Maintenance Question
 

In need of a little help.

Very simple question - Use of Ty-Wraps and which type.

The engineers have it in their heads but are not sure, the use of Ty-wraps with the metal barbs on electrical wiring has been stopped, due to the potential hazard that the metal barb could cause arcing/fire, if the ty-wrap fails.

Therefore only ALL plastic ty-wraps should be used ?

Does anyone know if this is true and if so, where does it state it ????

Keepitup
EASA Land

I haven't seen a metal barbed ty-wrap used for quite a few years across different aircraft type. I don't know if this is mandated anywhere.

Read the IPC it will give you the correct one to use at the specific location or is this a trick question to catch the engineers/company out.

As has already said it depends what is written in the IPC. The ones that I'm aware of that are of the MS-xxxx type all have a metal insert. None of the aircraft we work on have all plastic Ty-raps. Read and follow your aircraft's IPC.

The UK company I worked for for 15 years were engaged in deep-strip modifications to bring former N reg Falcons onto the UK reg., invariably involving partial or complete rewiring of Avionics systems and more latterly complete glass cockpit installations. At no time were metal barbed ty-wraps used and none were found in the original wiring installed by Dassault, FalconJet or Little Rock Airmotive. Don't think I've ever encountered them in any aircraft installation.

LOKON,

Not a trick question !!, it was a question asked by the engineers.

We do follow the IPC as required, but then again you normally have commercial stock of ty-wraps as well, the question was only, can you fit Ty-wraps with the metal barbs or not ?

Keepitup

NB. I have been told an MD11 had an avionics fire and the cause was put down to the failing of a ty-wrap with the metal barb and the barb caused arcing which resulted in a fire.

keepitup...

Haven't come across any instances of barbed tywraps causing a fire but the potential is there. Your 'incident' could however have been brought about by a related problem... there are many reported incidents of arcing and tracking caused by insulation failures and breaddown of Kapton wiring which I believe was used extensively by both M-D and Boeing.

pp