James Cameron, who has also become an expert on deep sea craft, commented that carbon fiber is great in tension but poor in compression. Hence he concluded that it was the wrong choice of material from the start.
The problem with cf composite isn’t actually the carbon filament, its the epoxy matrix that it sits in.
The epoxy is so rigid, it doesn’t deflect under pressure, it cracks/crazes. Very often, that cracking/crazing happens deep in the structure between the layers, which is called delamination. When a composite structure delaminates, it might as well be made of wet cardboard….
Each successive pressure/release cycle causes the crazing to progress. The problem is its an insidious failure. Meaning: you can’t see it until it fails. There are some NDT techniques that may so it up, but I don’t get the feeling the “maverick” CEO/pilot was in to doing a lot of maintenance or inspection.
My last Helo was a high percentage of CF, kevlar, etc. It took a lot of very specific maintenace and inspection to keep it on the line. Was wondrous stuff, but you have to use it
EXACTLY in the application it was designed for and it was silly delicate in any manner it was not designed to be loaded.
We actually had a problem with the tail rotor half plates because they used CF in a way that it wasn’t really designed for. Basically, they loaded it in a direction it shouldn’t have been.
I landed once and went up the ladder to inspect the tail rotor (called an A check) and we were about 30 mins or so away from a total failure. It was cracked and split so badly I coukd barely make it back down the ladder and had to lie in the infeild grass for about 20 minutes before I was able to stand again.
My aircraft commander came back to see why I was laying in the grass, all I could do was point up the ladder at the tail rotor. He climbed up, took a look and a few seconds later he was lying in the grass beside me….shaking almost uncontrollably.
We used to call loss of tail rotor “smoke meat 2” because loose the tail rotor and its all over…you were basically “smoked meat”, hence the name.
We didn’t move it an inch that day, got a hotel and went out to the bar and drank heavily that night…