The 400W/500W series of navigators with WAAS now offer many enhancements over the previous non-WAAS
models. Advancements include new WAAS-enabled GPS antenna, receiver, and associated software. The 400W/500W
series system complies with WAAS TSO C146a and also includes a significant hardware upgrade with a new and much
faster micro-processor. A terrain database for terrain awareness is included as a standard feature and now provides
even greater detail. The WAAS GPS receiver now allows you to use the 400W/500W series unit for primary navigation
and use GPS with vertical guidance for LPV, L/VNAV, and LNAV+V approaches. Non-precision approaches are annun-
ciated as LNAV approaches. The Comparison of Features Summary table provides a quick view of the differences and
is followed by a more detailed description of feature changes.
Comparison of Features Summary
Feature
Classic 400/500
New 400W/500W
1
TSO
C129a – Supplemental navigation
WAAS TSO C146a – Primary navigation
2
WAAS Capable
No
Yes
3
Approach Annunciations
C129a non-precision annuncia-
tions
C146a precision annunciations of LPV, L/VNAV,
LNAV+V, LNAV, and MAPR
4
SBAS Selection
No
Yes for WAAS
5
GPS Position Calculation Rate
Once per second
Five times per second
6
GPS Software
Level-C
Level-B. More robust
7
Vectors-To-Final
Yes
Auto-Suspend (SUSP) is active for Vectors To Final
(VTF) until on the “TO” side of the FAF and the
aircraft ground track is within a 45° course of the
published in bound course. At this point, the SUSP
annunciation will automatically extinguish.
8
GPS/WAAS-Based Vertical Guid-
ance
No
GPS WAAS provides vertical guidance on the
available GPS approaches
9
Holding Patterns
Yes
Holding pattern depiction on the Nav mode
moving map shows aircraft position and provides
active guidance
10
Autopilot Roll Steering
Yes
Includes active guidance during holding patterns
and procedure turns
11
OBS Operation
Yes
OBS/SUSP behavior around the MAP is different
12
Hold to Altitude
Yes
Hold to Altitude legs will now use baro-corrected
altitude if it is available
13
Parallel Track
No
Yes
14
Magnetic Variation Options
True, Magnetic, or User
True or Magnetic
