perature, vibration, etc. are covered by the simulated tests) when these may be critical, and to determine whether the installation and connected systems are satisfactory. The T. C. Board will then make a consolidated estimate of the total flight time required, allowing for overlapping, and adjust this in accordance with the "test time" section outlined in paragraph (e) of this section.

(3) The program will be arranged to permit the Aviation Safety Agent in e charge to become thoroughly familiar with the characteristics of the airplane, particularly those not specifically covered in the routine CAR tests.

(4) In accordance with paragraph (b) (1) of this section, all components of the airplane should be intensively' operated and studied under all operating conditions expected in service and obtainable within the time and geographic limitations of the tests. Particular attention I will be given to the emergency procedures which would be required in the event of malfunctioning of any component, source of crew error, and overtaxing of crew abilities. This intensive type of testing should be conducted in all cases, but the length of time for which it is continued will depend upon the simulated and supplementary experience available for the particular type, as outlined in "test time" under paragraph (e) of this section.

(5) Ground inspections should be made at appropriate intervals during the test program to determine whether there are any failures or incipient failures in any of the components which might be a hazard to safe flight.

(6) When design changes are made during the course of the test, or when the official test airplane differs from those on which supplementary experience is obtained, or from modified versions of the same basic airplane type, the revised or modified items should be

This does not imply that flight tests must be conducted under the most severe outside air temperatures likely to be encountered in service. It should normally be possible to determine the effects of extreme outside temperatures on local temperatures by extrapolation or by suitable correction factors.

5 Intensive operation means repeated operation of components in various sequences and combinations likely to occur in service.

rechecked in accordance with the above procedure, but every effort should be made to include such items in the program in such a way as to avoid unduly extending the over-all test time. Το this end, the Administrator may accept, in lieu of additional flight tests:

(i) Special tests of the original and revised components in which the conditions causing failure are intensified, and (ii) Simulated tests of differing components.

(e) Test time. It is highly desirable that functioning and reliability test programs be administered uniformly in the sense that the program and flight time for a given project would be approximately the same regardless of which T. C. Board administered the project. This is difficult to achieve without establishing fixed arbitrary test times. However, such fixed arbitrary times would obviously be contrary to the intent of the Regulations. The following procedure with regard to establishing the required test time which permits considerable flexibility is, therefore, established for the guidance of T. C. Boards.

(1) The times suggested in this paragraph apply when supplementary experience is not taken into account, and are for airplanes which are conventional in regard to complexity and design features. Those times may be reduced to allow for supplementary experience, as outlined in subparagraph (2) of this paragraph, and for simulated testing, as outlined in paragraph (d) (1) of this section. In extreme cases of complexity radically new design features, or difficulties in earlier flights, these times may be increased. Non-Transport (this part)-40 to 150 hours, depending on complexity.

(2) When satisfactory supplementary experience is available and taken into account, the following allowances should be used as a guide and applied with

An example of extreme complexity would be transport intended for operation at 40,000 feet altitude, with automatic dive recovery flaps, turbos, variable jet exhaust, two speed cooling fans, retractable wind screens, automatic control of engine cooling, turbos, intercoolers, jet exhaust, etc. The test program for such an airplane might require as much as 300 hours if no supplementary experience were available.

judgment in reducing the official flight test time determined in accordance with subparagraph (1) of this paragraph. However, in any case, the official program should provide sufficient time to accomplish the objective in paragraph (b) (1) of this section in accordance with paragraph (d) (3) and (4) of this section.

When

(i) For intensive experience. the allowance is based on the total time of any one airplane in airline crew training and similar intensive operations, two hours of such operation may be considered equivalent to one hour of official testing.

(ii) For miscellaneous experience. When the allowance is based on the total time of any one airplane, five hours of such experience may be considered equivalent to one hour of official testing.

(iii) Reduction for supplementary experience. Whenever a reduction of official test time is desired on the basis of supplementary experience, such experience must be adequately recorded and submitted to the T. C. Board, as described in paragraph (f) of this section.

(f) Reports and records. (1) A log should be kept of all flight tests, and accurate and complete records kept of the inspections made and of all defects, difficulties, and unusual characteristics and sources of crew error discovered during the tests, and of the recommendations made and action taken. Items for which design changes may be required will be reported to the manufacturer and the appropriate FAA engineering

division.

(2) If supplementary experience is to be taken into account, similar records of such experience should be kept and submitted to the T. C. Board, together with a list of the differences between the airplane on which the experience was obtained and the official test airplane. When supplementary experience is obtained on a large fleet of airplanes (for example, military operations) of the same or a comparable type (see item 5 under Test Program), these records may consist of statistical summaries in lieu of complete records for each individual airplane.

(3) At the conclusion of the official tests, a summary report should be prepared by the T. C. Board and forwarded

to Washington for inclusion in the Type Inspection Report.

(g) Administration. The FAA Aviation Safety Agent in charge should act as coordinator of all flight activities of the T. C. Board during the official program and the agent or an alternate designated by him will participate in all flights. He should collaborate with the manufacturers' pilots in all these activities, particularly in regard to flight plans and procedures. The manufacturers' pilot should be in command of all flights, but FAA pilots should fly the airplane at least sufficiently to accomplish paragraph (d) (3) of this section.

(1) Other FAA personnel (e.g., representatives of other Divisions and specialists) should participate in the flight tests when deemed necessary by the T. C. Board to accomplish the purposes of the tests.

(2) When supplementary experience is obtained in airline operations, an FAA Aviation Safety Agent should be assigned to follow the operations, review the operator's records, and supplement these by reports to the T. C. Board.

(h) Test airplane. Section 3.19 contains the phrase "If practicable, the flight tests * shall be conducted

on the same airplane. This phrase will be liberally interpreted to facilitate completion of the type certification procedure. Thus, one airplane may be used for the official functioning and reliability tests while another airplane (or airplanes) is used for the routine CAR tests. In this case the test time on at least one airplane must be sufficient to accomplish the objective of paragraph (b) (2) of this section.

(i) Modified types. The procedure outlined above applies to new type designs. When a design employs components identical to those used in previous designs, credit may be given for the supplementary experience available for such components. When a design is modified (for example, several versions of the same basic type with different engines, propellers, etc.) the modified features and components should be treated in accordance with paragraph (d) (6) of this section.

[Supp. 10, 16 F. R. 3279, Apr. 14, 1951, as amended by Supp. 14, 17 F. R. 9065, Oct. 11, 1952]

H

§3.17 Airworthiness, experimental, and production certificates.

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

§3.18 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 airplane, 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.

§3.18-2 Application of the Technical Standard Orders (TSO) System; C Series (FAA policies which apply to §3.18).

(a) Purpose of Technical Standard Orders. Technical Standard Orders are a means by which the Administrator adopts and publishes the specifications for which authority is provided in §3.18 (a).

(b) Applicability of Technical Standard Order requirements. (1) The applicability of and effective dates for TSO items are set forth in each TSO.

(2) Each Technical Standard Order sets forth the conditions under which materials, parts, processes, and appliances approved by the Administrator prior to establishment of an applicable TSO, may continue to be used in aircraft.

(3) The establishment of a Technical Standard Order for any product does not preclude the possibility of establishing the acceptability of a similar product as part of an aircraft, engine, or propeller, under the type certification or modification procedures, if there is established a level of safety equivalent to that provided in the regulations in this subchapter as implemented by the appropriate Technical Standard Order and the product is identified as part of the airplane, engine, or propeller.

(c) Administration of the Technical Standard Order (TSO) system. The principles which apply in administering the Technical Standard Order system are as follows:

(1) Technical Standard Orders will reference performance provisions of recognized government specifications, or established industry specifications which have been found acceptable by the FAA. If no satisfactory specification exists, the Orders will include criteria prepared by the Administrator. In preparing criteria of this type, the Administrator will give consideration to recommendations made by the industry.

(2) Minimum performance requirements established by the Civil Aeronautics Administration and published in Technical Standard Orders will serve as a means by which materials, parts, proc

esses, and appliances intended for use in certificated aircraft will be accepted.

(3) TSO's set forth the minimum requirements for safety. Every effort will be made by the FAA to keep the requirements at the minimum levels of safety and TSO's will not be used to set forth "desirable" standards.

(4) It will be the responsibility of the person submitting a statement of conformance to the FAA, certifying that his product meets the requirements of the TSO, to conduct the necessary tests demonstrating compliance therewith. This person will be held responsible for maintaining quality control adequate to assure that products which he guarantees to meet the requirements of a TSO do, in fact, meet these standards. The FAA will not formally approve such products as meeting the requirements of TSO's nor exercise direct inspection control over them. The statement of conformance with the provisions of a Technical Standard Order normally will be accepted by the FAA as sufficient indication that the applicable requirements have been fulfilled.

Any TSO item which is modified must continue to comply with the requirements of the TSO; and the person authorizing the modification will be responsible for such compliance.

(d) Numbering of Technical Standard Orders. Each Technical Standard Order will be assigned a designation consisting of the letters "TSO," a series code letter "C" indicating aircraft materials, parts, processes, and appliances, and a serial number to be assigned in sequence for each of the TSO's issued in the "C" series, e. g., TSO-C-1, "Smoke Detectors." Revisions are indicated by the addition of letters a, b, c, etc., after the number.

[Supp. 14, 17 F. R. 9065, Oct. 11, 1952] §3.18-3

Manufacturer (FAA interpretation which applies to § 3.18(b)). (a) For the purpose of accepting a statement of conformance for a Technical Standard Order product, the word "manufacturer" is interpreted to mean a person who fabricates, or both fabricates and assembles, a product by cutting, drilling, bolting, riveting, glueing,

soldering, sewing, or other fabrication and assembly techniques.

(b) A person is not regarded as the manufacturer solely by his engaging in the following activities:

(1) Distributing a completed product fabricated or fabricated and assembled by another person.

(2) Cleaning and reassembling products, repairing products, or replacing components or parts in products. [Supp. 34, 23 F.R. 10323, Dec. 25, 1958] §3.18-4 Approval of products under the type certificate or modification procedures (FAA policies which apply to §3.18).

A material, part, process, or appliance (called "product" in this section) 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 CAA by means of letters of approval, Repair and Alteration Form ACA337, or listing on CAA Product and Process Specifications will continue to be eligible for installation in aircraft 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 § 3.10.

(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 (1) or (2) of this paragraph, whichever is applicable.

[Supp. 34, 23 F.R. 10324, Dec. 25, 1958] §3.19 Changes in type design.

(For requirements with regard to changes in type design and the designation of applicable regulations therefor, see § 3.11 (d) and (e), and Part 1 of this subchapter.)

§3.19-1 Changes of engines (FAA pol

icies which apply to § 3.19).

(a) There are currently available newly designed engines of approximately the same size and weight as previously designed engines, but with considerable variations in power. It is possible to interchange these engines with little or no installation changes, and although minor changes in engine weight may be involved, it will still be practical to operate the aircraft at the originally approved gross weight. Under § 3.185, the maneuvering load factor is not dependte ent upon engine power, and under § 3.184 =the design airspeeds can be independent

of engine power. Therefore, a change which involves or permits a practical power increase by exchange of engines shall be approved by the Administrator: re Provided, That such exchange of engines is not accompanied by an increase in the gross weight of the aircraft, or an increase in placard speeds. Under those conditions it will not be necessary to restrict the maximum continuous horsepower by a placard because of the airplane speed limitations since the latter are indicated on the speed placards.

(b) Aircraft alterations involving be weight or speed changes beyond those set

10.

forth above will be approved by the Administrator, if the applicant shows compliance with the applicable airworthiness requirements.

(c) Under § 3.19, it will be necessary to require such investigations of local structure, weight and balance, power plant installations and flight tests as are normally involved in a change of engine type. However, every effort will be made by reference to data already on hand to minimize the amount of testing and structural analysis required of the applicant.

[Supp. 10, 16 F. R. 3281, Apr. 1951, as amended by Supp. 14, 17 F. R. 9065, Oct. 11, 1952]

AIRPLANE CATEGORIES

§3.20 Airplane categories.

(a) For the purpose of certification under this part, airplanes are divided upon the basis of their intended operation into the following categories:

(1) Normal-suffix N. Airplanes in this category are intended for nonacrobatic, nonscheduled passenger, and nonscheduled cargo operation.

(2) Utility-suffix U. Airplanes in this category are intended for normal operations and limited acrobatic maneuvers. These airplanes are not suited for use in snap or inverted maneuvers.

NOTE: The following interpretation of paragraph (a) (2) was issued May 15, 1947, 12 F. R. 3434: The phrase "limited acrobatic maneuvers" as used in § 3.6 (now § 3.20) is interpreted to include steep turns, spins, stalls (except whip stalls), lazy eights, and chandelles.

(3) Acrobatic-suffix A. Airplanes in this category will have no specific restrictions as to type of maneuver permitted unless the necessity therefor is disclosed by the required flight tests.

(b) An airplane may be certificated under the requirements of a particular category, or in more than one category, provided that all of the requirements of each such category are met. Sections of this part which apply to only one or more, but not all, categories are identified in this part by the appropriate suffixes added to the section number, as indicated in paragraph (a) of this section. All sections not identified by a