- 14 CFR Part 91 Subpart
EMaintenance, Preventive Maintenance, and
Alterations
- Sec. 91.401 Applicability.
- (a) This subpart prescribes rules
governing the maintenance, preventive maintenance, and
alterations of U.S.-registered civil aircraft operating
within or outside of the United States.
- (b) Sections 91.405, 91.409, 91.411,
91.417, and 91.419 of this subpart do not apply to an
aircraft maintained in accordance with a continuous
airworthiness maintenance program as provided in part
121, 127, 129, or Sec. 135.411(a)(2) of this chapter.
- (c) Sections 91.405 and 91.409 of this
part do not apply to an airplane inspected in accordance
with part 125 of this chapter.
-
- Sec. 91.403 General.
- (a) The owner or operator of an aircraft
is primarily responsible for maintaining that aircraft in
an airworthy condition, including compliance with part 39
of this chapter.
- (b) No person may perform maintenance,
preventive maintenance, or alterations on an aircraft
other than as prescribed in this subpart and other
applicable regulations, including part 43 of this
chapter.
- (c) No person may operate an aircraft for
which a manufacturers maintenance manual or
instructions for continued airworthiness has been issued
that contains an airworthiness limitations section unless
the mandatory replacement times, inspection intervals,
and related procedures specified in that section or
alternative inspection intervals and related procedures
set forth in an operations specification approved by the
Administrator under part 121, 127 or 135 of this chapter
or in accordance with an inspection program approved
under Sec. 91.409(e) have been complied with.
-
- Sec. 91.405 Maintenance required.
- Each owner or operator of an
aircraft
- (a) Shall have that aircraft inspected as
prescribed in subpart E of this part and shall between
required inspections, except as provided in paragraph
- (c) of this section, have discrepancies
repaired as prescribed in part 43 of this chapter;
- (b) Shall ensure that maintenance
personnel make appropriate entries in the aircraft
maintenance records indicating the aircraft has been
approved for return to service;
- (c) Shall have any inoperative instrument
or item of equipment, permitted to be inoperative by Sec.
91.213(d)(2) of this part, repaired, replaced, removed,
or inspected at the next required inspection; and
- (d) When listed discrepancies include
inoperative instruments or equipment, shall ensure that a
placard has been installed as required by Sec. 43.11 of
this chapter.
-
- Sec. 91.407 Operation after maintenance,
preventive maintenance, rebuiding,
- or alteration.
- (a) No person may operate any aircraft
that has undergone maintenance, preventive maintenance,
rebuilding, or alteration unless
- (1) It has been approved for return to
service by a person authorized under Sec. 43.7 of this
chapter; and
- (2) The maintenance record entry required
by Sec. 43.9 or Sec. 43.11, as applicable, of this
chapter has been made.
- (b) No person may carry any person (other
than crewmembers) in an aircraft that has been
maintained, rebuilt, or altered in a manner that may have
appreciably changed its flight characteristics or
substantially affected its operation in flight until an
appropriately rated pilot with at least a private pilot
certificate flies the aircraft, makes an operational
check of the maintenance performed or alteration made,
and logs the flight in the aircraft records.
- (c) The aircraft does not have to be flown
as required by paragraph (b) of this section if, prior to
flight, ground tests, inspection, or both show
conclusively that the maintenance, preventive
maintenance, rebuilding, or alteration has not
appreciably changed the flight characteristics or
substantially affected the flight operation of the
aircraft.
-
- Sec. 91.409 Inspections. Airworthiness
- (a) Except as provided in paragraph © of
this section, no person may operate an aircraft unless,
within the preceding 12 calendar months, it has had
- (1) An annual inspection in accordance
with part 43 of this chapter and has been approved for
return to service by a person authorized by Sec. 43.7 of
this chapter; or
- (2) An inspection for the issuance of an
airworthiness certificate in accordance with part 21 of
this chapter.
- No inspection performed under paragraph
(b) of this section may be substituted for any inspection
required by this paragraph unless it is performed by a
person authorized to perform annual inspections and is
entered as an "annual" inspection in the
required maintenance records.
- (b) Except as provided in paragraph © of
this section, no person may operate an aircraft carrying
any person (other than a crewmember) for hire, and no
person may give flight instruction for hire in an
aircraft which that person provides, unless within the
preceding 100 hours of time in service the aircraft has
received an annual or 100-hour inspection and been
approved for return to service in accordance with part 43
of this chapter or has received an inspection for the
issuance of an airworthiness certificate in accordance
with part 21 of this chapter. The 100-hour limitation may
be exceeded by not more than 10 hours while en route to
reach a place where the inspection can be done. The
excess time used to reach a place where the inspection
can be done must be included in computing the next 100
hours of time in service.
- (c) Paragraphs (a) and (b) of this section
do not apply to
- (1) An aircraft that carries a special
flight permit, a current experimental certificate, or a
provisional airworthiness certificate;
- (2) An aircraft inspected in accordance
with an approved aircraft inspection program under part
125, 127, or 135 of this chapter and so identified by the
registration number in the operations specifications of
the certificate holder having the approved inspection
program;
- (3) An aircraft subject to the
requirements of paragraph (d) or (e) of this section; or
- (4) Turbine-powered rotorcraft when the
operator elects to inspect that rotorcraft in accordance
with paragraph (e) of this section.
- (d) Progressive inspection. Each
registered owner or operator of an aircraft desiring to
use a progressive inspection program must submit a
written request to the FAA Flight Standards district
office having jurisdiction over the area in which the
applicant is located, and shall provide
- (1) A certificated mechanic holding an
inspection authorization, a certificated airframe repair
station, or the manufacturer of the aircraft to supervise
or conduct the progressive inspection;
- (2) A current inspection procedures manual
available and readily understandable to pilot and
maintenance personnel containing, in detail
- (i) An explanation of the progressive
inspection, including the continuity of inspection
responsibility, the making of reports, and the keeping of
records and technical reference material;
- (ii) An inspection schedule, specifying
the intervals in hours or days when routine and detailed
inspections will be performed and including instructions
for exceeding an inspection interval by not more than 10
hours while en route and for changing an inspection
interval because of service experience;
- (iii) Sample routine and detailed
inspection forms and instructions for their use; and
- (iv) Sample reports and records and
instructions for their use;
- (3) Enough housing and equipment for
necessary disassembly and proper inspection of the
aircraft; and
- (4) Appropriate current technical
information for the aircraft.
- The frequency and detail of the
progressive inspection shall provide for the complete
inspection of the aircraft within each 12 calendar months
and be consistent with the manufacturers
recommendations, field service experience, and the kind
of operation in which the aircraft is engaged. The
progressive inspection schedule must ensure that the
aircraft, at all times, will be airworthy and will
conform to all applicable FAA aircraft specifications,
type certificate data sheets, airworthiness directives,
and other approved data. If the progressive inspection is
discontinued, the owner or operator shall immediately
notify the local FAA Flight Standards district office, in
writing, of the discontinuance. After the discontinuance,
the first annual inspection under Sec. 91.409(a)(1) is
due within 12 calendar months after the last complete
inspection of the aircraft under the progressive
inspection. The 100-hour inspection under Sec. 91.409(b)
is due within 100 hours after that complete inspection. A
complete inspection of the aircraft, for the purpose of
determining when the annual and 100-hour inspections are
due, requires a detailed inspection of the aircraft and
all its components in accordance with the progressive
inspection. A routine inspection of the aircraft and a
detailed inspection of several components is not
considered to be a complete inspection.
- (e) Large airplanes (to which part 125 is
not applicable), turbojet multiengine airplanes,
turbopropeller-powered multiengine airplanes, and
turbine-powered rotorcraft. No person may operate a large
airplane, turbojet multiengine airplane,
turbopropeller-powered multiengine airplane, or
turbine-powered rotorcraft unless the replacement times
for life-limited parts specified in the aircraft
specifications, type data sheets, or other documents
approved by the Administrator are complied with and the
airplane or turbine-powered rotorcraft, including the
airframe, engines, propellers, rotors, appliances,
survival equipment, and emergency equipment, is inspected
in accordance with an inspection program selected under
the provisions of paragraph (f) of this section, except
that, the owner or operator of a turbine-powered
rotorcraft may elect to use the inspection provisions of
Sec. 91.409(a), (b), ©, or (d) in lieu of an inspection
option of Sec.
- 91.409(f).
- (f) Selection of inspection program under
paragraph (e) of this section.
- The registered owner or operator of each
airplane or turbine-powered rotorcraft described in
paragraph (e) of this section must select, identify in
the aircraft maintenance records, and use one of the
following programs for the inspection of the aircraft:
- (1) A continuous airworthiness inspection
program that is part of a continuous airworthiness
maintenance program currently in use by a person holding
an air carrier operating certificate or an operating
certificate issued under part 121, 127, or 135 of this
chapter and operating that make and model aircraft under
part 121 of this chapter or operating that make and model
under part 135 of this chapter and maintaining it under
Sec. 135.411(a)(2) of this chapter.
- (2) An approved aircraft inspection
program approved under Sec. 135.419 of this chapter and
currently in use by a person holding an operating
certificate issued under part 135 of this chapter.
- (3) A current inspection program
recommended by the manufacturer.
- (4) Any other inspection program
established by the registered owner or operator of that
airplane or turbine-powered rotorcraft and approved by
the Administrator under paragraph (g) of this section.
However, the Administrator may require revision of this
inspection program in accordance with the provisions of
Sec. 91.415.
- Each operator shall include in the
selected program the name and address of the person
responsible for scheduling the inspections required by
the program and make a copy of that program available to
the person performing inspections on the aircraft and,
upon request, to the Administrator.
- (g) Inspection program approved under
paragraph (e) of this section. Each operator of an
airplane or turbine-powered rotorcraft desiring to
establish or change an approved inspection program under
paragraph (f)(4) of this section must submit the program
for approval to the local FAA Flight Standards district
office having jurisdiction over the area in which the
aircraft is based. The program must be in writing and
include at least the following information:
- (1) Instructions and procedures for the
conduct of inspections for the particular make and model
airplane or turbine-powered rotorcraft, including
necessary tests and checks. The instructions and
procedures must set forth in detail the parts and areas
of the airframe, engines, propellers, rotors, and
appliances, including survival and emergency equipment
required to be inspected.
- (2) A schedule for performing the
inspections that must be performed under the program
expressed in terms of the time in service, calendar time,
number of system operations, or any combination of these.
- (h) Changes from one inspection program to
another. When an operator changes from one inspection
program under paragraph (f) of this section to another,
the time in service, calendar times, or cycles of
operation accumulated under the previous program must be
applied in determining inspection due times under the new
program.
-
- Sec. 91.411 Altimeter system and altitude reporting
equipment tests and inspections. Airworthiness
- (a) No person may operate an airplane, or
helicopter, in controlled airspace under IFR unless
- (1) Within the preceding 24 calendar
months, each static pressure system, each altimeter
instrument, and each automatic pressure altitude
reporting system has been tested and inspected and found
to comply with appendix E of part 43 of this chapter;
- (2) Except for the use of system drain and
alternate static pressure valves, following any opening
and closing of the static pressure system, that system
has been tested and inspected and found to comply with
paragraph (a), appendices E and F, of part 43 of this
chapter; and
- (3) Following installation or maintenance
on the automatic pressure altitude reporting system of
the ATC transponder where data correspondence error could
be introduced, the integrated system has been tested,
inspected, and found to comply with paragraph ©,
appendix E, of part 43 of this chapter.
- (b) The tests required by paragraph (a) of
this section must be conducted by
- (1) The manufacturer of the airplane, or
helicopter, on which the tests and inspections are to be
performed;
- (2) A certificated repair station properly
equipped to perform those functions and holding
- (i) An instrument rating, Class I;
- (ii) A limited instrument rating
appropriate to the make and model of appliance to be
tested;
- (iii) A limited rating appropriate to the
test to be performed;
- (iv) An airframe rating appropriate to the
airplane, or helicopter, to be tested; or
- (v) A limited rating for a manufacturer
issued for the appliance in accordance with Sec.
145.101(b)(4) of this chapter; or
- (3) A certificated mechanic with an
airframe rating (static pressure system tests and
inspections only).
- (c) Altimeter and altitude reporting
equipment approved under Technical
- Standard Orders are considered to be
tested and inspected as of the date of their manufacture.
- (d) No person may operate an airplane, or
helicopter, in controlled airspace under IFR at an
altitude above the maximum altitude at which all
altimeters and the automatic altitude reporting system of
that airplane, or helicopter, have been tested.
-
- Sec. 91.413 ATC transponder tests and inspections. Airworthiness
- (a) No persons may use an ATC transponder
that is specified in 91.215(a),
- 121.345©, 127.123(b), or Sec. 135.143©
of this chapter unless, within the
- preceding 24 calendar months, the ATC
transponder has been tested and
- inspected and found to comply with
appendix F of part 43 of this chapter; and
- (b) Following any installation or
maintenance on an ATC transponder where data
correspondence error could be introduced, the integrated
system has been tested, inspected, and found to comply
with paragraph ©, appendix E, of part 43 of this
chapter.
- (c) The tests and inspections specified in
this section must be conducted by
- (1) A certificated repair station properly
equipped to perform those functions and holding
- (i) A radio rating, Class III;
- (ii) A limited radio rating appropriate to
the make and model transponder to be tested;
- (iii) A limited rating appropriate to the
test to be performed;
- (iv) A limited rating for a manufacturer
issued for the transponder in accordance with Sec.
145.101(b)(4) of this chapter; or
- (2) A holder of a continuous airworthiness
maintenance program as provided in part 121, 127 or Sec.
135.411(a)(2) of this chapter; or
- (3) The manufacturer of the aircraft on
which the transponder to be tested is installed, if the
transponder was installed by that manufacturer.
-
- Sec. 91.415 Changes to aircraft inspection
programs.
- (a) Whenever the Administrator finds that
revisions to an approved aircraft inspection program
under Sec. 91.409(f)(4) are necessary for the continued
adequacy of the program, the owner or operator shall,
after notification by the Administrator, make any changes
in the program found to be necessary by the
Administrator.
- (b) The owner or operator may petition the
Administrator to reconsider the notice to make any
changes in a program in accordance with paragraph (a) of
this section.
- (c) The petition must be filed with the
FAA Flight Standards district office which requested the
change to the program within 30 days after the
certificate holder receives the notice.
- (d) Except in the case of an emergency
requiring immediate action in the interest of safety, the
filing of the petition stays the notice pending a
decision by the Administrator.
-
- Sec. 91.417 Maintenance
records.Airworthiness
- (a) Except for work performed in
accordance with Secs. 91.411 and 91.413, each registered
owner or operator shall keep the following records for
the periods specified in paragraph (b) of this section:
- (1) Records of the maintenance, preventive
maintenance, and alteration and records of the 100-hour,
annual, progressive, and other required or approved
inspections, as appropriate, for each aircraft (including
the airframe) and each engine, propeller, rotor, and
appliance of an aircraft. The records must include
- (i) A description (or reference to data
acceptable to the Administrator) of the work performed;
and
- (ii) The date of completion of the work
performed; and
- (iii) The signature, and certificate
number of the person approving the aircraft for return to
service.
- (2) Records containing the following
information:
- (i) The total time in service of the
airframe, each engine, each propeller, and each rotor.
- (ii) The current status of life-limited
parts of each airframe, engine, propeller, rotor, and
appliance.
- (iii) The time since last overhaul of all
items installed on the aircraft which are required to be
overhauled on a specified time basis.
- (iv) The current inspection status of the
aircraft, including the time since the last inspection
required by the inspection program under which the
aircraft and its appliances are maintained.
- (v) The current status of applicable
airworthiness directives (AD) including, for each, the
method of compliance, the AD number, and revision date.
If the AD involves recurring action, the time and date
when the next action is required.
- (vi) Copies of the forms prescribed by
Sec. 43.9(a) of this chapter for each major alteration to
the airframe and currently installed engines, rotors,
propellers, and appliances.
- (b) The owner or operator shall retain the
following records for the periods prescribed:
- (1) The records specified in paragraph
(a)(1) of this section shall be retained until the work
is repeated or superseded by other work or for 1 year
after the work is performed.
- (2) The records specified in paragraph
(a)(2) of this section shall be retained and transferred
with the aircraft at the time the aircraft is sold.
- (3) A list of defects furnished to a
registered owner or operator under
- Sec. 43.11 of this chapter shall be
retained until the defects are repaired and the aircraft
is approved for return to service.
- (c) The owner or operator shall make all
maintenance records required to be kept by this section
available for inspection by the Administrator or any
authorized representative of the National Transportation
Safety Board (NTSB). In addition, the owner or operator
shall present Form 337 described in paragraph (d) of this
section for inspection upon request of any law
enforcement officer.
- (d) When a fuel tank is installed within
the passenger compartment or a baggage compartment
pursuant to part 43 of this chapter, a copy of FAA Form
337 shall be kept on board the modified aircraft by the
owner or operator.
-
- Sec. 91.419 Transfer of maintenance
records.
- Any owner or operator who sells a
U.S.-registered aircraft shall transfer to the purchaser,
at the time of sale, the following records of that
aircraft, in plain language form or in coded form at the
election of the purchaser, if the coded form provides for
the preservation and retrieval of information in a manner
acceptable to the Administrator:
- (a) The records specified in Sec.
91.417(a)(2).
- (b) The records specified in Sec.
91.417(a)(1) which are not included in the records
covered by paragraph (a) of this section, except that the
purchaser may permit the seller to keep physical custody
of such records. However, custody of records by the
seller does not relieve the purchaser of the
responsibility under Sec. 91.417© to make the records
available for inspection by the Administrator or any
authorized representative of the National Transportation
Safety Board (NTSB).
-
- Sec. 91.421 Rebuilt engine maintenance
records.
- (a) The owner or operator may use a new
maintenance record, without previous operating history,
for an aircraft engine rebuilt by the manufacturer or by
an agency approved by the manufacturer.
- (b) Each manufacturer or agency that
grants zero time to an engine rebuilt by it shall enter
in the new record
- (1) A signed statement of the date the
engine was rebuilt;
- (2) Each change made as required by
airworthiness directives; and
- (3) Each change made in compliance with
manufacturers service bulletins, if the entry is
specifically requested in that bulletin.
- (c) For the purposes of this section, a
rebuilt engine is a used engine that has been completely
disassembled, inspected, repaired as necessary,
reassembled, tested, and approved in the same manner and
to the same tolerances and limits as a new engine with
either new or used parts. However, all parts used in it
must conform to the production drawing tolerances and
limits for new parts or be of approved oversized or
undersized dimensions for a new engine.
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