Originally Posted by
jccho
guv1976, thank you very much for your reply. I feel so much better, since I don't have to worry about the security/immigration.
You're welcome. Very glad to help. Just keep in mind that if you ever fly this itinerary in reverse (i.e., MAD-JFK-LAX), you
will have to re-clear security at JFK: after clearing Immigration and Customs upon arrival from Spain, you will find yourself landside at JFK, and will have to pass through security to get to your connecting flight to LAX.