Federal Aviation Agency AC NO: AC 20-14
STATION AGE AIRCRAFT EFFECTIVE :
10/25/63 * STATES OF ARE SUBJECT : AIRCRAFT AIRWORMNINESS; RESTRICTED CATEGORI: CERIIFICATION OF
AIRCRAFT WITH UNCERIIFICATED ENGINES OR ENGTHES TO WHICH MAJOR
ALTERATTONS HAVE BEEN MADE 10 Federal Aviation Agency for type certification of aircraft in the PURPOSE. This circular sets forth the information needed by the meinee to match restricted category with uncertificated engines or engines to which major alterations have been made.
20 REFERENCE® Civil Aeronautics Marmal, Part 8.
BACKO ROUND. Under Part 8 of the Civil Air Regulations, it is perndasible, and has been the practice in the past, to use uncertificated engines in aircraft eligible for type certifiostion in the restricted category, under the provisions of CAR, Section 8.10, when the Administrator finds, among other things, that "no feature or characteristic of the aircraft renders it unsafe when operated in accordance with the limitations prescribed for its intended use. In the case of alterations to highlystressed engine parts, it is obvious that such alterations may seriously affect the integrity of the engine and cannot be assessed by simple inspection. The altered engine must, therefore, be evaluated or have acquired suitable operating experience before it can be found to meet the required level of safety.
PROCEDURES. To assist the Administrator in making the finding required by Section 8.10 of the Civil Air Regulations and to assure uniforaity in the type certification, under Part 8, of aircraft with uncertificated engines or engines to which major alterations have been made, an applicant for type certification of such aircraft should submit the folloving additional information with his application:
e. Previously approved data, Do petual end or deed part abstentiating taste with the
Page 2 AC 20-14 10/25/63
c. Satisfactory operating history of similar engines or of similarly altered engines.
8. Deta shoving that the altered or added part 1s unquestionably of sufficient strength for the purpose intended, When an application involves the use of an uncertiricated engine, or an engine to which major alterations have been made, and for wiich there is no previous service experience or previously approved data, the data submitted will be revieved by an FAA Regional Engineering and Manufacturing Branch Office. That office will approve the data 1f it finds that the requirements of Section 8.10 of the Civil Air Regulations are met, or, if it does not so find, prescribe additional substantiation requirements, or deny the application. The local for this reviev. district office, as a convenience to the applicant, vill arrange roun sorge S. Moore Director Flight Standards Service Par 4 04-1210
Page 2 AC 20-14 10/25/63 Satisfactory operating history of sindlar engines or of similarly altered engines.
8. Data shoving thet the altered or added part 1s unquestionably of sufficient strength for the purpose intended, When an application involves the use of an uncertificated engine, or an engine to which major alterations have been made, and for which there is no previous service experience or previously approved data, the data submitted will be reviewed by an FAA Regional Engineering and Manufacturing Branch Office. That office will approve the data 11 1t finds that the requirements of Section 8.10 of the Civil Air Regulations are net, or, if it does not so find, prescribe additional substantiation requirements, or deny the application. The local district office, as a convenience to the applicant, will arrange for this review.
leorge S. Moore / Fight standards service Par 4 64-1213