Which aircraft classification is identified by being less than 90'?

The classification of aircraft that is defined as being less than 90 feet is recognized as a specific category in aeronautical operations. This classification is significant because it helps in determining the appropriate airport facilities, including taxiway widths and runway design standards, which vary according to the size and type of aircraft.

Aircraft that fall into this category (less than 90 feet) are typically smaller regional or corporate jets and general aviation aircraft. Knowing the size of the aircraft is crucial for airport operations to ensure that safety regulations are adhered to and that the infrastructure is adequate to accommodate different types of aircraft.

Other classifications, such as those that include ranges starting from 90 feet and higher, do not pertain to the specific category that is less than 90 feet, and therefore do not fit the criteria set by the question. The specificity of "less than 90 feet" identifies the correct classification distinctly, differentiating it from other size categories.