Cox Sky Ranger

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Cox Sky Ranger
Transmitter and battery supplied with the Sky Ranger. The "000" readout represents the 0 - 100% throttle position

The Cox Sky Ranger is an RTF micro-sized R/C electric trainer/sport plane distributed by Cox Models, a division of Great Planes Hobby Distributors of Champaign, Illinois USA.

Construction is of Hobbico's "FlightFlex" foam. The material is so flexible, the unreinforced wing can be bent at extreme angles and still spring back into shape. As such, the airframe will easily survive crashes that a beginner is likely to make.

Essentially a rebadged Nine Eagles Sky Eagle, the 20" (508mm) wingspan Sky Ranger is modeled after the full-scale Cessna 182 but is not badged as such. The included 2.4GHz four-channel transmitter with its comprehensive LCD display flies the Sky Ranger via rudder, elevator and throttle. Dual rates are selectable via pressing down on the right stick with the transmitter in as-shipped Mode 2 default. Pressing the left stick in Mode 2 places the transmitter in bind mode; no binding plug is required for the receiver since the process is automatic. The onboard electronics consist of a "brick" which incorporates the ESC, receiver and linear servos.

A unique safety feature is the "SafeProp" propeller mounting system. This allows the propeller and spinner to pop free from their mounting hub in the event of a crash or hard landing, preventing damage to both the propeller and direct-drive brushed motor. The propeller/spinner are easily snapped back into place.

Accessories include a lithium polymer balancing battery charger with AC adapter, 2S lithium-polymer battery, spare propeller, spare hardware, photo-illustrated instruction manual and a small phillips screwdriver. The enclosed transmitter comes preset for Mode 2 control, but is easily converted to Mode 1 simply by removing the antenna hold-down strap from the rear of the unit, lifting and swiveling the antenna into the Mode 1 position and remounting it to point in the opposite direction. This procedure engages a microswitch which automatically switches the transmitter's controls and display, but it should be noted that the decals will appear to be upside down and the power switch will seem to be at the bottom left instead of the top right.

Replacement of the factory-installed motor may prove difficult due to the cement used to secure the mount to the fuselage. A technical bulletin outlines the motor replacement procedure and is listed below.

Care should also be exercised when handling the onboard electronics. If the servo gears are damaged, they are not available as a service part. Inquiries regarding replacement of the gears should be directed to Hobbico's product support department.

The Cox Sky Ranger is recommended for ages 14 and older.

Flight characteristics

Since this is a model aimed at beginners and occasional flyers, flight characteristics are quite stable, but the model's size needs to be taken into consideration. Because it is so small, it should be flown in relatively calm conditions, but it will handle breezes quite well as long as the airspeed is kept up. Average top speed is approximately 20 MPH (32km/h). Control response is somewhat slow at the low rate setting, again to accomodate new pilots. The Sky Ranger is more responsive at the higher rate setting. With its rudder-only steering, the Sky Ranger handles somewhat differently than an aileron- and rudder-equipped model since it introduces both yaw and bank via the same stick. That characteristic combined with the flat-bottomed airfoil makes aerobatics impossible. As with any model steered via rudder, the Sky Ranger may fall into a spiraling dive if the stick is held too far over for too long. The Sky Ranger glides exceptionally well for landings, but even a slight noseover will pop the propeller off of its safety mount.


  • Wingspan: 20" (508mm)
  • Wing area: 54 in² (3.48dm²)
  • Wing loading: 5.9 oz/ft² (18g/dm²))
  • Weight: 2.2 oz. (62g)
  • Length: 15.5" (393mm)
  • On-board electronics: Cox/Nine Eagles three-channel receiver/ESC/servo "brick"
  • Transmitter: Four-channel, Mode 2 2.4GHz spread-spectrum, switchable to Mode 1
  • Battery: 180mAh 2S lithium-polymer with JST connector and JST-XH balancing plug (COXA5817)
  • Motor: High-speed direct-drive brushed (COXA5816)
  • Construction: FlightFlex expanded polypropylene foam airframe and spinner; plastic propeller; steel wire landing gear with plastic wheels and foam tires; steel pushrods
  • Typical flight duration: Ten minutes
  • Distributor: Great Planes Model Distributors, Post Office Box 9021, Champaign, Illinois 61826 USA
  • Catalog number: COXA6501
  • Recommended age range: 14 years or older
  • Skill level: Beginner; assistance from an instructor is recommended for totally inexperienced pilots
  • Available from: Any hobby dealer which stocks Hobbico/Great Planes products
  • Retail price (USD): $99.98

External links and references