Port Louis is the capital city of Maurtius and it's the major harbor of the island. The Airport is located in the south east at Plaisance and the name of the Airport is Sir Seewoosagur Ramgoolam International Airport. Airport identifier is FIMP with runway 14 and 32 both over 3000 meters in length.
The only major air service in Mauritius is Air Mauritius and according to their website they have 12 planes.
Mauritius strip
land
Flights to Mauritius are operated every Wednesday and Saturday. Both flights take off at 1105 and land in Mauritius at 1530.For returning to Singapore both flights again land at 0945.
The main export of Mauritius is Sugarcane. It takes up 90% of cultivated land and accounts for 25% of Mauritius's export earnings
There are no direct scheduled flights from Belfast to Mauritius. You would need to take a few flights through different airports to get there. There would be many options.
RUNWAY
No because the air around the plane has pressure. If two planes take off at the same time the planes will crash. The planes might crash if they land at the same time.
Mauritius is itself a small Island. Islands are made out of land surrounded by water. Therefore one cannot have an island in an island.
Because the land is fertile
Planes cannot land straight up and down
Planes can land on airfields normally. Specifically on a runway. However some planes can land on water. FloAt planes for example. Others can land on snow if they equipped with skis and still other may land on unprepared surfaces like tundra when they are equipped with big tires that prevent them from sinking into the muck. There are many formal and informal airports around the world both on land, water and the stuff in between.