Piper ARCHER III Pilot Operating Handbook page 306

SECTION 9
SUPPLEMENT 19
SECTION 2 - LIMITATIONS (continued)
2. Accomplishment of ILS, LOC, LOC-BC, LDA, SDF, MLS or any other
type of approach not approved for GPS overlay with the GNS 530's
GPS receiver is not authorized.
3. Use of the GNS 530 VOR/ILS receiver to fly approaches not approved
for GPS require VOR/ILS navigation data to be present on the external
indicator.
4. When an alternate airport is required by the applicable operating rules,
it must be served by an approach based on other than GPS or Loran-C
navigation, the aircraft must have the operational equipment capable of
using that navigation aid, and the required navigation aid must be
operational.
5. VNAV information may be utilized for advisory information only. Use
of VNAV information for Instrument Approach Procedures does not
guarantee Step-Down Fix altitude protection, or arrival at approach
minimums in normal position to land.
F. If not previously defined, the following default settings must be made in the
"SETUP 1"menu of the GNS 530 prior to operation (refer to Pilot's Guide
for procedure if necessary):
1. dis, spd
2. alt, vs .
3. map datum.. WGS 84 (sets map datum to WGS-84, see not below)
4. posn ...
In some areas outside the United States, datums
other than WGS-84 or NAD-83 may be used. If the
GNS 530 is authorized for use by the appropriate
Airworthiness authority, the required geodetic
datum must be set in the GNS 530 prior to its use
for navigation.
REPORT: VB-1611
9-106, 4 of 8
n k
m t (sets navigation units to "nautical miles"and "knots")
ft fpm (sets altitude units to "feet"and "feet per minute")
deg-min (sets navigation grid units to decimal minutes)
NOTE
PA-28-181, ARCHER III
ISSUED: JULY 12, 1995
REVISED: JUNE 14, 2004