VOLUME 4 AIRCRAFT EQUIPMENT AND OPERATIONAL AUTHORIZATIONS
CHAPTER 14 GENERAL OPERATING AND FLIGHT RULES—MAINTENANCE ISSUES
Section 5 Approve Area Navigational Systems
4-1451 PROGRAM TRACKING AND REPORTING SUBSYSTEM (PTRS) ACTIVITY CODES.
4-1452 OBJECTIVE. This section provides guidance for approving area
4-1453 GENERAL. The aviation safety inspector (ASI), may need to
refer to specific advisory circular(s) (AC) and regulations for individual systems
in order to accomplish this approval.
A. Approvals. Field approval for an Area Navigation System (RNAV)
should not be considered unless the applicant has provided previously approved
data. This data must be in the form of a Type Certificate (TC) or Supplemental
Type Certificate (STC) for an airplane or rotorcraft of like or similar configuration
using approved system components.
1) For Title 14 of the Code of Federal Regulations
(14 CFR) part 121 operators, inertial navigation systems and Doppler’s must
meet the requirements specified in
14 CFR part 121, appendix G, before formal approval. Under these requirements
an STC must be obtained by the applicant.
2) Installation approvals of other types of area navigation equipment should
be obtained with an STC. However, approval can also be obtained by submission
of substantiating data with either a Federal Aviation Administration (FAA) Form
337 or an air carrier engineering authorization.
3) The applicant must furnish all of the installation data necessary to
determine the adequacy of the installation. Such data should include the following:
schematics and failure protection
information and/or photographs
of structural changes
of capability of electrical system and failure protection to handle additional
· Any other
data determined necessary for approval
4) FAA-approved manufacturer service bulletins which lists approved instructions
for the installation of certain RNAV may be used.
a) In some cases, the facility making the installation has demonstrated
its ability to install this equipment on a representative number of similar
type installations through field approvals.
b) References to previous approvals on FAA Form 337 would constitute previously-approved
data and may not require a separate field approval. In this case, a letter from
the Flight Standards District Office (FSDO) or General Aviation District Office
authorizing the installation facility to perform similar installations would
c) Alterations which do not differ appreciably from previously approved
changes may not require new or additional approval.
B. Visual Flight Rules (VFR) Operation. An installation may be approved
for Visual Flight Rules (VFR) operation after meeting the provisions discussed
above. The aircraft should be placarded to limit the use of the RNAV to VFR
only, unless the aircraft itself is limited to VFR.
C. Instrument Flight Rules (IFR) Approval. Systems do not require
VFR approval before IFR approval. An application for Instrument Flight Rules
(IFR) approval should contain data substantiating that the equipment and installation
meet the criteria in Air Circular
(AC) 90-45, appendix A, Approval of Area Navigation Systems for Use in the
U.S. National Airspace System, current edition.
D. Original VFR Approval Changes to IFR Approval. Operators have
installed RNAVs in a variety of aircraft for use in VFR operations only. Operators
have the option of upgrading these systems to allow for IFR operations as well.
1) When such a request is received, an FAA Form 337 should be prepared on
which the approval for IFR operations will be properly documented. Item 8 of
FAA Form 337 should provide at least the following information:
to FAA Form 337 which recorded the original VFR RNAV installation
to confirm that the requirements of
AC 90-45, appendix A, paragraphs 2 and 3, have been met
· If a flight
test is conducted, a statement to document the modes of IFR operation for which
the system is being approved
2) The data approval stamp, properly completed, should be placed in block
3 of FAA Form 337.
3) If the aircraft has an FAA-approved flight manual, a supplement to the
manual may be prepared and submitted for approval, in accordance with regional
a) An additional copy of FAA Form 337 detailing the original installation
must accompany the flight manual supplement approval request.
b) The date of the flight manual supplement must not be later than the approval
for return to service date, as shown on FAA Form 337.
4) If the aircraft does not have an FAA-approved flight manual, then information
on equipment operating limitations and manufacturer’s operating instructions
must be provided to the pilot by means of a placard.
4-1454 PREREQUISITES AND COORDINATION REQUIREMENTS.
completion of Airworthiness Inspector Indoctrination course for General Aviation
and Air Carrier Inspections, or previous equivalent
and authorization to perform field approvals by the regional Flight Standards
B. Coordination. Engineering assistance should be obtained for a
field approval unless the aviation safety inspector (ASI) has previous experience
with area navigation installations and feels competent to make such an approval.
4-1455 REFERENCES, FORMS, AND JOB AIDS.
A. References (Current Editions).
14 CFR part 121, appendix G
AC 20-101, Omega and Omega/VLF Navigation Systems Approvals for Use in the
Conterminous United States and Alaska
AC 20-121, Airworthiness Approval of Airborne Loran-C Systems for Use in
the U.S. National Airspace System
AC 25-4, Inertial Navigation Systems
AC 90-45, appendix A, current edition, Approval of Area Navigation Systems
for Use in the U.S. National Airspace System
AC 120-31, Operational and Airworthiness Approval of Airborne Omega Radio
Navigation Systems as a Means of Updating Self-Contained Navigation Systems
AC 120-33, Operational Approval of Airborne Long-Range Navigation Systems
for Flight Within the North Atlantic Minimum Navigation Performance Specifications
AC 120-37, Operational and Airworthiness Approval of Airborne Omega Radio
Navigational Systems as a Sole Means of Long Range Navigation Outside the United
AC 121-13, Self-Contained Navigation Systems (Long-Range)
· This book’s
Volume 4, Chapter 9, Section 1, Perform Field Approval of Major Repairs
and Major Alterations
B. Forms. FAA Form 337, Major Repair and Alteration
C. Job Aids. None.
A. Follow the Procedures Detailed in the Applicable AC(s).
B. Review the Operator’s Data. Review STC(s) and installation data,
as applicable. Extra consideration must be given to the following:
instructions and limitations, including necessary modification and calibration
of all units in the system and previously installed equipment.
with auxiliary equipment, sensor inputs, meter loading and sensitivity, etc.
reasonable probable failure of the equipment which would cause a flight hazard
or affect the normal operation of required equipment to which it is connected.
C. Conduct Inspections, as necessary.
1) Conduct a conformity inspection to ensure the installation conforms to
the approved data.
2) Monitor the ground operational/functional check performed by the installing
3) Ensure that the aircraft is appropriately placarded regarding the limitations
of the equipment.
D. Review FAA Form 337.
1) Ensure that certification dates of flight and/or bench tests are provided.
2) Ensure that limitations on types of approval are clearly stated in block
8 of FAA Form 337 and on any required approved operations specifications.
E. Review the Operator Training Programs. Ensure that the operator
establishes training programs on the new equipment and reviews the existing
programs on associated equipment. In addition, accomplish the following:
spot checks of the training records
the actual training sessions
that the training emphasizes the new equipment, new maintenance techniques,
and new procedures and standards
4-1457 TASK OUTCOMES.
A. File PTRS Data Sheet.
B. Completion of this task may result in the following:
of the installation of the equipment
· If the
facility making the installation has demonstrated its ability to install the
equipment on a representative number of similar type installations through field
approvals, an approval letter sent by the FSDO or General Aviation District
Office authorizing the installation facility to perform similar installations
4-1458 FUTURE ACTIVITIES. None.
RESERVED. Paragraphs 4-1459 through 4-1475.