Safety

Date: 17 December 1998
Source: This is an authorized forwarding message from Center of Gravity Inc
Email: cgravity@dreamscape.com
Tel: +1 315-687-3724

There have been two incidents reported that the main webbing on the C-G 2000 has slid off the side of the frame. This causes the pilot to hang off to one side of the harness making it difficult to control the glider. On the C-G 2000 the slider moves farther forward than on the C-G 1000, putting pressure on the metal clips that keep the webbing in the center of the frame.

Date : 17 April 1997
Source : Fédération Française de Vol Libre (FFVL)

LETTER FROM FFVL TO FRENCH PARAGLIDING COMMUNITY

Dear Pilots,

The second paraglider line failure in less than a month has proved fatal.

On 23 March 1997, a member of the French National Paragliding Team was killed. Yann ESPINASSE's lower paraglider lines failed during a series of 360 turns prior to landing. He was using micro-lines. Yann pulled his reserve parachute, but the main reserve parachute strop broke at the point where it meets the V-shaped strap attached to the harness.

During the past season several cases of spinning have been reported by pilots of rigid wing hang gliders. It is time to reconsider how and why this phenomenon occurs. Marcus Hoffman-Guben offers some valuable advice.

About the author:
Dipl.-Math. Marcus Hoffmann-Guben
German rigid wing hang glider champion 2001
Rigid wing hang glider test pilot for A.I.R. (2 years): Atos testing including world championships in 1999 & 2000.
Rigid wing hang glider test pilot for Flight Design (2 years): Exxtacy 135, Exxtacy Bi, Ghostbuster, Axxess, Axxess+ testing including world championships 2001.

Translated: WildArt! Creations 2002

Not just a beginners problem

Potential spinning problems in rigid wing hang gliders are not merely due to inadequate flying experience!

Several experienced pilots have reported entering spins completely unexpectedly under "normal flying conditions". The physical explanation for this is usually that the pilots in question do not recognise the point when air-flow across the wing breaks off partially and the wing goes into a stall, until it is too late. However, there are some constructional trimming steps which can be taken to reduce the danger of spinning.

Goals
In order to develop effective strategies for the prevention of spinning it is initially necessary to recognise when, how and why spinning occurs.
The following points have been put together with the aim of sharpening the awareness of rigid wing pilots - firstly to help them analyse their instinctive and conditioned responses learnt from flying flexible hang gliders, and secondly to help them change or adapt their reactions and responses accordingly. Additionally, specific constructional details are highlighted which can result in an increased susceptibility to spinning in rigid wing hang gliders.

To emphasize: neither it is wished to stir up fears of spinning a rigid wing hang glider, nor should real existing problems be ignored or relativized.

The spin
Spinning a hang glider is a three-part process:

1. Entering
2. Spinning
3. Recovering

1. Entering a spin
A spin on a rigid wing hang glider is induced when the pilot causes air-flow on one wingtip to break off and hence stalling it, by pushing the control bar too much while trying to tighten a curve.

Aerodynamically viewed, provoking a spin is not a question of air-speed but only dependant on the angle of attack of the wing !

However, as a reduction in airspeed is achieved through changing the gliders angle of attack, spinning rigid wing hang gliders is often associated with slow flying in practice.

2. Spinning
While in a spin, the rotation speed, flight-path diameter and bank angle of the glider can not be controlled through normal steerage impulses, they are far more dependant on the mass distribution within the wing:

While spinning, gyro-forces are dominant and result in non-controllable, non-steerable flight !

This makes spinning with rigid wing hang gliders particularly dangerous !

Larger versions of rigid wing hang gliders are initially more difficult to set spinning (i.e. show a reduced spin susceptibility), but should they be put into a spin, then they are extremely unpredictable, chaotic and consequently very difficult to control!

(photo : Vol Libre)

We can enjoy the freedom of flying hang gliders and paragliders only when we fly safely. The International Pilot Rating System and the IPPI Card represent a safe and international agreed training standard that can be used by all pilot as a reference.

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