My parents, who are from Mexico, want to visit the US but they only speak Spanish and they are worried about getting lost trying to get to the connecting flight. We have thought about booking a direct flights but they are more expensive.
Do airlines offer assistance in this cases?
This depends a lot on which flight, airline, and city. But as a general rule, it shouldn't be any trouble finding Spanish assistance in most airports--especially the large ones.
Certainly their flight out of Mexico will have Spanish speakers on the ground at both ends. So there should be no trouble getting assistance once they land.
As a worst-case scenario precaution, you can give your parents your mobile phone, or that of a bilingual friend, and in a pinch, they can call for an over-the phone translation.
If you can tell us which airports they will be in, it will be easier to provide a more thorough answer.
The thing about airports is that every day, people from around the world with many different languages are passing through.
In the US, especially in Texas (where you mentioned) and Arizona, they're likely to speak some Spanish. However, even if the staff don't, they're used to dealing with people every day who don't speak English - they may speak Russian, Mandarin, French or whatever else comes up.
As long as they have their travel documents and ID, showing this to someone with a questioning expression is pretty much guaranteed to get someone to help you in the airport, from staff to other passengers.
Remind them also, that in the airports, everything is well signposted in international symbols for this very reason. Departure signs, passport stamp signs, boards with flight numbers and destinations. Aside from the check in and if you go through passport control, you hardly even need to communicate with anyone, just follow the signs.
However, even if they can't find staff, asking passengers around if they speak Spanish - in the US I found many people tended to even have basic Spanish (especially in certain States, like Texas and Florida) and if not, people are often happy to try and help regardless.
Hope they enjoy their flight and the fun experience of travelling!
If they allow extra time I wouldn't worry about it no matter what the language. Holding out a ticket or boarding pass and looking lost is pretty much a universal language for where-should-I-go? So long as you can recognize the airport people that should let you navigate any airport in the world. Language only becomes an issue when dealing with immigration and the US doesn't have outgoing border controls.
Besides, in an airport you're normally doing expected things and around a bunch of other people doing the same sort of thing. You can accomplish a lot of communication with very little language, not to mention that if you go around trying Spanish on Hispanic-looking people it shouldn't take long to find someone who understands you.
Apart from all the above answers, one most important thing that I have seen a few buddies do. They give their parents letters to carry. The letters are written in English and the content is the question. You can label the envelopes as "Terminal inquiry" and the content can be "Which terminal do I take for flight X". Then in the worst case, they can show this letter to an airport personnel and figure things out. Logically, to me, this seemed like the best way to deal a worst case scenario.
In fact, I am told that from people who cannot speak English, immigration officers at an American Port of Entry will accept a letter as a statement of purpose of the aliens intent of entering America. Most people coming in as domestic help take this route.
