I was just looking through Amadeus and noticed that on Saturdays and Sundays both Iberia flights to and from JFK are both operated by the A340-600 instead of one A340-300 and one A340-600 or two A340-300s. Sorry if this isn't too interesting of news but I thought it might be useful info for people trying to catch the A340-600.

Iberia 6251 arrives at JFK at 3:10 PM
Iberia 6250 departs JFK at 6:10 PM

Iberia 6253 arrives at JFK at 7:10 PM
Iberia 6252 departs JFK at 9:10 PM