Hi Hollis,

You wrote:
>   I have just experienced my first incident of a main gear unlocking
during taxi.  

I believe you may have problems with the springs on the over center link
in addition to any other gear problems.  It is my understanding the
spring/over-center link should maintain a down & locked gear without any
help from hydraulic pressure.  Otherwise, we would be 'up the creek'
landing without an operational hydraulic pump.  ie electrical failure,
broken hydraulic line etc.  I surely hope I am correct.  Earl