Aeronautical Information Manual (AIM), page 136

Index   135 -- Page 136 -- 137

FIG 2-3-28
Holding Position Sign for ILS Critical Area

FIG 2-3-29
Sign Prohibiting Aircraft Entry into an Area

3. ILS Critical Area Holding Position
Sign. At some airports, when the instrument landing
system is being used, it is necessary to hold an aircraft
on a taxiway at a location other than the holding
position described in paragraph 2-3-5, Holding
Position Markings. In these situations the holding
position sign for these operations will have the
inscription "ILS" and be located adjacent to the
holding position marking on the taxiway described in
paragraph 2-3-5. An example of this sign is shown
in FIG 2-3-28.

4. No Entry Sign. This sign, shown in
FIG 2-3-29, prohibits an aircraft from entering an
area. Typically, this sign would be located on a
taxiway intended to be used in only one direction or
at the intersection of vehicle roadways with runways,
taxiways or aprons where the roadway may be
mistaken as a taxiway or other aircraft movement
The holding position sign provides the pilot with a visual
cue as to the location of the holding position marking. The
operational significance of holding position markings are
described in the notes for paragraph 2-3-5, Holding
Position Markings.

2-3-22 Airport Marking Aids and Signs

Page 136 of the Aeronautical Information Manual (AIM.pdf)
AIM: Official Guide to Basic Flight Information and ATC Procedures

Index   135 -- Page 136 -- 137