E-flite UMX Carbon Cub SS

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E-flite UMX Carbon Cub SS.jpg

The E-flite UMX Carbon Cub SS is an ultra-micro scale model of the Cub Crafter's Carbon Cub SS. It is part of E-flite's Ultra Micro Extreme (UMX) range of aircraft which feature Horizon Hobby's AS3X stabilization system. The Carbon Cub SS includes a steerable tail wheel, flaps, LED navigation lights, and optional floats. It is available only in the BNF trim, which includes a 2S DC Celectra charger (AC adapter is not included), and a 2S 180mAh 20C LiPo battery with 2S JST-PH connector.

The Carbon Cub SS comes completely assembled, although the control surface centering may need to be adjusted by bending the servo pushrods. The tail wheel may also need to be adjusted to roll straight with the rudder.


The Carbon Cub SS is a scale model of a civillian light aircraft and isn't 3D-capable; however, it has excellent performance for its weight and is able to perform rolls, loops, and inverted flight without issue.

The control surfaces come from the factory set to the shortest throw, which can increase flying difficulty (especially when nearing stall conditions). Control throw can be increased by moving the servo pushrods to the hole on the control horns nearest the control surface. If this makes the aircraft too sensitive, decrease sensitivity in the transmitter using expo rather than limiting control throw, as this still leaves the whole throw available for emergency maneuvers.


The Carbon Cub SS includes operational flaps which can be controlled with the gear channel (-100% fully retracted, 0% half-extended, and 100% fully extended). Flying behavior with flaps extended can be unpredictable if inputs are not applied carefully since the airframe's extremely low stall speed limits the amount of air moving over control surfaces at flap speeds. Turns are best initiated with the rudder to avoid unexpected snap-rolls. If control is lost, retract the flaps, apply full throttle, and climb. It is best to start out practicing low-speed flaps-extended flight from a high-enough altitude to give room to recover from mistakes.

Transmitters capable of gradual flap extension and retraction make the flap transitions less jaring and less likely to result in loss of control.

Aftermarket parts

Horizon's asking price for the UMX batteries is higher than quality aftermarket options. Hyperion offers both the 2S 180mAh and the 240mAh pack with the JST-PH connector used in the UMX-series aircraft. Both provide excellent performance and are easy to balance. The 240mAh pack will provide about 7-10 minutes of flight time.


Wingspan 610 mm (24 in)
Wing Area 540 cm2 (83.5 in2)
Length 398 mm (15.7 in)
Flying Weight 3.17 oz (90 g) (Stock battery is 13 g (0.45 oz))
Motor Size 180-size, 2500Kv brushless outrunner
Center of Gravity 27 mm back from the leading edge of wing
Battery 1x 180mAh 2S 7.4V 20C LiPo (EFLB1802S20) (34x20x11mm) (plug is JST-PH)
Charger E-flite™ Celectra™ 2S DC LiPo balancing charge