FlyingLonghorn

This is incorrect information.
You do not have to use your US passport outside the United States.
You should use whichever one gets you the easiest/visa free travel (outside of those areas where you are required to use one or the other e.g. Schengen and the USA).
I posted something on the thread about US passports and exiting the US that I will repost here since it is somewhat relevant on the US side. I do this having dual citizenship, and having worked with the US DoD, DHS/CBP, NATO and Schengen authorities arranging certain travel in said manner
From me:
The part at the bottom is key. Though I would tell you to take both passports at all times because you never know when plans could change.
On a roundtrip journey from the US to Germany it goes normally something like this, and I'll use a sample Houston (IAH) to Frankfurt (FRA) flight.
At Houston airline check-in show German passport. If names are different you can show the US one also. Airline staff are used to this.
At TSA ID check it is best to show US passport (without going on too much of an anti-TSA rant they sometimes get too confused by foreign passports)
At gate to board flight show German passport. If they ask for an I-94, state you don't have one as a US citizen also, though often they don't even ask.
Upon landing at FRA show German passport to the border authorities (they normally will not speak with you) Presuming nothing to declare, walk out green channel and you are done.
On return flight to US show US passport at check-in, and answer their inane questions about packing your own bags.
At exit control, show German passport, most likely getting a grunt or wave of the hand to move on (German polizei don't talk much)
At boarding show US passport.
At IAH point of entry give US passport to CBP.
Note-if you travel overseas get Global Entry, then you don;t even have to talk to the CBP normally. I have had it nearly 5 years now and love it.

Huh?
http://www.colombiaemb.org/Consular_Directory
There are 11 Consulates of Colombia in the USA (if you count San Juan, 10 if you don't) plus the Embassy in D.C
Atlanta
Boston
Chicago
Houston
Los Angeles
Miami
Newark
New York
Orlando
San Francisco
D.C. (Emb)
and San Juan P.R.
and it was not alwaysthe case about keeping Colombian citizenship: (The new Colombian constitution changed it)
"If you obtained American citizenship before July 4, 1991, under Colombian law you are no longer considered a Colombian national due to the fact that, under the Colombian Constitution of 1886 — which was valid until 1991— holding dual nationality was prohibited. Therefore, you must enter Colombia with your U.S. passport. (In this case, we encourage you carry a copy of your naturalization letter.) Be advised that if you enter Colombia with a U.S. passport you will be subject to Colombian immigration laws.
Please note that those who obtained American citizenship after July 4, 1991 did not lose their Colombian nationality and therefore hold dual nationality."

This is incorrect information.
You do not have to use your US passport outside the United States.
You should use whichever one gets you the easiest/visa free travel (outside of those areas where you are required to use one or the other e.g. Schengen and the USA).
I posted something on the thread about US passports and exiting the US that I will repost here since it is somewhat relevant on the US side. I do this having dual citizenship, and having worked with the US DoD, DHS/CBP, NATO and Schengen authorities arranging certain travel in said manner
From me:
The part at the bottom is key. Though I would tell you to take both passports at all times because you never know when plans could change.
On a roundtrip journey from the US to Germany it goes normally something like this, and I'll use a sample Houston (IAH) to Frankfurt (FRA) flight.
At Houston airline check-in show German passport. If names are different you can show the US one also. Airline staff are used to this.
At TSA ID check it is best to show US passport (without going on too much of an anti-TSA rant they sometimes get too confused by foreign passports)
At gate to board flight show German passport. If they ask for an I-94, state you don't have one as a US citizen also, though often they don't even ask.
Upon landing at FRA show German passport to the border authorities (they normally will not speak with you) Presuming nothing to declare, walk out green channel and you are done.
On return flight to US show US passport at check-in, and answer their inane questions about packing your own bags.
At exit control, show German passport, most likely getting a grunt or wave of the hand to move on (German polizei don't talk much)
At boarding show US passport.
At IAH point of entry give US passport to CBP.
Note-if you travel overseas get Global Entry, then you don;t even have to talk to the CBP normally. I have had it nearly 5 years now and love it.

The address doesn't matter.
If asked you can show both passports. It is not illegal and 100s of people fly on multiple passports everyday.
You should not have any problems. It is rare but sometimes, especially in Europe they can ask to see the credit card you bought the ticket with otherwise how you buy is a non-issue re:passports/ Plenty of people with US passports have overseas addresses (like me) and still buy tickets.
you will be fine!

Unless you are checking in at the gate with a print at home boarding pass, and are not checking bags then you would have to show a travel document at the presecurity check-in desk/kiosk. They do not take I-94 normally, but if asked you can simply say you do not have nor need one as you have a US passport
Normally Americans do not need a Visa to enter the Schengen party countries but if a person is on a oneway flight or does get questioned about being admissible to the EU you just show the German passport.
I never show the TSA anything with an address on it but yes you can use your license should you want to pull out another document.
You can use either. But they are not checking names but admissibility so as to avoid being fined. Your name is already checked against the PNR list when the pass is scanned. This is where they could ask for an I-94 but you don't have to have one so you can proceed.
CBP does do random outbound checks in the jetway. It is easiest to show them the US obviously.
Correct
incorrect. Schengen party countries have exit controls. YOu need to check in with the airline using the US passport but showthe German one at exit control, then your US one at bordering and when you get home.

I am more than well aware of that, which is why in my first response I noted the OP should check-in with the EU passport.
That is certainly what I do when flying to the EU...
However my "#######" comment was less about the fine than newer agents that do not understand the system and often go fishing (while they might have good intentions they are often misguided or completely wrong).
I've witnessed agents deny BPs to travellers on oneway tickets, even if they had land based travel out of the EU, which is permissable.
Proof of onward travel or intent to leave is not done simply by having a round trip ticket.
Most veteran CSRs at airlines know this.

yes, it is easier that way, as I noted in my post. Because the OP has a US passport and is allowed into the Schengen area for up to 90 days (presuming no other travel there in the last 180) the airline employees can start asking questions about how you plan to leave if you are on a one way ticket or one that stays longer than 90. Some are more ####### than others about it. Some will pull Timatic and go by "the book" others with more experiance know better.
You can show them both if you like, again is fairly common.

Having worked with DHS on some of these issues before let me add some things.
Can/Could you leave without a US Passport?...the answer is yes...maybe.
Normally the USA does not have exit controls, and the airlines that send your PNR data to DHS to run watch-list matching do not care which passport you enter when you buy your ticket. That ticket can be roundtrip BTW.
When you check-in they want to ensure you can legally enter the country you are going to (and/or through). Thus if flying to the UK, for example, a dual US/UK would just need to present the UK passport at check-in.
The big catch is DHS (Normally CBP) run random and sometimes targeted exit checks at the gate (normally in the jetway) for outbound flights, often times with portable computers linked to DHS systems and/or the systems that link immigration data around the globe (for those that participate). During these they are often looking for undeclared cash, meaning those that did not file a FINCEN 105 form for cash over 10kUS$. But they can and do check for immigration data too. If you were to be checked on one of these flights you could be stopped/denied boarding and/or fined.
So the easiest solution is to have a valid US travel document at exit.
Technically, a US national does not need a US passport to enter the USA, and I don't mean just those with military IDs, green card, tribal IDs, gov't orders or refugee documents.
By law, CBP has to admit US Citizens and Nationals. The key is satisfying them that you are a US citizen/national. Normally a passport does this (quickly, unless you don’t answer their questions, which you legally do not have to do, but you can be detained), also presuming they don't think the passport is altered.
CBP has other ways of verifying citizenship/ID but it takes time. People lose their passports on their flights into the US all the time. People present at land and sea borders without passports too (For various reasons). All that being said, getting an airline, who can risk a big fine, to transport you into the US without a passport, military ID, green card, or refugee document are slim-to-none (and slim just left the building).
(Also as an aside, airline personnel are normally very used to seeing those with multiple citizenships, so one does not need to “hide” extra passports if it helps facilitate visa-free travel.)

This is incorrect information.
You do not have to use your US passport outside the United States.
You should use whichever one gets you the easiest/visa free travel (outside of those areas where you are required to use one or the other e.g. Schengen and the USA).
I posted something on the thread about US passports and exiting the US that I will repost here since it is somewhat relevant on the US side. I do this having dual citizenship, and having worked with the US DoD, DHS/CBP, NATO and Schengen authorities arranging certain travel in said manner
From me:
The part at the bottom is key. Though I would tell you to take both passports at all times because you never know when plans could change.
On a roundtrip journey from the US to Germany it goes normally something like this, and I'll use a sample Houston (IAH) to Frankfurt (FRA) flight.
At Houston airline check-in show German passport. If names are different you can show the US one also. Airline staff are used to this.
At TSA ID check it is best to show US passport (without going on too much of an anti-TSA rant they sometimes get too confused by foreign passports)
At gate to board flight show German passport. If they ask for an I-94, state you don't have one as a US citizen also, though often they don't even ask.
Upon landing at FRA show German passport to the border authorities (they normally will not speak with you) Presuming nothing to declare, walk out green channel and you are done.
On return flight to US show US passport at check-in, and answer their inane questions about packing your own bags.
At exit control, show German passport, most likely getting a grunt or wave of the hand to move on (German polizei don't talk much)
At boarding show US passport.
At IAH point of entry give US passport to CBP.
Note-if you travel overseas get Global Entry, then you don;t even have to talk to the CBP normally. I have had it nearly 5 years now and love it.

Having worked with DHS on some of these issues before let me add some things.
Can/Could you leave without a US Passport?...the answer is yes...maybe.
Normally the USA does not have exit controls, and the airlines that send your PNR data to DHS to run watch-list matching do not care which passport you enter when you buy your ticket. That ticket can be roundtrip BTW.
When you check-in they want to ensure you can legally enter the country you are going to (and/or through). Thus if flying to the UK, for example, a dual US/UK would just need to present the UK passport at check-in.
The big catch is DHS (Normally CBP) run random and sometimes targeted exit checks at the gate (normally in the jetway) for outbound flights, often times with portable computers linked to DHS systems and/or the systems that link immigration data around the globe (for those that participate). During these they are often looking for undeclared cash, meaning those that did not file a FINCEN 105 form for cash over 10kUS$. But they can and do check for immigration data too. If you were to be checked on one of these flights you could be stopped/denied boarding and/or fined.
So the easiest solution is to have a valid US travel document at exit.
Technically, a US national does not need a US passport to enter the USA, and I don't mean just those with military IDs, green card, tribal IDs, gov't orders or refugee documents.
By law, CBP has to admit US Citizens and Nationals. The key is satisfying them that you are a US citizen/national. Normally a passport does this (quickly, unless you don’t answer their questions, which you legally do not have to do, but you can be detained), also presuming they don't think the passport is altered.
CBP has other ways of verifying citizenship/ID but it takes time. People lose their passports on their flights into the US all the time. People present at land and sea borders without passports too (For various reasons). All that being said, getting an airline, who can risk a big fine, to transport you into the US without a passport, military ID, green card, or refugee document are slim-to-none (and slim just left the building).
(Also as an aside, airline personnel are normally very used to seeing those with multiple citizenships, so one does not need to “hide” extra passports if it helps facilitate visa-free travel.)

Having worked with DHS on some of these issues before let me add some things.
Can/Could you leave without a US Passport?...the answer is yes...maybe.
Normally the USA does not have exit controls, and the airlines that send your PNR data to DHS to run watch-list matching do not care which passport you enter when you buy your ticket. That ticket can be roundtrip BTW.
When you check-in they want to ensure you can legally enter the country you are going to (and/or through). Thus if flying to the UK, for example, a dual US/UK would just need to present the UK passport at check-in.
The big catch is DHS (Normally CBP) run random and sometimes targeted exit checks at the gate (normally in the jetway) for outbound flights, often times with portable computers linked to DHS systems and/or the systems that link immigration data around the globe (for those that participate). During these they are often looking for undeclared cash, meaning those that did not file a FINCEN 105 form for cash over 10kUS$. But they can and do check for immigration data too. If you were to be checked on one of these flights you could be stopped/denied boarding and/or fined.
So the easiest solution is to have a valid US travel document at exit.
Technically, a US national does not need a US passport to enter the USA, and I don't mean just those with military IDs, green card, tribal IDs, gov't orders or refugee documents.
By law, CBP has to admit US Citizens and Nationals. The key is satisfying them that you are a US citizen/national. Normally a passport does this (quickly, unless you don’t answer their questions, which you legally do not have to do, but you can be detained), also presuming they don't think the passport is altered.
CBP has other ways of verifying citizenship/ID but it takes time. People lose their passports on their flights into the US all the time. People present at land and sea borders without passports too (For various reasons). All that being said, getting an airline, who can risk a big fine, to transport you into the US without a passport, military ID, green card, or refugee document are slim-to-none (and slim just left the building).
(Also as an aside, airline personnel are normally very used to seeing those with multiple citizenships, so one does not need to “hide” extra passports if it helps facilitate visa-free travel.)

This is incorrect information.
You do not have to use your US passport outside the United States.
You should use whichever one gets you the easiest/visa free travel (outside of those areas where you are required to use one or the other e.g. Schengen and the USA).
I posted something on the thread about US passports and exiting the US that I will repost here since it is somewhat relevant on the US side. I do this having dual citizenship, and having worked with the US DoD, DHS/CBP, NATO and Schengen authorities arranging certain travel in said manner
From me:
The part at the bottom is key. Though I would tell you to take both passports at all times because you never know when plans could change.
On a roundtrip journey from the US to Germany it goes normally something like this, and I'll use a sample Houston (IAH) to Frankfurt (FRA) flight.
At Houston airline check-in show German passport. If names are different you can show the US one also. Airline staff are used to this.
At TSA ID check it is best to show US passport (without going on too much of an anti-TSA rant they sometimes get too confused by foreign passports)
At gate to board flight show German passport. If they ask for an I-94, state you don't have one as a US citizen also, though often they don't even ask.
Upon landing at FRA show German passport to the border authorities (they normally will not speak with you) Presuming nothing to declare, walk out green channel and you are done.
On return flight to US show US passport at check-in, and answer their inane questions about packing your own bags.
At exit control, show German passport, most likely getting a grunt or wave of the hand to move on (German polizei don't talk much)
At boarding show US passport.
At IAH point of entry give US passport to CBP.
Note-if you travel overseas get Global Entry, then you don;t even have to talk to the CBP normally. I have had it nearly 5 years now and love it.