Zenith Aircraft Company offered a firewall-forward package for the EA-81 Subaru engine conversion (from Stratus Inc.) for the ZODIAC CH 601 series.

The firewall-forward package was supplied by Zenith Aircraft Company.

Cycle: 4 stroke
No cylinders: 4
Bore: 92 mm / 3.62 in
Stroke: 67 mm / 2.64 in
Compression: 9
Displacement: 1781 cc / 109 cu. in.
Cooling: Liquid
Ignition: Electronic, single spark plugs
Reduction: 2.2/1 HTD belt (60 mm. wide)
Dimension: 660 x 533 x 444 mm
Weight: 84 kg / 185 lb (approx. 220 lb installed)
Max pwr: 100 hp / 75 kW at 5400 rpm
Max torque: 145 at 3800 rpm
Fuel consumption: 0.48 lb./hp/hr @ 75% power
Fuel: unleaded (automotive)
Carburetion: Dual Bing altitude-compensating carbs
Alternator: 45 amp
Starter: electric gear reduction
Price 1998: $6495

Stratus Inc / Stratus 2000

1998:
7750 Twelfth Avenue N.W.
Seattle
Washington 98117
USA

Since 1992, Stratus, Inc. has converted Subaru EA-81 engines for use in Avid Flyers and similar light, home-built aircraft. The company installed a 100-hp engine in a Cessna 150F with good results.

Originally founded as Stratus, Inc. in 1992 by Reiner and Petra Hoffmann, the company was sold in 1999 to Mykal Templeman and renamed Stratus 2000, Inc.

Based in Camano Island, Washington and later in Corvallis, Oregon. Stratus 2000, Inc specialized in the design and manufacture of engines based on Subaru automotive engines for homebuilt aircraft. Zenith Aircraft Company offers a firewall-forward package for the EA-81 Subaru engine conversion (from Stratus Inc.) for the ZODIAC CH 601 series.

The company built two Subaru-derived designs, the Stratus EA 81 based on the Subaru EA 81 automotive engine and the Stratus EJ 22 based upon the Subaru EJ 22 automotive engine. The company also designed its own 2.2:1 ratio propeller speed reduction unit.

Some existing airframe designs, like the Zenith CH 601, have been adapted for the Stratus engines, while other aircraft have been designed around the engines from the start, such as the Airdale Backcountry. Stratus powerplants have also been used as retrofits in production aircraft, such as the Cessna 150.

The company seems to have gone out of business about 2008 and engine production ended.

Stratos Aviation Stratos

Single seat single engined mid wing monoplane with conventional three axis control. Wing has unswept leading and trailing edges, and constant chord; cruciform tail. Pitch control by elevator on tail; yaw control by fin mounted rudder; roll control by one third span spoilers; control inputs through stick for pitch/roll and pedals for yaw. Wing braced from below by struts; wing profile NACA Series 23000; double surface. Undercarriage has three wheels in tricycle formation; suspension on all wheels (type NC). Push right go right nosewheel steering connected to yaw control. Aluminium tube/fabric/ steel tube framework, with optional pod. Engine mounted at wing height driving pusher propeller.

The prototype Stratos made its first flights during the summer of 1982. It had been designed and built by Larry Burke, an engineer specialised in the study of fatigue problems and the breaking points of materials at Lawrence Livermore National Laboratory.

Commencing design studies on this single seater in December 1981, Larry included in his design target a minimum load factor of +6, 3g at 5001b (227kg) weight. The Stratos was designed to be a low profile fully triangulated strut braced aircraft that places the pilot ahead of the wing, almost giving 360 degrees visibility. The machine is expected to be on sale in ready built form during the summer of 1983 and Stratos Aviation has plans for a two seater which will be classified as an experimental aircraft in the United States.

The Stratos single seater is fitted with a Cuyuna 430R but the manufacturer intends that alternative engines shall be offered eventually as an option.

Engine: Cuyuna 430R, 30 hp at 5500 rpm
Propeller diameter and pitch 50 x 32 inch, 1.27 x 0.81 m
Belt reduction, ratio 2.0/1
Power per unit area 0.18 hp/sq.ft, 1.9hp/sq.m
Fuel capacity 5.0 US gal, 4.2 Imp gal, 18.9 litre
Length overall 19.0ft, 5.79 m
Height overall 4.5ft, 1.37m
Wing span 33.0ft, 10.05m
Constant chord 5.0 ft, 1.52 m
Sweepback 0 degrees
Total win area 166 sq.ft, 15.4 sq.m
Total spoiler area 4.0 sq.ft, 0.36 sq.m
Wing aspect, ratio 6.5/1
Empty weight 250 lb, 113kg
Max take off weight 500 lb, 226kg
Payload 250 lb, 113kg
Max wing loading 3.01 lb/sq.ft, 14.6 kg/sq.m
Max power loading 16.7 lb/hp, 7.5 kg/hp
Load factors +6.0, 3.0 design
Max level speed 63 mph, 101 kph
Never exceed speed 70 mph, 112.5 kph
Cruising speed 63 mph, 101 kph
Stalling speed 27 mph, 43 kph
Max climb rate at sea level 750 ft/min, 3.8 m/s
Min sink rate 250 ft/min at 35 mph, 1.3 m/s at 56 kph
Best glide ratio with power off 8/1 at 35 mph, 56kph
Take off distance 100ft, 30 m
Land¬ing distance 100ft, 30m
Service ceiling 16,500 ft, 5030 m
Range at average cruising speed 150 mile, 241 km