A chandelle is more than a climbing 180-degree turn with a fanciful French name that flows trippingly off the tongue. (Actually en Français, it’s just “candle“.) Having tactical origins over Europe during World War I, it is one of several required performance maneuvers in the single-engine commercial pilot Practical Test Standards (SEL only; Section 1, Chapter V). It’s also a great arrow to have in your quiver if you ever have to beat a hasty retreat from rising terrain, and acquiring proficiency in it will doubtless improve your piloting skills. In addition to requiring maximum airplane performance, it also requires planning, coordination, smoothness, and moment-by-moment awareness of where you are inside the flight envelope — as well as in three dimensions.
You might say it requires maximum pilot performance, as well.
HOW TO (An Overview)
You start with a “clean” airplane (gear and flaps up), at least cruise power (but below design maneuvering speed), crank in some bank, slowly pitch up to a max when you’re ninety degrees through the turn. At that point you hold it there, then slowly roll out so you’re wings-level and nose-high at minimum controllable airspeed and within five knots of a stall as the aircraft comes through 180-degrees of turn. Sounds simple, right?
PIECE OF CAKE
It is in theory, sure, but there’s a lot going on there. If you prefer pretty airplane pictures, well, you can go buy a King video, but here’s a simpler way to visualize what you’ve gotta make the airplane do — without any hand waving and Hollywood glitz. That blue curve represents bank, and the brown one shows pitch:
SEE IT, DO IT
To generalize: for the first half, like the figure shows, it’s constant bank, increasing pitch. For the second half, it’s constant pitch, decreasing bank. Back to simple again?
You really need to visualize what you’ve got to do, for starters, to have something solid to build on. Here’s how it goes:
- Gear and flaps should be up. For fixed-pitch props, you can go at full throttle, as long as you don’t exceed Va. For constant speed props, max rpm (then add power, of course).
- Clear the area! Then start off into the wind, no lower than 1500 AGL. (Having a perpendicular ground reference helps, too.)
- Establish a coordinated turn (your choice: left or right) with 30-degrees of bank.
- As soon as you’re at 30-degrees, apply back pressure to increase at a constant rate so that the highest pitch (perhaps a 15-degree deck angle, in a typical training airplane) is attained halfway through the turn. All this time, you’re keeping that bank angle in.
Important: Establish the bank prior to the pitch.
- Then, at that 90-degree point, begin rolling out bank while maintaining that mid-point pitch attitude. (Since the vertical component of lift will now be increasing, it will probably be necessary to release a little back pressure.)
- At the 180-degree point, wings are level with the pitch momentarily held and then returned to straight and level, as the aircraft is allowed to accelerate to cruise speed.
BUT… THERE’S MORE
Airspeed: There’s a third factor I could’ve plotted, but I didn’t. Your airspeed is constantly decreasing throughout the maneuver. That means left turning tendencies become more noticeable. A chandelle to the left has a very different feel than one done to the right. (It’s OK to “cheat“, by checking the turn coordinator ball, but the real finesse comes when you can do it just by feel.) Also, just as in vaudeville, timing is everything. If the roll-out is done too slowly, you’ll be headed the other way before you’re wings-level again. If it’s too quick, you’d run out of bank before you finish the turn.
Bank. Another wrinkle in this maneuver: rate of turn is a function of bank angle and (inversely) airspeed. So as your airspeed is dropping, and you’re turning, you have to take that into account, too!
Adverse yaw effects will be more prominent on either roll-in or roll-out, depending on direction. And as the airplane slows down, slight opposite aileron might be needed to avoid over-banking.
BOTTOM LINE: In the whole picture, constant changes in control pressures for pitch and bank, will get you what you want. I hasten to add here that although this is a good way to gain the most altitude in the shortest time while reversing direction, the PTS has no specific altitude gain criteria whatsoever. Clearly the altitude gain would be a function of the aircraft design and entry speed. For the test, it’s smoothness they’re looking for. Exactly how you might quantitatively define “smoothness” is another matter, but evidently it’s quantifiable enough to pull it off … or not.
“Pilots Handbook of Aeronautical Knowledge” Advisory Circular 61-23C (1997)
Jeppesen Instrument/Commercial Manual,
Commercial Pilot PTS, FAA-S-8081-12B (2002)