Firewall to Tunnel Hardware.

[Allen B]

Hello. The callout sheet for my 5 says to use k1000-06 nutplates for the entire boot cowl. The sides, the bottom, the top. So that’s what I did. Everywhere except the area where the tunnel attaches to the firewall. In this area it says to use #6 screws with nylon nuts and washers. Is there a specific reason for this I’m missing? It calls for 20 screws in a really small area. Having nuts on the back seems like an additional pain whenever I want to remove it

I’m wondering if I’m misinterpreting the callout sheet or if nutplates are acceptable in this area as well?

As always, thanks for the advice.

Allen

 

[Bearhawk Aircraft]

Typically the tunnel does not come out once complete the only maintenance item in that location is the park brake valve but that can be accessed by removing floor #1. A row of screws attaching the firewall lip to the tunnel with Nylocs is called for. K1000-06 nutpaltes could be used alternatively if desired.

 

[Allen B]

Ok. That sounds good to me. That’s what I’ll do. Thanks for the help.

 

[TLyon]

I’ve been contemplating the fasteners around there too. I like nutplates over nylocks, but is there any reason not to just rivet the tunnel piece in? I was thinking rivets in front and nutplates at the back with the tunnel piece and belly former captured by the k-1000 rivets. Any headaches I’m going to make for myself later on that I’m not thinking of? I’m coming from an RV perspective where the belly is all riveted and any maintenance (fuel pump and filter) is top down through the floor panels.

 

[Allen B]

My reasoning is for panting alone. I plan on disassembling the boot cowl to paint it. It just seems like an easier job to hang the panels and spray both sides vs attempting to paint while assembled. With the tunnel permanently attached this would be an issue for me. Aside from painting I can’t think of a reason it would matter. I’m planning on taking the advice above and probably make it removable.