I THINK it depends on the route itself as well. No 100% for this. With their random check I dare not to take the risk. For my travel for the past 3 years, I always buy check-in luggage and have my heavy lenses checked-in. Normally I'll pack them in a neoprene case, then in a camera insert, then the camera insert is locked and surrounded with my clothes. Till date haven't encountered any problem.