R44 Astro tech question
I'm not not a helicopter man though flying rotary. A guy who is flying very old R44 Astro here asked me to find some spares for that his can of bolts. He needs in particular to replace TR teeter hinge spherical bearings which are B115-1 or D115-1 in parts catalogs. My questions are what is the difference between these B and D, how can I guess which ones are used in his TR and what are best sources to get these spares?
Thanks to all,
Alex