In our ongoing commitment to safety, we want to address an issue regarding the nyloc (locking) nut loosening on the top fittings on our gliders with Zoom uprights.

Previously we've made improvements by increasing thread lengths, introducing countersunk hexagon heads to locate the locking nuts and applying loctite.

However, despite these improvements, there have still been instances of nuts loosening over time.

It appears that this can occur when the pin is locked while the fitting rotates. From experience we believe this may happen in a couple of ways:

  1. When levering the glider using the bottom upright corner while rolling it overhead particularly during setup and breakdown procedures.
  2. When opening and closing the uprights to attach and detach the base bar.

Depending on the pilot’s technique for set up and pack up, the instance of the nut loosening, can occur for some pilots, whilst other pilots have never experienced this problem.

We recommend the following:

  1. Adding to your pre-flight check, ensure that the top fittings are securely tightened, paying close attention to the nuts and ensuring there are 2 threads exposed.
  2. Awareness of setup and breakdown procedures: Be mindful of how you set up and pack your glider, as repeated motions can lead to nuts loosening over time. Consideration of alternative techniques.
  3. Furthermore, it's imperative to note that once a nut has come loose, it must be replaced with a new nyloc nut to ensure continued safety and integrity.

Your safety is our top priority. Please take these precautions seriously to ensure safe and enjoyable flights. If you have any questions or concerns, don't hesitate to contact us.

Fly safely,
The Moyes Team

 

upright top fitting good

Correct: Zoom upright top fitting with thread exposed.

upright top fitting good

Incorrect: Zoom upright top fitting with NO thread exposed