Ray Mansfield wrote:
> In other words, is this going to be a problem in the next hours of
> flight or next years of flight. Does anyone have experience here?
Ray,
If the line failed right at the flare, it was probably due to improper
fabrication. I've seen many cases where someone has made a line and
didn't know that aircraft aluminum lines use a different flare angle
than copper lines. The tool you'll find at your local hardware store to
flare line ends is for copper only and makes too sharp an angle for
aluminum. This causes cracks to form.
You also mentioned that you've been repairing corrosion in other areas.
The aluminum used for aircraft lines is fairly prone to corrosion. It
also "work hardens" from vibration and becomes more brittle with age.
You may simply be dealing with aging aircraft issues. During my
commander restoration, we ended up having to replace virtually every
hard line in the airplane for these reasons. I'd suggest a very careful
inspection of all your hard lines - especially the ones exposed in the
nacelles. Make sure they are well supported and that the adel clamps
are not loose or missing. If the lines are allowed to vibrate due to
old, worn-out supports, that can lead to rapid fatigue cracking. Clean
the lines carefully with scotch bright and look for corrosion pitting.
Even small pits lead to failure. Look for any areas where the lines are
chaffing (usually due to something coming loose) and address those areas
immediately. It's all just part of being the care-taker of a complex
old airframe.
good luck,
chris
