JC's Planes and Projects

Hanger 9 CAP 232 (1/4 Scale) Finishing and Flying

Upon completion of the airframe, a preliminary CG check was performed without the RX battery installed. The CG was found to be forward of the recommend point. This was actually good news, and the CG was brought into spec by positioning the RX battery where shown above (Note: The battery was moved forward of the servos as the airplane was slightly tail heavy on the first flights). I then did the final assembly of all components using thread-lock on all screws and cable ties on all fuel tubing connections.

The kit comes with a totally white bottom wing. To break this up, I added two eleven inch five pointed stars. It always helps to be able to quickly distinguish between the top and bottom sides of the wing. The radio was set to give the recommended high and low rate travels. The 3D travels were not set because this is not the intended use of this airframe. I also setup differential aileron as indicated in the manual and also added exponential.

After a nice cleaning to remove dust, the decal set was applied as directed. I had no fear in applying these decals because I knew that they would not be deluged with glow fuel residue and eventually lift. Fully assembled, and decal-ed, I finally was able to step back and admire my work. You know it really is a handsome airplane!

At the field on a beautiful Summer day ready to fly!

Flying the Hanger Nine CAP 232

5/4/02 - Today was the first flight of the CAP/MVVS. Conditions were good with a 5-10 mph wind at about a 45 degree cross from the runway. Temperature in the evening started out at 60-degress F, and declined to 50-degrees F as dusk approached. The airplane was assembled and all radio functions double-checked. With Mike's help, I prepared to start and tune the engine. I was able to use my "pinkie" finger to block the carb throat to choke the engine. After five turns of the prop while choked, the ignition was turned on and the engine started within a few flips (love it!).

The engine had never been run with the Bisson muffler or in the aircraft. I let it warm up a little, and noticed that the top end was sounding a little rich. I slowly adjust the high-end needle to find a peak rpm of 7900 rpm. That is 400 more rpm than with the stock muffler. I went a tad rich from peak and this produced a solid 7800-rpm. The low-end needle needed no adjustment.

With the antenna collapsed, I did a range check with the engine running. No glitching of the standard Futaba 7-channel PPM RX was found - great! Well, no more excuses, I went over the linkages again, got a drink of water, and waited for the only other flyer at the field to land. I wanted the sky to myself on this test flight.

The engine was started and the CAP taxied out on to the field. I was using low rates for the take off. I did a few figure-eight's on the ground to get a good feel for the handling. The CAP handles like a sports car on the ground with no tendency to nose over. At this point I was very glad that I had upsized the main wheels as it rolled nicely. I turned the nose down the runway for takeoff and advanced the throttle slowly as she gained speed. The CAP tracked superbly despite the crosswind. As I neared full throttle she was dancing on her mains and I rotated and climbed out under full throttle.

Once in the air only a click or two of aileron and elevator were needed for trim. This airframe nearly flew "off the board." This was my first "big" airplane and I was very pleased with how rock solid and precise it was. Bigger really does fly better! The MVVS was performing very well with linear power delivery and only 50% power needed for a good cruise speed. The roll rate was slow at the low rates, so I switched to the high rates. Rolls are very nice and axial. I also threw in a loop with no problems. Most of the flight was just gentle circuits of the field. The sound was quite mellow and I have no fear of meeting our field's 98-db at 3-meter sound limit. After 11 minutes I set up for a landing. The airplane is rock solid on final with the MVVS at idle. I was caught by surprise by how the CAP wanted to "tuck" it's tail as airspeed got very low. As airspeed decreases, you need to reduce up-elevator pressure or she will balloon. The good news is that the first landing was a greaser and I proudly taxied back to the pits.

On the second flight I started to wring the plane out. I was very comfortable flying at high-rates and did the whole flight at this setting. I started out with very large loops and noticed a tendency to "rainbow" to the left. I may need more right thrust, but I will try a touch of rudder trim first. I did a few Cuban-eight's and was having a great time flying what is for me a large airplane. Inverted flight was very good with just some gentle down elevator to maintain altitude. I had to mentally adjust by flying a bigger aerobatic box and getting a better feel for speed and distance. Full power at straight and level speed was well tolerated and I believe that the propeller 8-pitch speed is about right. About halfway into the flight it was time to go vertical! I roared past at full throttle and pulled into the vertical line. It maintained a good pace and reached a towering height before slowing to a stop, hanging, and then falling away. I did a couple wild snap rolls on high-rate and over rotated both. Climbing knife-edge was easily performed, with the aircraft predictably pitching negatively. This will be mixed out in the future. I shot a few landings and pulled into the pits after 13-minutes.

Summary:

Based on these two flights, I really like this airframe and power-plant combination! It is very solid and the only quirk is that tail-tucking on landing. It will be an excellent IMAC Basic and maybe Sportsman competitor. The MVVS was bulletproof and ran with absolute consistency throughout the flights. It started easily, idled well, and had a nice linear power output. At no time was I worried about a flameout, as I would be with a new glow-powered ship. This combo is not for you gonzo-3D guys. Vertical is towering, but limited. I expect it to get better as the engine breaks in, but it clearly does not have the 1.5:1 power surplus needed for hovering. Of course, the best part is that I burned less than 20-ounces of gasoline and clean up took a minute with a half of a paper towel!

5/20/02 - I flew the CAP three more times yesterday. I installed a 3W 18x8 propeller (Menz S clone). The max rpm was 7300. The performance was not as good as with the 17x8. In addition, the lighter wood prop seemed to exacerbate what I think is a tail-heavy condition. The airplane did not groove well, and landing was very touchy. I have repositioned the battery to the front of the radio compartment to move the CG forward. I also added a little up-thrust to the engine. I will report my findings after more flight testing.

5/30/02 - I put three more flights on the CAP over the weekend. The tail-tucking tendency is solved and the CAP is now very stable on landing. It was just a symptom of an aft CG. Moving the RX battery pack in front of the servos gave a more stable CG. I reinstalled the APC 17x8 propeller for these three flights. The airplane has better vertical with this prop - although I will do more testing with the 3W 18x8. I cut off the curled ends of the Bisson muffler to try to get a few revs. This had no effect. I was still getting a max rpm of 7900 with the APC 17x8. I am enjoying this airframe and powerplant and look forward to a calm evening to further trim it out. I now have nearly a gallon of gas through the engine.