Originally Posted by
noooby
Could you perhaps expand on the "all other manufacuters fit a safety mechanism" passage please? Specifically, which aircraft models have this safety mechanism and what exactly is it?
The Elastomerics on the 169 are pretty stiff and help with self centering a bit. I'm trying to think what other tail rotors do for self centering if the control linkage is broken and I can't really think of anything.
Remember, the servo got disconnected. No point in centering an item that isn't part of the control system anymore.
Hi Nooby, that’s the point, if the servo becomes disconnected either an inherent aerodynamic force or a spring will act on the control valve to return the servo to neutral. If the servo control arm disconnects from the spider, aerodynamic force or spring should return the blades to a neutral value. The idea is to prevent a hydraulic or aerodynamic hardcover one way or tother. Eg, in the S61 and 332 series, a force spring does the job. In 412 the pitch horns do it. Leonardo seem to have forgotten these simple safety features.
Unless I am wrong (happened once, not nice) all Leonard’s have this latent failure mode.
DB