Fixed-Wing Proximity Flying

        After viewing many videos of quadcopters racing through trees and various obstacles, I felt the pull to join in with the fun. Although I have FPV gear, I unfortunately did not own, or want to buy at the moment, any kind of multirotor. So I made use of my familiarity with scratch built foamboard airplanes and whipped up one that I thought would suit the proximity flying style. Soon enough, after finding a good area, I was having a great ol' time weaving all around the place--and recording the best parts of course.

If you are opposed to the sound of an electric motor, mute the video (unless you are like me and kind of like it for some reason).

I have been fortunate, so far, that the crash at the end of the video is the only one I have had in a dozen flights (not counting close calls), and I was able to keep flying that day without any repairs. 
 

      The twin-boom plane I made is not the conventional flying wing used for fixed wing proximity flying. The reason for my choice, although I probably sacrificed some durability, is that I find the elevator response on a tailess platform to be less reliable than on a tailed one (if you can call that a tail). This is particularly true with the design I used, as the control surface is directly behind the rear-mounted motor's propwash, which allows me to have complete, extremely tight control over the elevator even in a stalled position, with just the application of some thrust-- which, I might add, is a handy 1.2X the weight.  

      The airframe is of course hot-glued foamboard, but, as I do with almost all my planes, it is also layered with packing tape for some water resistance against the moist environment I live in. As an even stall is important to me considering what I was going to put this plane through, I gave the wings Flite Test style undercambered wingtips, with barbeque skewers embedded along the two high point creases of the airfoil in the camber, which gives that single layer of foamboard a surprising amount of strength. I wanted this plane to be aerobatic and carry FPV gear, a GoPro in its protective case, a 3200 Mah battery, and a decent sized motor, yet still not be too big to fit through smallish gaps. I ended up with a 40 inch span and 410 square inches of wing area, which gives enough performance that I might make V2 a little smaller to increase its durabilty and hole-clearing capability.

      Although I would definitely prefer a mini quad for proximity flying for multiple reasons, the one big thing in favour of my plane is that 15-20 minutes of continuous flight per battery (down to 3.80 volts a cell) is the norm. From what I have heard, that is at least a twice as long as its multirotor competition. I also enjoy just FPV cruising around and enjoying the scenery, so this extra uninterupted flight time is quite appreciated.

      Aside from the evident disadvantages in a comparison (size, lack of brakes, etc.), my biggest gripe with a plane is that it can be difficult to look where you want to go--to see any obstructions immediately ahead of you in a sharp turn before it is too late. In an effort to reduce this disability, I attached my flight camera to a 180 degree pan servo controlled by my rudder stick, since this is only an aileron/elevator plane. Being able to glance over before I pivot does help a fair bit, but only during horizontal flight. As soon as I bank into a turn, I am uselessly looking into the ground, plus it is hard to judge the roll and angle of attack of the aircraft when looking to the side. A quadcopter, however, can look anywhere in 360 degees while traveling in another direction and still maintain orientation...I can't wait to get my hands on one of them! Nontheless, I love the challenge that this endeavour presented for fixed-wing, both flying and design-wise, and I have no doubt I will continue with improving both areas for a while yet.   

      Anyone with FPV equipment, competent flying skills, and the ability to assemble a nearly disposable airframe should give this style of flying a shot; it is the most fun I've had in RC since I successfully flew my first scratchbuild!

Basic Dimensions:

SPECS:

AUW: 38.5 OZ

Wingspan: 40 inches

Wing area: 410 sq. inches

Battery: 3s 3200Mah LiPo

Motor: Power up sport 15 1000Kv

Prop: 9X6 APC (Motor-prop combo 45 OZ thrust)

FPV transmitter: Fatshark 250mw 5.8Ghz (with Immersion RC spironets)

FPV camera: 600 TVL Fatshark CMOS 

Recording camera: GoPro 3+ silver

I hope you enjoyed my first attempt to share my experiences in the RC hobby on Flite Test!