My goffin's was doing fly and land on my shoulder and bite the face almost a year after I got him. Right around March. I thought it might be hormones but he was also rehomed, so I expected some aggression at some point regardless. I can only tell you what I did. He's a graceful flyer so I didn't want to clip him. I had his cage in my bedroom at the time and most days he got out of cage time in the evening.
I started out just putting him immediately back in his cage after a bite attempt. That didn't really work, it didn't get worse, but didn't get better either. And I was giving him almost but not completely my full attention. Apparently holding him and reading a book or holding him and playing on the internet was not good enough for him. I ended up just resetting our relationship. I just left him in his cage for about a week. I'd walk up and talk to him and if I saw even the slightest bit of the evil squinty eye cockatoo I'm going to bite look, I'd just leave it to talking with him and leave him alone. If I saw round eyes, I might take him out for a few minutes of 100% attention on the bird play time and cuddles. As soon as he started acting wound up, I'd put him back in his cage with a treat. After a couple weeks it occurred to me that since his cage is in my bedroom and I only sleep in there, I can bird proof the room and let him out and just shut the door so he can't go after me. That way he gets out of cage time but any time I spend with him is 100% my attention on him. If I let him out for an hour and then went in to give him some attention and I saw squinty eyes, I just put him back in his cage. If I let him out for an hour and went in for attention and saw round eyes, then I'd give him some cuddles or attention. The very instant I see squinty eyes, he went back in his cage. I also didn't let him on my shoulder. If he flew to my shoulder, I'd shove him off immediately. He can fly so being tossed off of me was no big deal. If I had to toss him back to his cage more than a couple times, then he'd just have to go back in his cage. It lasted for about 3 months and then I started relaxing the rules and have rarely had a problem with him since.
In short, don't give him the opportunity to bite Howie. Howie should give him 100% his attention, time with Howie should be very structured. No fly up and get attention any time he wants. Set time for Howie and Howie only. Any other time, he's not allowed access to Howie. If Howie is around and bird starts screaming, jumping around acting excited, watch those eyes. You'll start to recognize the evil cockatoo squint. If you see it, he goes back in his cage. Possibly for the rest of the day or at least for plenty of time to pass and him to calm down and forget about trying to conquer the world. I think it should probably be Howie that reinforces this. Otherwise, the bird might learn that biting Howie gets you to come running. That might not be good.