Paraglider micro-line failure

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.

This terrible accident serves as a reminder to all pilots of the precautions they should take:

• Microlines should be replaced at least every 200 hours, and should be used and maintained with enormous care.
• Extreme manoeuvres which put excessive loads on the lines are to be prohibited (e.g. 360 steep turns).
• Inspect all equipment regularly; avoid unnecessary exposure to sunlight and dust; don't pull on the lines if they get snagged on a root at the moment of take-off.

Any pilot who wishes to sell a paraglider equipped with microlines must first fit a complete new set of lines, approved by the airworthiness authority.

CONCERNING THE LINES:
The lines are under a considerable load factor during steep spirals. In comparison with normal straight flight, the load factor on the lines increases in steep 360 turns by the following amounts:

A lines: 3.5 times the normal load.
B lines: 4.6 times the normal load.
C lines: 6 times the normal load.
D lines: 5.3 times the normal load.

These greatly increased loads, when added to poor maintenance of equipment, mean that one is coming dangerously close to the breaking strain of the lines. It is therefore timely to issue yet another reminder not to carry out series of steep spiral turns.

CONCERNING THE RESERVE PARACHUTE:

It is likely that the lower strop of the reserve sheared through over-heating.

This shearing was probably caused by the system of knotting used to connect the two strops, which was of the half hitch variety and not a reef knot. The over-heating was also caused by the very rapid opening of the reserve (after the lines failed, the pilot was in free fall) and the consequent large amount of energy that the knot had to absorb in a very short space of time.

This was undoubtedly one of the reasons for this heat -induced shearing.

It is therefore important for all pilots to check the knot used to connect the main reserve strop to the V-shaped strap on the harness. If the knot appears to be a half-hitch, it is essential to change this knot immediately into a reef knot.

In every case, you should contact the supplier of your reserve parachute to ask him what system he recommends.

It would appear that, although the reserves themselves are satisfactorily trialled, as are the seat harnesses, the links between the two may not have been properly tested.

The FFVL Safety Commission contacted manufacturers, importers and suppliers of seat harnesses and reserves during the Bassano meeting and, in cooperation with "Aerotests", planned a series of trials which will take place during the months of April and May 1997. The results of these trials will of course be published, in the magazine "Vol Passion"
.
In the meantime, it is important to check the state of your lines and the system of knots between the reserve strop and the V-strap on the seat harness.

Marion VARNER
FFVL Safety Commission President