A pilot needs only a glance at a satellite photo of the ridge off the end of Runway 2 at the Sisters, Oregon, airport to know that a takeoff in that direction is anything but a routine departure.
Now consider other features of the airport, such as a runway of modest length (3,560 feet) and a notably altitudinous field elevation (3,168 feet), and the operational challenge grows even more attention-getting.
Using standard atmospheric pressure as a baseline, you can approximate the density altitude for those conditions at 5,600 feet, with takeoff and climb performance mimicking a departure from an airport at that elevation.
Checking the takeoff-distance chart for your aircraft in the 30 degrees Celsius column, your ground roll distance in Sisters will be about 270 feet longer than it would be at the same temperature at sea level; the distance to climb over a 50-foot obstacle increases by roughly 540 feet. (Climbing to that height also would consume about 60 percent of the modest-length runway, leaving perhaps 1,500 feet of pavement ahead before you exit the airport environs.)
That’s the takeoff. Now, what about that ridge?
The airport listing in the chart supplement cautions pilots to be aware of density altitude and aircraft performance prior to takeoff, and it adds this procedural note: “Pilots may consider a departure climb over meadow approximately 45 degrees to the left of the departure end of Rwy 02.”
When planning for scenarios like this, it’s worthwhile to find out what the local pilots do. Julie Benson, the airport proprietor, agreed that “hot days require extra caution,” and she concurred with the chart supplement that when departing on Runway 2, “most planes will not attain altitude to make it over the hill, so we typically make a hard left turn before the hill and climb over the grass meadow that runs parallel to the hill.”
That’s not all.
“The runway is not aligned with prevailing wind direction, so crosswinds are the norm here.”
And, “Since we are at the base of the Cascades Range, mountain waves can be prevalent.”
As always in aviation, forewarned is forearmed.