Can I upgrade my economy flight with Etihad to the USA at the airport?

Don't bother to upgrade your ticket. I travelled on Tuesday and the Flight was almost empty. You'll have enough space for yourself

Yes, and you can do it on the app sometimes it even prompts you with good deals nearer the date of your flight.

Normally when i fly with Etihad they email upgrade offers about 2 or 3 days before the flight and again 12 hours or so before check in

The very first thing you should do is go to the airlines web site and check the seat availability on all of your flights. That will show you how empty or full your flights are and you can decide what to do from there.

I flew to the US three weeks ago. 1st leg 787 20 passengers and the 2nd one 787 70-80 passengers.

Before you pay to upgrade check out the seat availability on the whole plane including premium economy.

at your age amigo, buck up for business class and enjoy. We can't take it with us. Have a great flight

You can always upgrade at the full price. In normal times sometimes you could have one for free if lucky. If they overbooked their flight (what most companies as hotels do, calculating last cancels into the system) Free upgrade as first class or business is not full, cost them less than have a call on the gate to pay new ticket, hotel and give extra pocketmoney for dubbel booked seats... So don't believe when you got a free upgrade it si because you look so important... 😃 But I wouldn't count on that in these times on long distance flights .... But half a flight upgrade you should ask on the desc if they have one manned and is possible... You have 2 boarding passes anyway if you make a stopover...

you do realize, then, the difficulty, and potential costs involved,in returning to Thailand?

I have done it on the airplane. I let the flight attendant know as I boarded I would be interested in an upgrade if seats are available. There were. I did.

I have also done it at check in.

It’s very possible.

Flew etihad BKK to Abu Dhabi to Chicago just last week. The flights were maybe 20% full and the passengers were all spaced out. You may already have plenty of room. But you can certainly talk it over with the staff when you check in.

If there's avaliablity yes, you can always pay for an upgrade. It's almost always the same price though as just booking the premium seat.