iacisrmma:
“R’ Moshe held Queens is different then Brooklyn as the neighborhoods are clearly defined as recognized by the US Postal Service. When you address a letter to a Queens address it is not to Queens NY but to an individual neighborhood (i.e. Forest Hills, Flushing) whereas you address a letter to Brooklyn, NY (not Flatbush or Boro Park.”
“Joseph: I heard it from Harav Hillel David when the same question was asked in 1979. I do not know if R’ Moshe wrote it or it was just an oral explanation.”
“Gaon: I don’t remember you being in the room when Reb Hillel David told this to me. As you may know, not every psak made it to the igros Moshe. Just because you never heard it doesn’t mean an oral interpretation was not given.”
You see an oral explanation cannot be in direct contradiction to a written teshuvah. The fact is Rav Moshe maintained that an eruv cannot be erected in any part of an area of 12 mil by 12 mil containing a population of approximately 3 million. Therefore, it is irrelevant (based on Rav Moshe’s teshuvos) if an area encompassing such a population consisted of individual neighborhoods, since an eruv cannot be erected in any part of this area. Sorry, Rav Moshe could not have made such a distinction.