There are two regional airports on the island, but no international airports. Therefore, flying to Dominica requires travelling through San Juan, Puerto Rico or other nearby islands in the Caribbean such as Martinique, Guadeloupe, or Barbados. The primary airport, Douglas-Charles Airport (DOM), is on the northeast coast and is about a 45-minute drive from Portsmouth (1 hour from Roseau). The second is Canefield Airport (DCF), about 15 minutes from Roseau on the southwest coast. Douglas-Charles Airport is suitable for limited use of commercial jets because of runway length. Douglas-Charles currently has regular service by Air Sunshine, Winair and Seaborne Airlines using twin turboprop aircraft like the ATR and Saab 340, as well as Conviasa and Amerijet, which, using Boeing 727 Freighters, is the only airline with jet service to the republic. A runway extension and service upgrade project began at Douglas-Charles Airport around 2006 and was finished in 2010. In March 2013, airline American Eagle halted flights to the island citing high labour costs.