Is this a trick question? If you say there aren’t any prescribed takeoff minimums for Part 91 operators, you would be correct; however, just because something is legal doesn’t make it smart. You might even have heard an instructor saying you can take off if it’s “zero-zero.” That advice is as impractical as it is, well, stupid. Flying involves risk. We can’t let ourselves be paralyzed by those risks, but we certainly need to manage them, so here are some factors you might want to consider in making an IFR takeoff decision.
Obstacle Clearance
First and foremost, you need to know if your aircraft performance is adequate to meet the climb requirements for the specific departure you’re about to execute. These minimums are found in the Takeoff Minimums and (Obstacle) Departure Procedures. Not sure what I’m talking about? You aren’t alone. You might be surprised to know how many applicants for an instrument rating don’t know where to find this information or how to apply it.
