TOST Hang Glider Retaining Release

Valid from July 2001

TBO (Time Between Overhauls) 2000 launches accordingly 10,000 actuations

Life limiting part is the release spring, with a life expectancy of about 10,000 actuations. With about 5 actuations in normal flight operation - like in Germany - this is, as before, 2000 launches.

Should you have more actuations per launch in pure training operation the TBO is reduced accordingly (e. g. with 8 actuations per launch the TBO would be 1250 launches).

If you have only 2 actuations per launch, the TBO consequentially would be 5000 launches.

This decision – after how many launches the 10,000 actuations are accomplished – is in the responsibility of the aircraft holder.

If both releases are actuated together (like in Germany) both releases have to be sent for overhaul after having performed the adequate number of launches.

The life limit of 4 years is replaced by a manufacturer's recommendation.

The new regulation had been published from the LBA in the "NfL" on July 12, 2001 and therefore is valid right now.

Please note that the new regulation can be applied only to releases which had a valid certificate in 2001!

Since 1952 Tost company has manufactured releases for gliders. The first product was the manual actuated nose release type “BUG”.

1953 followed the first Tost safety release (Universal), that has been installed near to the center-of-gravity. Its automatic release at a defined cable angle made the winch launch safe.

Tost releases are the standard worldwide for safe gliding starts for all types of starts and are being operated “from Australia to Cyprus”.

In total, more than 73.000 units have been produced. All are still being serviced, also those units from the very beginning. Most of the releases are still serviceable and even in service for further decades.

History of Tost releases

During the decades, Tost releases have been developed further and optimized as well. The sequence of the release types is as follows:

For the nose and tail releases: BUG - E 72 - E 75 - E 85

For the center-of-gravity releases: UNIVERSAL - KK - G 72 - G 73 - G 88

One important step to high dimensional accuracy and rigidity of the releases was the use of precision casting components: hook, segment, ring automatic as well as fi ne cast release housing as successor of the welded release housing (up to type
E 72 and G 72). When used in vintage gliders, please always check the installation space: narrow release brackets possibly may not allow the installation of the latest release types G 73/G 88 and E 75/E 85, which need a bit more space.
A further milestone was the increase of the cable force from 11,7 kN for the predecessor types to 14,1 kN for the E 85 and G 88 series.

The exchange of the elder release types against the recent ones has always been guaranteed through the retention of the outer dimensions and fixation holes of the releases.