Desde

Adposición

  entonces

Adverbio

  su

Determinador

  operación

Substantivo

  principal

Adxectivo

  es

Auxiliar

  servir

Verbo

  a

Adposición

  vuelos

Substantivo

  sanitarios

Adxectivo

,  oficiales

Adxectivo

  y

Conxunción coordinadora

  privados

Adxectivo

.

Since then, its main operation has been to serve medical, official and private flights.

Since then, its main operation has been to serve medical, official and private flights.