Your nav radios are set and your assigned heading is noted prominently on your trip log as you urge the aircraft down Runway 31 in zero wind and a mile visibility on a misty morning. Acceleration, rotation, positive rate, gear up. Throttle to 25 inches, prop to 2,500 rpm, pitch for 95 knots. That was one nice IFR departure, you think as you slip into the ragged overcast.
The Runway 31 takeoff procedure calls for a climb to 1,500 feet on a 311-degree heading before turning northbound.
"That was nice and smooth," says your right-seat companion and teacher.
Before you can acknowledge the compliment, it is elbowed out of the way by a question. "Did you have a particular climb rate in mind for that first thousand feet?"
Wherever he is going with this inquiry, you are certain that "No" isn’t the expected answer. (It’s also time to turn northbound, so you discard the distraction and get to work, knowing that the issue will be revisited later.)
Later happens at a table in the destination airport’s café. He points out that, with the warm, wet day and a weighty load aboard, the initial rate of climb was barely 500 feet per minute. You concede disappointment at that figure and resolve to climb to a higher altitude at full power in the future, before making the initial power change.
But that’s not where the discussion is going. At 500 feet per minute and 95 knots of groundspeed in the windless conditions, was the altitude gain per nautical mile acceptable?
He opens the terminal procedures volume for the area to the departure notes for the airport: "Rwy 31, 600-2½ or std. with min. climb of 345' per NM to 1000."
You crunch the numbers—after a brief struggle recalling the formula—and a smidge of the pride you felt in your perfect piloting performance pales.
"Good thing I was keeping an eye out for trains," says the sage.
There, further down among the notes for Runway 31: "trains beginning at DER, 437' left of centerline, up to 23' AGL/222' MSL".
Now all you can do is hope he won’t ask you what a DER is—at least until you can sneak a peek at the list of abbreviations used in terminal procedures, where DER is translated to "departure end of runway."