i was helping a friend document construction of his new condo complex with my year-old Air when it suddenly took off On its own. I received an interference error message and I hit return to home but it didn’t respond. Then I lost video and it began yawing to the right and took off in a strange line. According to the log it also increased altitude to exceed the limit. Final message I received was motor obstruction before loosing contact. Video contact was never regained. I was able to track it into some woods with the flight log and after tracking around with my iPhone in 90+ heat found it apparently undamaged. Looking for advice. The Condo’s are behind a large steel building and we’re coated with foil Insulation, but I have flown here before without problems.