since 1940

Aircraft Hose Installation Tips

• 1. Proper application
• 2. Do not twist hose. High pressure applied to a twisted hose may cause loosening of the nut or failure of the hose.
• 3. Make sure hose has enough slack so that the hose isn't pulling at the nut and allowing for thermal contraction and movement.
• 4. Provide a large a bend radius as possible.
• 5. Use clamps and lacing to prevent hose chafing
• 6. AC43.13-1, Chapter 10, covers installation procedures for hose assemblies.
• 7. Do not let hose lay against hot exhaust carrying components.

1. Heat damage
2. Chafe damage
3. Improper assembly

Heat Damage What happens here is that the hose rests against an exhaust carrying component. No hose, whether fire sleeved or not, will withstand direct contact to an exhaust stack. This type of heat damage is usually not visible from the outside of the hose. At the point of contact the hose liner overheats and becomes brittle (if rubber) or melts (if non rubber). If the hose is moved or bent a crack developed at the heat damage area. This usually occurs after the aircraft is in the maintenance shop.
If you see a hose laying against an exhaust stack then throw away the hose. You can't see the damage but the hose liner, if it hasn't already failed is about to.

Chafe Damage The most common hose failure that we see. Chafing is almost never visible during a visual examination and therefore missed during most inspections. Think about it, the chafe point is where the hose rests against something - you can't see the chafe damage, you can only see that the hose is resting innocently against something. Pull the hose away from any points of contact and look behind the hose, or if your brave run your hand carefully behind the hose and see if any broken hose braid pricks your hand.

Chafe damage to 124J hose

Chafe damage to fire sleeved Teflon hose

Any hose can be damaged if allowed to rub that is one reason why every type of hose needs to be inspected on a regular basis. Any place the hose is touching you must inspect for chafing, cutting, or damage.

Copyright 2003 by Sacramento Sky Ranch Inc. All rights reserved.  Prices subject to change without notice. Not responsible for typographical or misprint.
Disclaimer: sacskyranch.com contains abundant information relating to aircraft maintenance. The information provided  is not intended to supercede or supplement the F.A.A. approved  maintenance and/or operator’s manuals. Those F.A.A. approved manuals must be utilized when performing maintenance and/or operating aircraft.