No. All airplanes can't carry weapons but some airplanes can carry weapons. If it is a military aircraft so yes they can carry weapons but if it is a friendly aircraft so no they cannot carry weapons.
people carry weapons for protection
Yes, airplanes can carry weapons. That's quite true that some airplanes can really carry weapons.
he carried a spear
For weapons so Zeus could beat Cronus and the other Titans who had locked the cyclops in Tartarus.
Cyclops are creatures from greak myths and they spend time crafting weapons and other things. One cyclops I know of was a shepard. At the time of the titanomancy cyclopes were forgers and ironsmiths.
Cyclops built weapons and worked with Hephaestus.
The Helm of Darkness forged for him by the Cyclops during the Titan war.
Yes: fire doesn't affect them. Not necessarily, Odysseus puts out the cyclops, Polyphemus' eye with a burning Poker. Maybe the cyclops born of Gaia: resistant to fire, given that they forged weapons for the gods,
A two pointed staff, and a helmet of invisibility given to him by the cyclops after the war with the titans...oh and in the Thor comics he has an inchanted Axe made by the Cyclops two.
No
No. Friendly airplanes are civilian aircraft, civilian aircraft do not carry weapons at all, they just carry passengers and items.