Gulfstream Spring 2004

• GIV Wing Inspection –— Vortex Generators
• WWW.EGPWS.COM
• ELT Registration
• Paint and RVSM Criteria

GIV Wing Inspection –— Vortex Generators

— Jim Overheul

During your next wing exterior inspection or
exterior paint you may want to take a close look
at your vortex generators. Vortex generators are
one of those items that many think, "If they're all
there then they must be okay." This may be
because there is no aerodynamically acceptable
information in the maintenance manual. There
are three quick visual inspections that you can
perform on vortex generators without the need for
special tooling:

1. Inspect the fillet seal around
   the vortex generation bases for excessive width or
   height;
2. Inspect the forward and aft end height
   for reduced height and damaged corners;
3. Inspect for excessive paint build-up around the
   forward tip and vertical blade of the vortex generators.

If any discrepancy is found during these
inspections then the vortex generator is aerodynamically
unacceptable. The location and angularity
of the vortex generators, which require templates
to verify, are also important. If they go
uncorrected, shock wave induced flow separation
at lower air speed may result. If this is the case,
expect to experience aileron buffet at speeds
above Mach 0.80. The best time to change these
vortex generators is just prior to a paint input.

For more information, contact Jim Overheul
at 800.525.2376 or Doug Donahue at 269.968.8905.

WWW.EGPWS.COM

— Jim Wheaton

If you have a Honeywell EGPWS system (Mk
V, VI, VII or VIII) you should visit www.egpws.com. This site allows aircraft operators to download
and install terrain database updates as they
become available. The site also gives instructions
to accomplish database updates as well as info
about additional equipment requirements. A note
of caution: updating the EGPWS database
may negate the EGPWS certification. Before
making any updates, review your EGPWS
Flight Manual Supplement and contact the
holder of your EGPWS STC installation.

ELT Registration

— Dennis DeCook

Have you registered your ELT? All emergency
locator transmitters must be registered
with the National Oceanic and Atmospheric
Administration. Immediate registration with
the NOAA can be accomplished online at www.
sarsat.noaa.gov. Registration is required every
two years.

Paint and RVSM Criteria

— George Bajo

An aircraft kept in a quality coat of paint is
less likely to develop corrosion. For this reason,
aircraft should be stripped, inspected and
repainted by a reputable aircraft paint facility
every five to seven years. Inferior or old paint can
cause electrical problems affecting comm radios
and navigation receivers. In addition, many aircraft
manufacturers' "continuing maintenance
instructions" for RVSM aircraft stress that the
paint around the static ports needs to be kept in
"new condition" with no paint chips allowed to
disrupt the airflow over the static-sensing areas,
which could cause altitude errors.

As more of the fleet undergoes the RVSM
certification process, we are learning paint continues
to be a critical area. During complete or
touch-up paint in areas around the static
ports, it is essential that it is finished to the
RVSM criteria for your aircraft. Dealing with
a paint shop experienced with this issue is an
important key to avoiding significant
rework.

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