Killerwatt (oz13085)


Killerwatt (oz13085) by Colin Usher 2010 - plan thumbnail

About this Plan

Killerwatt. Radio control sport aerobatic model. Wingspan 1485 mm, for .40 engines.

Note this is a clone of the Chris Foss Acro Wot design.

Note this plan was previously available as a free download, from the now-defunct Colin Usher website. We found this file in 2021 using the Wayback machine, see datafile link.

Quote: "The Killerwatt (Kilowatt) is a perfect follow on model from a Watt Four. It is a low wing design, slightly bigger at 1485 mm and uses a modified shape of tailplane & fin similar to a Watt Four. In fact the wing is so similar a friend uses an old Watt Four wing on his Killerwatt. Apart from the added 50mm it is more or less identical, even using the same airfoil.

As with the Watt Four a plan for the ACROWOT was never issued, so if you crash, need a spare or just like building you have a problem. Again the Killerwatt is not, for copyright reasons, identical to any other design.

I am reliably informed that this model will fly very well on a good 25 but a 40 is probably better. The prototype was fitted with an OS 46 MAX FX. The constructional details are my own and the outline shapes vary slightly, as does the airfoil. This is an NACA 63 0 18 at the root & 63 0 15 at the tip.

Electric Version hence the Killerwatt (Kilowatt): The plan as drawn is for an OS 46 MAX FX, but a version is flying with an AXI 4120/14 660 kv Brushless motor, a JETI 70w Advanced SB ESP, together with a Winforce 5 cell Li-Po pack running a 12 x 8 prop. Cheaper alternatives are a KSM 4120/06 660kv with a Wasp 70W Opto ESP from BRC. A 4 cell Li-Po also works but without the extra power of a 5 cell. You will need to put a hatch in the fuselage in front of the canopy for battery access.

Flying: The model has now flown more or less straight off the building board. A small amount of up trim was required but otherwise perfect. No signs of a tip stall, even on tight slow turns, ** nice flat even stall with no wing drop and a very flat glide on tickover. Very stable with an almost vertical climb. Needs plenty of aileron for Rolls, Loops and Stall turns no problem. A nice docile model all round.

** The original Acro Wot had a tendency to tip stall I am told but the slight dihedral, and most importantly the 2° washout seems to have cured this often fatal problem.

Supplementary file notes

Ribs drawing.


Did we get something wrong with these details about this plan (especially the datafile)? That happens sometimes. You can help us fix it.
Add a correction

No model pic found for this plan


Do you have a photo you'd like to submit for this page? Then email

User comments

No comments yet for this plan. Got something to say about this one?
Add a comment



Download File(s):


* Credit field

The Credit field in the Outerzone database is designed to recognise and credit the hard work done in scanning and digitally cleaning these vintage and old timer model aircraft plans to get them into a usable format. Currently, it is also used to credit people simply for uploading the plan to a forum on the internet. Which is not quite the same thing. This will change soon. Probably.


This model plan (like all plans on Outerzone) is supposedly scaled correctly and supposedly will print out nicely at the right size. But that doesn't always happen. If you are about to start building a model plane using this free plan, you are strongly advised to check the scaling very, very carefully before cutting any balsa wood.


Terms of Use

© Outerzone, 2011-2021.

All content is free to download for personal use.

For non-personal use and/or publication: plans, photos, excerpts, links etc may be used, provided that full and clear credit is given to Outerzone with appropriate and specific direction to the original content i.e. a direct hyperlink back to the Outerzone source page.

Unauthorized use and/or duplication of this material without express and written permission from this site's owner is strictly prohibited. If we discover that content is being stolen, we will consider filing a formal DMCA notice.