Helicopter Tension Torsion Straps. 

Thanks for a really clear explanation. Sadly, looked here to find out about TT straps following the GSH accident at Fort Good Hope NWT.

I worked on MD 500s. I never really got into the bell design. I learned something new today.

Great explanation and video. I had no idea that blades were held on like this! Obviously it’s due to vibration and other forces but is there a reason a solid bar isn’t incorporated to act as a failsafe? I just saw the 212 report and am a new OH-58 owner. My previous experience was on an AS350 and I wasn’t aware of this design feature. This video was really helpful. Thanks!

Well gosh I thought the strap went from blade bolt to blade bolt or grip to grip. I didn’t know the yolk handled all the centrifugal loads. I guess I never looked at a diagram.

What study did u do

Great info! I never knew these take up the entire centrifugal blade load. How much would such a piece cost and what is their lifespan? Thanks.

Those were some ugly safety wire jobs shown at the end of the video.