Paragliding
between constant rising air and constant sinking air, so turn to technology to help. Modern variometers are capable of detecting rates of climb or sink of 1 cm per second, such is the case of the Flymaster B1 which uses extremely low noise electronics and complex algorithms to detect such minute changes in air pressure.
A variometer indicates climb-rate (or sink-rate) with short audio signals (beeps, which increase in pitch and tempo during ascent, and a droning sound, which gets deeper as the rate of descent increases) and/or a visual display. It also shows altitude: either above takeoff, above sea level, or (at higher altitudes) “flight level.”
The main purpose of a variometer is in helping a pilot find and stay in the “core” of a thermal to maximise height gain and, conversely, to indicate when a pilot is in sinking air and needs to find rising air.
The more advanced variometers have an integrated GPS. This is not only more convenient, but also allows one to record the flight in three dimensions. The track of the flight is digitally signed and stored and can be downloaded after the landing. Digitally signed tracks can be used as proof for record claims, replacing the ‘old’ method of photo documentation.
2m-band radio
Radio
Pilots use radio for training purposes, for communicating with other pilots in the air, particularly when travelling together on cross-country flights, and for reporting the location of landing.
Radios used are PTT (push-to-talk) transceivers, normally operating in or around the FM VHF 2-metre band (144148 MHz). The “2 Meter” band is an amateur radio band, sometimes used for interpersonal communications, and Aviation Frequencies are usually 108MHz to 136MHz. Usually a microphone is incorporated in the helmet, and the PTT switch is either fixed to the outside of the helmet, or strapped to a finger.
GPS
GPS (global positioning system) is a necessary accessory when flying competitions, where it has to be demonstrated that way-points have been correctly passed.
It can also be interesting to view a GPS track of a flight when back on the ground, to analyze flying technique. Computer software is available which allows various different analyses of GPS tracks (e.g. CompeGPS, See You).
Other uses include being able to determine drift due to the prevailing wind when flying at altitude, providing position information to allow restricted airspace to be avoided, and identifying one location for retrieval teams after landing-out in unfamiliar territory.
More recently, the use of GPS data, linked to a computer, has enabled pilots to share 3D tracks of their flights on Google Earth. This fascinating insight allows comparisons between competing pilots to be made in a detailed ‘post-flight’ analysis.
Control
Speedbar mechanism.
Brakes: Controls held in each of the pilot hands connect to the trailing edge of the left and right sides of the wing. These controls are called ‘brakes’ and provide the primary and most general means of control in a paraglider. The brakes are used to adjust speed, to steer (in addition to weight-shift), and flare (during landing).
Weight Shift: In addition to manipulating the brakes, a paraglider pilot must also lean in order to steer properly. Such ‘weight-shifting’ can also be used for more limited steering when brake use is unavailable, such as when under ‘big ears’ (see below). More advanced control techniques may also involve weight-shifting.
Speed Bar: A kind of foot control called the ‘speed bar’ (also ‘accelerator’) attaches to the paragliding harness and connects to the leading edge of the paraglider wing, usually through a system of at least two pulleys (see animation in margin). This control is used to increase speed, and does so by decreasing the wing’s angle of attack. This control is necessary because the brakes can only slow the wing from what is called ‘trim speed’ (no brakes applied). The accelerator is needed to go faster than this.
More advanced means of control can be obtained by manipulating the paraglider’s risers or lines directly:
Most commonly, the lines connecting to the outermost points of the wing’s leading edge can be used to induce the wingtips to fold under. The technique, known as ‘big ears’, is used to increase rate of descent (see picture).
The risers connecting to the rear of the wing can also be manipulated for steering if the brakes have been severed or are otherwise unavailable.
In a ‘B-line stall’, the second set of risers from the leading-edge/front is gently pulled down to put a crease across the lower surface of the wing (this will also distort the upper surface) acting as an ‘air brake’ significantly reducing airspeed. The combination of reduced forward airspeed and increased vertical airspeed destroys the laminar flow of air over the aerofoil, dramatically reducing the lift produced by the canopy, thus