In air transport change of gauge for a passenger

Passenger

A passenger is a term broadly used to describe any person who travels in a vehicle, but bears little or no responsibility for the tasks required for that vehicle to arrive at its destination....

 or cargo

Cargo

Cargo is goods or produce transported, generally for commercial gain, by ship, aircraft, train, van or truck. In modern times, containers are used in most intermodal long-haul cargo transport.-Marine:...

 means a change of aircraft without the change of flight number

Flight number

A flight number, when combined with the name of the airline and the date, identifies a particular flight. This callsign should not be confused with the tail number of the aircraft, although both can be used as a call-sign as used in general aviation...

. The term is borrowed from and in analogy with the rail transport

Rail transport

Rail transport is a means of conveyance of passengers and goods by way of wheeled vehicles running on rail tracks. In contrast to road transport, where vehicles merely run on a prepared surface, rail vehicles are also directionally guided by the tracks they run on...

 practice of gauge change

Break-of-gauge

With railways, a break-of-gauge occurs where a line of one gauge meets a line of a different gauge. Trains and rolling stock cannot run through without some form of conversion between gauges, and freight and passengers must otherwise be transloaded...

.

The Y-type change of gauge is the one when one flight is transferred into two with different destinations.

United States

In the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, change of gauge is standard practice amongst the major airlines. As of 2001, 6 US airlines (American Airlines

American Airlines

American Airlines, Inc. is the world's fourth-largest airline in passenger miles transported and operating revenues. American Airlines is a subsidiary of the AMR Corporation and is headquartered in Fort Worth, Texas adjacent to its largest hub at Dallas/Fort Worth International Airport...

, Continental Airlines

Continental Airlines

Continental Airlines was a major American airline now merged with United Airlines. On May 3, 2010, Continental Airlines, Inc. and UAL, Inc. announced a merger via a stock swap, and on October 1, 2010, the merger closed and UAL changed its name to United Continental Holdings, Inc...

,
Delta Air Lines

Delta Air Lines

Delta Air Lines, Inc. is a major airline based in the United States and headquartered in Atlanta, Georgia. The airline operates an extensive domestic and international network serving all continents except Antarctica. Delta and its subsidiaries operate over 4,000 flights every day...

, Northwest Airlines

Northwest Airlines

Northwest Airlines, Inc. was a major United States airline founded in 1926 and absorbed into Delta Air Lines by a merger approved on October 29, 2008, making Delta the largest airline in the world...

, US Airways

US Airways

US Airways, Inc. is a major airline based in the U.S. city of Tempe, Arizona. The airline is an operating unit of US Airways Group and is the sixth largest airline by traffic and eighth largest by market value in the country....

, and United Airlines

United Airlines

United Air Lines, Inc., is the world's largest airline with 86,852 employees United Air Lines, Inc., is the world's largest airline with 86,852 employees United Air Lines, Inc., is the world's largest airline with 86,852 employees (which includes the entire holding company United Continental...

) had change of gauge flights. Title 14 CFR

Code of Federal Regulations

The Code of Federal Regulations is the codification of the general and permanent rules and regulations published in the Federal Register by the executive departments and agencies of the Federal Government of the United States.The CFR is published by the Office of the Federal Register, an agency...

Part 258, "Disclosure of Change of Gauge Services", requires air carriers to disclose
to passengers, traveling on a single flight number, if they will be required to
change planes during the flight. Part 258 requires the air carriers to inform the
consumer that there is a change of gauge in the itinerary before the reservation is
made. Some passengers, such as persons with disabilities or who otherwise are
not disposed to make a connection, prefer to book on flights without a change of
aircraft. However, passengers could incorrectly assume that if they are traveling
on a single flight number they will not be required to change planes. Single flight
numbers are typically used for an originating domestic to international destination
or the return (e.g., San Francisco to Chicago to Paris).