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Stainless Steel Firewall Penetration Kit 1 Inch

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Part# 09-00979


During the testing phase of our all stainless steel heater bypass box, we were astounded at the affects of a simulated engine fire on aluminum firewall components. Watching how fast the aluminum melted away (only 16 seconds) took us by surprise. It became very apparent that fireproofing the firewall was more important than most people realize.

After many months of trial and error, a fireproof pass through was designed. The firewall Penetration Kits offer a fireproof method of getting wires and cables trough the firewall in a clean, professional looking manner that allows easy removal for replacement if necessary.

Testing was initiated on most common methods of wire and cable penetrations available on the market. Simulated engine fire was directed at the stainless shields with rubber grommets, high temperature silicone, eyeball fittings, plain rubber grommets and several untried methods. All failed the fire test with the exception of the steel eyeball, and it only accepts one cable.

The kit comes complete with stainless steel fabricated fitting, fire sleeve tubing, two ALL stainless steel hose clamps and a tube of fire block sealant to seal the ends from moisture and gasses. Includes installation instructions.

  • Fireproof seal of the firewall for penetration of wires and cables.
  • Seals out moisture and gasses.
  • Easy replacement of wires and cables if necessary.
  • Very clean looking installation.
  • Available in three sizes.

To determine the size you need, plan where you want to run your wire and cable bundles. Use a tie strap or twist tie to bundle the wires and cables. Measure what size holes the bundle will fit through and choose the NEXT LARGER size (see installation instructions.) You need enough clearance between the bundle and stainless fitting to push the second fire sleeve into the fitting creating the fireproof, chafe proof seal.

Typical installation. Wires can be run straight out or turned back to attach on firewall reducing vibration.

There are so effective that they received an STC under Advisory Circular AC 20-135 Power plant Installation and Propulsion Systems Component Fire Protection Test Methods, Standards and Criteria. STC covers the Cessna 140.

California Prop 65 Warning Symbol

WARNING: The product may contain and/or expose you to a chemical(s) or substance(s) which are known to the State of California to cause cancer and/or birth defects or other reproductive harm.



In The Box

  • 1 - Firesleeve tube
  • 1 - Stainless Steel Fitting
  • 2 - Hose Clamps
  • 1 - Biotherm 100 Firestop Sealant
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Worked perfect for coming thru the firewall for the Electroair Ignition sustem

Eastcoast S Verified Purchase


September 3, 2021

Aircraft Spruce has always been the best all around supplier for everything I need, service is always great, and shipping is fast. A+

Stacy S
August 16, 2019

Extremely expensive for what it is..but it worked great

Monte H
March 4, 2019

The penetration appears to be reasonably well made. The rest of the kit is COTS parts. While it certainly does the job for which its intended, Id have to agree with some of the other comments regarding the high cost. That leaves it at 4 stars for me.

Chris N Verified Purchase


May 4, 2022

I should have read more of the other reviews that mention the kit doesnt include mounting hardware. The item is overpriced for what you get, but convenient so I bought it. Irritating they dont include hardware, so another order to Spruce for SS Cherrymax rivets, wait a week and pay $6.00 shipping. Price and lack of mounting hardware keep it at only four stars.

Gary M
November 12, 2020

Dennis C Verified Purchase


June 22, 2021


Please note, Aircraft Spruce's personnel are not certified aircraft mechanics and can only provide general support and ideas, which should not be relied upon or implemented in lieu of consulting an A&P or other qualified technician. Aircraft Spruce assumes no responsibility or liability for any issue or problem which may arise from any repair, modification or other work done from this knowledge base. Any product eligibility information provided here is based on general application guides and we recommend always referring to your specific aircraft parts manual, the parts manufacturer or consulting with a qualified mechanic.

Q: How long is the pass through tube? How long is the fire sleve?

The fire sleeve is 9 long and the tube is 31/32 long.

Q: How thick can the wire bundle be, for each size of your penetration kits? (accounting for the space the tube takes) Thanks

The size listed is the ID of the pass through hole, 1/2, 3/4, or 1 inch.

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