So, You Want to Fly at Night!
Let's face it, we all live in New Mexico where three months out of the year we have a building season due to high winds during the day. But, has anyone noticed that most of the time, windy days are followed by calm evenings? There are not too many weeks during windy season that the wind continues to blow when it is dark. I could go into the reasons for this, but suffice it to say, as modelers it would be nice to take advantage of some prime flying weather.
Some years ago, I started flying at night using a GWS Slow Flyer with standard FAA Navigation lights on the wingtips and a flasher on the tail. I transitioned to a glider with the same lighting system. With these minimal lights on the wings, at least one nav light would completely disappear from the ground when the plane would bank in a turn. The pilot needed to fly the plane all the time, anticipating the return of the light and if it did not come into view, you would need to change the control input. While this is very thrilling, you could not do anything but fly very slow airplanes in a great big circle. And, of course, at night there is no thermal action, so the sailplane really turns into a big powered trainer type airplane!
Fast forward a few years and the invention of LED lighting. Now, for very few watts, many high intensity LED's can be added while keeping the current draw to a minimal, thus not affecting the flight time of your electric plane. There are many options when looking at lighting systems so choose wisely!
My recent project is a vintage Hobby People powered glider, with V tail and ailerons. My father picked this plane up at a yard sale for $10 which included the 2.4GHz radio. The only real issue is the 6 blade prop was damaged and replacements are not available. So, a bit of tinkering and a two blade modified prop was found that will fly the plane. It is the perfect candidate to transform to a night flyer as it is EPO foam, has a mild personality in the air, and will roll/loop with a bit of convincing.
For lighting, I had been looking at the LED strip lighting available at most auto parts stores. These are a bit pricey, but they are rubber coated so the lights are protected and the system is designed for 12 volts. Advantage: I can wire this directly to my 3S LiPO at 11.7 volts and will have plenty of light without any further voltage conversion. Disadvantage: they are a bit heavy since they are rubber coated.
Since the plane is white EPO foam, if you shine a high intensity LED into the foam, it glows that color for several inches. So I decided a 6 inch strip of color on each wing and a 12 inch strip of white along the fuselage would be enough. Remembering the FAA system of Red on the Left, Green on the right, I chose Red, Green and White strips from the parts store. I also found that these strips can be trimmed to length, and if you take care, you can remove the rubber coating and re-solder leads to the left over for another airplane!
I soldered a JST connector in parallel with my deans battery connector, this way I can unplug the lights for daytime use. All lighting strips are wired in parallel using the wire provided with the light strips. This provides the 12 volts from the flight battery to be provided at each LED strip. Since the wattage of the light strips is so low, it really does not affect the battery usage much. At all costs, avoid plugging these strips into your receiver or using your existing BEC for this. You don't want to over-tax your BEC or receiver power source and loose control of the airplane!
I use hot glue to attach the strips directly to the EPO foam. Along the bottom of the fuse I cut a V notch and recessed the lights, then covering the system with clear duct tape (available at our local Hobby Lobby). On the tail I used the same V notch on the top of the tail in order to recess the lights and not create too much drag on the tail. The wing lights are surface mounted on the bottom of the wing using hot melt glue. (Note: when using hot melt glue, make sure you check that the temperature of the glue will not melt the EPO foam! If it does, use a cooler temp glue or unplug the glue gun and let cool a few minutes before gluing the foam)
After several flights with the red/green/white, I decided I really needed some additional lights on the tail. For this I chose to put a 3 inch strip of blue on the tail.
You can tell the top from the bottom since the wing lights are mounted on the bottom, they are very bright when you view the bottom of the airplane. When the plane is inverted or you bank it only viewing the top, the lights are subdued due to the diffusion of the foam.
These lights are bright enough, that when I bring it in for landing, at about 5 feet of altitude, it lights up the runway! At times, they almost seem too bright, but what fun.
Last thoughts, avoid random blinking or fun patterns of blinking lights on your plane. It is easy to get disoriented while flying at night and the confusion blinking lights would bring might end up costing an airplane.
Since I created this night flyer, I have ordered additional LED light strips off e-bay by the roll. I don't know how these will work, but I do know that the 12 volt lights from the auto parts store really work nice.
If you have any questions, give me a call. I would be glad to assist!
I was able to get video of the plane while recently flying at our field. Note that there was no moon the night we shot this video! https://www.youtube.com/watch?v=eyjrSkYJ9-Y&t=52s