Final answer:
When encountering IIMC and entering controlled airspace, the crew should notify ATC, request IFR clearance, and follow ATC instructions.
Step-by-step explanation:
When encountering IIMC (Inadvertent Instrument Meteorological Conditions) and entering controlled airspace, the crew should take the following steps concerning Air Traffic Control (ATC):
- Notify ATC: Inform ATC immediately about the IIMC encounter and provide your current position, altitude, and intentions.
- Request IFR clearance: If the flight was initially conducted under Visual Flight Rules (VFR), request an Instrument Flight Rules (IFR) clearance from ATC to safely navigate the aircraft through controlled airspace.
- Follow ATC instructions: Comply with all instructions given by ATC, including altitude changes, heading adjustments, and clearances. ATC will guide the aircraft safely through the airspace.