Will be traveling to Bangkok from Las Vegas on United and ANA. Need to know if both airlines fly into the same terminal at Narita? Also I will be using FF miles so I need to know if I can select my seats on the ANA leg and if so how do I do that?

here's the link to the Narita airport website where you can find details about the airport and your flights.

http://www.narita-airport.jp/en

Thanks, I am hoping someone on the forum can tell me if I can select seats on the ANA leg of our journey?

You can get the ANA reservation confirmation code at fly-ana dot com by entering your United (016) ticket number and name (concatenate your first and middle names, like JOHNQUINCY ADAMS). You will be able to view but probably not change anything. I think that is where I got the phone number to call ANA. Call the number and you will likely be connected to an agent in Japan (tho it is still a toll-free call) who can make your seat reservations. Then go back to the ANA website and you should see your seat assignments.

That is what I did with a United ticket for ANA flights. The ANA agent spoke English very well.

You best bet is to to do as mrwunrful said and try calling ANA. have a look at your ticket confirmation paperwork (the email) that United sent. The eTicket number will be there. YOu also might see assigned seat numbers..I am not sure why this happened on a recent award seat I booked using United Miles (Avianca/TACA) and I haven't bothered messing around with them since they were not middle seats. I think United also gave me the Avianca confirmation code at some point in the purchase process.

mlgb, I would presume that your seat assignments are totally imaginary and that Avianca doesn't know anything about your trip. United should be presumed guilty until Avianca proves otherwise.

LOL... probably a good policy....although I can see my reservation as confirmed on the Avianca site "Ticket status" using the reservation code that I got . But I don't see seat assignments on Avianca. I will call in a few days..and not on a Sunday.

Thanks everyone. I did call the ANA 800 number and the agent said I could just call them back when I book and they will be able to assign seats.

When I checked the airport website it indicated that United and ANA go out of the same terminal. I wanted to be sure as the flights I am thinking of booking have a 1 hour and 35 minuteS layover in Narita coming from the US. In the past when I have had to change planes in Narita it involved a very very long walk followed by a bus ride to another terminal. I get a little nervous when the layover is less than 2 hours as these long flights from the US can often run late.

You might be interested that our SIA flight out of LAX was an hour late getting into Tokyo due to headwinds. They couldn't make up the time in the air (it actually left on time). Even though we needed to get back on the same plane and flight number, they needed to refuel and move it to another gate. We were escorted through the airport where they were holding the flight for all the continuing passengers. I don't know if you can find out what would happen if the plane is delayed, and if your luggage will be checked all the way.

I am a bit concerned about a 90 minute layover, I always like to see at least 2 hours on these trans Pacific flights.
I will continue to look for flights that give me that cushion.

We had a tight flight connection coming from LAX to Fukuoka by way of Narita.Our only saving grace was that my SIL needed assistance in a wheelchair and the attendant knew exactly where we needed to go.

Not suggesting you take advantage of using a wheelchair when not needed, but if there is anyone traveling with you that does, don't hesitate to set it up beforehand.