ELT Bracket & Components

Time: 10 Hours

This weekend I wanted to finish up the support brackets for both the ELT and transponder. Before I got to those I riveted the parts of the COM shelf together pretty quickly with the pneumatic squeezer and put it into its place.  Some of you might notice that the aft end, side with the notch, have an unusual rivet pattern. I did my best to lay out the rivets so as to not interfere with the attach hardware of the avionics that will be housed there. We will see how my planning is when I get to that stage!

   For the ELT and transponder I decided to do side mounts, one on each side. I started with the ELT bracket and made some marks using the actual ELT to make sure there was clearance for the antenna wire and others cables. With the location figured out I used some angle brackets to create a top and bottom bracket and two side supports.  I spaced the side supports perfectly for the screw holes in the ELT bracket that comes with it.  
   With everything lined up and marked I removed the bracket and drilled for holes, one in each corner for screws.  With the four screw holes drilled I return the bracket to the sidewall and drilled rivet holes in the top and bottom bracket.  The top and bottom bracket will be riveted permanently and the two side brackets will be removable with the screws. 
 With everything aligned I remove the bracket again to match drill the ELT’ssupport to the bracket. This support has two clamps that will hold it in place.  

   My son Chandler came to the shop and helped drill and countersink the holes for the nutplates on the top and bottom brackets. I took all the parts apart and cleaned and primed them. 
 it’s a common practice in the RV-8 to put the ELT antenna laying horizontally in the tail area.  This area is covered up by fiberglass fairing and conceals antenna. So I drilled a 3/4″ hole with my step bit and put a grommet in it for the antenna to slide through.  The aft and of the antenna will be secured with a adele clamp on the horizontal stabilizer after it is installed. 

   I screwed in the ELT’s control head in the instrument panel as well.  There’s a short cable that connects to a battery powered alert speaker that connects to the control head. There will be a cable run from that alert speaker back to the ELT itself. 
 While I was upfront I went ahead and put in the grommet edging that I had receivedAircraft Spruce in the upper gear towers lightening holes where wires will pass through.  

   I used some on the pass through for the ELT’s antennas cable. 
  After the parts were dry from priming I riveted the nutplates to the top and bottom supports. I marked out 4 holes on the top bracket and 3 on the bottom to drill for the blind rivets I would use to attach them to the mid and lower longeron.  

 I used the holes in the supports to match drill the longeron’s with my angle drill. With all the holes drilled and deburred I attached the ELT cradle to the two side supports.  

   There was a little play with the holes in the cradle so I left them a little loose and place these parts on the side wall with their screws. I tightened them down and then tightened up the cradle screws.  
 With the parts all secure now I grabbed the ELT and put it in the cradle.  

 I connected the cable that runs from the ELT to the panel mounted control through the flexible conduit I have installed. I also hooked up the antenna wire and secured it with a couple adel clamps and a zip tie anchor. 

   I still have one more bracket left for the transponder but decided to take a break from building these. I decided to work on the rudder cable fairings.  I bought these fairings from Avery tools as they look a lot better than the ones you have to fabricate from scratch. I made some marks on the side of the fuselage and came up with a design I liked for the final cut. 
 after a few minutes at the bandsaw and deburring wheel I had both the left and right side done. I carefully align them and came up with a rivet pattern that wouldn’t interfere with any of the items inside. I match drilled the fairings to the skin and clecko’ed them in place. The area that needs riveting on these fairings is pretty small and you have a potential for slipping off the faring with the rivet gun. So I used some sheet the same thickness, .032, to create a ledge to support the gun and secure them with tape.   

 The riveting went perfect on both side and I had them done in about an hour.  

 I decided to get the supports and sheet cut for the transponder bracket and drilled the holes for the nutplates. 

 I decided to call it a weekend and cleaned up shop. This was a fun weekend in the Hanger. I need to finish up the transponder bracket and do the smoke tank installation and I think I have most of the items wrapped up for the aft fuselage top skin to be riveted on. 

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