In article ,
"Mortimer Schnerd, RN" mschnerdatcarolina.rr.com wrote:
I actually posted this in another aviation newsgroup in which I actively post
all the time but didn't get a reply... I assume because of the crash in
Manhattan got everybody's attention. That being said, I'm still hoping for
some
insight from the more recently trained.
==== cut begins ====
I'm still a little confused how I'm expected to legally fly an ILS approach
that
uses a NDB as its IAF with a GPS on board instead of an ADF.
http://www.faa.gov/ATPubs/AIM/
from chapter 1:
f. Use of GPS in lieu of ADF and DME
1. Subject to the restrictions below, operators in the U.S. NAS are authorized
to use GPS equipment certified for IFR operations in place of ADF and/or DME
equipment for en route and terminal operations. For some operations there is no
requirement for the aircraft to be equipped with an ADF or DME receiver, see
subparagraphs f(b)(7) and (8) below. The ground-based NDB or DME facility may be
temporarily out of service during these operations. Charting will not change to
support these operations.
(a) Operations allowed:
(1) Determining the aircraft position over a DME fix. GPS satisfies the 14 CFR
Section 91.205(e) requirement for DME at and above 24,000 feet mean sea level
(MSL) (FL 240).
(2) Flying a DME arc.
(3) Navigating to/from an NDB/compass locator.
(4) Determining the aircraft position over an NDB/compass locator.
(5) Determining the aircraft position over a fix defined by an NDB/compass
locator bearing crossing a VOR/LOC course.
(6) Holding over an NDB/compass locator.
NOTE-
This approval does not alter the conditions and requirements for use of GPS to
fly existing nonprecision instrument approach procedures as defined in the GPS
approach overlay program.
(b) Restrictions
(1) GPS avionics approved for terminal IFR operations may be used in lieu of ADF
and/or DME. Included in this approval are both stand-alone and multi-sensor
systems actively employing GPS as a sensor. This equipment must be installed in
accordance with appropriate airworthiness installation requirements and the
provisions of the applicable FAA approved AFM, AFM supplement, or pilot's guide
must be met. The required integrity for these operations must be provided by at
least en route RAIM, or an equivalent method; i.e., Wide Area Augmentation
System (WAAS).
(2) For air carriers and operators for compensation or hire, Principal
Operations Inspector (POI) and operations specification approval is required for
any use of GPS.
(3) Waypoints, fixes, intersections, and facility locations to be used for these
operations must be retrieved from the GPS airborne database. The database must
be current. If the required positions cannot be retrieved from the airborne
database, the substitution of GPS for ADF and/or DME is not authorized.
(4) The aircraft GPS system must be operated within the guidelines contained in
the AFM, AFM supplement, or pilot's guide.
(5) The Course Deviation Indicator (CDI) must be set to terminal sensitivity
(normally 1 or 1 1/4 NM) when tracking GPS course guidance in the terminal area.
This is to ensure that small deviations from course are displayed to the pilot
in order to keep the aircraft within the smaller terminal protected areas.
(6) Charted requirements for ADF and/or DME can be met using the GPS system,
except for use as the principal instrument approach navigation source.
(7) Procedures must be established for use in the event that GPS integrity
outages are predicted or occur (RAIM annunciation). In these situations, the
flight must rely on other approved equipment; this may require the aircraft to
be equipped with operational NDB and/or DME receivers. Otherwise, the flight
must be rerouted, delayed, canceled or conducted VFR.
(8) For TSO-C129/129A users, any required alternate airport must still have an
approved instrument approach procedure other than GPS that is anticipated to be
operational and available at the estimated time of arrival, and which the
aircraft is equipped to fly. If the non-GPS approaches on which the pilot must
rely require DME or ADF, the aircraft must be equipped with DME or ADF avionics
as appropriate.
NOTE-
Coincident with WAAS commissioning, the FAA will begin removing the Inverse A
Icon NA (Alternate Minimums Not Authorized) symbol from select RNAV (GPS) and
GPS approach procedures so they may be used by approach approved WAAS receivers
at alternate airports. This does not change the above alternate airport
requirements for users of GPS TSO-C129/129A, Airborne Supplemental Navigation
Equipment Using the Global Positioning System (GPS), receivers.
(c) Guidance. The following provides general guidance which is not specific to
any particular aircraft GPS system. For specific system guidance refer to the
AFM, AFM supplement, pilot's guide, or contact the manufacturer of your system.
(1) To determine the aircraft position over a DME fix:
[a] Verify aircraft GPS system integrity monitoring is functioning properly and
indicates satisfactory integrity.
[b] If the fix is identified by a five letter name which is contained in the GPS
airborne database, you may select either the named fix as the active GPS
waypoint (WP) or the facility establishing the DME fix as the active GPS WP.
NOTE-
When using a facility as the active WP, the only acceptable facility is the DME
facility which is charted as the one used to establish the DME fix. If this
facility is not in your airborne database, you are not authorized to use a
facility WP for this operation.
[c] If the fix is identified by a five letter name which is not contained in the
GPS airborne database, or if the fix is not named, you must select the facility
establishing the DME fix or another named DME fix as the active GPS WP.
NOTE-
An alternative, until all DME sources are in the database, is using a named DME
fix as the active waypoint to identify unnamed DME fixes on the same course and
from the same DME source as the active waypoint.
CAUTION-
Pilots should be extremely careful to ensure that correct distance measurements
are used when utilizing this interim method. It is strongly recommended that
pilots review distances for DME fixing during preflight preparation.
[d] If you select the named fix as your active GPS WP, you are over the fix when
the GPS system indicates you are at the active WP.
[e] If you select the DME providing facility as the active GPS WP, you are over
the fix when the GPS distance from the active WP equals the charted DME value
and you are on the appropriate bearing or course.
(2) To fly a DME arc:
[a] Verify aircraft GPS system integrity monitoring is functioning properly and
indicates satisfactory integrity.
[b] You must select, from the airborne database, the facility providing the DME
arc as the active GPS WP.
NOTE-
The only acceptable facility is the DME facility on which the arc is based. If
this facility is not in your airborne database, you are not authorized to
perform this operation.
[c] Maintain position on the arc by reference to the GPS distance in lieu of a
DME readout.
(3) To navigate to or from an NDB/compass locator:
NOTE-
If the chart depicts the compass locator collocated with a fix of the same name,
use of that fix as the active WP in place of the compass locator facility is
authorized.
[a] Verify aircraft GPS system integrity monitoring is functioning properly and
indicates satisfactory integrity.
[b] Select terminal CDI sensitivity in accordance with the AFM, AFM supplement,
or pilot's guide if in the terminal area.
[c] Select the NDB/compass locator facility from the airborne database as the
active WP.
[d] Select and navigate on the appropriate course to or from the active WP.
(4) To determine the aircraft position over an NDB/compass locator:
[a] Verify aircraft GPS system integrity monitoring is functioning properly and
indicates satisfactory integrity.
[b] Select the NDB/compass locator facility from the airborne database as the
active WP.
NOTE-
When using an NDB/compass locator, that facility must be charted and be in the
airborne database. If this facility is not in your airborne database, you are
not authorized to use a facility WP for this operation.
[c] You are over the NDB/compass locator when the GPS system indicates you are
at the active WP.
(5) To determine the aircraft position over a fix made up of an NDB/compass
locator bearing crossing a VOR/LOC course:
[a] Verify aircraft GPS system integrity monitoring is functioning properly and
indicates satisfactory integrity.
[b] A fix made up by a crossing NDB/compass locator bearing will be identified
by a five letter fix name. You may select either the named fix or the
NDB/compass locator facility providing the crossing bearing to establish the fix
as the active GPS WP.
NOTE-
When using an NDB/compass locator, that facility must be charted and be in the
airborne database. If this facility is not in your airborne database, you are
not authorized to use a facility WP for this operation.
[c] If you select the named fix as your active GPS WP, you are over the fix when
the GPS system indicates you are at the WP as you fly the prescribed track from
the non-GPS navigation source.
[d] If you select the NDB/compass locator facility as the active GPS WP, you are
over the fix when the GPS bearing to the active WP is the same as the charted
NDB/compass locator bearing for the fix as you fly the prescribed track from the
non-GPS navigation source.
(6) To hold over an NDB/compass locator:
[a] Verify aircraft GPS system integrity monitoring is functioning properly and
indicates satisfactory integrity.
[b] Select terminal CDI sensitivity in accordance with the AFM, AFM supplement,
or pilot's guide if in the terminal area.
[c] Select the NDB/compass locator facility from the airborne database as the
active WP.
NOTE-
When using a facility as the active WP, the only acceptable facility is the
NDB/compass locator facility which is charted. If this facility is not in your
airborne database, you are not authorized to use a facility WP for this
operation.
[d] Select nonsequencing (e.g., "HOLD" or "OBS") mode and the appropriate course
in accordance with the AFM, AFM supplement, or pilot's guide.
[e] Hold using the GPS system in accordance with the AFM, AFM supplement, or
pilot's guide.
(d) Planning. Good advance planning and intimate knowledge of your navigational
systems are vital to safe and successful use of GPS in lieu of ADF and/or DME.
(1) You should plan ahead before using GPS systems as a substitute for ADF
and/or DME. You will have several alternatives in selecting waypoints and system
configuration. After you are cleared for the approach is not the time to begin
programming your GPS. In the flight planning process you should determine
whether you will use the equipment in the automatic sequencing mode or in the
nonsequencing mode and select the waypoints you will use.
(2) When you are using your aircraft GPS system to supplement other navigation
systems, you may need to bring your GPS control panel into your navigation scan
to see the GPS information. Some GPS aircraft installations will present
localizer information on the CDI whenever a localizer frequency is tuned,
removing the GPS information from the CDI display. Good advance planning and
intimate knowledge of your navigation systems are vital to safe and successful
use of GPS.
(3) The following are some factors to consider when preparing to install a GPS
receiver in an aircraft. Installation of the equipment can determine how easy or
how difficult it will be to use the system.
[a] Consideration should be given to installing the receiver within the primary
instrument scan to facilitate using the GPS in lieu of ADF and/or DME. This will
preclude breaking the primary instrument scan while flying the aircraft and
tuning, and identifying waypoints. This becomes increasingly important on
approaches, and missed approaches.
[b] Many GPS receivers can drive an ADF type bearing pointer. Such an
installation will provide the pilot with an enhanced level of situational
awareness by providing GPS navigation information while the CDI is set to VOR or
ILS.
[c] The GPS receiver may be installed so that when an ILS frequency is tuned,
the navigation display defaults to the VOR/ILS mode, preempting the GPS mode.
However, if the receiver installation requires a manual selection from GPS to
ILS, it allows the ILS to be tuned and identified while navigating on the GPS.
Additionally, this prevents the navigation display from automatically switching
back to GPS when a VOR frequency is selected. If the navigation display
automatically switches to GPS mode when a VOR is selected, the change may go
unnoticed and could result in erroneous navigation and departing obstruction
protected airspace.
[d] GPS is a supplemental navigation system in part due to signal availability.
There will be times when your system will not receive enough satellites with
proper geometry to provide accurate positioning or sufficient integrity.
Procedures should be established by the pilot in the event that GPS outages
occur. In these situations, the pilot should rely on other approved equipment,
delay departure, reroute, or discontinue IFR operations.
g. Equipment and Database Requirements
1. Authorization to fly approaches under IFR using GPS avionics systems requires
that:
(a) A pilot use GPS avionics with TSO- C129, or equivalent, authorization in
class A1, B1, B3, C1, or C3; and
(b) All approach procedures to be flown must be retrievable from the current
airborne navigation database supplied by the TSO-C129 equipment manufacturer or
other FAA approved source.
(c) Prior to using a procedure or waypoint retrieved from the airborne
navigation database, the pilot should verify the validity of the database. This
verification should include the following preflight and in-flight steps:
(1) Preflight:
[a] Determine the date of database issuance, and verify that the date/time of
proposed use is before the expiration date/time.
[b] Verify that the database provider has not published a notice limiting the
use of the specific waypoint or procedure.
(2) Inflight:
[a] Determine that the waypoints and transition names coincide with names found
on the procedure chart. Do not use waypoints, which do not exactly match the
spelling shown on published procedure charts.
[b] Determine that the waypoints are generally logical in location, in the
correct order, and that their orientation to each other is as found on the
procedure chart, both laterally and vertically.
NOTE-
There is no specific requirement to check each waypoint latitude and longitude,
type of waypoint and/or altitude constraint, only the general relationship of
waypoints in the procedure, or the logic of an individual waypoint's location.
[c] If the cursory check of procedure logic or individual waypoint location,
specified in [b] above, indicates a potential error, do not use the retrieved
procedure or waypoint until a verification of latitude and longitude, waypoint
type, and altitude constraints indicate full conformity with the published data.
--
Bob Noel
Looking for a sig the
lawyers will hate