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The following stories from the April 30, 2010, edition of AOPA ePilot were provided to AOPA members who expressed an interest in the particular subject areas. Any AOPA member can receive information tailored to their areas of interest by updating their preferences online.


V X or V Y?

When you learned your training aircraft’s V speeds, it was clear that using them made good sense. Some speeds appear as color coding on the airspeed indicator and help to keep you from exceeding operating limits. Others, such as V A, for turbulence penetration and maneuvering, and the climb speeds V Y and V X, are in your pilot’s operating handbook.


Sometimes there’s a choice to make between two V speeds, as when deciding before takeoff whether to climb at best rate-of-climb speed (V Y) or best angle-of-climb speed (V X). This can be puzzling for a trainee, even after studying the definitions in Chapter 10 of the Pilot’s Handbook of Aeronautical Knowledge :


V Y—the speed at which the aircraft will obtain the maximum increase in altitude per unit of time. This best rate-of-climb speed normally decreases slightly with altitude.


V X—the speed at which the aircraft will obtain the highest altitude in a given horizontal distance. This best angle-of-climb speed normally increases slightly with altitude.


Think of best rate-of-climb speed (V Y) as your usual tool for gaining the most altitude in the least time. Why is that a pilot’s usual goal? Safety. The quicker your ascent, the less exposure to a low-level engine failure, when it would be unsafe to try to return to the runway. (See the Aug. 20, 2004, “ Training Tip: Why VY?”)


V X is in your toolbox for the more specialized situation of a takeoff with an obstruction along your departure path. “If I'm taking off from a runway with obstacles on the departure end, I'll want to quickly get to best angle-of-climb speed. That should get me up and over the obstacles in the shortest distance,” explained Mark Twombly in his April 2009 Flight Training Continuing Ed column. He wrote, “My climb rate may be better at a higher indicated airspeed, but with obstacles I'm not much interested in how quickly I can get to a safe altitude. My objective is to reach that altitude in the shortest horizontal distance. So what if it takes a few seconds longer?”


With the obstruction safely behind and below, transition to V Y for the quickest climb out of the low-altitude, higher-risk realm of the climb.


Red Canoe apparel

If you’re proud of your training airplane, you can show it through apparel from Red Canoe. The company makes shirts, bags, hats, and more with popular aircraft manufacturer designs. So if you’re happy to show off your Cessna, check out Red Canoe.


Note: Products listed have not been evaluated by ePilot editors unless otherwise noted. AOPA assumes no responsibility for products or services listed or for claims or actions by manufacturers or vendors. 


Question: When filing a flight plan, I have to enter an aircraft type designator. Where is the easiest place to find this information?


Answer: Aircraft type designators can be found in FAA Order JO 7110.65T, the Air Traffic Controller's Handbook, Appendix A. A more extensive list including some of the most popular light sport aircraft is also available at the ICAO (International Civil Aviation Organization) Aircraft Type Designator website. These two lists contain aircraft information, including the designator for each make and model of aircraft. The type designators assist air traffic controllers in identifying specific aircraft and understanding their performance characteristics, such as climb and descent rates, and typical airspeeds.

Got a question for our technical services staff? E-mail [email protected] or call the Pilot Information Center, 800/872-2672. Don’t forget the online archive of “Final Exam” questions and answers, searchable by keyword or topic.

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