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This flight review is not meant to be a construction article, for those looking for a step-by-step article on how to build the HET-RC - F-4 (Phantom) please click on the "Build Articles" section to the left.

My goal is to simply show some of the assembly process and the modifications that I made while building my plane. Since many build ARF's stock, I thought it would be interesting to make some minor changes and share my experience with those considering the same

I hope you find this article both interesting and informative, if you have any questions, feel free to drop me an email at: kpetrilla@ameritech.net .

Modification #1: (Wing Servos)

I personally do not like the servo control horns sticking out of the top of the wing, although I can understand why they are on top on a belly flopper. I decided to have the servo control horns and pushrod assembly on the bottom of the wings. The whole assembly was then covered with (Graupner) servo covers.

Modification #2: (Elevator Servos)

The manual from the factory recommends using two servos for the elevators. I chose to use one servo (Hitec HS-85) instead. I made a "Y" pushrod from two standard 2-56 pushrods to control the elevators.

NOTE: I chose note to modify my horizontal stabs as outlined in the manual. They were installed as provided in the kit.

Modification #3: (Canopy)

As provided by the factory, the canopy floor was a bit flimsy and warped. I duplicated the canopy floor with a piece of basswood that was a little bit thicker. The manual recommends installing a magnet retention system to hold the canopy in place. I wasn't completely comfortable with the recommended system so I installed a screw down system. There is a small blind nut installed in the fuselage at the rear of the canopy opening. The small lip at the front of the canopy is slid under the front of the canopy opening on the fuse. A small screw is then inserted through the back of the canopy (and canopy floor) and then screwed into the blind nut in the fuse.

NOTE : Make the hole in the plastic canopy big enough to pass the screw head. Make the hole in the canopy floor just big enough to pass the screw body, but not the head.

Modification #4: (Power System)

I chose to mount the controllers under the canopy in the F-4. These controllers are also used in other aircraft so I wanted to be able to remove them when needed. The controllers are mounted in parallel to the battery so they see the exact same battery voltage throughout the entire flight.

I made a custom battery tray for the two battery packs. Each individual pack is made from 2-2s Polyquest 3700 packs run in series for 4s. The 4s packs are then run in parellel to make one 4s 7400 pack. Having the battery and power system run in parellel ensures that each motor will see the same voltage. A small spacer was then added inside the fuselage for the battery tray to rest on. The tray is held in place with a screw into the spacer.

Ready for her Maiden Flight:

Maiden flight:

The F-4 was finally ready for flight. I packed up my gear and headed to the local field. This would be my first time launching a 5 pound plane from a bungee so I was a little concerned, although not overly concerned since I have launched four other HET jets successfully from this same bungee. My bungee system consists of the JEPE bungee system, a Wemotec pedal release, and about 8 feet of carpet. The carpet is used under the aircraft to keep the stabs and wings from snagging the grass immediately after release.

I set up my bungee directly into the wind with 22 pounds of pull. I like to have a little more than four times the models weight in bungee pull. My F-4 weighs 5lbs ready to fly. Before releasing the F-4 from the bungee, I ran the motors up to idle to make sure they were both running and in sync. I then stepped back and hit the release button on the pedal. The f-4 shot down the carpet immediately but did not jump into the air as is customary with my other lighter single fan jets. The F-4 needed an additional few feet in the grass (after the carpet) and then it climbed out aggressively. The first thing I immediately noticed was that I needed about ten clicks of up elevator trim to fly level. After I dialed in the elevator trim I flew around for a couple of laps just to get used to the airframe. No additional trim was needed to fly straight and level.

Now that the F-4 was trimmed out I wanted to see what it could do. I made a downwind turn at the end of the field and went to full throttle for a high speed pass. The first thing that cought my attention was the perfect singing of the twin fans. What an amazing sound! The f-4 shot past me and I pulled up at the other end of the field. The F-4 is fast. It is not quite as fast as my HET F-16 or Sniper but they do not sound like this! And anyway it's not that far behind. The climb out after the high speed pass was impressive. Although the F-4 was slowing down slightly in the vertical climb out, I had to cut the power so I would not loose sight of it. At this point I was more than a couple hundred feet high so I decided to test the stall characteristics of the F-4. I pulled the throttle back to idle and slowly fed in some up elevator. The F-4 slowed way down and was barely crawling along before it abruptly dropped its nose. I was amazed at how slow it could fly. At this point I knew landing would be a breeze. Although the stall was fairly abrupt, It was straight ahead and was easy to recover from with a bit of up elevator and some power.

The F-4 is a superb flyer. It tracks like an arrow with no sign of tail waggle or shimmy. It is very predictable, no surprises with this airframe. Loops are easily accomplished and can be just about as big as you want them. Rolls are just a touch off axis and can be extremely fast on high rates. The F-4 flies upside down easily with just a touch of down elevator. At this point I had been in the air for 5 minutes. Even though I knew I could get a couple more minutes easily, I wanted to have some power left just in case I needed to go around for another landing attempt.

I headed downwind and slowly turned into the wind at the end of the field. I pulled the throttle back and watched as the F-4 quickly settled into the landing pattern. I had one small problem. The F-4 floats much more than I though, even after the stall test, so I had to go around again. I was now really glad that I saved some extra battery power. On the second attempt I started my approach at a much shallower angle. This time it was perfect and the F-4 settled in nice and slow for a very graceful fully controlled landing.

Some final thoughts:

Although the F-4 is a superb very predictable flyer, I would only recommend this aircraft to someone with at least one high performance edf experience in their past. The sound of the F-4 in the air is amazing, well worth the cost in both time and money for setting up two edf power systems.

The F-4 needs more up elevator than I would like to see. It might be the extra incidence that is added to the wing during construction. I plan to try different cg locations in the future to see if that will help.

If you take the time to build the HET F-4 you will be rewarded with a superb flying aircraft that will turn heads at the field every time.