Vintage Instructor THE
BY Steve Krog, CFI
The lost art of slips
W
hile recently attending the 25th Annual Sentimental Journey Fly-In held at Piper Memorial Airport in Lock Haven, Pennsylvania, my friend Mark Stewart and I were watching airplanes and their pilots hopping rides and demonstrating their piloting techniques doing takeoffs, landings, and flybys. Most every airplane, when on the approach to land, employed a forward slip to achieve a touchdown on the numbers and make the first turn-off comfortably and safely. Mark turned to me and commented, “The slip really is a lost art and a maneuver many pilots really don’t understand or use today.” I agreed. The slip, when implemented correctly, is a useful and safe tool for pilots young and old, provided it is practiced with some regularity. But with the introduction of flaps it has become a lost art, even though pilots flying flap-equipped airplanes should understand the slip and be able to perform it when needed. Ask yourself these questions: “When was the last time I performed a slip, and how often have I practiced slips?” When conducting flight reviews I frequently ask the individual to demonstrate a 50-foot obstacle short-field landing using a slip. The pilot will often look at me and state, “I haven’t done a slip in a long time!” “Sure you have,” I’ll reply, “you just didn’t realize it. How do you set up your approach for a crosswind landing? Each time you make
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a crosswind landing, you’re executing a side slip.” There are two types of slips: the forward slip and the side slip. In the simplest of definitions, the forward slip is used to lose altitude, while the side slip is used for runway alignment. Let’s take a look at their respective similarities and differences. The forward slip is often em-
“When was the last time I performed a slip, and how often have I practiced slips? ployed when a pilot has set up for the final approach to land and has excess altitude, when making obstacle landings (especially at short fields), or when making a spot landing. A forward slip allows for the aircraft to maintain a straight-line track over or on the runway centerline while on approach. However, when maintaining the track, the nose of the airplane is not aligned with the runway and needs to be realigned before landing. The side slip is often employed when making a crosswind landing or to align the airplane with the runway centerline. The nose of the airp lane (long itudin al axis) remains aligned with the runway centerline.
How to Practice Forward Slips The next time you make a pleasure flight, climb to an altitude of about 2,500 feet above ground level (AGL). Level off and align your airplane with a straight road that is also aligned with the surface wind. If the wind is generally from the south, fly south over a north/ south road. Reduce the power to the setting used on final approach to land and establish the final approach glide speed. Apply left aileron, lowering the left wing about 10-15 degrees (similar to a shallow bank turn). The airplane will want to turn left. Now apply opposite, or right, rudder using just enough rudder that the airplane continues to track in a straight line over the road. The airspeed will give you erratic readings whenever doing slips, so it is more important to focus on maintaining the correct descent or glide attitude. You may need to apply very slight forward pressure on the stick or yoke to do so. Continue the descent and track for 1,000 feet of descent; then return to cruise flight by slowly taking your foot off the right rudder and bringing the left wing back to a level-flight attitude. If you haven’t done a slip in a while, setting up for and holding the forward-slip attitude will feel awkward at first, as will the return to level flight. A few repetitions will significantly increase your comfort and coordination. Now try executing the forward slip with the right wing down and