No. Air brakes are not a factor in determining whether or not a CDL is required in any state. The only instance in which you would need a CDL is in cases where the vehicle is transporting an amount of hazardous materials which requires the display of placards, or when it's a bus designed to transport more than 15 persons (including the driver).
Only if it's transporting hazardous materials or else it's a bus designed to transport more than 15 persons (including the driver). Air brakes do not make a vehicle require a CDL.
No. The gross weight cannot exceed the gross vehicle weight rating and/or the registered weight rating of the vehicle, regardless of the license of the person driving it.
The "gross" weight of the truck and its cargo cannot weigh more than 26,000 pounds. This includes the weight of the fuel, driver, and any equipment on tne vehicle.
Only if it's either hauling a quantity of hazardous materials which requires placarding, or if it's a bus designed to transport more than 15 persons (including the driver).
Air brakes are entirely irrelevant as far as whether or not that vehicle needs a CDL is concerned. The only time you need a CDL to drive an RV is when you're operating it on a for-hire basis, either as a driver for hire or as a transporter.
Yes, so long as it is not classed as a Commercial Motor Vehicle (CMV). For a vehicle under 26,000 lbs. Gross Vehicle Weight Rating to be classed as such, it would need to either be a bus designed to transport more than 15 persons (including the driver) or carrying a quantity of hazardous materials which required the display of hazmat placards.
You only need a CDL for a vehicle under 26,000 lbs. GVWR if it's designed to carry more than 15 passengers (including the driver) or if it's carrying hazardous materials in an amount which requires placards to be displayed.
Only if you're operating it on a for-hire basis. For personal, recreational use, you do not.
If it's not a firefighting or first response vehicle, recreational vehicle, registered farm vehicle, or military vehicle (operated by military personnel in the course of their duties), then yes - not because of the the air brakes, but because of the weight rating of more than 26,000 lbs. GVWR.
26000 lbs. is the Gross Vehicle Weight Rating. That's the max it can legally weigh on the road. Subtract the vehicle's tare (empty) weight from that, and you have your allowable net weight. 4-1/2 to six tons is typical of the allowed net weight for a 26k GVWR truck.
Air brakes are not a factor in determining whether or not a vehicle requires a CDL, in any state or territory of the US, period. The only instances when such a vehicle as you describe would require a CDL would be in the case of hazmat haulers and buses designed to transport more than 15 persons (including the driver).
So long as the weight rating of the vehicle doesn't exceed 26k, yes, with two exceptions - you would need a Class C (minimum) CDL with hazmat endorsement if the vehicle is transporting a quantity of hazardous materials which requires placards to be displayed, and you would need a Class C (minimum) CDL with passenger endorsement if it is a bus designed to transport more than 15 passengers (including the driver).
Yes, so long as it doesn't transport hazardous materials, or isn't a bus designed to transport more than 15 persons (including the driver).