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Guide to Antonio B. Won Pat International Airport (GUM)

Lumbered with the rather cumbersome name of Antonio B. Won Pat International Airport (GUM), it is hardly surprising that the former Naval Air Station at Agana is most commonly simply referred to as Guam International Airport. Nor should it come as a surprise that it is the only international airport on Guam as the island is a mere one square mile in size and is home to around a thousand residents.

The airport is located 3 miles (5 km) to the east of Hagåtña, the capital city formerly called Agana, which is the islands center of commercial activity and government.

Covering just 1,700 acres, Guam International is a small airport with a single terminal building and two asphalt runways but is a major hub for Asia Pacific Airlines and a Pacific Ocean hub for United Airlines.

The airport is named in honour of Antonio Borja Won Pat who was the first delegate from the island to sit in the U.S. House of Representatives and bears the International Air Transport Association (IATA) designation code GUM.

Starting as a Japanese Airfield

An airfield first appeared on Guam around 1943 and was built by the Japanese as part of that country's defence system protecting the area around the Mariana Islands. The Japanese named the military airbase Guamu Dai Ni which translated as Guam Number 2. However, Japanese possession of the island did not last long as it was recaptured by American troops a year later in 1944 and renamed Agana Airfield, the name of the nearest town on the island.

The airfield was badly damaged during the recapture but was swiftly repaired by the Americans and soon became a base for the U.S. Air Forces Seventh Air Force which flew Consolidated B-24 heavy bombers out of Guam before transferring operations to Okinawa in 1945. After bomber operations moved to Okinawa, Agana Airfield continued to be used by long-range Lockheed P-38 Lightnings reconnaissance aircraft until the beginning of 1946.

After the end of World War II in 1945, the airfield continued to be used by the U.S. Air Force as a base for fighter defence and also as a hub for transportation until 1947 when it was transferred into the hands of the U.S. Navy who continued to operate there until it was finally closed in 1993.

Use as a Civilian Airport

A prefabricated Quonset hut served as the airport's terminal building during the military years when only military personnel could use the airfield. When the U.S Army and navy no longer required Guam as a base it was decided to develop the airport for civilian use and the International Air Terminal was opened in March of 1967. Just two months later, Guam Airport welcomed its first international arrivals and civilian traffic began to build thereafter. In 1967 control of the airport was officially transferred to the Guam Department of Commerce and was passed on to the newly-formed Guam International Airport Authority (GIAA) in 1995.

In 1982 a new passenger terminal opened its doors with the present-day, larger terminal opening between 1996 and 1998. In the early years Guam Airport handled mainly charter flights and it was not until 2014 that the first regular international services commenced with flights to China's Shanghai Pudong Airport operated by major flight operator United Airlines.

Development continued at the airport with the launch of Project Hulo with a budget of over $165 million which is intended to increase passenger capacity, increase the number of security lanes, expand car parking facilities and improve the international arrivals area. The airport handles over 3.5 million passenger arrivals and departures annually and this number is expected to increase as Guam International Airport continues to upgrade its facilities and capabilities.

Immigration, Customs and Security

Although the island of Guam is a U.S. territory it is outside the jurisdiction of U.S. customs and all arriving passengers must pass through inspection by the Guam Customs and Quarantine Agency. The only exception to this are passengers destined for Honolulu in Hawaii which is the only flight out of Guam Airport to a U.S. state. These passengers will, as usual, be processed by American Custom and Border Protection (CBP) personnel.

Apart from this relatively minor difference, the requirements for airline passengers arriving at Guam Airport are the same as for any U.S. airport and these can be divided into two categories:

  • Citizens of Visa Waiver Program countries
  • Citizens of non-Visa Waiver Program countries

Visa Waiver Program citizens

The U.S. operates a Visa Waiver Program (VWP) for around 41 different countries around the world. It is a reciprocal arrangement with countries whose citizens are deemed to pose a low security threat. VWP citizens do not require a visa to enter the United States on short-term visits and, in return, U.S. citizens enjoy visa-free access to the participating nations.

However, VWP citizens must instead have sought, and been granted an ESTA before embarking on any visit to America. An ESTA, or Electronic System for Travel Authorization, is a digital form of visa which is linked to a passport but is much easier to acquire than a U.S. Visa. Once approval has been granted the ESTA application number is linked when an applicant's passport is scanned at a U.S. port of entry, either land or sea.

Non-Visa Waiver Program citizens

American national security is strict and acquiring a U.S. Visa is far from being a formality. The process involves filling out very detailed and personal and immigration questionnaires as well as providing supporting documentation. Mistakes can easily be made and any errors cannot be easily rectified and can result in the visa application being denied.

Citizens of countries who do not qualify for the VWP have no alternative but to go through the visa application procedure as arriving on American soil without the right paperwork will result in detention and deportation. Furthermore, non-VWP citizens must also complete a customs declaration form before approaching the customs area as this is also a mandatory requirement.

Whether traveling with an ESTA or visa, all non-American citizens must possess a valid, current passport and all paperwork must be presented to the Customs and Border Protection (CBP) agents on duty where new arrivals may also be briefly questioned about the purpose and duration of the visit.

Guam International Airport Layout

There are actually two terminal buildings at Guam Airport although the older of the two, the Commuter Terminal, is no longer used for handling flights since being leased out in 2003.

The first phase of the current terminal building was completed in 1996 and included a customs and immigration area. Today there are three levels in the terminal:


The basement level is for arriving flights and houses the necessary baggage reclaim and customs clearance desks as well as the Airport Police station.

Apron Level

This is the departures floor with ticketing facilities.

Third Floor

One floor up, the third floor is where the departure gates are located as well as the airport's immigration facilities.

In past years there was no dividing partition between arriving and departing travelers which was a security headache both for the airport and U.S. immigration officials. This was not a satisfactory (or secure) arrangement and, following the terrorist attacks of 9/11, the U.S. government demanded a secure separation of arriving passengers. Today, semi-permanent and movable walls are used to divide the terminal building into two sections which has brought about a more secure way of keeping arriving travelers away from the terminal proper until they have been properly screened and checked.

There are only two runways at Guam International Airport but these are capable of handling the world's largest aircraft including the Antonov An-225 Mriya. Most international flights out of Guam fly to Japan, China or the Philippines although United Airlines also flies to Honolulu in Hawaii.

Transfers and Ground Transportation

As Guam is such a small island there are no rail services to the airport. The main city of Hagåtña is only a short taxi ride away or local buses operate on the roads surrounding the airport which will take arriving visitors to most towns, villages and other destinations on the island.