Translation of an open letter to the german authorities:
Ladies and Gentlemen!
In the accrediting area of the rescue type test, it is possible to test a rescue for paragliders according to EN 1291: 2015 as well as LTF 91/09 point 6.
The tests according to EN 12491: 2015 are fully comprehensive accepted in the LTF 91/09 declaration of airworthiness requirements for hang gliders and paragliders to point 6.1.. (NfL 2-251-16)
Unfortunately, some manufacturers use the possibility to have their equipment tested exclusively according to LTF 91/09, since LTF, according to section 6.1.1, permits a considerably higher sink rate than EN 12491: 2015.
LTF 91/09 Point 6.1.11 When the pilot hits the ground, no serious injuries for the pilot may be expected.
With a sink rate of less than 6.8 m/sec, it can be assumed that no serious injuries occur. Instead of testing the sink rate with a given trailer mass, the test can also be carried out by determining the trailer mass at a given sink rate with a test vehicle.
EN 12491: 2015 Point 4.3.1At the double test according to 5.3.4:
(A) the mean sink rate (corrected for ICAO standard atmosphere, see Annex B) shall be less than 5.5 m/s for each test;
This fact is still permitted by LTF 91/09, which is often used by manufacturers who are not able to achieve an EN 12491 approval due to excessive sink rates. This means that the rescue parachute has not passed through directly during the type test of EN, but only receives an LTF approval, which obviously has the same priority for the pilot as the one according to EN 12491: 2015.
However, this is not the case! - There is a significant difference between 5.5 m / sec and 6.8 m / sec.
Kinetic energy = mass * velocity 2/2-E = m * v 2/2
120kg load 5.5m/s sink rate 1800 joules
120kg load 6.7m/s sink rate 2750 joules
This increases the energy of the impact between an EN 12491: 2015 and an LTF 91/09 type tested rescue by more than 50%.
The increase in a possible risk of injury for the pilot can be assumed, with such an increase in the kinetic impact energy.
The PMA therefore calls, in the interests of pilots safety, for the immediate suspension of the test of rescue equipment according to LTF 91/09 with a descent value of up to 6.8 m/sec.
We ask the authorities to change LTF 91/09 in point 6.1.11 to the lower value of <5.5 m/s or to permit the tests for paraglider rescue equipment only in accordance with EN 12491:2015.