Builder Tip #55 from HomebuiltHELP 
Firewall Penetrations: Keep the smoke out!
Cutting the Holes in your Firewall is the easy part!

Whenever we need to pass a fuel line, electric cable, or throttle cable from the inside of our cabin to the engine compartment, we need to make a breach in the firewall. Cutting the hole to route these items is the easy part  - how to properly seal the opening is the tougher step!

Because the firewall of our homebuilt aircraft is designed to protect the occupants from potential leaking exhaust carbon monoxide and smoke from an engine fire, we must consider carefully how best to make these holes so they properly maintain the firewall's intended protection

Our Tip this week presents some of the off the shelf components that can be used to properly route your fuel, electric and control cables through the firewall and still maintain the fire and gas rating that the firewall intended.The components in the video were supplied by Aircraft Spruce.

Above: Popular nylon bushing for cables
    Eyeball cable fitting
Fuel lines through the firewall are best implemented with bulkhead fittings

One of the best ways to pass fuel lines through a firewall is with the fuel bulkhead fitting (as shown in the photo). These fittings are commonly used with flared rigid tubing for fuel lines, but there are bulkhead fittings and adapters for flexible rubber lines as well.

The bulkhead fitting is also a perfect place on the firewall to make the transition from one type of fuel line (rigid) to another (flexible) as we need to go "flexible" on the engine side to accommodate for engine vibration.

Our DVD: Fuel System Plumbing explains and presents the types of fittings that can be used when planning your homebuilt aircraft's fuel system. It discusses the various options for fuel line choices and how to match them to their appropriate fittings. This DVD is targeted for the first time homebuilder.

    Bulkhead fuel fitting
Large variety of fittings for any type of fuel line
Watch a previous Tip?
  Don't forget that past Tip of the Week articles and videos are listed on the Archive Listing page on our website.  You can check back there for future reference and review of these tips.You can also reach that page from a link on the top, right side of our home page.  
HomebuiltHELP | PO Box 111 Brussels WI 54204 | email:
HomebuiltHelp's Engine installation videos make the daunting task of an engine installation a LOT easier! Watch someone else do it first! This is part of your engine evaluation process. Featuring:
Rotax,   ULPower,   Jabiru,   Viking, Continental

Confirm that you like this.

Click the "Like" button.