§ 4b.18-4 Approval of products under the type certificate or modification procedures (FAA policies which apply to § 4b.18(b)).

A material, part, process, or appliance (hereinafter called "product") may be approved as a part of the airplane type design under a type certificate or a supplemental type certificate in accordance with the procedures provided in this section.

EXPLANATORY NOTE: Products previously approved by the FAA by means of letters of approval, Repair and Alteration Form ACA-337, or listing on FAA Product and Process Specifications will continue to be eligible for installation in a'craft unless the eligibility is restricted by applicable regulations or airworthiness directives issued under § 1.24 of this subchapter.

(a) Policies controlling where there is an applicable Technical Standard Order. If a Technical Standard Order covering the product is in effect, the applicant for approval should submit type design data showing that the product meets the performance standards of the Technical Standard Order. Deviations from such performance standards may be allowed to the extent that the applicant for the type certificate or the supplemental type certificate substantiates that certain provisions of the Technical Standard Order are not required for the product as installed in the airplane.

(b) Policies controlling in the absence of an applicable Standard Technical Order. Where no TSO covering the product exists, the applicant for approval should submit type design data showing compliance with all the requirements of this part which are applicable to the product. Any deviation from standards prescribed in this part may be allowed only in accordance with § 4b.10.

(c) Methods of identifying products approved under this section. (1) Products approved as a part of the airplane type design under a type certificate should be identified by an airplane part number on the approved drawing list.

(2) Products approved as a part of the airplane type design under a supplemental type certificate should be identified by a part or drawing number on such certificate.

(3) Each TSO product that is approved as a part of the airplane should have the TSO identification removed and be identified as set forth in subparagraph

(a) Compliance with the requirements prescribed in this subpart shall be established by flight or other tests conducted upon an airplane of the type for which a certificate of airworthiness is sought or by calculations based on such tests, provided that the results obtained by calculations are equivalent in accuracy to the results of direct testing.

(b) Compliance with each requirement shall be established at all appropriate combinations of airplane weight and center of gravity position within the range of loading conditions for which certification is sought by systematic investigation of all these combinations, except where compliance can be inferred reasonably from those combinations which are investigated.

(c) The controllability, stability, trim, and stalling characteristics of the airplane shall be established at all altitudes up to the maximum anticipated operating altitude.

(d) The applicant shall provide a person holding an appropriate pilot certificate to make the flight tests, but a designated representative of the Administrator shall pilot the airplane when it is found necessary for the determination of compliance with the airworthiness requirements.

(e) Official type tests shall be discontinued until corrective measures have been taken by the applicant when either:

(1) The applicant's test pilot is unable or unwilling to conduct any of the required flight tests, or

(2) It is found that requirements which have not been met are so substantial as to render additional test data meaningless or are of such a nature as to make further testing unduly hazardous.

(f) Adequate provision shall be made for emergency egress and for the use of parachutes by members of the crew during the flight tests.

(g) The applicant shall submit to the Administrator's representative a report covering all computations and tests required in connection with calibration of instruments used for test purposes and correction of test results to standard atmospheric conditions. The Administrator's representative shall conduct any flight tests which he finds necessary to check the calibration and correction report.

§ 4b.100-1

Procedure for demonstrating compliance with the flight requirements (FAA policies which apply to § 4b.100(a)).

(a) Responsibility. The burden of showing or implementing compliance with the requirements for an airworthiness or a type certificate rests with the applicant. The applicant should at his own expense and risk, conduct such official flight tests as determined by the FAA to demonstrate compliance with the minimum requirements. During the type inspection the applicant should make available the airplane for that purpose as well as all of the personnel and equipment necessary to obtain the required data.

(b) Tolerances permitted for flight tests (1) General. The tolerances in (b) (2) of this section are the allowable deviation from specified flight conditions for a particular test. They are not allowable tolerances on specific requirements, nor are they to be considered as

Item:

Weight..

Critical items affected by weight__ C. G

Air speed..

Power---.

allowable inaccuracy of measurement or of the method of determination. As an example, when demonstrating stability with specified trim speed of 1.4 V1, the trim speed may be 1.4 Vs,±3 mph or 3 percent; however, no positive tolerance is permitted when demonstrating the minimum prescribed trim speed of 1.4 V31.

(i) Where the variation in the parameter on which a tolerance is allowed will have an appreciable effect on the test, the results should be corrected to the standard value of the parameter; otherwise, no correction is necessary. The applicant may adhere to closer tolerances if he so desires.

(ii) The following list indicates the cases in which correction for tolerances should be made:

(c) Type Inspection Report. (1) All information and data obtained as a result of the type inspection investigation and tests should be reported in Form ACA 283-4b, Type Inspection Report.

(2) Upon completion of the type inspection, the applicant should prepare

1

12 percent Vs, or 12 m. p. h., whichever is lower, along the runway-measured at a height of 6 feet above the runway surface.

the information necessary to show compliance with the requirements. This material together with the Airplane Flight Manual required by § 4b.740 should be completed as promptly as possible and forwarded to the FAA.

[Supp. 24, 19 F. R. 4448, July 20, 1954]

§ 4b.100-2 Selection of weight, altitudes, speeds and wing flap positions (FAA policies which apply to § 4b.100(b)).

Before starting official flight tests, certain data should be obtained by the applicant in order that the options prescribed in paragraphs (a) through (e) of this section can be executed.

(a) The selection of the range of weight and altitude to be covered by the flight testing required for certification. This selection should be based upon the extent to which the applicant for certification is concerned with the operating limitations which will be imposed upon the airplane. If the applicant is not concerned with this point, he may elect to conduct only the flight tests required to demonstrate compliance with the minimum performance requirements contained in § 4b.110 together with those required to demonstrate compliance with the flying qualities and other requirements specified in §§ 4b.130 through 4b.190. If it is practicable to limit the operation of the airplane by a scheduled air carrier to sea level airports containing runways of ample length and to terrain altitude not in excess of 4,000 feet, this procedure appears satisfactory. It should be noted that this case could apply to a seaplane in scheduled operation. If the applicant wishes to provide for the greatest possible flexibility in the matter of compliance with the operating limitations contained in § 40.70 of this subchapter, considerably more performance tests will be necessary. It may be entirely practicable, for example, for operation over routes involving appreciable differences in the altitude of airports, to take advantage of the improvement in performance which is possible by means of reducing the weight at which the airplane is operated. It may also be desirable to alter the various flap settings in order to improve the climbing performance at a given weight. In cases such as these, it will be necessary to determine by flight testing and calculation, the effect of weight, altitude, and flap setting, throughout the range of each for which it is desired to provide, upon the take-off, landing, and climbing performance and to include this information in the FAA Approved Airplane Flight Manual. This selection will be left to the applicant since, even though he may find it difficult to anticipate the uses to which the airplane may subsequently be put, he is nevertheless in

better position to forecast this than anyone else.

(b) The selection of the weight range to be covered by the terms of the certification. This selection is closely related to paragraph (a) of this section and should be based upon essentially the same considerations. The simplest possible selection of weights is a single maximum weight to be used both for take-off and landing and as a basis for the operating limitations. The next simplest choice would appear to be a maximum take-off weight and a maximum landing weight differing from take-off weight. This choice requires the installation of fuel jettisoning equipment (when the take-off weight exceeds the landing weight by more than 5 percent) of sufficient capacity to reduce the weight of the airplane from the maximum takeoff weight to the maximum landing weight in compliance with § 4b.437. The operating limitations may then be based upon the assumption that these two weights exist throughout each flight. The most flexible possible arrangement in the matter of weights is provided by selecting a range of weights for take-off and a range for landing, and determining the performance as functions of these weights so that, in showing compliance with the operating limitations, any weight within these ranges may be selected to fit the requirements of a particular route. This selection should be left with the applicant.

(c) The selection of the range of altitude to be covered by the terms of the certification. This selection is also closely related to paragraph (a) of this section and is analogous in its nature to paragraph (b) of this section. The simplest possible selection is that indicated by the minimum performance requirements contained in § 4b.110, namely, sea level for the purposes of the determination of the take-off and landing distances and certain of the rates of climb at 5,000 feet for the purpose of determining the en route rates of climb. The selection providing the greatest possible flexibility is the one in which these items of performance are determined for a range of altitude great enough to cover all anticipated routes over which the airplane may be operated.

(d) The selection of the wing flap positions desired for certification. Policies outlined in § 4b.111-1 will apply to this selection.

(e) The selection of the critical speed' to be used in the determination of the take-off distance. Policies outlined in § 4b.113-2 will apply to this selection. [Supp. 24, 19 F. R. 4449, July 20, 1954] § 4b.100-3 Flying qualities (FAA policies which apply to § 4b.100(c)).

(a) It should be possible to operate the airplane safely at all anticipated altitudes without requiring exceptional attention and skill by the pilot or appropriate crew members.

(b) If there is less than two mph difference in the forward and rearward C. G. stalling speeds, all flying qualities may be based upon the forward C. G. stalling speeds. Otherwise, the stalling speed appropriate to the C. G. position should be used.

(c) If there is reason to believe that any of the flying qualities would be affected by altitude, they should be investigated for the most adverse altitude condition expected in normal operation. [Supp. 24, 19 F. R. 4449, July 20, 1954] § 4b.101

Weight limitations.

The maximum and minimum weights at which the airplane will be suitable for operation shall be established as follows:

(a) Maximum weights shall not exceed any of the following:

(1) The weight selected by the applicant;

(2) The design weight for which the structure has been proven;

(3) The maximum weight at which compliance with all of the applicable flight requirements has been demonstrated.

(b) It shall be acceptable to establish maximum weights for each altitude and for each practicably separable operating condition (e. g., take-off, en route, landing).

(c) Minimum weights shall not be less than any of the following:

(1) The minimum weight selected by the applicant;

(2) The design minimum weight for which the structure has been proven;

The practical effect of the selection of this speed is that it permits the applicant to define in the type certificate the limits of airplane weight and airport altitude within which the airplane may be operated by a scheduled air carrier in compliance with Part 40 of this subchapter.

(3) The minimum weight at which compliance with all of the applicable flight requirements has been demonstrated.

§ 4b.102

Center of gravity limitations.

Center of gravity limits shall be established as the most forward position permissible and the most aft position permissible for each practicably separable operating condition in accordance with § 4b.101 (b). Limits of the center of gravity range shall not exceed any of the following:

(a) The extremes selected by the applicant;

(b) The extremes for which the structure has been proven;

(c) The extremes at which compliance with all of the applicable flight requirements has been demonstrated. [15 F. R. 3543, June 8, 1950, as amended by Amdt. 4b-6, 17 F. R. 1088, Feb. 5, 1952] § 4b.103

Additional limitations

weight distribution.

on

If a weight and center of gravity combination is permissible only within certain load distribution limits (e.g., spanwise) which could be exceeded inadvertently, such limits shall be established together with the corresponding weight and center of gravity combinations, and shall not exceed any of the following:

(a) The limits selected by the applicant;

(b) The limits for which the structure has been proven;

(c) The limits for which compliance with all the applicable flight requirements has been demonstrated.

§ 4b.104 Empty weight.

(a) The empty weight and the corresponding center of gravity position shall be determined by weighing the airplane. This weight shall exclude the weight of the crew and payload, but shall include the weight of all fixed ballast, unusable fuel supply (see § 4b.416), undrainable oil, and total quantity of hydraulic fluid.

(b) The condition of the airplane at the time of weighing shall be one which can be easily repeated and easily defined, particularly as regards the contents of the fuel and oil tanks and the items of equipment installed.

[15 F. R. 3543, June 8, 1950, as amended by Amdt. 4b-3, 21 F. R. 990, Feb. 11, 1956]

It shall be acceptable to use removable ballast to enable the airplane to comply with the flight requirements. (See §§ 4b.738 and 4b.741(c).)

§ 4b.105-1 Use of ballast during flight tests (FAA policies which apply to § 4b.105).

Ballast should be carried during the flight tests whenever it is necessary to simulate pay load. Consideration should be given to the vertical as well as horizontal location of the ballast in cases where it may have an appreciable effect on the performance or flying qualities of the airplane. The strength of the supporting structures should be adequate to preclude their failure as a result of the flight loads that may be imposed during the tests.

Supp. 24, 19 F. R. 4449, July 20, 1954]

(a) With respect to all airplanes type certificated on or after February 12, 1951, the performance prescribed in this subpart shall be determined, and compliance shall be shown, for standard atmospheric conditions and still air, except that the performance as affected by engine power, instead of being based on dry air, shall be based on 80 percent relative humidity.

(b) Each set of performance data required for a particular flight condition shall be determined with the powerplant accessories absorbing the normal amount of power appropriate to that flight condition. (See also § 4b.117.)

[Amdt. 4b-3, 16 F. R. 314, Jan. 12, 1951, as amended by Amdt. 4b-6, 17 F. R. 1089, Feb. 5, 1952]

§ 4b.110-1 Engine power corrections

(FAA policies which apply to § 4b.110).

(a) Engine power corrections for vapor pressure. The following standard vapor pressures, specific humidities, and densities versus altitude have been established for the purpose of correcting airplane performance data in accordance with § 4b.110.

(b) Engine power corrections for cylinder head temperatures. Official flight tests should be discontinued whenever engine limitations are exceeded. This procedure automatically makes corrections of this type unnecessary.

(c) Engine power corrections for fuel flow. Official flight tests should not be conducted when the metering characteristics of the carburetor are outside the range of acceptable tolerances. This procedure automatically makes corrections for fuel-air mixture ratio in performance evaluation unnecessary.

[Supp. 23, 19 F.R. 1817, Apr. 2, 1954, as amended by Supp. 39, 23 F.R. 7482, Sept. 26, 1958]

§ 4b.110-2 Engine power calibration (FAA policies which apply § 4b.110).

to

The performance of an airplane established in accordance with the requirements of §§ 4b.110 through 4b.125 and shown in the performance section of the Airplane Flight Manual should be reproducible by any airplane of a similar model having engines that deliver no more than 100 percent certificated rated power. This means that the power used to drive all accessories, other than those necessary to the functioning of the engine, should be deducted from the certificated rated or installed engine power, whichever is less. To assist in meeting these objectives, the engine power of all new type airplanes as defined by § 4b.11 (e) should be calibrated in accordance with paragraphs (a) through (c) of this section.

(a) Corrections to the calibrated power for engines producing power above the certificated ratings. (1) The