When bernard leaves he asks the pilot if lenina will be safe the pilot responds safe as helicopters what does he mean?

This line is from Aldous Huxley's 'Brave New World'. In this scene, the pilot could be commenting on the safety of helicopters as compared to the safety of being "high" as in flight versus high on Soma. In this case, the metaphor of the helicopter (it being relatively safe, but seemingly very dangerous) is the same for Lenina being high on Soma. She is relatively safe, yes, but produces much fear. This phrase could also be pure sarcasm, in which case the pilot is saying they are not at all safe as helicopters are dangerous.

Cotton was the very first