TOST Connecting Ring Pair
TOST Connecting Ring Pairs are forged from a fine steel cast. The small ring and large ring are caste into each other without a weld. This is a difficult and elaborate process.
TOST connecting ring pairs are vital for safe connection and reliable separation of tow cables and tow releases. The type certification stipulates that every TOST tow release must be operated only wit a ring pair meeting the Aeronautical Standard LN 65091. Rings must be stamped with the manufacturer's name and standard number.
Welded rings are prohibited!
Use of welded rings voids tow release warranties. Welded rings cause damage to releases. Also, undersized or deformed rings can cause the ring pair to jam the release and inhibit correct operation under load, a potential danger for the pilot.
Connecting ring pairs must be visually checked and measured at regular intervals. Ring pairs that deviate from standard dimensions must be replaced.
2005 Edition of LN 65091
The links of the connecting ring pair shall not be welded!
Permissible constant load:
The permissible constant load shall not exceed 15 kN (i. e. it must withstand this load without deformation). A momentary (3 seconds) load of 18 kN is permissible.
Operation and technical specification:
Prior to each commissioning of the connecting according to LN 65091 testing shall be carried out for scratches, cracks and burrs in accordance with DIN EN ISO 8785 as well as for permanent deformation.
Surface imperfections and permanent deformation shall be determined by visual inspection. The detectable deformations and surface imperfections, which were determined during the test, are not permitted.
All connecting ring pairs supplied according to this standard shall be accompanied by an EASA Form-1 issued by the manufacturer for each production lot.
*Actual color may vary from pictures