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Old 12-03-2005, 06:27 PM
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tonystro
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Default RE: NEED HELP FROM BIPLANE GUYS

mrbiggs,

Not sure I'm the one to provide the correct answer to 'proper way to do a Chandelle.'[] However, I have loved the maneuver ever since my Uncle took me through one back in my college and my pilot training days. It can look so good, or so bad! I found this description on an internet website:

On the FAA power commercial pilots test a Chandelle is defined as a maximum performance climbing turn through 180 degrees while maintaining a constant turn rate. This is a "plan ahead" maneuver. You first establish a medium bank depending on the performance of your aircraft. Then a smooth pullup is started. The angle of bank stays constant during the first 90 degrees of turn, while the pitch angle increases steadily. At the 90 degree point the plane has the maximum pitch angle which should be close to the critical angle of attack. During the second 90 degrees of turn, the pitch angle is held constant, while the bank angle is smoothly decreased to reach 0 degrees of bank at 180 degrees of turn with the airspeed close to the stall speed. The plane should not settle during the last part of the maneuver and the recovery. The decreasing bank angle during the second half of the Chandelle will maintain a constant turn rate together with the decreasing airspeed. The turn needs to be kept coordinated by applying the right amount of rudder. A Chandelle to the left is quite different than one to the right because of the ever increasing amount of p-factor in the second half of the maneuver.

With an rc aircraft I usually perform the intial back stick in conjunction with the initial roll input, much as you would starting a slow roll. Practice will help you find the correct bank angle and back stick input needed to give you the 'picture' you like best. Specifically with the Stearman I use approximately 40-45 degrees of bank and 'a little' back stick, as this seems to provide the best radius of turn compared to altitude gained for the 90 degrees of turn., ie., the best looking picture to my eyes. Then it is a matter to determining the 'proper' rate of roll out so as to be on a heading 180 degrees from entry when wings reach level. ByTheWay, judicious increase/decrease of 'top' rudder definitely assists in maintaining a smooth arch. I get maybe 1 in 5 that I think are OK.

edited to add: description for the Chandelle, and nearly all other aerobatic figures, are on the IAC website; http://www.iac.org/begin/figures.html