What requirements must be met for the structural integrity of interior exit stairways in airport traffic control towers located more than 75 feet above the lowest level of fire department vehicle access?

Interior exit stairways in airport traffic control towers over 75 feet high must comply with Section 403.2.3 for structural integrity. They must also be smokeproof enclosures as per Section 909.20.

For airport traffic control towers where the control cab is located more than 75 feet above the lowest level of fire department vehicle access, the structural integrity of interior exit stairways must comply with Section 403.2.3. Additionally, these stairways must be smokeproof enclosures, adhering to one of the alternatives provided in Section 909.20. This ensures that the stairways are protected against smoke infiltration and maintain structural integrity during a fire.