I filled up all tanks on the C421 a few weeks back ready for an early morning departure.
I cancelled the flight on the morning at the last minute due to other commitments.
I returned to the aircraft a week later. Did the fuel drain checks starting starboard main - Not a drip!
Checked inside the tank - Zero!
Went to inboard tank - still full. Port main - Not a drip! Port inboard was half full. Lost nearly 500Lts
I went straight to the airfield manager and advised my findings. He stated that it was not the airfields responsibility
I then asked them to check CCTV footage of the 2 cameras facing the aircraft but was then informed that they were not working
Apparently, I was parked in a problem area of a North London airfield where fuel had been stolen in the past to fuel gypsy machinery.
Thankfully, we do not suffer this at home airfield.