During the operation of the TL 3000 Sirius and the TL 2000 Sting fleet of aircraft that have been fitted with the main landing gear wheels with the brake disc top hat washers in the main landing gear hub, it was found that with an overall brake pad wear exceeding 3 mm, the contact between the rotating washers in the wheel hub and the brake caliper pistons could occur.
As a solution to this condition, the TL-ULTRALIGHT suggests the replacement of the six original top hat washers on each wheel with the new version of top hat washers. At the same time, it is also necessaryto replace the M5x12 screws for the shorter M5x10 screws, with which the washers are attached to the wheel hub. This modification will allow for a better leeway space between the critical parts of the wheel, preventing their contact prior to reaching the permitted brake pad wear limit.
This SB contains a step by step main landing gear wheels modification manual, so that it can be correctly performed by the aircraft operator. It is not necessary to dismantle the wheel to perform the SB. Removal of the wheel fairings will be required only.
The new washers and screws can be obtained via the manufacturer TL-ULTRALIGHT. Upon written request with stated delivery address and upon the payment of costs, the washers and screws will be supplied by the manufacturer.
In case of not complying with this bulletin, the manufacturer reserves the right to not accept any wheel, caliper or any other aircraft part damage claims, resulting from not complying with this bulletin.
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- bulletin_en.pdf (PDF 2.89 MB)
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