Here's a good one. It just makes me roll my eyes...

It's still a codeshare as UAL,, Aer Lingus and Spanair assigns their own flight number to it Remember, a codeshare is simply an agreement between two or more airlines to share the same flight. You can buy a seat through one airline even though it's operated by another airline with its own flight number. Technically, you are on a Spanair codeshare. The Open Skies Agreement basically just says that any airline can fly between any two cities (one in the U.S. and one in the EU) depending on consumer demand. That's why Aer LIngus flies between IAD and Madrid, and British Airways has flights between New York and Paris. No more need to only fly to the airline's home country. It has very little to do with codesharing.

I've flown the IAD-MAD route; you will check in with UA at IAD. The IAD-MAD route is a United partnership with AerLingus under the Open Skies agreement rather than a "code share". United markets the flight. You will be an AerLingus plane with AerLingus crew. The check in and baggage at Dulles is handled by United. SpanAir is a Star Alliance partner so I guess that is where they come into the mix.

I was on this flight (so to speak) last year. The pilot was Irish but the flight attendant in my area of the plane was an American but wearing an Aer Lingus uniform. I asked her why United when I bought my ticket but on Aer Lingus aircraft, she told me that United was getting into this market but didn't have the aircraft for it. No problems what so ever nice flight, good crew, good experience overall.

The the reason that I said this was a bit different from a typical "code share" in that United and Aer Lingus have some type of partnership with an agreement to split the revenue. There were protests at United headquarters and at IAD when this was started. It was viewed that United was getting around using United crew by outsourcing to Aer Lingus. I guess technically it is still a code share, but it did not get the same press as when a Lufthansa flight or other Star Alliance partner has a UA number. By the way, my flight was fine too.

I am interested in buying a plane ticket from Kansas City to Barcelona for July. should I wait or will prices go up and what about the super low and changing airlines?

Lori, Based on what is happening in the Middle East I expect a spike in oil prices accompanied by a spike in airfare. I'm not ready to book yet or I might consider buying quickly.

What are the "super low and changing airlines" you are referencing? July is peak season, with the unrest in all the oil producing countries, it's going to be expensive to travel to Europe this year.