Roping in a safe landing

Mission Aviation Fellowship (MAF) trains pilots to be “thinking” pilots—equipped to make decisions in situations when they might not have all the information or technology available. One technique every MAF pilot must become skilled in is called the three pass Wind LASSO. Used when encountering a new or unknown runway, the three pass Wind LASSO not only gives the pilot necessary information—it can save his life.

Wind LASSO stands for wind (strength and direction), length, altitude, slope, surface, and obstructions—all crucial information for landing on any airstrip. A strip chart is available for most of the airstrips on which MAF pilots land. These charts provide the pilot with all pertinent information about an airstrip, including the normal Wind LASSO. Yet occasionally MAF pilots must open new airstrips for which a strip chart is not available. At these times a pilot must know how to gather this information while airborne, and that is where the three pass Wind LASSO is put to use.

A mountaintop airstrip in Papua, Indonesia. Photo by Dennis Bergstrazer.

Arriving at the new airstrip, the pilot plans three passes along the strip. Each pass will allow the pilot to determine more information about the strip. Each pass allows the pilot to determine more information about the strip. The first pass is conducted at pattern altitude where the pilot gathers information on the wind and the overall slope of the land, allowing the pilot to determine the direction he will fly when he makes the next two passes at lower altitudes—he is careful to not fly into rising terrain! The pilot makes note of the altitude and looks to see if there are any obstructions along the flight path or on the runway.

The second pass is lower than the first—barely 100 feet above the airstrip. On this pass the pilot will determine length, and again verify the altitude of the strip. Multiplying the plane’s speed by the time it takes to cross the landing strip gives the distance to within roughly 50 feet, allowing the pilot to determine if the strip is long enough for normal landing. Again, as in each pass, the pilot is checking for obstructions on the strip.

Finally, the pilot does a low pass. On this pass, the pilot looks at the condition of the surface, determining strip composition—rocks, clay, grass—and the quality of the surface whether rough, wet, or dusty, as each of these would influence the landing in different ways. After these three passes, if the pilot has determined it is safe to land, he will return to the strip for the first landing, usually greeted with cheers and great enthusiasm by the local population.