r/A330

I’ve always made it a habit to preset my target heading on the FCU before pulling the knob. Recently came across the write-up for the "NOT COMMANDED TURN AT HDG/TRACK MODE ENGAGEMENT" bug, and it made total sense why that habit pays off.

If you pull without presetting, the PRIM briefly uses the old stored heading value. If your new target happens to be 180 degrees off, the system glitches—it starts a 180-degree turn, and as the memory updates a split second later, it turns into a full 360-degree orbit. Presetting first completely avoids this.

Curious about your daily technique—do you guys always preset first out of habit, or do you just pull and turn?