Funny you should say that... I saw an electric take off with a funny noise and shortly after I asked him when he had the smoke system installed...

He was very lucky to get the model on the ground to disconnect the LiPo. It was a .40 size electric and one thing he didn't have was an external arming pin/connector. He had to remove the battery hatch to disconnect things and risked getting burnt.

Cheers
Jason.