My understanding is that and AD is issued by the airworthiness
authority (e.g. the LBA) and the corresponding TN by
the manufacturer to formally describe what needs to
be done and why. Then there might be an appendix issued
by the manufacturer with the real gen about how to
do it.

A typical example that affected myself was the Duo
spar problem. See Technical Note No. 890-3 and AD
No. 2003-245-2 at:

http://www.schempp-hirth.com/en/serv...lungen/index.h
tml

But to confuse things the German LBA for AD seems to
be LTA and for TN read TM:-)

And there are also many manufacturer TNs without an
LBA AD (LTA) having been issued - sometimes for optional
modifications.




At 21:12 14 February 2006, Marc Ramsey wrote:
HL Falbaum wrote:
Please help with my education. Is a German TN the
same as a German AD or is
it not the same thing. Are they equivalent?


Well, a Technical Note of this sort is approved by
the LBA (and/or EASA,
these days) and becomes a part of the aircraft type
certificate. So
yes, I guess it is sort of a German AD. For those
of us who have
Special Airworthiness Certificates in the US, the operating
limitations
almost always state that the aircraft must be maintained
in compliance
with all technical notes and service bulletins, so
effectively they are
equivalent to an AD for US experimental aircraft.
The German technical
notes that apply to certified aircraft wend their way
through the
various bureaucracies, and become a real US AD within
a year or so. In
any case, if I had a certified DG, and a technical
note like this came
out, I wouldn't wait for the US AD...

I know the guy who had the rudder fall off. It was
during the landing
roll out, so it wasn't a big problem, but still rather
disturbing to
consider what would have happened if it had fallen
off a few moments
earlier...

Marc