https://www.aopa.org/news-and-media/all-news/2003/september/04/1234-transponder-code-implemented-at-towered-airports-in-adiz-areas
1234 transponder code implemented at towered airports in ADIZ areas - AOPA
Late today the FAA issued two notams allowing pilots operating at towered airports in the Washington, D.C., and New York City air defense identification zones...
transponder code1234implemented