As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE MEDICAL CREW REPORTED TO THE PILOT THAT THEY SMELLED FUEL IN THE CABIN SHORTLY AFTER TAKEOFF. THE PILOT IMMEDIATELY RETURNED TO THE HELIPAD. THE MECHANIC PERFORMED AN INPSECTION OF THE FUEL SYS AND FOUND THAT THE LOWER FITTING OF THE EXPANSION TANK WAS LEAKING. THE ACFT IS CURRENTLY OOS AWAITING THE ARRIVAL OF A REPLACEMENT EXPANSION TANK. THIS PARTICULAR TANK WAS REPLACED IN THIS ACFT JUST AFTER IT INITIALLY ARRIVED FROM THE MFG WITH VERY LITTLE TIME.