What to do with my abusive father?

Well I'm 15 turning 16 this may... and well my father is an immigrant who can't understand english well. I've been living in america my whole life. So today during school I found out that I had a band rehearsal after school so I had to tell my dad (he normally picks me up). However since cell phones aren't allowed in school I have to use the office's telephone and since my dad can't understand english well I have to repeat what i say many times. So I found it easier to tell my 19 year old sister to just tell him herself, so I can save everybody in the office unnecessary repetition. My sister ended up texting my dad and only found out when school ends and he was already there... so when he looked at his phone and saw this he got really mad.(I never answer back at my Dad, quite frankly I try to avoid conversation all year round) On my way back home in the car he threatened to stab me/ beat me till I bleed. I don't feel threatened by my Dad considering that I'm much much much more stronger than he is, no exaggeration. But my dad has beaten my mom, myself, and my sister in past years. When I was 12-13 that's when I got my last beating. My sister was just a couple months ago, but I stopped it. My mom was last beaten probably around 2003. I really can't stand my dad because every time small tiny things like this happen, he over-reacts and tends to even give himself fake reasons to get even angrier. So what should I do? I'm not afraid of his abuse anymore because I can easily protect my family even if my dad has a knife or his machete sword. I'm a 1st degree black belt and I'm perfectly able to defend against such weapons. It's unlikely he has a gun considering that he's too stupid to get one. (he doesn't work=no money & he wouldn't know how to apply for a gun license) My dad just always misinterprets english and any situation in general and will make a bigger deal out of it, which leads him to his threats of abuse. It's only rare that my family and myself make tiny slip ups like what I did today. My Mom is the only one who works as a nurse so we can make ends meet.