The keyword phrase "sep 11 flights" is a noun phrase. The main point and core component of this phrase is the word "flights," which functions as a noun.
In this construction, "flights" is the head noun, identifying the subject matter. The preceding term, "sep 11," acts as a compound adjectival modifier. It is composed of "Sep," an abbreviated proper noun (September), and "11," a cardinal number. Together, they specify and restrict the noun, clarifying precisely which flights are being referenced. This type of modifier, placed before the noun it describes, is known as an attributive modifier.
For the purpose of determining the article's main point, the operative part of speech is the noun ("flights"). The modifier ("sep 11") provides the essential context, but the central topic is the flights themselves. The article should therefore be structured around this subject, using the date as a defining characteristic.
