Don't forget that hill a mile beyond the threshold. Then there's always that ridge, several miles away that you intend to cross on your route of flight. The reason is because we have no charts in our POH or owners manuals to give us the answer. What we desperately need to know is what kind of climb gradient we can reasonably expect once we're airborne. Here's How To Figure Climb Gradient Don't let this climb gradient thing bumfuzzle you.
Climb gradient is simply the ability of the airplane to climb once it leaves the ground.
We can talk in terms of feet per nautical or statute mile, depending on whether you have an airspeed calibrated in knots or miles per hour. When we depart from our sea level, standard day airport, most of our GA airplanes climb pretty well. For example, according to its owner's manual, the ubiquitous Cessna 172N is capable of climbing at 770 feet per minute. What we need to know now is the climb gradient. Next, we look at climb rates.