Caboolture Gliding Club
Handling Notes
Club Libelle VH-GJY
Flight Preparation
D I and wash glider.
Gliders, like people, tend to put on weight as they get older so ALWAYS REFER TO THE COCKPIT PLACARD FOR FLIGHT AND WEIGHT LIMITATIONS.
The ballast bag has 4 removable bars in a slotted bag, sits under your thighs, and must be secured to seat anchor points before flight.
Minimum pilot weight: 76 kg
Maximum pilot weight: 91 kg
Battery. The battery is located in a box behind the seat. It is secured by some foam rubber or other padding between the battery and the cover of the battery compartment. Do not fly without this padding in place.
The Canopy
The canopy is hinged at the rear and held in the open position by an “over centre” spring loaded mechanism. Ease this forward to support the canopy in the open position and to the rear to release the lock.
Never leave the canopy open unless the cockpit area is closely attended. Damage can occur even in very light wind conditions.
When closing the canopy always pull the red release knob before the locking pin touches the top of the fuselage. (Note the damage in the photograph by past failure to do this). Also ensure that the canopy frame is properly seated on both sides–get someone else to check this as you lower the canopy. If necessary have them push in on the canopy frame (NOT the perspex) to ensure a proper seat.
Seat Position. Always spend some time before flight ensuring that you have a comfortable seat position. The adjustment for the seat back is a ring on the right side of the cockpit and can be locked in a number of recesses. If you are too upright you will tend to hit your head on the canopy, while if too reclined you won’t be able to reach the instrument panel. Learn which position suits you best and always fly with the seat in that position.
Ground Handling
Secure wing walker to port wing and lock with safety pins.
Fit tail dolly and lift into trailer.
Tow out slowly; remember you now have a 15 meter wide trailer behind you.
Take Off - Aero Tow
Aileron and rudder controls are not effective at low speed and there is a tendency to drop a wing. Therefore ask the wing person to support the wing as long as possible, but without retarding it. Positive control movements will be required in the early part of the ground roll to prevent a wing from dropping.
The control column should be well forward initially and then eased back as the tail comes up. Allow the glider to lift off when it has sufficient speed.
Once airborne the glider is very sensitive to pitch, so be careful not to over control. Use a light touch on the controls, rest your forearm on your leg and generally relax.
On tow the airspeed indicator will not be accurate as the rings sit right in front of the pitot tube.
Maximum aero tow speed: 73 Knots
Dual Tow. In dual tow situations, the aircraft MUST be flown in the high tow position. The reason for this is that, in low tow, it has a tendency to pitch up if air brakes are opened to counter slack rope. Note that this restriction only applies to dual tow.
Take Off - Winch
Keep the stick well forward until the aircraft is running on the main wheel. Allow it to separate then, at 50 knots minimum speed, ease gently into the initial climb. At a safe height of 150 - 200 ft ease into full climb (maximum wing tip angle to horizon 45 degrees). Do not allow the glider to climb too steeply especially in the early part of the launch.
Although explained in three stages, if done properly the launch will result in a smooth continuous curve.
At low pilot weights the aircraft will tend to pitch up on initial separation despite full forward stick. If this happens, just maintain full forward stick until the nose starts to drop and then ease it back to maintain the required attitude. Be careful not to over control at this critical part of the launch.
In the event of a cable break or power loss, the nose must be lowered immediately to the normal flying position.
When nearing the top of the launch reduce the climb angle to remove unnessesary stress on both the glider and the cable, when the winch driver cuts the power, or you feel the glider back release, lower your nose to flying attitude and pull the release twice.
Maximum Winch Launch Speed: 65 kts
Minimum Winch Launch Speed: 50 kts
Flight
Controls are very light and there is little feed back through them, so monitor your ASI and attitude closely until you become familiar with the aircraft.
The aircraft does “talk” to you a bit as the wings flex. This is not a problem.
Trimming. The trim is spring loaded and is adjusted by depressing a green button at the base of the control column. To trim for take off, just move the stick forward and depress the button. The small lever forward of the button moves as the trim setting is changed. During flight, whenever there is a need to trim for a new attitude, just do the same thing. On take-off fingers should be kept well cleat of the trim button to avoid an inadvertent change of trim.
The Stall. The stall occurs in the 35 to 38 kts range depending on pilot weight. Unless entered from a significantly nose high position, the stall is quite gentle and a light shudder is felt as it approaches. Use standard recovery action to return to normal flight. However, due to the very light controls, be careful not to move the stick too far forward, just relaxing the back pressure is all that is needed to effect recovery in most situations.
Spinning. If the C of G is near the forward limit (heavy pilot), the spin may develop into a spiral dive. So unless you are near the minimum weight, only incipient spins are recommended. Spin recovery is conventional and quick using the standard recovery action. As for stall recovery take care not to move the stick too far forward.
Flight Data
Max smooth air (VNE) / 103 ktsMax rough air (VRA) / 81 kts
Max manoeuvring (VA) / 81 kts
Minimum sink / 2.03 fps at 40 kts
Best glide / 35 to 1 at 47 kts
Stalling speed auw 300 kg air brakes closed 35 kts air brakes open 33 kts.
Stalling speed auw 350 kg air brakes closed 38 kts air brakes open 35 kts.
Air Brakes
The air brakes are of the rotating trailing edge type and are very effective. In a speed limiting situation they can be safely opened up to VNE, but they should be opened fully and then not closed until the speed has been reduced to normal. When pulling out of a dive with air brakes deployed, minimize G forces to avoid over stressing the wings.
During descent control you can open and close the brakes as required but, when close to the ground, or when your speed is less than 40 kts, they must be handled with care. This is because fully deployed brakes have a slight flap effect which reduces the stalling speed by 2-3 kts. Conversely, closing the brakes increases the stalling speed by the same amount. For this reason, a sound practice to adopt is:
Never close air brakes when less than 50 feet from the ground or when your speed is less than 40 kts.
Landing
The down wind safe speed near the ground is 55 kts. Final approach speed is 55 kts plus half wind speed.
Due to the effect of the trailing edge brakes, a rather steeper approach angle will be required to maintain the required speed. So monitor your speed carefully throughout the approach.
The round out (Check 1) is conventional, but remember that the controls are light and the aircraft is sensitive in pitch control. So relax, use a light touch and guard against over control. Likewise the hold off (Check 2) is conventional, but the flap effect of the brakes will tend to prolong this phase. Just keep holding the aircraft off the ground until it won’t fly any longer. Do not try to fly it on.
Take particular care to maintain directional control during the landing roll. If directional control is lost there is a very real risk of a ground loop. Remember that rudder and aileron control will diminish as the speed decays and you must be pointing in the right direction when this occurs.
Use the wheel brake carefully (lever is on the air brake handle) as you slow down and lose elevator authority. To do otherwise results in the nose dropping and damage occurring to the underside of the fuselage.
Tie down kit
The tie down kit is secured behind the seat. Tie down into wind, remove the winglets, slide in the wooden rods and secure the aircraft with ropes and pegs, wings level. Always use good quality tape and check condition on DI.
Tie down the tail, with a peg each side and protect rear fuse with a cushion.
In the Hangar
Check security of the winch harness shackles and position front strap just in front of the main wheel. The rear strap must be positioned well to the rear of vertical. To confirm correct positioning, raise the glider and check that the two wheels leave the ground at about the same time.
Before winching make sure the winch cables are not twisted. Winch up the glider and secure one wing using the two ropes attached to the wing walker.
Close hangar doors if leaving during the day.