The new XTRA-WOT

1.8m (71 in") span low wing semi-scale aerobatic R/C model for .90-1.50 cu. in. (15-25cc) 2-stroke and 1.20-1.80 cu. in. (20-30cc) 4-stroke engines  
Xciting looks           Xceptional quality       Xhilarating performance

Forget the Sukhois, CAPs, Extras, and Giles’s. If you want a modern scale-looking aerobatic aircraft without the associated constructional complexities and aerodynamic compromises, then this is the one!

The Xtra-Wot is essentially a 25% enlargement of our hugely popular Acro-Wot, retaining all the key elements of the original design while incorporating a number of significant styling changes to create stronger visual ties with the current generation of full-size high performance aerobatic aircraft.

The broad nose, prominent canopy with its ascending waistline, deep rear decking, substantial underfin, bold fin and rudder – all these individual styling elements not only complement one another but harmonise to create a cohesive and uniquely distinctive design.


Kits are now available either from selected hobby shops or direct from Chris Foss Designs.

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The wing, not surprisingly, retains the extraordinarily versatile Acro-Wot aerofoil section to ensure class-leading handling characteristics and aerobatic performance. The redesigned tips have been optimised, in conjunction with the virtually zero dihedral angle, to eliminate any rudder roll in knife-edge flight. The large and powerful rudder incorporates an aerodynamic counterbalance to both reduce servo loads and increase effective area.

And the flying qualities? Simply brilliant! Not only has the Xtra-Wot inherited all the legendary qualities of the Acro-Wot, the exceptional low-speed handling, the superb manoeuvrability and amazing wide speed range, but these are all positively accentuated by the size increase. Furthermore the controls respond with a greater degree of smoothness and progressiveness, making precision aerobatics not only easier but more rewarding.

Further gains have been achieved by virtue of the styling revisions. For example, the increase in fuselage side area and larger redesigned rudder improve knife-edge flight and hesitation rolls, while spins, stall turns and flick manoeuvres also benefit from the additional control authority. The increased drag created by the larger frontal area not only contributes to greater aerobatic realism, by maintaining more consistent speed through manoeuvres, but provides valuable speed control on the approach making landings a real doddle with a remarkably short ground run.

The fact that the Xtra-Wot virtually lands like a trainer makes it an ideal introduction to low wing models, particularly when fitted with an engine at the lower end of the recommended power range. At the other extreme a maximum size engine will deliver a performance that will excite the professional, with stunning vertical performance, prop hanging, knife-edge loops, violent flick manoeuvres and so on, while still retaining its docile low speed handling. The final production prototype Xtra-Wot, incidentally, weighs 4.8 kg (10.6 lb), is fitted with Multiplex radio equipment using regular size servos on all controls and performs more than adequately with a Laser 150 4-stroke engine.



Wing Span    1800mm (71")
Wing Area    0.6sq.m (936 sq. in)
Length Inc.Spinner    1510mm (59.5 in)
Average Weight    4.8Kg (10.6 lb) (prototype)
Radio    4 Channel/5 Standard servos
Engine Range    .90 - 1.50 cu. in (15-25cc) 2-Stroke
                         1.20 - 1.80 cu. in (20 - 30cc) 4-stroke

Structurally, the Xtra-Wot has undergone a thorough simplification process, resulting in an even speedier construction than the Acro-Wot, principally by eliminating the majority of time-consuming shaping and profiling work. The CNC precision cut ply fuselage doublers, after being laminated to the balsa sides, accurately locate onto the CNC cut formers, servo tray and wing fixing plate. A ply undercarriage plate, balsa rear top and underside sheeting complete the basic structure. The final shape is created by adding the lightweight quality glass-fibre top decking, from bulkhead to cockpit, and the veneered foam rear decking behind the cockpit.

The veneered foam core wing panels each contain a recess for an outboard servo and a channel for the servo lead in the core. After the balsa leading and trailing edges have been fitted the integral ailerons are separated from the panels and the edges faced with balsa, resulting in ailerons that perfectly match the profile of the wing. The tailplane and elevator are jig cut to shape from solid balsa sheet. The main rudder component is supplied as a veneered foam core with pre-formed sectional taper, providing a light and rigid structure.

Kit contents:

Quality veneered foam core wing panels : CNC precision cut ply doublers, formers, servo tray etc : jig cut quality matched balsa fuselage sides : lightweight glass-fibre nose top decking : veneered foam core rear decking : pre-shaped balsa tail surfaces : veneered foam core rudder : lightweight glass-fibre cowl and side cheek extensions : flexible composite undercarriage : moulded transparent canopy : pilot : spinner : wheels : sprung steel tailskid : moulded engine side-thrust wedge : comprehensive fittings pack : self adhesive graphics : instruction manual.

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Kits are now available either from selected hobby shops or direct from Chris Foss Designs.