When a flight attendant smuggles on a chainsaw and starts butchering passengers mid-flight, an aerophobe must bottle his panic to take down the killer and save his family on board.

Tone of this? Horror or spoof? Smuggles on a chainsaw is so absurd it seems like a spoof (but... Snakes on a Plane was an odd mix of horror over the top that worked for audiences). But chainsaw is so large, loud, short span of use... just not sure it'd work for a feature film.

I suggest refocusing the logline on the story hook, the grab. Which, IMHO, is not one passenger's flight phobia. What grabs my attention, what stokes my imagination and curiosity is the flight attendant.

What's her (his?) backstory? What motivates her (him?) to plan and execute the massacre? And surely the setup scenes showing how the attendant contrives to smuggle the chainsaw aboard is vastly more interesting to watch than a passenger getting on board despite his flight phobia.

FWIW

Well put together. Sounds like fun. Not sure how long it'd last as a feature given the situation but I'd be intrigued to read/watch it.