Hello,The tires of my C185f looks flat. How can I solve this problem?Greetings,Addy

Add more air to them .OK, sorry :(. Seriously, tundra tires are often appear soft for better shock absorption. Those are a bit much, but check it on a paved surface. Sometimes add-on scenery with dirt and grass allows gear to "sink" a bit to the hardened surface below (the skids on my helicopters mostly disappear at Bob Quinn airport in the Tongass scenery, but are fine elsewhere). Regardless, I wouldn't worry about this at all. It's not that unrealistic.

Tundra tires are routinely under-inflated by bush pilots to improve their shock absorption and to create a larger surface area for soft and boggy ground.