On Instruments: Low-vis takeoffs

One is the freedom to make takeoffs in “zero-zero” weather conditions. Where those flying under Parts 135 and 121 need to observe at least their standard, one-statute-mile (for single- and twin-engine aircraft) or one-half-statute-mile (for more than two engines, or helicopters) takeoff visibility minimums, under Part 91 we’re able to take off in zero-ceiling, zero-visibility conditions. This sounds crazy, but it does make you wonder if anyone actually exercises this “privilege.” Obviously, it’s a very dangerous procedure.

And yet, some CFIIs feel like they have to put their students through the experience—under the hood, that is. Doing an instrument takeoff can be a good exercise in heading control, but there’s virtually no carryover into real-world IFR flying. You don’t have to demonstrate an instrument takeoff on the instrument rating practical test, and I can’t imagine a situation where you’d ever do one in actual conditions. But if your training was like mine, you’d find yourself storming down the runway one day, hood down, squeezing the rudder pedals ever so slightly as you speed toward liftoff, all the while being coached by your instructor. Does this encourage you to do the same in actual conditions once rated? Or does it scare you into swearing off any thought of doing a real instrument takeoff on your own? Put me in the latter group.

So, what can we use for guidance for takeoffs when ceilings and/or visibilities are low? We could follow the Part 121/135 one-mile rule for visibility in singles and twins. But a mile may not give you much of a safety margin when you’re climbing and terrain or obstacles are nearby. Still, it’s better than an instrument takeoff should a malfunction occur right after takeoff.

For safer takeoffs, be sure to find out if your departure airport has any published takeoff minimums or notams for the runway you’ll be using. You know there are published takeoff minimums if you see a white “T”—the so-called “Trouble T”—inside a black triangle in the briefing box at the top of an FAA approach plate.

On Jeppesen plates, they’re in the Takeoff and IFR Departure Procedures box on the back of an 11-1 approach plate (the first of the approach plates for a particular airport). Takeoff minimums—expressed in terms of ceiling, visibility, or both—are published in order to raise these variables above the standard, one- or one-and-a-half-mile visibility minimums prescribed for Part 121/135 operations.

Additional obstacle information, minimum climb rates, and any obstacle departure procedures (ODPs) are also listed in the “Takeoff Minimums and (Obstacle) Departure Procedures” sections of an FAA approach chart book. Sometimes certain departure procedures are graphically printed on dedicated departure procedure charts.

Now let’s say that you’ve taken off and have a problem as you’re climbing out. By using alternate takeoff minimums you’ll probably have a better chance of completing a return to the airport using an instrument approach because the takeoff minimums may be higher than any precision approach minimums.

Here’s an even better rule: Don’t take off unless the ceiling and visibility are higher than the lowest published minimums for any approach serving your departure airport.

Time for a “there I was” story. There was an 800-foot ceiling and two-mile visibility at Frederick Municipal Airport in Maryland, AOPA’s home base. I took off from Runway 23 with three passengers in a Beechcraft Bonanza A36 and was cleared to 3,000 feet, direct to a nearby VOR. Soon enough, I was in the soup.

Bonanzas’ front doors are known for their tendency to suddenly pop open if they aren’t closed and latched just right—a slam and three clicks as you turn the handle counterclockwise. The first sign of a door about to pop is the sound of hissing air. I thought I heard that sound just after liftoff, and definitely heard it passing through 1,000 feet. Then boom!—the door popped open. I called ATC, told them what happened, and they vectored me around for the ILS back to 23. The noise was distracting and made it hard to hear the controller, and there was some commotion as the right-seater tried to pull the door shut. (This never works, by the way.) But I intercepted the ILS, went down the pipe, and landed. While taxiing back for takeoff, the door was shut with much care and we took off once more. The door stayed shut this time.

The outcome certainly would have been different if the weather was zero-zero, but it was above the ILS minimums of 684 feet and one and a half miles. Add one more item to my roster of personal minimums: No more takeoffs in low IMC!

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