By US regulations, a chainsaw would certainly be considered a deadly or dangerous item and would be prohibited from carryon luggage. From TSA's prohibited items website,
http://www.tsa.gov/travelers/airtrav...ted-items.shtm
under tools, specifically mentions - Saws (including cordless portable power saws) and
Tools (greater than seven inches in length) as prohibited for carryon.
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Maryland (DC Suburbs) - first 51 years

The Villages - next 51 years