Chandelles | Lazy Eights
The Chandelle is a MAXIMUM PERFORMANCE CLIMBING COURSE REVERSAL. Named for the French aviator who first perfected the maneuver as a combat tactic during the early days of World War 1, it is now REQUIRED FOR THE COMMERCIAL PILOT AND FLIGHT INSTRUCTOR PRACTICAL TESTS in single engine airplanes.
Initially, the Chandelle was a very abrupt maneuver. The nose of the airplane was lowered to attain the maximum speed possible, then the wings were rolled to 60-80 degrees of bank. As the airplane began to turn, the pitch was raised to well above a power-on stall attitude while full throttle was applied. As the turn progressed and the airspeed bled off, the bank was rolled out and the pitch was lowered so that when the airplane had turned 180 degrees, the wings were level and the airspeed was just above the stall. Then the pilot would recover to level flight. The maneuver was used as both an aggressive maneuver to position the airplane in back of, underneath and pointing up at a higher flying enemy going in the opposite direction, and as a defensive maneuver to shake an enemy off the pilot's tail.
Today's training maneuver Chandelle is used TO EXACT MAXIMUM PERFORMANCE FROM THE PILOT, NOT THE AIRPLANE. By accomplishing the same maneuver using gentle but firm control inputs rather than abrupt ones, and using more moderate pitch and bank attitudes, the aerodynamic forces imposed are drawn out over a longer period of time. This requires the pilot to develop their planning, orientation, coordination, and feel for maximum performance flight, and their control usage techniques while changing attitudes and airspeeds.
The maneuver may be broken down into THREE CONTROL FUNCTIONS: BANK, PITCH, AND POWER. Looked at as separate functions, the Chandelle becomes quite understandable.
BANK: The airplane is rolled firmly into a 30 degree bank turn. This bank is held constant until reaching the 90-degree point of the maneuver. Then you roll out of the bank smoothly and at a constant roll rate so as to reach wings-level flight just as you reach the 180-degree point of the turn. This function can be practiced beforehand while in level, cruise flight or while transitioning to slowflight.
PITCH: Once the bank is established, the pitch will be raised to an attitude which, when full power is applied (climb power with a constant speedpropeller), will end up giving you an airspeed of 1.2 Vs1 (1.2 times the power-off stall speed in the clean configuration). This function can be practiced in conjunction with the power function while in straight-ahead flight.
POWER: Once the bank is set and you have begun increasing the pitch, power will be smoothly applied. In training airplanes equipped with a fixed-pitch prop, you will be applying full throttle. As you first hear the rpm begin to lug down, add just enough throttle to maintain the rpm at your entry setting. Of course, once full throttle is reached, the rpm will lug down anyway, but you will not have over-revved the engine in the process.
In a trainer with a constant speed prop, increase the rpm to the climb rpm setting as part of your set-up for the maneuver. As you raise the pitch, increase your throttle setting slowly and smoothly to the climb power manifold pressure.
SETTING UP FOR THE CHANDELLE:
As with all flight training maneuvers, SAFETY IS OF PRIMARY IMPORTANCE. You must accomplish the Chandelle in such a way so as to remain at or above 1,500 feet above ground at all times. A slight descent may be required to attain the recommended entry speed in some aircraft, so you may need to start the maneuver a few hundred feet higher. And due to the concentration level required, especially during the initial practicing of this maneuver, THE AREA MUST BE THOROUGHLY CLEARED prior to beginning the maneuver. Be sure to CLEAR THE AREA INTO WHICH YOU WILL BE TURNING during the maneuver. If you are to accomplish a Chandelle to the right, your clearing turn should be to the left.
As you are clearing, establish visual references for your 90- and 180-degree points. When you are ready to start your Chandelle, your 90-degree reference point should be directly off your wingtip in the direction you are going to turn.
Also as you are clearing, or immediately after completing your clearing turn, establish your entry speed and power setting. The manufacturers of most trainers have recommended entry speeds for the Chandelle. If the recommended entry speed is greater than Va (maneuvering speed), or if no recommendation is made, use Va as your entry speed. If your airplane has a constant speed propeller, advance the rpm to the climb rpm setting.
EXECUTING THE CHANDELLE:
With a fixed-pitch propeller, listen for a change in engine rpm as your nose begins to rise. Holding your 30 degrees of bank as you turn, increase throttle progressivel and smoothly, trying to maintain the initial rpm until full throttle has been applied.
With a constant speed propeller, smoothly apply climb power manifold pressure as you hold your 30 degrees of bank.
As you reach the 90-degree point of the Chandelle, your pitch should be just reaching it's high point and you should still have 30 degrees of bank.
As you pass the 90-degree point, you will begin to roll out the 30 degrees of bank as you hold your pitch constant for the rest of the maneuver. The coordinated roll-out should be made smoothly and continuously so as to reach a wings-level attitude just as you reach the 180-degree point.
At the 180-degree point you should be wings level and your speed should be 1.2 Vs1 +5/-0 knots. Now your task is to recover to straight and level flight while maintaining altitude within 50 feet and heading within 5 degrees.
THINGS TO BE AWARE OF:
During a CHANDELLE TO THE LEFT, you will be ROLLING OUT OF THE LEFT BANK BY APPLYING RIGHT AILERON. This, of course, WILL REQUIRE ADDITIONAL RIGHT RUDDER TO COORDINATE. During a CHANDELLE TO THE RIGHT, however, you will be ROLLING OUT BY APPLYING LEFT AILERON pressure. You PROBABLY WON'T NEED TO APPLY ANY LEFT RUDDER PRESSURE TO COORDINATE with the left aileron. All you'll need to do is RELAX SOME OF THE RIGHT RUDDER you are holding to offset the engine torque and P-factor.
WATCH YOUR PITCH. DON'T RAISE YOUR PITCH TOO QUICKLY. Many students will tend to raise the nose so quickly they're at their maximum pitch attitude before they've reached the 45-degree point in the Chandelle. You are only going to RAISE THE PITCH A TOTAL OF ABOUT 15 DEGREES during the first 90 degrees of turn. And during that phase, your airspeed is still relatively high, giving you a slower rate of turn, so TAKE YOUR TIME. Also be aware that AS YOU ROLL OUT, THE PITCH WILL TEND TO RISE even further. This is because of the reduction in bank during the last 90 degrees of the maneuver. Just like in a level flight turn, as you roll out of the bank you need to relax your back pressure a little.
DON'T TRIM FOR THE MANEUVER. Part of the objective of the Chandelle is to help you DEVELOP A FEEL FOR THE CONTROL FORCES NEEDED when changing bank, pitch, and airspeed.
LEVEL OFF SMOOTHLY when you have completed the maneuver. KEEP YOUR HEAD OUTSIDE THE AIRPLANE to HOLD YOUR HEADING while you level off, taking ONLY BRIEF GLANCES AT YOUR ALTIMETER to assure you are remaining level.
Set up at maneuvering speed or the manufacturer's recommended entry speed. Reference out the left wingtip (or right wingtip for Chandelle to the right). Roll firmly into and maintain a 30-degree banked turn. Initiate pitch up. Constant Speed Prop: Add throttle as assigned.
1a. Fixed Pitch Prop RPM Drop:
The LAZY EIGHT is normally the last VFR maneuver introduced to you during your commercial pilot training. There is good reason for this: the LAZY EIGHT requires that the pilot plan and execute a complex maneuver involving pitch, bank, airspeed, altitude and P-factor which are constantly in a state of change over an extended period of time.
Simply stated, the LAZY EIGHT is a series of opposing 180-degree turns combined with climbs and descents. When looked at from the side, the airplane will scribe a path resembling an 8 laying on it's side, hence the name "LAZY" EIGHT. Another very important meaning of the word "LAZY" is SLOW. In order to gain maximum benefit from this maneuver, it must be accomplished slowly and methodically.
SET-UP FOR THE LAZY EIGHT:
As you pass through the 45-degree point of the turn, the pitch is smoothly brought back downward so that it passes through the horizon just as the 90-degree point of the turn is passed. A snapshot taken through the windshield at this point would look like a level 30-degree bank turn.
Continuing to lower the pitch, the lowest point is reached at the 135-degree point of the turn. Here the attitude is a nose low 15-degree banked turn, and you will start to raise the pitch again.
Just as you reach the 180-degree point, completing the first turn, your pitch should pass through the set-up attitude and start your turn in the opposite direction.
ADDITIONAL REQUIREMENTS AND SIDE EFFECTS:
Your airspeed will decrease and increase pretty much in concert with with your altitude. Your slowest speed should be about 1.2Vs1. Your speed at the completion of each turn should be the same as your set-up airspeed.
P-factor will be constantly changing, requiring varying amounts of additional right rudder pressure to coordinate the turn. During the right-hand turn, more right rudder will be required between the 45- and 90-degree points of the turn and less left rudder will be needed during that portion of the left-hand turn.
At maneuvering speed or the manufacturer's recommended entry speed.
References for the 90- and 180-degree points set.
Initiate very slowly by starting bank and pitching up.