Love Doctor - From the POH -
"The landing gear is designed to extend even in the event of hydraulic failure. Sine the gear is held in the retracted posisition by hydraulic pressure, should the hydraulic system fail for any reason, gravity will allow the gear to extend."
I was not saying it is impossible, but I was expressing my amazement at what chain of mechanical failures could lead to such a situation. Having had experience with PA34's over the years, I was surprised to see this come about. For both the hydralic system to fail, AND the emergency extention to fail, that's pretty unlucky, considering it's just a cable that pulls a PRV in the hydraulic system.
Remoak - Maybe I should have made myself clearer. It's not all they are there for, but having seen the results on a Seneca wheels up where the disconnect in the landing gear system was seated in the left seat, they are certainly strong enough and thick enough to withstand such an occurance with minimum damage to the underside of the plane. I've even seen one proped up on them in the hangar.