70-80' movie, plane crash island jungle paradise camp

The movie i'm looking for,

* is a family film,

* probably from end 70's - begin 80's.

* definetly in color

* Spoken language = English (but not per sé Amercian)

- Due to a plane crash, a group of people ends up on a jungle-like island.

- On the island, there's an abandoned camp, where they make base.

- This camp is also used by bad guys (pirates? Drug smugglers?)

Characters: there's 1 that's supposed to be the alcoholic (might be 2nd Pilot)

Any help is appreciated !