Richard Bavin from the UK writes:

The Tethered Trainer is a lovely model full of character; the laser cut parts are a superb fit of course, with excellent wood selection. It is nice to see that the plan has been kept near original, leaving the opportunity to modify the design to the discretion of individual modellers.

During my build I incorporated various modifications that I suggest are worth consideration, a list follows:-

1) Addition of 1/8 wing seat doublers
2) Addition of 1/32 ply doublers from front of fuse to rear of wing at former C.
3) Addition of 1/8 ply gussets from top and bottom of engine bearers to front of firewall
4) Fill tailplane centre with 1/8 sheet (grain across the fuselage) about ¼ beyond fuselage. This allows support for covering and tail seat security.
5) Change tailplane TE to 1/8 x ¼ and elevator LE to 1/8 x ¼ spruce (or laminate 1/8sq balsa & 1/8sq spruce) this gives extra covering support and stiffness at the hinge point
6) Add 1/8 x ¼ longerons to top and bottom of fuselage sides to spread stress.
7) Add 1/8sq diagonals to tail assembly (stiffness and covering support)
8) Add extra vertical spar to fin and build separately from rudder, use rudder offset rather than aerofoiled section as it is easier to blend the shapes
9) Sheet centre of wing with 1/16 to W2 and add extra ribs at location of fuselage sides. (provides hard point for wing fixing)
10) Add 1/8 balsa to canopy support to aid fixing canopy.

The plan indicates the line guide to be fitted to W6, but I fitted it to W7 and found that this gave the correct line sweep and routed the lines over the wingtip.

The plan does not indicate a CoG position or suggested flying line length so help was sought from Gabrielle Macri who has built and flown a Tethered Trainer powered by an O & R 23 glow. Gab advised that his model balances 11/2in back from wing LE and that he flies on 52ft lines. I found that I had to fit the 3 cell AA ignition battery under the engine to achieve this. I incorporated a hatch to access the coil fitted behind the firewall, if the wing was held on by rubber bands this would be unnecessary.

None of the foregoing is intended to be negative as this is a super kit that builds in to a very nice model. The nature of the design means that it is only likely to built by experienced modellers and no doubt they will welcome the opportunity to incorporate their own ideas in to the construction. However I hope that my observations prove useful and now I am really looking forward to flying the Tethered Trainer. This will take place as soon as the weather allows and I am anticipating that the model will be a nice gentle flier perfect for antique modellers like me.

Cheers,
Richard Bavin