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High Flight Articles

Volume XII No. 3 Page 12 1991



PRIME SPORT - R/C Sports
By Irv Allison IMAA 820

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As we all know, there are three basic construction levels used in the various kits that we build. The first is the ARF that requires only assembly of the finished parts. The second level are those kits with various degrees of wood and foam precutting so that much of the elementary work is done. The third level involves those kits that require much careful bench construction time. The Prime Sport falls in the second category with almost everything already cut for you. In fact, I boned it out up to the point of covering in about 30 hours of easy bench time and I use the slow aliphatic glues. This thing builds FAST!

I received the kit in a single neatly packed box with no damaged or warped wood. Included was an 11 page instruction booklet that lacked pictures, but did have a figure showing the wing component locations. The plans were rolled blueprints and all the material was of top quality. The hardware is available as a separate kit that I did not purchase. Therefore, the only two hardware type items in the kit were the landing gear and the formed canopy, I particularly liked the landing gear - it is rugged. The kit also included a fiberglass cowl and pants of excellent quality.

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A quick examination convinced me that this was going to be a fast and easy building plane. I would have to compare the ease of construction to an Ugly Stick with foam wings. The fuselage is 1/8" balsa slab sided with a ply liner back through the wing saddle. I built the fuselage on a fuselage jig from Gator R/C Products that resulted in a perfectly true structure. This jig also saved me the time of measuring and trying to get a good alignment. The addition of several formers and stringers for the turtleback completed the body.

The tail is built up of balsa strips and covered with balsa sheet. The wing is balsa sheeted foam and is built into a single structure. I used Dave Brown's Sorguni on the sheeting and I recommend it highly.

My Prime Sport is covered with lightweight glass cloth and K&B resin, except for the wing tips and the turtle back. I used Coverite Supershrink for these two areas. I always seem to try something new on every plane I build and this time it was the resin thinner. In the past I have used Styrene to thin K&B resin for attaching aud filling light weight glass cloth. This time, on a tip from a friend, I tried Sears Epoxy and Paint Thinner (Stock # 30-62034). This Sears thinner was less than 1/4 the price of styrene and it worked just fine. For the painting I used my old standbys of a water based acrylic automotive primer and Rust-oleum, thinned 15% with mineral spirits for the color coats. The use of paint on the plane did cause me to add a small amount of lead in the nose for balance. If you use a plastic film, the Prime Sport should balance with no weights needed.

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The only problem I encountered was strictly my fault. When it came time to fit the canopy, I followed the prints that do not show any cockpit fairing. And the canopy wouldn't fit. I solved the problem very simply by making the plane an open cockpit version which I now believe that I prefer. After completing the plane I talked with the people at R/C Sports about this canopy. They very tactfully pointed out that this fairing is called out in the instructions. They also said that they will show this fairing on the prints iii the future so there will be no more errors like mine. Oh well, like they say, "When all else fails, try reading the instructions."

The radio is a Futaba FM 7 channel FG series with model S-148 servos. I have one servo located next to each surface. This means that there are two servos in the wing and three in the tail. Each servo lead has two .001 ufd disc capacitors (Radio Shack) for noise suppression: one capacitor is located next to the servo and the other is located next to the receiver. These capacitors go from the servo lead signal wire to the ground wire. This is a noise control technique developed and written up by Don Lowe several years ago and it works like a charm.

When the time came to select an engine, I had the opportunity to watch two Prime Cuts with Quadra 40s fly at the Regional IMAA Fly-in in Lakeland, FL. The Prime Cut is a sister kit to the Prime Sport with many same characteristics. I watched these Prime Cuts and saw two good performing planes that were also well flown. In talking with the two pilots, both commented that a bit more power would be a help. Based on this recommendation, I selected a 2.6 cubic inch Sachs on electronic ignition and this has shown itself to be an ideal combination. The muffler is a stock J'TEC Snuffler unit that does the job of getting much bark out of the exhaust.

And just 2 1/2 weeks after I opened the box, my Prime Sport was in the air. I set up the throws per the instructions and proceeded to have a ball. I found the plane to be stable, responsive and with no bad habits. With the specified throws, it makes a good entry into giant scale. Then when you are ready, you can increase the throws and carefully move the CG rearward until you develop the responsiveness to suit your style. The takeoffs are easy with good tracking. In the air, the Prime Sport cannot be considered as a pattern airp1ane but rather a very good sport flying plane. It flies with a style that gives you confidence in the plane very quickly. Landing approaches are steady and predictable with no problems during flare and touchdown. Very smooth three point landings can be made consistently and most of the spectators don't realize how easy it is.

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Now I have a story to tell on myself. I said that the Prime Sport is stable and so it is. About 5 minutes into the first flight, I noticed that my ailerons were more sluggish than I remembered at the beginning of the flight. It crossed my mind that I had probably lost one aileron but I didn't think much about it. I decided to not try anything fancy with just one aileron so I just flew around making figure 8s and a couple of low camera passes. After the plane was down, I discovered that I had put the screws into the aileron servo arms only finger tight and both ailerons had disconnected. I had been flying the plane rudder only and I didn't even realize it. Normally, I fly coordinated rudder and aileron from habit and this saved the day. However, it took the combination of a very stable plane, coordinated controls and a true aircraft construction line from the jig for this to happen so easily.

In summary, I thoroughly enjoy my Prime Sport and recommend it for those pilots who are past the trainer stage in their flying skills. I found the material in the kit to be top quality and it goes together exceptionally fast and easy. But the best part is when you get your Prime Sport into the air. This is when the real fun starts!

	SPECIFICATIONS: 

	Name: Prime Sport 
	Manufacturer: R/C Sports; Carmel, IN 
	List Price: Aircraft Kit: $209.95 + $10.00 
	S & H - Hardware Kit: $114.95 
	Span: 90" 
	Cord: 15 1/2" 
	Area: 9.7 Sq. Ft. 
	Weight: 17 Lbs. 
	Wing Loading: 28.1 Oz / Sq. Ft. 
	Height: 19" 
	Engine: 2.6 C.u. In. Sachs: A&M Aircraft 
	Propeller: 18 x 10 Dynathrust 
	Ignition: CH Electronics 
	Spinner: Tru Turn 
	Fatbric Covering: Coverite Supershrink 
	Resin: K&B 
	Primer: BASF Automotive RM-100 
	        Acrylic-Hyclrosol 
	Color Paint: Rust-oleum 
	Pilot Figure: Officers & Gentlemen 
	Radio: Futoba FP-7FG 7 Channel FM 
	Flight Photos: Al Priez 


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