Last year I took my family on vacation to a friends cabin on Cascade lake in Idaho. While there I was able to build the first prototype for my 800 Series nnSpitfire and fly it around. Unfortunately, the location where I was flying had a tail wind landing and a VERY short runway... Oh and I only brought a few propellers, d'oh! Sooo, I only got to fly the prototype a few times and didn't get to capture much video. I decided to leave the plane with its electronics with my friend at his cabin in the hope that I'd be back one day.
Fast forward to July of this year. We were able to arrange another vacation with the same family friends and this time I brought plenty of props :-) I was able to fly high up in the mountains and over the Cascade lake (right off the cabin deck). I packed a lighter battery so the tail wind landing on the short runway gave me slightly less trouble, but was still a challenge each flight.
I captured some video to share with you, and I hope you enjoy it.
I clipped a multi rotor gate last week and cartwheel landed. The wing was slightly damaged and the fuse joint had some sponge. Seemed to fly fine, though. :-) Soooo, I took her out again and about 30 seconds into my first flight I did a high speed snap roll from about 150 feet up. I was probably doing about 80mph when I started the snap and mid roll the wing flexed where the previous damage was and the fuse started to torsion under the new angle of pressure.
The plane was too far away and going to fast to see the finer details of the failure but it looked liked the fuse crunched and forced the wing into a negative G which snapped it in half instantly. My poor 2lb plane never stood a chance.
One half of the wing ripped off and fluttered down while the rest of the plane entered a death spiral. I had about 10% control at this point and tried to slow down the rate of spiral and descent but I don't know that I helped any. The plane pile drove so hard into the grass that the entire motor, 10x10 prop, and a good inch of the fuse was completely underground.
As I walked over to the mangled remains I was worried about battery damage. The Tacon 10 motor I'm using has the fun inward protruding motor shaft and I didn't have my trusty Dollar Tree pool noodle in place for protection. There was no sign of fire until I moved the plane.
Pulling the fuse shifted the motor shaft that had embedded into the 2nd cell of my, at this point, still fully charged 4s 2200. Once the shift happened huge amounts of white smoke started pouring out.
I quickly pulled all the electronics I could away from the battery. One by one each cell went up, letting out more and more smoke. This was my first 'in person' lipo fire, so I was impressed to be honest. I wasn't too worried about fire since the grass was so green. There is a nice little burn patch that remains, but no real risk of fire was ever present.
It took about 15 minutes for the battery to finish hissing and smoking. Even after that, though, it was still too hot to touch. All my electronics survived. Crazily enough, The motor has no damage. It was buried so far into the ground that all the surrounding dirt kept it protected.
I haven't run it up yet so that will be the real test, but the bearings still feel nice. I guess since the shaft was connected to a super heated chemical fire there might be some internal damage I'm not aware of yet, but we'll see :-)
Story time! Here's how I crashed my nnMiG 800mm. No video to share but here is a rundown of what happened.
Plane was set, CG was good, throws were medium. I throttled up to 50% and threw her hard. Torque roll hit immediately and I rolled right to correct. My elevator must have been trimmed down because she started to dive 30 feet out. Quickly I pulled back on the stick to correct but I had too much throw. Immediately I stalled the plane. At about 40 feet up she rolled over very fast and nosed into the ground. My heart sank. A few other pilots who I see often were watching and it was the worst walk of shame in my RC career so far.
I walked over to my busted plane and could see it was wrecked. The wing broke free, nose was bent in half, motor mount was broken, pod shredded, and electronics were ejected.
Determined to fly this thing I quickly made use of my field hot glue gun and patched her up. After about 10 minutes she was ready to go, ugly, mangled, and about 20g heavier, but she was ready to fly. My level of disappointment in myself at this point was pretty high.
I adjusted my trim, dialed my elevator from 50 to 40, ailerons from 65 to 44. Set throttle to 75% and threw her harder than the first flight. I tried to correct lightly for torque roll and didn't touch the elevator until I was stable in flight.
She flew amazing. I cannot believe how fast this plane is, I didn't have radar ready but it was significantly faster than my nnChipmunk 800mm and I got that on radar last week at 107mph. The sound this thing makes is very quiet as it zooms by, there is little to no 'air' noise coming off of it. It felt better than the full size with how slippery it is in the air. Ailerons were still too touchy and my elevator needed some more expo. The 4 minutes I was in the air felt like only a few seconds and I wasn't ready for it to end. My voltage telemetry started to chime telling me I'd hit 3.4v on a cell and that meant it was time to land. I'm never nervous to fly a new plane, but the first landing always puts me on edge. You never know how it's going to handle a landing and a hard hit can be the end of a plane. Even though she was already mangled, I was still uneasy about the landing.
I cut throttle very far away and started my glide in. She came in fast and didn't bleed speed at all. Normally I cut throttle at the same point with my other planes and can land close to my feet every time. Not this time. By the time I made it to where I was standing I was still 5 feet off the ground and doing at least 40. I've had issues in the past trying to land going away from myself, I usually underestimate my speed and land hot. Welp, that's exactly what I did here too. I hit so hard that I somehow broke both of my prop blades.. and I use a brake.. and my prop was not vertical. No idea how that happened. This thing is a fuel prop too, not a thin electric one, you could cut a steak with this thing, or go ice climbing or something.
Changed my prop, dialed back ailerons to 35, added 50 expo to elevator and was ready for my next battery. With the added expo I was able to launch very smoothly and it looked great. I was doing large racetrack laps and enjoying how awesome this thing sounded as it flew me at full throttle. After about 3 minutes I was high up to my left and about to begin my dive/return home when suddenly she started to dive and spiral. I was about as far as line of sight would allow for this size plane and wasn't able to tell orientation during the dive. At about 150 feet up she plummeted into a huge tree. I must have been 300 yards away and I could hear the tree branches snap and crack. AUW with my speed setup is over 800g so this thing is solid.
As I watched and heard the crash I waited to see if she made it through the tree and hit the ground. Nope. This makes 4 planes I've gotten stuck in trees to date. It was just about sundown, cold, my wife and son wanted to go home, and I was completely defeated. It was also dinner time, and I was starving. My wife encouraged me to go try and get it down from the tree though, so we walked over together to see how bad it was.
As we approached I could see a wing on the ground, "how did this happen?" I kept thinking to myself. "All that hard work.." There were a few kids that had run over to investigate the crash, their parents stood back and observed also. My plane was stuck up really high, about 50 feet up or so. The tree had no branches for the first 10 feet so it wasn't climbable.
I started to collect sticks and rocks to throw. After a few tosses some of the kids went and got a soccer ball and helped me find more sticks. Some of their parents joined in as well. I didn't ask for help they just started helping. My plane was just high enough that you had to throw as hard as you could to even get close, it seemed hopeless. All of us were throwing sticks and balls into the air trying to get this plane down for a good 40 minutes. Now that I think of it, I can't believe they even helped to begin with. I half expected them to yell at me for crashing since it was fairly close to a little play area where they had been. So that was actually really cool to see them want to help. A half dozen kids and 4 parents all trying to get a RC airplane out of a tree, it was a sight to see for sure, lol.
The sun had now gone down and it was starting to get dark. One of the parents had been collecting long sticks and trying to use it as a poker to knock the plane down. There weren't any sticks long enough so I focused on throwing the soccer ball. I hit the plane many times and was able to shift it here and there but no luck. It was really wedged. The kids found some of my servo extensions, battery, and battery telemetry sensor on the ground 20-40 feet from the tree. Impact must have sent everything flying.
A few of the kids had to leave and parents said good luck and left. There was just a few people left and the guy who was looking for big sticks to poke the plane came up with an idea to tie more than 1 stick together. This was the best idea yet and my arm was getting really tired throwing that ball over and over. We took off our belts and fashioned the sticks together to make 1 big, mega, poker stick. It must have weighed 60lbs and took 3 of us to lift and put into place. As we moved it to the tree we saw that it was tall enough to reach.
It took about 5 minutes to move the plane enough to get it down. Lifting up from the bottom allowed us to knock it from the branches it was stuck in. It came crashing down and one of the kids caught it, awesome. I was really glad to have my plane down as the motor, ESC and RX were still in the plane. The airframe is 100% destroyed but all electronics seem to be okay.
I've never been so bummed about losing an airplane as I was tonight. I spent a lot of extra time on this one getting it perfect. I'm still looking over my TX logs to see if I just suck at flying or if there was some kind of failure. I don't trust my ESC or RX right now and that's really crappy. So with all that being said I'm grounded for now until I can figure this out. It was really cool to see all the people come and help me, that was really unexpected and ended up being what got my plane down.
The failure was caused from being tail heavy. I have since adjusted the CG on my nnMiG 3 (plans are updated too) and it flies even better now!