LinkedIn Pinpoint

Here is how each clue relates to that word:
Tailfin: Tailfin is a type of fin that comes after sweet.
Gondola: Gondola is a type of car that comes after sweet.
Propeller: Propeller is a type of machine that comes after sweet.
Ballonets (inflatable bags): Ballonets (inflatable bags) are types of bags that come after sweet.
Helium gas envelope: Helium gas envelope is a type of envelope that comes after sweet.