Ex taking DC flying

[Fuzzybum]

My ex's family member has his own helicopter. Ex has just collected the DC, DD (5) and DS (2) and said he's taking them up in it. I said I don't like the thought of it and would prefer it if they didn't. He will ignore me and go against my wishes. He has already taken DD up a few times since when she was 2. I have told him every time that I hate it and don't want them flying but he doesn't listen.
Ex is an abusive narcissist so there's no point in trying to reason with him.
His family member is an irresponsible twat too and ex has told me many horror stories of near misses when he has been up.
Theres nothing I can do, is there? Like I can't stop him doing crazy stuff when he has them?

I’d be shitting myself tbh. I wouldn’t want that either. I’ve seen far too many things go wrong.

It's not in his interest to harm them because it would harm him too surely.

I dont think he would deliberately hurt them but like I said his relative is an irresponsible twat who likes to show off and it just seems daft to be taking such young kids up in the air and taking unnecessary risks.
I'm absolutely crapping myself now and have asked that he update me when they are done but he will conveniently forget and leave me worrying all afternoon