A single-engine aircraft with a pilot and nonpilot passenger aboard is No. 2 for takeoff before launching on a VFR cross-country flight. The passenger has flown before with other pilots, and has become somewhat accustomed to the sights, sounds, and sensations of flying.
This time, the passenger’s expectations are upended immediately after the flight is cleared for takeoff. This pilot appears intent, despite the long runway, on becoming airborne in the shortest possible distance; the aircraft breaks ground well before reaching the large white stripes painted on either side of the runway centerline.
Another surprise springs itself as the aircraft begins to climb: After a brief straight-ahead climb, the pilot banks left and climbs on a new heading. Is something wrong? Doesn’t seem so. Nor did it seem to be just sloppy flying because the pilot performed each operation smoothly and deliberately.
Now let’s reset the scene back to the takeoff clearance, and consider this scenario from the pilot’s vantage point: The preceding departure, a small business jet, broke ground in the vicinity of the runway aiming-point markings. As the pilot of the single began the takeoff run on Runway 15, he planned to become airborne well before reaching that point, lessening the chance of a low-altitude wake turbulence encounter.
When the tower issued the flight its takeoff clearance, the controller also reported current surface winds of 130 degrees at 10 knots. So, as soon as is safe and practical after initiating the climb, the pilot makes a left (upwind) turn in an additional step to avoid any wingtip vortices from the business jet—especially a vortex generated by its upwind wing. “When the vortices of larger aircraft sink close to the ground (within 100 to 200 feet), they tend to move laterally over the ground at a speed of 2–3 knots. A crosswind decreases the lateral movement of the upwind vortex and increases the movement of the downwind vortex,” explains Chapter 13 of the Pilot’s Handbook of Aeronautical Knowledge.
For the passenger, the familiar ambiance of flight returns as the aircraft nears cruise altitude. The passenger debates whether to query the pilot about the unusual takeoff. But discussion will have to wait; the pilot has made it clear that sterile cockpit procedures are in effect until otherwise indicated.
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