Only if it's a: transporting hazardous materials or b: a bus designed to transport more than 15 persons (including the driver).
Air brakes have absolutely ZERO determination in whether or not a vehicle requires a CDL.
No, unless you're hauling something which requires a hazmat endorsement, such as contaminated soil.
Only if it's a vehicle equipped with air brakes.
No. Air brakes are not a parameter in determining whether or not a vehicle needs a CDL.
To answer you we need to know what country's traffic regulations you are asking about.
Only if it's transporting 16 or more persons (including the driver) or sufficient quantities of hazardous material to require placarding with HAZMAT warning signs.
The air brakes are irrelevant. And you'd need a medical card in that instance if you were doing interstate operations, but not intrastate operations.
Only if it's hauling hazmat or is a bus designed to transport more than 15 passengers (including the driver). Air brakes have absolutely nothing to do with whether or not a vehicle requires a CDL.
Not unless it's a bus designed to transport more than 15 passengers (including the driver).
No.
Only if it's either designed to transport more than 15 persons (including the driver), or else carrying a quantity of hazardous materials which requires the display of placards under the FMCSR. In both instances, you would need at least a Class C CDL without an air brake restriction (there is no actual air brake endorsement), as well as a passenger endorsement (for a passenger bus) or hazardous materials endorsement.
On a US drivers licence, there is no air brake endorsement - there is only an air brake restriction, and it is only applicable to CDL licences and commercial vehicles. Vehicles of 26,000 lbs. or less GVWR only require a CDL if they're hauling hazardous materials, or if they're designed to transport more than 15 persons (including the driver). Otherwise, most states will allow you to drive it on the same licence you use to drive any regular passenger car, without any requirement to be trained in the proper use of air brakes.