Não. PM2 não seria um ID válido no sistema FAA. De acordo com a ordem da FAA que define o sistema :
1−2−7. ASSIGNMENT SYSTEM §c. Most one−number, two−letter identifiers have been assigned to aviation weather reporting and observation stations and special−use locations. Some of these identifiers may be assigned to public−use landing facilities within the United States and its jurisdictions, which do not meet the requirements for identifiers in the three−letter series. In this identifier series, the number is always in the first position of the three−character combination. (emphasis mine)
Portanto, duas letras seguidas de um número não são um ID válido.