Yes, a knife is useful too. When I travel on airlines it is in my checked baggage, a Kershaw Leek assisted opening. Sometimes when my CCW license has reciprocity with the state I am travelling to I will check my pistol and a box of ammo. But the airline personnel are so uninformed it is a different hassle every time. Some just make up their own rules.
I watched “Robin Hood” back in the 50s or so. I remember seeing a lot of his men using staffs as weapons. Extremely cheap to make one too. In fact they are free.
To this day, and I am 70 now, I always carry a hickory staff around 7 feet long. This is when walking around the yard or nearby woods. I also keep a little .22 auto, either a Walther, FEG or Unique in my pocket. For concealed carry it is usually a Browning Hi-Power with a high capacity Mec-Gar magazine. Another spare mag too.
I have never used a staff in a fight so have no idea how effective they really can be. For some reason I really like the 7 foot length even tho a hiking stick is supposed to be shoulder height.