Upvote:0
1) No, you don't need a transit visa; see
https://www.dus.com/en/flights/transferring
Departure airport outside the Schengen Area/Destination outside the Schengen Area:
No border control in DΓΌsseldorf No transit visa required
2) There is a caveat that this rule applies to citizens of most but not all countries. There is an exception for several countries, whose citizens need a transit visa; see http://www.germany.info/Vertretung/usa/en/05__Legal/02__Directory__Services/01__Visa/__Transit__Visa.html
Nationals of the following countries are required to be in possession of an airport transit visa when passing through the international transit area of airports in Germany:
AFGHANISTAN, BANGLADESH, DEMOCRATIC REPUBLIC OF THE CONGO, ERITREA, ETHIOPIA, GHANA, INDIA, IRAN, IRAQ, JORDAN ** (please see below), LEBANON, MYANMAR, MALI, NIGERIA, PAKISTAN, SOMALIA, SRI LANKA, SUDAN, SOUTH SUDAN, SYRIA, TURKEY
However, if citizens of the countries have a US visa they are exempt from the requirement of having an airport transit visa. (Since you are flying to JFK, I assume that you either have a US visa or you are a US resident/citizen.)