Air services in the USA are generally excellent and relatively inexpensive， and travel by air is a very convenient（方便的） way of getting around such a large country.there are often cut-price arrangements that foreign visitors are able to get， especially if you book before you leave home， but these change from year to year， so you should check with a travel agent. There are also， from time to time， price-cutting wars and other competitive struggles between the different internal airlines， so it is sensible to make inquiries about what the b est deals are at any given time. （American travel agents will know better about these.） It may well be that some airlines are offering better prices or better arrangemengts than others for the particular journey you want to make.
Note that in America a return ticket is called a "round-trip" ticked， and a single ticket is called "one-way" ticket.
Major Internal（国内的） Airlines
The major airlines for internal flights include American Airlines， Coutinental， Delta， Eastern， Northwest Orient， Unite and Western. Airlines covering smaller areas of the country include Frontier（the West）， Ozark（Midwest）， Pacific（West Coast）， Republic（the South and Midwest）， Texas， and US Air（the Northest）。
American airports are organized on a rather different basis from those in China.For obvious reasons the international sections（国际航班区） are very small， and the domestic（国内的） sections， which normally include flights to Canada and Mexico， are very large by comparison. The airports are organized by different airlines； each has not only separate check-in desks but also separate gates， lounges（候机室） or even terminals（旅客集散地）。 It is especially important， therefore， to know which airline you are flying with.
At American airports it is very often possible for people who are not traveling themselves to accompany passengers on domestic flights right to the departure gate， provided that they also pass through the security check（安全检查）。 Similarly， arriving flights can be met right at the gate.
Baggage regulations（规定） are the same as for international flights， and passengers are allowed to take free of charge two pieces of luggage， （each weighing no more than 70 pounds or 32 kilos） if the length＋height＋width of one does not exceed（超过） 65 inches（1.65 meters）。
When you check in at an airport you can request a smoking or a non-smoking seat. However， current（目前的） American law requires that everybody who wants a non-smoking seat must be given one. In other words， the non-smoking sections on planes must be made larger enough in order to meet the needs of everyone who wants this type of seating. And even in smoking secyions it is not permitted to smoke cigars or pipes.
it is very possible to check in for a flight at the departure gate if you are taking only hand baggage.
Service on Board
Some internal flights are long-it takes seven or eight hours to fly from Seattle（西雅图） to Miami（迈阿密）， for example， and five and a half hours to fly from Los Angeles（洛杉机） to Boston（波士顿）。 Service on longer flights is very much like that on international flights. Passengers are provided with meals， drinks and films. The longer flights usually offer frist class and tourist rates while short flights often make no difference in fares.