 |
|
 |
|
|
|
|
          |
            |
 |
This item is discontinued. GREAT PLANES F-4 Phantom II 
Model: F-4 Phantom II Hits
Misses
FROM THE CORNER of my eye, I saw the MiGs glint in the sunlight. I was in perfect position to surprise them–behind and above, with the sun to my back. I went to full afterburner, pushed the nose down and accelerated to 650 knots. I came in from 200 feet above the ground, homing in on the lead MiG. "Rick, Rick." With the mention of my name, Larry Marshall brought me back to reality because he wanted a shot at flying the new Great Planes* F-4 Phantom II. For a moment, it sure felt as though I was in the cockpit chasing MiGs over Vietnam! THE KIT The Great Planes F-4 Phantom II is a .60-size, semi-scale, propeller-driven jet. This is Great Planes' fifth jet-like model that requires only sport model building and flying skills. This approach allows modelers to build and fly jets without the hassle and expense of using ducted fans. The engine nacelles, inlets, exhaust nozzles and tail cone are molded ABS plastic, and the rest of the model is built using usual methods. The model can be built with flaperons and with fixed or retractable gear. One nice feature is that all of the control linkages are internally concealed. The kit contains very nice die-cut balsa and plywood parts, rolled CAD plans, a clear canopy, landing-gear legs, decals and a photo-illustrated construction manual. The hardware package includes hinges, horns, pushrods, clevises, adjustable engine mount and other needed items. I dressed up the model with Great Planes drop tanks. Note that because of size and balance limitations, Great Planes does not recommend a 4-stroke engine that's equivalent to a .60. TAIL FEATHERS For all construction, I used Great Planes thick and thin Pro CA and epoxy. Both the stabilizer and the fin are assembled directly over the plans out of shaped 3/8-inch balsa pieces. The parts fit was excellent. The elevators and the rudder are built in the same way, but using tapered balsa. I tack-glued the control surfaces to their respective surfaces, tapered everything to match the plans, then cut the hinge slots and beveled the elevators and the rudder leading edges (LEs). All other edges were then rounded. I fit the torque rods on the elevator halves and the rudder and fit and glued a lower fin extension to the bottom of the fin. At this point, I jumped ahead in construction to glue the stabilizer halves together. I assembled a jig using the supplied die-cut, lite-ply parts. Make sure the jig is square. Next, I sanded the stab roots halves to the proper angle to create a good joint. The halves were then placed into the jig and epoxied together. Be sure the halves are firmly seated in the jig while the epoxy cures. WING Don't let the angles of the wing frighten you. The wing is a D-tube design that's easily built in three sections. I made the sub spars out of various lengths of 1/8x3/8-inch basswood. I decided to install retracts, so I epoxied the appropriate ribs to plywood doublers, being sure to make a set of left and right assemblies. I built the main (center) section first, upside-down on the plans. I pinned the main spars to the plans, and I epoxied them together at the same time with a preshaped center piece, then I epoxied a plywood plate on top of this. I added the ribs, ensuring the jig tabs were contacting the plans. I added another center piece and plywood plate to the center and then added the bottom spars (remember, the wing is upside-down). Sub trailing edges (TEs) are added to the ribs. I made sure everything was square and straight and then glued everything together. Next, I sanded the LEs of the ribs to match the angle on the plans and glued the shaped LEs to the ribs. Next, I added the shear webs to the front of the main spars. The retract mounts and reinforcements were added next, and the retracts were mounted when the epoxy had cured. The bottom of the wing is now sanded while still pinned to the plans, and the LE, TE and center-section sheeting is added along with the capstrips. Remove the wing when dry. Two crutches are now assembled from die-cut plywood pieces. These support the wing at the tips of the main section when you add the top LE and TE sheeting. Before adding the top sheeting, I made the cutouts for the retracts in the bottom sheeting, added the wheel wells, routed the air lines and made sure the retracts functioned properly. I sanded the top of the wing and tack-glued the crutches to the tips on the bottom of the wing. I replaced the wing on the plans, making sure the crutches and the main spar in the center section were in contact with the building surface. I added the LE, TE and center-section sheeting along with the capstrips. The main section is now completed by adding the aileron torque rods and plywood tip ribs for the outer panels. I also added the servo tray and final-sanded the wing. The outer panels are built in the same way as the main section and attached after the wing has been covered using plywood braces and dowel pins. The ailerons are also built now and hinged. Because I was using the optional drop tanks, I added plywood mounts and blind nuts where I planned to attach the tanks. FUSELAGE The fuselage is built using Great Planes' "Auto-Lock" construction. This allows the basic box to be built without glue so that all components can be lined up straight and true before final gluing. First I made up all the sub-assemblies and the fuselage sides. When you align the front and rear fuselage sides on the doublers, leave a small gap for the nacelles to fit into. When you assemble the formers into the fuselage sides, be careful when you rotate them into their slots. The firewall and tank floor are now added. Ensure the tank floor is not upside-down, or you will build left thrust. I placed the fuselage assembly over the plans to align everything and applied glue where directed. Next, I fitted the engine mount. The plans call for a belly-mounted nose retract; however, the retract I had on hand was made to be mounted on a firewall, so I made the changes necessary for the retract and epoxied the firewall into place. Balsa triangle stock was now added to reinforce the front end. The ends of the fuselage sides were pulled together with the radio tray in place and glued together. Be sure to thoroughly wet the fuselage sides behind former F7B, or you might crack the sides. I now added the 1/4-inch-square stringers and sheeted the turtle deck. I used the fin assembly as a spacer and added the rear blocks to the fuse. The fin was removed and the blocks carved and sanded to shape. The area behind the firewall on the bottom of the fuselage was sheeted next. Because I used a nose retract mounted on the firewall and planned to mount a steering servo in this area, I made this sheeting a removable hatch for access. I used 1/16-inch birch ply as a base and then sheeted it. Before adding the sheet to the hatch base, I made the cutout for the nose retract using the pattern supplied on the plans. To start nose construction, you will need to have your engine and spinner on hand. I first mounted the spinner backplate on the engine and then tack-glued the plywood nose ring to the back of the backplate using 1/16-inch ply spacers. The engine is now mounted on the mount with the ply nose ring the correct distance from the firewall. Three balsa blocks are glued between the firewall and the nose ring. I carefully removed the engine and added 1/2-inch triangle stock to the corners, added the final nose block and then roughly carved and shaped the blocks. Starting in the center of the right side, I made a small hole and gradually enlarged it to accommodate my O.S.* .61FX. I then remounted the engine and attached the spinner to final shape the nose. The wing is now mounted on the fuselage and the belly pan is built. After these have been squared up, the stabilizer is epoxied to the fuse. Because there is not a lot of surface area for the stab-to-fuselage joint, I decided to pin the stab to the fuselage using dowel pins. FINAL TOUCHES Now it's time to fit the nacelles, inlets, exhaust cover (which is the radio hatch) and tail cone. First, the nacelles are trimmed to the molded lines. I ran into a problem here: when trimmed to the lines, the nacelles were 1/4 inch too short in the wing saddle and on the aft end. I rechecked the fuselage against the plans and found everything correct. Measuring the nacelles against the plans confirmed the problem. The fix is easy though: just trim the nacelles past the molded lines and then fit them into place. Remember the gaps that were made in the fuselage sides? The nacelles fit into these gaps for a positive fit. Once the nacelles had been fit, I attached the inlets. [Editor's note: this has been corrected in subsequent kits.] I assembled the radio hatch halves and added the front plate. Then I fitted the hatch to the fuselage and added blocks for the retaining screws. I now fitted the tail cone and glued it into place. I also fitted the canopy and added Williams Bros.* pilots. The airframe is now ready for final sanding. The instructions call for gluing the nacelles to the fuselage after they have been painted and the fuselage has been covered. This would require filling the joint and touch-up painting of the nacelles and fuse. Instead, I glued the nacelles to the fuselage before covering using Zap-A-Dap-A-Goo, then I filled the joints. The plastic parts quickly give you a finished fuselage with a minimum of work. Next, I covered the Phantom with Polytex* and painted it using a combination of LustreKote* dove gray, tan, olive drab and aluminum paints. I also used Testor's dark green paint, since LustreKote is not available in dark green. Next, I added panel lines and decals and sealed everything with a coat of Lustrekote flat clear. The radio gear, pushrods, retracts, engine and fuel system were now installed and final operation checks made. I balanced the model and set up the control throws as recommended. The Phantom was now ready for its first flight. SUMMARY Did Great Planes come through with a simple jet? I think so! Although it's not a beginners' model, it's easy to build and looks great. The use of ABS molded plastic for the complex shaped parts really cuts down on the building time. The model flies well and looks great in the air, especially with the gear up and the drop tanks attached. If you're looking for a neat-looking jet that's easy to build, the Great Planes F-4 Phantom II is hard to beat. FLIGHT PERFORMANCE Because the engine was new, I ran a few tanks of fuel through it first and then proceeded with taxi tests. Takeoff and Landing Just like its full-scale counterpart, the Phantom uses a lot of runway on its takeoff roll. When flying speed is reached, up-elevator is needed for rotation. Once airborne, backpressure is relaxed to build up speed and to gain some altitude. I made a few trim passes for straight-and-level flight; a little up-trim was all that was needed. Landing the Phantom is easy: set up your approach, start pulling the throttle back, lower the flaps (it also lands well without flaps) and head for the numbers. Once proper attitude is achieved, sink rate is controlled with throttle. Once I was over the end of the runway, I cut power, added up-elevator and let the Phantom settle to a beautiful on-the-mains, nose-high landing. Great fun! Low-speed Performance With its big wing and up-swept wingtips, the Phantom handles low speeds well. When it stalls, the break is clean with no surprises. Apply power and the Phantom is flying again. With the flaps deployed, a little down-elevator is needed to keep the nose level. Slow speeds are then even slower. With the ailerons inboard, good control is maintained up to the stall. On my Phantom, a little up-trim was needed to maintain level flight. High-Speed Performance This is where the Phantom shines! It's very solid and tracks as if it were on rails. Set up as per the manual, controls are good. Aileron and elevator are very positive but not sensitive. Wide, sweeping turns are the order of the day, but pull a turn too tight and airspeed will bleed off quickly. No pylon turns here! High-speed, on-the-deck passes with pull-ups to victory rolls sure are fun! Aerobatics Although the Phantom is capable of loops and rolls, it is not an Extra 300, nor is it claimed to be. Aerobatics are realistic and smooth–perfect for this type of aircraft. Rolls are axial and smooth. Loops could use a little more power, but vertical performance is still surprisingly good. All told, the Phantom is a fun jet to fly. Reprinted with permission.April, 1999 Model Airplane News Editor: Gerry Yarrish
|
|
 |
