Building a Giant Lifting Body Aircraft

by FliteTest | August 7, 2018 | (3) Posted in Projects

Huge builds are a common sight at Flite Fest. Here's what happened when we tried to make one to join in with the fun. 

The task was simple: build a behemoth to compete in one of the combats happening at Flite Fest Ohio 2018. Armed with just a stack of foamboard, some electronics and heaps of patience, I took on the challenge. We've built huge planes before, such as the Super Circle Plane in 2015, but this one would be a little different! 


Video

If you want to see what happened from beginning to end, check out this video.



The Concept

The initial inspiration for this aircraft came from a completely random sketch on the back of a scrap sheet of paper whilst on a flight to the USA. After thinking, 'hey, that would be a neat idea', I decided to do a few more drawings to flesh it out.  


Skipping forward a week, Jeremy, Alex and I were talking about potential ideas for the Flite Fest combat that was just around the corner. After an enthusiastic response to my suggestion of a lifting body 'target' for people to crash into, I set to work getting things ready for the big build. 


The Build

Starting with the powerplant, the motors and ESCs, I had a good rummage through the various stashes of spare electronics strewn around the Flite Test shop. After some thinking, I decided to go with a couple of these EMAX outrunners. They're from Power Pack B and can use a 4s battery for extra thrust. They seemed like they might be a little on the small size, but the aircraft was planned to weigh around 3kg (6.5lbs). Fingers crossed they would be sufficient! 


After testing all of the power systems together to see if everything was working (some of it had been in the boneyard for quite a while!), the gear was packed up and thrown in the back of a car bound for Flite Fest. It's a really good idea to check your gear before permanently installing it in your airplane or quad. 


Construction of the airframe began by tape-gluing sheets of foam together. If you're not familiar with this building technique, all it involves is taping two pieces of foam together, flipping them over and gluing in the seam. This creates a strong joint for larger models. This aircraft took around nine sheets of foam in total. 


After an evening's work, the strange looking aircraft was taking shape. The structure was very minimal relying on a triangular 'spar' in the center. This allowed for a pretty lightweight airframe.  


Formers were added to both the front and rear sections to give the top sheets of foam something to support them. Again, this was a lightweight solution and quick to build. If I were to have spent a lot longer on the aircraft, I would have spent a good while longer planning the internals before starting on the build. I think it might have been possible to build some sort of frame which you could clad with sheets of foam board later on. 


Incredibly basic winglets were made from foamboard. These didn't contribute much to the overall lift of the aircraft, instead, they were meant for attaching control surfaces. Ailerons on here, in the propwash of the motors, were intended to solely control the roll axis. 


Like most things on this build, the wings were then bodged together with the main body of the aircraft. Wires were fed through a small access hole cut into the top surface. 


Around ten minutes before the combat was due to start, the finishing touches were added to the behemoth and it was named 'The Whale' - an appropriate title for a rather ungainly looking machine. Next stop, the flight line!


"No joke, The Whale doesn't look like it should fly" - Stefan. 


Assessing the 'Flight'

Unfortunately, The Whale was a massive, belly-flopping failure. After a good old toss from a couple of willing Flite Fest volunteers, it went up, out, rolled over and crashed into the floor. What a fail. 


Sadly, I never got the chance to fly The Whale again. Right before the 1pm combat, after a quick rebuild of the damaged winglet and motor pod, the Spektrum transmitter I was using ran out of battery. Great! Although this wasn't a happy ending, The Whale will live on as the airplane that tried to fly without wings. Good on it. 


The MK2

The story doesn't end at Flite Fest. The Whale showed enough promise that the concept of an RC lifting body aircraft will be revisited in the future. With the experience of this one under my belt, I feel confident that a MK2 will have (a little) more success. Watch this space!


Resources for Scratch Building!

Foam board

Electronics

Pro Glue Gun


Article by James Whomsley

Editor of FliteTest.com

james@flitetest.com

www.youtube.com/projectairaviation

COMMENTS

Munk on August 9, 2018
Maybe you could build some dihedral into the lifting body for added stability. This thing is awesome, can't wait to see mk2!

Dan
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rblubaugh on August 7, 2018
I believe I saw that you are using the motors for yaw, but you also need som (big) rudders, IMHO.

Bob
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Building a Giant Lifting Body Aircraft