Have you ever had one of your models catch fire from turbine operation of any type? (Only answer if you fly turbines).
This all happened last weekend: Sunday, April 23, 2023. After immediately inspecting the wreckage and the mechanics to determine what happened, I saw that the spline on the front of the tail's drive shaft was completely missing... it backed out while in flight. No drive shaft spline = no power going to the tail rotor.
I was attempting to autorotate the 429 down, despite what it may or may not...
This all happened last weekend: Sunday, April 23, 2023. After immediately inspecting the wreckage and the mechanics to determine what happened, I saw that the spline on the front of the tail's drive shaft was completely missing... it backed out while in flight. No drive shaft spline = no power going to the tail rotor.
I was attempting to autorotate the 429 down, despite what it may or may not look like in the video. I was trying to first get it stabilized, and then get it lower to a decent and more manageable altitude to start an autorotation. My mindset is to get a higher elevation at first to give myself time to think and make a plan for action. I had NO idea it was going to break apart in the air like it did. None of the other helis I have that had a tail issue and spun ever tore itself apart like this 429 did.
Fast foward to today: Sunday, April 30, 2023. Today makes a full week since I lost my Bell 429 and I figured I'd bring the wreckage into the house today to sift through it to see what's salvageable and to also document and share my findings.
Firstly, I found the front drive shaft spline - it's stuck inside of the front tail gear box which is what the first photo illustrates. Secondly, look at how the front of the torque tube boom sheared! The front portion is still inside of the clamp with the top locationing screw still going through it. I find it interesting that the front of the torque tube sheared so cleanly. I'm assuming it twisted? I dunno... weird. The bearings on the tail drive shaft are fine.
Amazingly, the vertical tail stabilizer and the right-side horizontal stabilizer didn't get damaged at all. The tail rotor hub assembly and blades are fine. Aside from two bent screws for the ball links, the main rotor head is fine. The main mechanics are fine. I may fire it up in a few days to see how the one-way bearing sounds.
Except for the pilot and the seat harnesses, EVERYTHING in the interior cabin was demolished, including the seat the pilot is still strapped to. The seat is broken in half just like the rest... the harness is holding all the parts together.
Back to the torque tube boom, though... that's crazy! It kinda sheared like it was made out of plastic! At any rate, I would HIGHLY advise you inspect the spline on your torque tube and then drill and pin it like I just recently learned a few other RC heli pilots have done.
Michael K.
Good H.
CARLOS C.