But there’s a subtlety to that last step, which I see being rushed far too often. I can’t tell you how many times I hear the starter engaging before the pilot completes the word “clear” as if the propeller has begun to spin on  voice command.

Ask yourself: What’s the point of shouting “Clear?” It’s the final warning to anyone in earshot on the ramp that you are about to turn a (relatively) harmless slab of metal into a whirling blade of death and dismemberment. No recent data exists on how common prop injuries are, but one older FAA study found they happen about 20 times a year, with one-third of those incidents ending in death. At the time of the study, in the late 1970s, these kinds of accidents were on the decline, but given how many people I see on crowded flight school ramps, eyes glued to their smartphones, I would not be at all surprised if propeller injuries are back on the rise.

The point is, what good is a final verbal warning if there is no time to react? To, for example, shout a counter-warning to you that your towbar is still attached, a lineperson is trying to remove your nose chock, or a wayward child is examining your nose gear?

When I was a kid, all railroad crossings had iconic X-shaped black-and-white signs with the words “Stop. Look. Listen.” printed in bold letters. The idea was that you should stop your car/truck/motorcycle. Look (both ways, please) to ensure a train wasn’t coming. And then listen for the warning whistle or horn of an approaching train. It’s pretty sound advice, and advice we can take to heart in aviation.

So, after you shout, “Clear prop,” and before you engage the starter, take a couple of beats to listen. And to do that right, you need to do more than crack open the window an inch or two. You also need to crack your headset. Move the ear cup closest to the window off your ear so that you can clearly hear any counter-shout to your final warning.

Then, and only then, have you truly cleared your prop.