Navigator (oz306)

About this Plan

Jetco Navigator Seaplane. Plan also shows plug-in wheeled landing gear, for amphibian operation.

Update 07/07/2016: Added supplementary file of scanned kit instructions, thanks to PeterKraus.

Note this Jetco kit plan does not include any wing rib templates. See the Flying Models version of the Navigator (oz19) plan for ribs.

Quote: "Hi, I am building a Jetco Navigator from an original kit. I note that you have this plan in Outerzone. However you don't have the instruction sheet which is actually quite helpful but I do as it is in the kit. Would you like a copy of this to put with the plan and if so how can I get it to you? Thanks for a great website and keep up the good work, Peter."

Update 05/11/2019: Added kit review, from, R/C Model World, March 2017, thanks to RFJ.

Quote: "Jetco Navigator. Peter Kraus builds a vintage seaplane from an old kit - but uses 2.4 radio and a brushless motor to satisfy modern expectations.

I live close to a body of water that tends to be calm in the evenings, especially at low tide. So the thought naturally occurred to me that it would be nice to have a seaplane. Although I have been building models for a very long time my recent aircraft acquisitions have all been ARF electric foamies. I started to look at the various, rather nice, flying boats available but I must confess to some guilt as I had spent my allocated money on models that I really want around and here I was looking to spend more.

Like most long time modellers I have numerous kits and half built planes stored in my workshop, most for many years. Among these was an original, circa 1960 Jetco kit of a Navigator flying boat, bought years ago from the estate of one of our elderly club members who had passed on.

Not only would building the Navigator give me my flying boat but it would also be fun and reduce by one the number of kits waiting to be built. It would also serve to polish up my rusty building skills and allow me to experiment a bit before embarking on other projects which, notwithstanding the years they have lain dormant, are cherished items on my bucket list,

Preliminary Thoughts: The Navigator is a 52 in span flying boat with an NACA long planing hull. it was designed by Don McGovern and kitted under the Jetco brand name by the CA Zaic Company of Brooklyn, New York. All great names in their day so it really is a nice exercise in vintage nostalgia.

It was designed as a free flight or single channel R/C model for use with the rudimentary radio control systems available in 1960, rudder only or rudder and throttle, or even elevator! Yes, on only one channel and, as much as those small engines of that day could be, it could be throttled too! As such I expected it to be inherently quite stable and therefore suitable for a beginner flyer, or in my case an old guy with rusty thumbs. But in those days people who built models actually built them, if you know what I mean. But this model is not a beginner's build.

Power Selection: The original was for minimum power of an .049 cu in engine, or .8 cc in British English, up to .10 cu in or 1.5 cc, the latter being recommended for water operations with radio gear on board.

Electric is the way to go today. I have a Precision Aerobatics PA Thrust 10 motor which I guess is the equivalent of a good 1.5 cc but I didn't want to risk this fine motor on the water, so I looked for a cheaper equivalent. Fortunately I miscalculated and bought a Turnigy Park 480 850 KV and a 45A ESC. This motor is about twice the weight of the PA Thrust 10 and is more powerful. Despite its low cost it seems very well made and with excellent reviews. I stopped worrying about the weight when I checked and found that at 80 g it is on a par with the venerable ED Bee and is much more powerful than the dear old diesel. Also, today's radio gear is but a feather compared to what they had in 1960.

The other aspect of the electric gear is cooling. The motor will be up on a pylon in the breeze but the ESC and battery had to be protected from water so they would reside in the hull/fuselage as any airflow over them would also allow ingress of water. As the motor requires a 30 to 35A ESC this leaves plenty in reserve, the whole power train just loafing along with a 3S battery and, hopefully, creating sufficiently little heat to dissipate in the space available in the hull. That's the theory.

Glues And Covering Materials: o build the model I used aliphatic resin and CA glues, not the original balsa cement. I built many models as a young bloke using cement and although this is still available the new stuff is so much better.

The original could be covered in tissue or silk. Although some of my traditionalist friends who build old aeroplanes still use tissue, I am very pleased not to, at least on the open areas where it will tear just because it sees your finger coming. Solarfilm is great but somehow not quite in the right spirit for a model such as this.

The tougher alternative to tissue was silk, or nylon which is readily available. I got some nylon from a haberdashery store, it's cheap and tough and will shrink OK with dope but is not heat shrink. That's just as well as the lady getting it off the roll gently folded it for me to take home. Unfortunately this put creases into it which don't come out with dope, so either get it rolled when you buy it or use a very gentle dry iron before applying. Dope the structure first then apply dope through the cloth to stick it to the framework. Get it reasonably smooth, then coat the entire surface with dope to seal and shrink it.

There are some very good modern lightweight heat shrink fabrics that I think would do the best job but they cost more than I wanted to spend. However, I did use some old heat shrink film on some parts, which I have had for over 20 years. It needs painting so it does not come under my category of 'plastic films'. It has an adhesive on one side (to my surprise, the dull surface) but as this was old I felt it was as well to use some Deluxe Materials Cover Grip to ensure it stuck. Balsaloc is similar.

For sheeted areas on the tail I used tissue. Good old Modelspan isn't so easy to get so I just bought a pack of ordinary tissue paper from the newsagent and it does the job, more or less, on solid sheeted areas.

To seal the balsa I used dope, which is still available. Brushes can be cleaned with acetone but I don't bother; I just soak the brush in a bit of acetone for a minute or two before its next use. To seal balsa and fill up cracks make a putty with dope and talcum powder. This sands beautifully and although it pre-dates epoxy and micro-balloons by some years it's still very useful but without any structural strength.

Before even thinking of covering don't forget that, although the Bible may tell us that in life love covers a multitude of sins, with model aircraft its sandpaper! Sandpaper includes Perma-Grit tools and it's remarkable how quickly block balsa gets shaped with these. Do it outside though. While on that subject, make sure your area is well ventilated when using dope.

I found that the nylon and dope were quite practical. You can even adjust it by brushing some more dope, or even just acetone, over bits with wrinkles and then pull on it and hold for a moment until the dope dries out a bit. I did this where needed to get it smooth before doping the open areas.

It did seem a tad heavy for use on a light model so after covering the bottom of the wing, and as I found the above mentioned heat shrink material in the dark recesses of my workshop, I decided to use it for the top of the wing and for the tailplane. I tried it on the underneath of the hull but found that it wasn't that easy to use on the concave sheeting and here I would have been better off with dope and tissue, or nylon if extra strength was needed on the hull bottom. As you can see, I didn't use modern coverings as I wanted to use what I had, for economy as much as for keeping in the right spirit. The whole exercise was to experiment, polish my rusty skills and use what I had on hand. I am NOT recommending mixing covering methods!

Plans And Design: While an experienced modeller can use the plans alone, the instructions were most helpful. However, the plans do have all formers and ribs illustrated so if anyone does want to build a Navigator the plans can be found online.

Don't forget to plan ahead with regard to placement of radio gear, in particular a spot for the battery pack where you can access it after the plane is complete. Make arrangements during the building, not after! I didn't want to compromise waterproofing by cutting hatches so the wing has to come off to access the innards. The wing is held on by rubber bands over dowels, as per the original. It would be no problem to alter this to nylon bolts if desired.

I used flexible 'snakes' for pushrods to avoid the openings where conventional pushrods exit the fuselage. I didn't bother with ailerons; they are little use on a model designed for rudder only, unless you reduce the dihedral and I didn't want to alter the model that much - or worry about water getting into wing servos!

For today's proportional radio gear I enlarged the elevators. These, and the vertical tail, are from 1/8 sheet..."

Update 28/12/2023: Added decal, thanks to dfritzke.

Supplementary file notes

Decal.
Instructions, one large sheet.
Review.

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