Sec.

13.259 Engine-propeller systems tests. 13.260 Thrust reversers.

AUTHORITY: §§ 13.0 to 13.260 issued under sec. 205, 52 Stat. 984, as amended; 49 U. S. C. 425. Interpret or apply secs. 601, 603, 52 Stat. 1007, as amended, 1009, as amended; 49 U.S. C. 551, 553.

AUTHORITY NOTE: Additional citation of authority to Part 13 was appended by Amendment 13-3, 24 F.R. 7077, Sept. 1, 1959, as follows: "(Secs. 313(a), 601, 603, 72 Stat. 752, 775, 776; 49 U.S.C. 1354 (a), 1421, 1423)"

SOURCE: 13.0 to 13.260 appear at 21 F.R. 4305, June 20, 1956, as amended at 24 F.R. 5, Jan. 1, 1959, except as otherwise noted.

Subpart A-General

APPLICABILITY AND DEFINITIONS

§ 13.0 Applicability of this part.

This part establishes standards with which compliance shall be demonstrated for the issuance of and changes to type certificates for engines used on aircraft. This part, until superseded or rescinded, shall apply to all engines for which applications for type certification are made after the effective date of this part (August 20, 1938).

As used in this part terms are defined as follows:

(a) Administration—(1) Administrator. The Administrator is the Administrator of the Federal Aviation Agency.

(2) Applicant. An applicant is a person or persons applying for approval of an engine or any part thereof.

(3) Approved. Approved, when used alone or as modifying terms such as means, devices, specifications, etc., shall mean approved by the Administrator. (See 13.18.)

(b) General design-(1) Standard atmosphere. The standard atmosphere is an atmosphere (see NACA Technical Note 3182) defined as follows:

(i) The air is a dry, perfect gas,

(ii) The temperature at sea level is 59° F.,

(iii) The pressure at sea level is 29.92 inches Hg,

(iv) The temperature gradient from sea level to the altitude at which the temperature equals -69.7° F. is -0.003566° F./ft. and zero thereabove.

(v) The density po at sea level under the above conditions is 0.002377 lbs. sec.'/ft.'

(2) Brake horsepower. Brake horsepower is the power delivered at the propeller shaft of the engine.

(3) Take-off power or thrust. (i) Take-off power for reciprocating engines is the brake horsepower developed under standard sea level conditions, under the maximum conditions of crankshaft rotational speed and engine manifold pressure approved for the normal take-off, and limited in use to a maximum continuous period as indicated in the approved engine specification.

(ii) Take-off power for turbine engines is the brake horsepower developed under static conditions at specified altitudes and atmospheric temperatures and under the maximum conditions of rotor shaft rotational speed and gas temperature approved for the normal take-off, and limited in use to a maximum continuous period as indicated in the approved engine specification.

(iii) Take-off thrust for turbine engines is the jet thrust developed under static conditions at specified altitudes and atmospheric temperatures and under the maximum conditions of rotor shaft rotational speed and gas temperature approved for the normal take-off, and limited in use to a maximum continuous period as indicated in the approved engine specification.

(4) Maximum continuous power or thrust. (i) Maximum continuous power for reciprocating engines is the brake horsepower developed in standard atmosphere at a specified altitude and under the maximum conditions of crankshaft rotational speed and engine manifold pressure, and approved for use during periods of unrestricted duration.

(ii) Maximum continuous power for turbine engines is the brake horsepower developed at specified altitudes, atmospheric temperatures, and flight speeds and under the maximum conditions of rotor shaft rotational speed and gas temperature, and approved for use during periods of unrestricted duration.

(iii) Maximum continuous thrust for turbine engines is the jet thrust developed at specified altitudes, atmospheric temperatures, and flight speeds and under the maximum conditions of rotor shaft rotational speed and gas temperature, and approved for use during periods of unrestricted duration.

(5) Gas temperature. Gas temperature for turbine engines is the tempera

ture of the gas stream obtained as indicated in the approved engine specification.

(6) Manifold pressure. Manifold pressure is the absolute pressure measured at the appropriate point in the induction system, usually in inches of mercury.

(7) Critical altitude.1 The critical altitude is the maximum altitude at which in standard atmosphere it is possible to maintain without ram, at a specified rotational speed, a specified power or a specified manifold pressure. Unless otherwise stated, the critical altitude is the maximum altitude at which it is possible to maintain, at the maximum continuous rotational speed, one of the following:

(i) The maximum continuous power, in the case of engines for which this power rating is the same at sea level and | at the rated altitude,

(ii) The maximum continuous rated manifold pressure, in the case of engines the maximum continuous power of which is governed by a constant manifold pres

sure.

[21 F.R. 4305, June 20, 1956, as amended, 22 F.R. 5569, July 16, 1957]

§ 13.10

CERTIFICATION

Eligibility for type certificates.

An engine shall be eligible for type certification under the provisions of this part if it complies with the airworthiness provisions hereinafter established or if the Administrator finds that the provision or provisions not complied with are compensated for by factors which provide an equivalent level of safety: Provided, That the Administrator finds no feature or characteristic of the engine which renders it unsafe for use on aircraft.

§ 13.11 Designation of applicable regulation.

The provisions of this section shall apply to all engine types certificated under this part irrespective of the date of application for type certificate.

(a) Unless otherwise established by the Administrator, the engine shall comply with the provisions of this part together with all amendments thereto effective on the date of application for

1 These definitions may not apply in the case of less conventional engines such as compound, variable discharge turbine, etc.

type certificate, except that compliance with later effective amendments may be elected or required pursuant to paragraphs (c) (d), and (e) of this section.

(b) If the interval between the date of application for type certificate and the issuance of the corresponding type certificate exceeds three years, a new application for type certificate shall be required, except that for applications pending on May 1, 1954, such three-year period shall commence on that date. At the option of the applicant, a new application may be filed prior to the expiration of the three-year period. In either instance the applicable regulations shall be those effective on the date of the new application in accordance with paragraph (a) of this section.

(c) During the interval between filing the application and the issuance of a type certificate, the applicant may elect to show compliance with any amendment of this part which becomes effective during that interval, in which case all other amendments found by the Administrator to be directly related shall be complied with.

(d) Except as otherwise provided by the Administrator, pursuant to § 1.24 of this subchapter, a change to the type certificate (see § 13.13(b)) may be accomplished, at the option of the holder of the type certificate, either in accordance with the regulations incorporated by reference in the type certificate pursuant to § 13.13(c), or in accordance with subsequent amendments to such regulations in effect on the date of application for approval of the change, subject to the following provisions:

(1) When the applicant elects to show compliance with an amendment to the regulations in effect on the date of application for approval of a change, he shall show compliance with all amendments which the Administrator finds are directly related to the particular amendment selected by the applicant.

(2) When the change consists of a new design or a substantially complete redesign of a major component of the engine, and the Administrator finds that the regulations incorporated by reference in the type certificate pursuant to § 13.13 (c) do not provide complete standards with respect to such change, he shall require compliance with such provisions of the regulations in effect on the date of application for approval of the change as he finds will provide a level

of safety equal to that established by the regulations incorporated by reference at the time of issuance of the type certificate.

(e) If changes listed in subparagraphs (1) and (2) of this paragraph are made, the engine shall be considered as a new type, in which case a new application for type certificate shall be required and the regulations together with all amendments thereto effective on the date of the new application shall be made applicable in accordance with paragraphs (a), (b), (c), and (d) of this section.

(1) A change in the principle of operation;

(2) A change in design, configuration, power limitations, or speed limitations, which the Administrator finds is so extensive as to require a substantially complete investigation of compliance with the regulations.

§ 13.12 Recording of applicable regulations.

The Administrator, upon the issuance of a type certificate, shall record the applicable regulations with which compliance was demonstrated. Thereafter, the Administrator shall record the applicable regulations for each change in the type certificate which is accomplished in accordance with regulations other than those recorded at the time of issuance of the type certificate. (See § 13.11.)

§ 13.13 Type certificate.

(a) An applicant shall be issued a type certificate when he demonstrates the eligibility of the engine by complying with the requirements of this part in addition to the applicable requirements in Part 1 of this subchapter."

(b) The type certificate shall be deemed to include the type design (see § 13.14 (b)), the operating limitations for the engine (see § 13.16), and any other conditions or limitations prescribed by the regulations in this subchapter.

(c) The applicable provisions of this part recorded by the Administrator in accordance with § 13.12 shall be considered as incorporated in the type certificate as though set forth in full.

2 Prior to approval for use of a type certifcated engine on a certificated aircraft, the engine will be required to comply with pertinent provisions of the applicable aircraft airworthiness parts of the regulations in this subchapter.

§ 13.14 Data required.

(a) The applicant for a type certificate shall submit to the Administrator such descriptive data, test reports, and computations as are necessary to demonstrate that the engine complies with the requirements of this part.

(b) The descriptive data required in paragraph (a) of this section shall be known as the type design and shall consist of such drawings and specifications as are necessary to disclose the configuration of the engine and all the design features covered in the requirements of this part, such information on dimensions, materials, and processes as is necessary to define the structural strength of the engine, and such other data as are necessary to permit by comparison the determination of the airworthiness of subsequent engines of the same type. § 13.15 Inspections and tests.

Inspections and tests shall include all those found necessary by the Administrator to insure that the engine complies with the applicable airworthiness requirements and conforms to the following:

(a) All materials and products are in accordance with the specifications in the type design,

(b) All parts of the engine are constructed in accordance with the drawings in the type design,

(c) All manufacturing processes, construction, and assembly are as specified in the type design.

§ 13.16 Required tests.

The block tests prescribed in this part shall be conducted to establish the engine operating limitations, as chosen by the applicant, and the reliability of the engine to operate within those limitations. The provisions of paragraphs (a) through (d) of this section shall be applicable.

(a) The applicant shall furnish all testing facilities, including equipment and competent personnel, to conduct the prescribed block tests.

(b) An authorized representative of the Administrator shall witness such of the block tests as are necessary to verify the test report.

(c) The Administrator shall establish engine operating limitations determined on the basis of the engine operating conditions demonstrated during the block

tests. Such operating limitations shall include those items relating to power, speeds, temperatures, pressures, fuels, and oils which he finds necessary for safe operation of the engine.

(d) It shall be permissible to use separate engines of identical design and construction in the vibration, calibration, detonation (if applicable), endurance, and operation tests prescribed in subparts B and C of this part, except that if a separate engine is used for the endurance test it shall be subjected to a calibration check before starting the endurance test.

§ 13.17 Production certificates.

(For requirements with regard to production certificates see Part 1 of this subchapter.)

§ 13.18 Approval of materials, parts, processes, and appliances.

(a) Materials, parts, processes, and appliances shall be approved upon a basis and in a manner found necessary by the Administrator to implement the pertinent provisions of the regulations in this subchapter. The Administrator may adopt and publish such specifications as he finds necessary to administer this regulation, and shall incorporate therein such portions of the aviation industry, Federal, and military specifications respecting such materials, parts, processes, and appliances as he finds appropriate.

NOTE: The provisions of this paragraph are intended to allow approval of materials, parts, processes, and appliances under the system of Technical Standard Orders, or in conjunction with type certification procedures for an engine, or by any other form of approval by the Administrator.

(b) Any material, part, process, or appliance shall be deemed to have met the requirements for approval when it meets the pertinent specifications adopted by the Administrator and the manufacturer so certifies in a manner prescribed by the Administrator.

§ 13.18-1 Approval of spark plugs for reciprocating engines (FAA policies which apply to § 13.18).

(a) General. Spark plugs are considered to be an integral part of an aircraft engine and therefore should be tested with the engine to determine that the spark plug-engine combination will operate and perform satisfactorily. Upon successful completion of the applicable tests specified in this section the spark

plugs will be aproved and listed on the pertinent Aircraft Engine Specification.1 This approval may be extended to other approved models of the same series of engines having equal or lower BMEP ratings or different series of engines of the same manufacture having similar combustion chamber characteristics and equal or lower BMEP ratings.

(1) Facilities for testing: The applicant requesting approval for the spark plug should provide the necessary facilities, equipment, personnel, etc., for conducting the tests. If the applicant does not possess such facilities, he may arrange for the tests to be conducted by qualified personnel at any appropriate agency which is available to undertake the work. Such agencies might include engine manufacturers, airlines, schools, universities, etc.

(b) Nomenclature. (1) Spark plugs of new design: Spark plugs of a type that has not been previously approved for use in any aircraft engine model.

(2) Spark plugs of an approved type: Spark plugs of a type that has been approved for use in one or more specific aircraft engine models.

(3) Spark plugs of a design similar to an approved type: Spark plugs of a given manufacturer which are similar to an approved type spark plug previously designed by that manufacturer. This classification does not include spark plugs of one manufacturer that may appear to be similar to approved spark plugs designed by another manufacturer.

(4) New engine models: Engines scheduled for, or undergoing type certification testing prior to approval.

(5) Active engines: Engines which are currently being produced under a Type and/or Production certificate.

(6) Obsolescent engines: Engines not in production; somewhat inactive in service, but the type certificates for which have not been canceled.

(7) Obsolete 150-hour engines: Engines certificated under 150-hour endurance test, but the type certificates for which have been canceled.

(8) Obsolete 50-hour engines: Engines certificated under 50-hour en

1 The aircraft engine specifications are contained in the Aircraft Engine Listing which may be obtained from the Federal Aviation Agency, Washington 25, D.C.

durance test, but the type certificates for which have been canceled.

(c) Tests'-(1) General. For engines with 6 cylinders or less, a full set of spark plugs of one type should be installed. For engines with 7 cylinders or more, either a full set of one type or two half-sets of different types of spark plugs may be installed. During the block or ground tests it should be determined that the spark plugs do not have an adverse effect in connection with the following:

Starting.
Acceleration.

Preignition.
Detonation.
Fouling.
Idling.

R. P. M. drop.

F/A ratio variations.

Distribution-F/A-leaded fuel.

T. O., M. C., cruising powers and speeds.
Gap erosion rate.

Mechanical breakdown.

Ease of installation in engine.

(2) Replacements. Normal replacement of spark plugs is permissible during any test, i. e., up to 20 percent of the spark plugs may be replaced during any test provided related engine conditions are satisfactory.

(3) Spark plug inspection. At the completion of all block tests and at the intervals specified in each of the flight service tests the spark plugs should be inspected for any unsatisfactory conditions such as mechanical breakdown, gap erosion rate, fouling, etc.

All

(d) Spark plugs for new engines. types of spark plugs proposed for use in new engines should be tested with the engine during the type certification tests.

(e) Spark plugs for active engines(1) Spark plugs of new design or of a type that has been approved for use with other engine models. Either of the procedures outlined below may be used to substantiate the airworthiness of spark plugs of these categories.

(i) Block test. This test should be conducted in accordance with the requirements of §§ 13.151 through 13.155.

(ii) Ground and flight service test. (a) A 50-hour engine block test should be conducted in accordance with the requirements of § 13.154. The total time

2 Table 1 provides a ready reference to spark plug testing requirements for various types of engines.