CHAPTER
1. INTRODUCTION 1-1.
GENERAL. a. The two objectives of Aircraft certification is to
encourage and foster the development of civil aviation, and
to ensure aviation safety. One method used by the Federal
Aviation Administration (FAA) to fulfill these objectives is
the aircraft certification system through which aircraft
design and modification must be approved. Title 14 of the
Code of Federal Regulations (14 CFR) and the Civil Air
Regulations (CAR) define the minimum required safety
standards for FAA certification. By demonstrating compliance
with these regulations, an aircraft modifier may obtain the
necessary FAA approval for a modification. b. Types of aircraft certification design approvals are
determined by the magnitude and complexity of the change.
Aircraft modifications can be subdivided into minor and
major changes (14 CFR part 21, section 21.93). Minor changes
are those which do not appreciably affect weight, balance,
structural strength, reliability, operational
characteristics, airworthiness characteristics, power and
noise characteristics, or emissions. Minor changes may be
approved under a method acceptable to the Administrator
before submitting to the Administrator any substantiating or
descriptive data (14 CFR part 21, section 21.95). Major
changes are those which are not minor. The type of FAA
approval is applicable to a given modification. Supplemental
Type Certificates (STC) are required for most major changes
to existing Type Certificate (TC) products affected by a
modification or installation when the change is not so
intensive as to require a new TC (14 CFR part 21, section
21.19). STC's are not issued for minor changes or for
approval of replacement and modification parts meeting the
provisions of 14 CFR part 21, section 21.303. More than one
STC may be necessary for a given modification. One STC may
be required to approve the change to an engine or propeller,
while a second STC may be necessary to approve the aircraft
installation of the modified engine or propeller. An STC
will probably be required if a significant amount of
analysis or flight tests are required, or if extensive
flight manual changes are necessary. An STC is issued
through the FAA ACO or Engine Certification Office (ECO)
which serves the geographic area of residence of the STC
owner. Significant STC applications will require
coordination with the Directorate, and may involve more time
to process the application. See Order 8100-5. NOTE: If there are any questions whether the modification
is major or minor, the applicant should contact the ACO. 1-2.
SUPPLEMENTAL
TYPE CERTIFICATES. a. Privileges are associated with the issuance of an
STC. (1) Standard Airworthiness Certificates may be granted to
specified aircraft that are modified in accordance with the
STC. (2) Multiple installations may be achieved on any
certificated aircraft designated in accordance with the
STC. (3) Parts Manufacturer Approval (PMA) may be obtained by
the STC holder to manufacture and sell parts/kits when it is
demonstrated to the FAA Manufacturing Aviation Safety
Inspector that the applicant has established a Fabrication
Inspection System which meets the requirements of 21.303(h)
to ensure that production is consistent to adequately
duplicate the parts. NOTE: The STC must be a "Multiple" Installation STC. b. Responsibilities of the STC holder are the
accomplishments of the modification or installation in
accordance with the STC, and reporting to the FAA any
failures, malfunctions, or defects per 14 CFR part 21,
section 21.3. The holder of an STC, is also required to
maintain an updated data file related to the STC. c. Types of STC's are classified as either "one-only" STC
(aircraft/engine/propeller) or "multiple" STC
(aircraft/engine/propeller). (1) "One-only" STC's apply to only one
aircraft/engine/propeller serial number. (2) "Multiple" STC's are necessary if two or more
aircraft/engines/propellers are to be modified, and it must
be demonstrated that the modification can be duplicated. d. AC 21-5M, Announcement of Availability: Summary of
STC's, is an FAA publication listing all existing MULTIPLE
STC's for each aircraft model. A copy of this publication is
available for review at the local FAA ACO, FSDO, and MIDO
and a disk (updated once a year) may be purchased from the
National Technical Information Service (NTIS). This
publication may be reviewed to determine if another STC has
been issued that would satisfy the intended requirement, and
thereby prevent a duplication of effort. NOTE: Pursuant to 49 U.S.C 44704; If the holder of an STC
agrees to permit another person to use the certificate to
modify an aircraft, aircraft engine, propeller, or
appliance, the holder will provide the other person with
written evidence, in a form acceptable to the administrator,
of that agreement. A person may change an aircraft, aircraft
engine, propeller, or appliance based on an existing STC
only if the person requesting the change is the holder of
the STC or has permission from the holder to make the
change. See chapter 9. e. No STC activity is covered under our bilateral
airworthiness agreements in any country except Canada.
Additional guidance should be sought from AIR head quarters
before proceeding on any STC project involving a foreign
entity to any degree. f. 14 CFR part 21, sections 21.137 and 21.601 require the
FAA to make a determination that there will be no undue
burden on the United States in administering the applicable
requirements of Title 49, U.S. Code (Transportation), and
Title 14 of the Code of Federal Regulations when production
approvals are requested at manufacturing facilities located
outside the United States. Once the foregoing criteria have
been satisfied by the certificate management Directorate and
the PC holder, the FAA office responsible for certificate
management of the PC holder should prepare a decision
paper. NOTE: The decision paper should be signed by the Aircraft
Certification Directorate Manager who has certificate
management responsibility for the PC holder prior to
forwarding the decision paper to AIR-200 for concurrence and
to AIR-1 for approval. See AC 21-24.. 1-3. KEY
ASPECTS OF THE STC APPLICATION PROCESS. a. The applicant's responsibility for substantiating the
modification is accomplished by showing the FAA that the
modified aircraft/ engine/propeller complies with the
applicable regulations. b. FAA Form 8110-12, Application For Type Certificate,
Production Certificate, or Supplemental Type Certificate,
should be submitted to the geographically responsible ACO.
See appendix 8. The most current version of AC 20-126,
Aircraft Certification Service Field Office Listing,
contains an address, telephone number, and geographic area
listing of all ACOs. c. Certification requirements are located in title 14
CFR's, or the predecessor to them, Civil Air Regulations.
These regulations are extensive but only certain portions
apply to a particular STC. See chapter 3. d. Design feasibility should be discussed with a local
FAA engineer to determine if the proposed modification
design is feasible for approval BEFORE MODIFYING THE
AIRCRAFT. An unapproved modified aircraft may be subject to
grounding and Airworthiness Certificate removal. e. Data submittals are to contain sufficient descriptive
and substantiating/compliance data to completely describe
the design of the modification or installation, and
demonstrate that the design meets the applicable
regulations. See chapter 5. f. Inspections are for conformity and compliance. The
conformity inspection verifies that the modification
conforms to the descriptive data, while the compliance
inspection verifies that the modification meets the
applicable regulations. See chapter 6. g. Tests may include verifying the component, ground
requirements, and flight requirements. Component or
certification testing demonstrates that detail parts,
components, or subassemblies function as required to meet
the applicable regulations. Ground testing and flight
testing are performed to demonstrate the completed
modification or installation complies with the regulations.
See chapter 8. h. Timing/scheduling necessary for obtaining FAA approval
varies with the complexity of each modification.
Inspections, meetings, tests, etc., should be planned,
scheduled, and provided well in advance to the FAA to assure
appropriate personnel are available. Scheduling flight tests
has the added complication of weather. All proposed changes
to the schedule should be kept to a minimum and provided to
the FAA immediately for concurrence. i. Use of designees authorized by the FAA to approve
data, conduct inspections, witness tests, etc., may expedite
the approval of a modification. See chapter 4. j. Issuance of an STC is the final product and goal of
the application process. See chapter 2 and chapter 9. k. Subsequent change procedures to the original
substantiating data should be submitted for approval and
inclusion in the FAA data files. Major changes must be FAA
approved prior to inclusion in the design data. Minor
changes may be accom-plished in any manner found acceptable
to the FAA. See 14 CFR part 21, sections 21.95 and
21.97.
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Closing
1-2. SUPPLEMENTAL
TYPE CERTIFICATES.
1-3. KEY
ASPECTS OF THE STC APPLICATION
PROCESS.
CHAPTER 1. INTRODUCTION
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