15
CURE 2-manual-EN-1-1 October 2019
B-line stalls are useful if you need to lose a lot of height quickly, perhaps to escape from a thunderstorm. They should
not be performed with less than 100m of ground clearance (see also also Chapter 5).
Spiral Dive
A normal turn can be converted into a spiral dive by continuing to apply one brake. The bank angle and speed of the
turn will increase as the downward spiral is continued. Be careful to enter the spiral gradually, as too quick a brake
application can cause a spin or an over-the-nose spiral.
If you increase the descent rate of the spiral to over 16m/s or initiate an over-the-nose spiral, the glider may require
input to recover. In this case you should apply some outside brake and steer the glider out of the turn.
If you make a sudden brake application during the spiral entry the glider can yaw around and enter an over-the-nose
spiral where the nose of the glider ends up pointing at the ground and it picks up speed very quickly. This technique is
very similar to SAT entry technique, and like the SAT it is an aerobatic manoeuvre which is outside the normal safe flight
envelope. Please do not practise this manoeuvre unless supervised by a qualified SIV instructor, as it can be dangerous.
Care should be taken when exiting from any spiral dive. To pull out of a steep spiral dive, release the applied brake
gradually or apply opposite brake gradually. A sharp release of the brake can cause the glider to surge and dive as
the wing converts speed to lift. Always be ready to damp out any dive with the brakes. Also be ready to encounter
turbulence when you exit from a spiral because you may fly though your own wake, which can cause a collapse.
CAUTION: SPIRAL DIVES CAN CAUSE LOSS OF ORIENTATION (black out) AND TAKE SOME TIME TO EXIT FROM.
THIS MANOEUVRE MUST BE EXITED IN TIME AND WITH SUFFICIENT HEIGHT!
4. Flight Characteristics