Just a blanket post to the list on the topic:
"Tinnermans are used for sheet metal screws and
Rivnuts are used for machine screws."
Not quite, Syd. Tinnerman nuts have special
screws, without points. Sheet metal screws
have points, and come in sizes that gow out
the Tinnerman nuts. Just check with any
Cessna 150/152.
"I had the idea that an high quality weld,
especially with a V - cut into the problem (crack) would be
significantly stronger than the as - manufactured piece."
What they didn't tell you, JBB, is that aluminum welds
different. Welding works for steel because of the nature
of the material. Aluminum welds are brittle to start
with, and dicey to say the least.
"Best thing is to ask your IA or call the FSDO and ask a
field inspector."
well, Al, you could come to A&P school here in Roswell and
get on the road to becoming your own IA.
"To see the images of the damage to my spar, go to:"
Thanks for the images, Glen. Please consider putting "a
paragraph on the back" (per Arlo Guthrie) describing what
is shown and emailing to Hartmut.
"Welding of highly stressed airframe members is specificalY
disallowed in 43.13."
I was going to look that up! It's required reading.
Thanks, Bill.
"My motor mount has a 337-documented welding repair."
It probably does, Bill (different Bill?). How some ever.
Motor mounts are 4130 steel; a different beast - see above.
Finally, `coupe fans, there is this thing called FAA Form
8010-4; "malfunction or defect reports" - can be filled out
by just about anybody and sent in. The FAA compiles them,
but beware: "Once is interesting, twice is a trend."
In other words, if they see too many on the same topic, an
AD ensues. And we all know what that can mean.
Percy (A&P student) in NM, USA
