Does EU 261 apply when connecting in US from EU?
 

A friend is returning home to the US from the EU with a connection at JFK. There was no problem with the flight on the first leg to JFK. But when she arrived at JFK she learned her connecting flight home was cancelled. I'm assuming she booked the trip as a single ticket through to her final destination.

Is she due any compensation under EU 261? Does it apply at all in this situation? Or does EU261 stop applying as soon as you land outside the EU?

No
No
Yes

The regulation applies to any passenger:

• departing from an airport located in the territory of a Member State to which the Treaty applies;The protection accorded to passengers departing from or to an airport located in a Member State should be extended to those leaving an airport located in a third country for one situated in a Member State, when a Community carrier operates the flight and where a community carrier is defined as any carrier licensed to operate within that community.
• departing from an EU member state, or
• travelling to an EU member state on an airline based in an EU member state

Then, can she claim some other compensation?

No idea. Reason for the cancellation? Which airline? Compensation rulings in the USA? Length of delay?
Hint: My experience of consumer protection in the USA would not have me holding my breath....

It's very difficult to answer the question accurately with the data given. If the airline operating the flight from JFK is EU based then my gut feeling is that EU261 rules probably apply. However, be very careful when talking to your friend. There is potentially a significant difference between the flight number booked and the actual plane that should have flown/operated.

It's unlikely that an internal US flight would be operated by an EU-based airline.