Garmin GNS 530 Manual page 8

DA 40 AFM
(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.
E. 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):
dis, spd: nm, kt (sets navigation units to 'nautical miles' and 'knots')
(1)
alt, vs: ft, fpm (sets altitude units to 'feet' and 'feet per minute')
(2)
map datum: WGS 84 (sets map datum to WGS-84, see note below)
(3)
posn: hddd°mm.mmm' (sets navigation grid units to decimal minutes)
(4)
fuel: gl (sets fuel units to gallons)
(5)
Doc. # 6.01.01-E Rev. 0 01 Dec 2001
Supplement A21
GNS 530
Page 9 - A21 - 7