Tail issue

[crashkit]

Here is my problem can not figure it out.My logo 500 2 weeks ago decided to let the tail go in mid flight,it jittered twice then let go so i fixed here up and found a small break in step down.got it up in the air and it was fine when there was no wind but the next day in wind tail did the same again jittered then let go.so i put new tail servo in it and it flew great in the evening with no wind.Thought i had it flew it the next day and about 30 seconds in tail jittered and same thing.anyone got any advice at the point i dont have any ideas.