Reading the MB, It appears that based on the "flight data" of the aircraft,
and high number of launches per flight hour, the concern is overstressing
from repeated winch launches. LET is requesting all users submit flight
statistics for further evaluation plus a one time inspection of the load
bearing aft spar cap in the fuselage carry through structure.

I do not know if the L-23 and the L-13 have the same construction for the
aft spar cap.

"Ernst" wrote in message
...
After a fatal accident in Austria LET issued a Mandatory Bulletin:
http://www.let.cz/files/bulletines/M...9a_english.pdf

EASA issued an Emergency Airworthiness Directive:
http://www.caa.co.uk/docs/33/easa_ad_2010_0119_E.pdf