Kawanishi K-8B (oz11606)


Kawanishi K-8B (oz11606) by Bill Noonan from Model Airplane News 1981 - plan thumbnail

About this Plan

Kawanishi K-8B. Free flight scale model floatplane.

Quote: "A parasol design that has perfect proportions for rubber scale, and ROW at that! And you won't find this obscure subject at every contest. Near ideal for small R/C as well. Kawanishi K-8B, by Bill Noonan.

In 1977, while thumbing through a copy of Encyclopedia of Japanese Aircraft at the old San Diego Aerospace Museum library, I came across a wealth of photos and 3-views of obscure Japanese aircraft of the 1920s. The only catch was that the text was printed in Japanese. Fortunately, the publishers saw fit to throw in a recognizable word now and then, and to give aircraft specifications in metric. The aircraft manufacturer's name and the designation of the aircraft were in English.

The Kawanishi K-8B 'Seaplane Transport' was one that could hardly be ignored. Proportions are perfect for rubber scale. There is an abundance of louvers, pipes, openings and other details that con-tribute to the character of what is basically a simple design.

Further search for information provided meager clues. It is known that at least four K-8Bs were built, as there were that many registrations issued. One can only guess at the purpose of the aircraft. After all, a two-seat 'transport' on floats seems a bit esoteric. Purpose aside, it makes a fine subject, extremely stable and easy to fly. Ours has won first place in two annual ROW competitions sponsored by the Flightmasters Club, the most recent of which required the models to fly from a 12 x 16 ft man-made 'lake' (a plastic water-filled reservoir, 4 in deep). The model had no trouble in getting off the water in a grand fashion after about a 15.5 ft run, landing back on asphalt; none the worse for wear.

You may be saying to yourself - it's strut city! The K-8B does not lack in the brace-work department, but this isn't as formidable as it seems. A little studying of plans and photos should make it clear.

FUSELAGE: Fuselage construction follows the conventional practice of securing longerons and structural components over the side view of the plans. Longerons are 3/32 square medium balsa; the uprights and diagonals, with the exception of the one at the extreme nose, and the 3/32 x 1/4 in aft rubber anchor supports, are hard 1/16 square. These are 'set in' the longerons, giving a 1/32' air space between the structure and covering.

Make a right and left side in this manner. Fill in nose section with 1/16 sheet balsa. Add 1/32 sheet ply gussets at strut anchor points.

When the cement is thoroughly dry, the two sides may be inverted and pinned (not through the wood) over the top view. Cement in crosspieces. The unusual method of fairing in the rudder with the fuselage allows you to build the rudder top and bot-tom separately, or by making the entire laminated outline in one continuous piece, cementing it to the fuselage, and filling in the crossbraces and tab.

Add 1/16 sheet balsa filler to fuselage sides where stabilizer passes through the fuselage. The stabilizer is made in two halves, the leading edges 'plugging in' to a 1/8 ID aluminum tube cemented in the fuselage. This means the leading edge is a hinge, allowing about 30 negative incidence if needed. The spar passes through an oversize slot..."

Kawanishi K-8B, MAN, June 1981

Direct submission to Outerzone.

Supplementary file notes

Article pages, thanks to RFJ.


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

Kawanishi K-8B (oz11606) by Bill Noonan from Model Airplane News 1981 - model pic

  • (oz11606)
    Kawanishi K-8B
    by Bill Noonan
    from Model Airplane News
    June 1981 
    40in span
    Scale Rubber F/F Floatplane
    all formers complete :)
    got article :)
  • Submitted: 23/07/2019
    Filesize: 424KB
    Format: • PDFbitmap
    Credit*: Circlip, RFJ

  • Kawanishi_K-8_Transport_Seaplane | help
    see Wikipedia | search Outerzone

    ScaleType: This (oz11606) is a scale plan. Where possible we link scale plans to Wikipedia, using a text string called ScaleType.

    If we got this right, you now have a couple of direct links (above) to 1. see the Wikipedia page, and 2. search Oz for more plans of this type. If we didn't, then see below.

    ScaleType is formed from the last part of the Wikipedia page address, which here is https://en.wikipedia.org/wiki/Kawanishi_K-8_Transport_Seaplane
    Wikipedia page addresses may well change over time.
    For more obscure types, there currently will be no Wiki page found. We tag these cases as ScaleType = NotFound. These will change over time.
    Corrections? Use the correction form to tell us the new/better ScaleType link we should be using. Thanks.

Kawanishi K-8B (oz11606) by Bill Noonan from Model Airplane News 1981 - pic 003.jpg
Kawanishi K-8B (oz11606) by Bill Noonan from Model Airplane News 1981 - pic 004.jpg
Kawanishi K-8B (oz11606) by Bill Noonan from Model Airplane News 1981 - pic 005.jpg

Do you have a photo you'd like to submit for this page? Then email admin@outerzone.co.uk

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, 2011-2020.

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.