Allen Epps wrote:

In article , Gord Beaman
wrote:

(Pechs1) wrote:

And this incident resulted in all our master arm switches being safety wired
down. "break the safety wire, arm, shoot".

Really dummm
P. C. Chisholm
CDR, USN(ret.)
Old Phart Phormer Phantom, Turkey, Viper, Scooter and Combat Buckeye Phlyer

'Safety wired' or 'witness wired'?...in the Canadian Air Force
'safety wiring' is to prevent accidentally flipping the switch
guard up and flipping the switch. It takes (even more of) a
deliberate action to activate a switch.

'Witness wiring' is to allow the guard/switch to be activated
with no difficulty but to show proof positive that the
guard/switch -was- activated. Witness wire is very fine copper
wire which is very easily broken while 'safety wire' is much
harder to break and may even require cutting.
--

-Gord.
(use gordon in email)

Indeed, I believe it was Rick Morgan who related a tale of a duitiful
airman that followed orders to "safety wire" the emergency gear
blowdown (IIRC) on an A-3 in VAQ-33. He did as instructed but when it
needed to be used there was no budging it. Thereafter instructions from
Maint were very clear about the difference between Safety wire and
Shear wire.

Pugs

Yes, certainly a good(?) spot to start (or continue) the chain of
events that leads to a tragic accident isn't it?

I've never heard the term 'shear wire', although it's quite
descriptive isn't it?
(it's known officially as 'witness wire' in the Canadian Air
Force)
--

-Gord.
(use gordon in email)