We published Service Info 2021-109 for the following aircraft:

DG-100, DG-200, DG-400, DG-600M, DG-800 A +B up to ser.No. 8-130
Note: This retrofit is approved for DG-300 with TN359/22.
Note: From DG-800B ser.No. 8-131 on the spring is standard.

To facilitate the locking of the landing gear in extended position a torsion spring which rotates the handle into the lock will be installed instead of the friction disc.

Please find more details in our list of Service Infos