Any ideas what set they belong?
You have the fuselage of 4618 Twin Rotor Cargo:
The red windshield is from one of these sets (the yellow sticker does not belong):
- 70706: Crater Creeper
- 4621: Jack Stone Red Flash Station
- 4796: Ogel Mutant Squid
- 9320: Voyage into Space (Journey Into Space Set)
And the 2x3 slope is from one of these sets.