I installed the ELT ( Emergency Locator Transmitter ) whip antenna. The factory use cable ties to secure the antenna along " rib 2 assembly " just behind the rear right hand seat. I did not want to drill through the upholstery, so I decided to paint some white polyamide P clips grey. They do the job very well and I did not need to do any additional drilling into rib 2. Then spent a couple of hours cleaning up the build shed.