itations shall show that the modifications re accomplished in accordance with the es of either Part 48 or Part 4b in effect on tember 1, 1953, which are applicable to modification being made: Provided, That applicant may elect to accomplish a dification in accordance with the rules Part 4b in effect on the date of application the modification in lieu of Part 4a or t 4b as in effect on September 1, 1953: d provided further, That each specific dification must be accomplished in acdance with all of the provisions contained the elected rules relating to the particular dification.

An

B. Specific conditions for approval. plicant for any approval of the following cific changes shall comply with section 2 this regulation as modified by the applible provisions of this section.

(a) Increase in take-off power limitation00 to 1,350 horsepower. The engine takepower limitation for the airplane may be reased to more than 1,200 horsepower but t to more than 1,350 horsepower per engine the increase in power does not adversely ect the flight characteristics of the air

ine.

(b) Increase in take-off power limitation more than 1,350 horsepower. The engine ke-off power limitation for the airplane ly be increased to more than 1,350 horsewer per engine if compliance is shown with e flight characteristics and ground hanng requirements of Part 4b.

(c) Installation of engines of not more an 1,830 cubic inches displacement and not ving a certificated take-off rating of more an 1,350 horsepower. Engines of not more an 1,830 cubic inches displacement and not aving a certificated take-off rating of more an 1,350 horsepower which necessitate a ajor modification or redesign of the engine stallation may be installed, if the engine e prevention and fire protection are equivent to that on the prior engine installation. (d) Installation of engines of more than 30 cubic inches displacement or having tificated take-off rating of more than 50 horsepower. Engines of more than 30 cubic inches displacement or having tificated take-off rating of more than 1,350 rsepower may be installed if compliance shown with the engine installation rerements of Part 4b: Provided, That where eral compliance with the engine installaIn requirements of Part 4b is extremely ficult to accomplish and would not conbute materially to the objective sought, d the Administrator finds that the exrience with the DC-3 or L-18 airplanes stifies it, he is authorized to accept such leasures of compliance as he finds will ectively accomplish the basic objective. 4. Establishment of new maximum certifiated weights. An applicant for approval of ewmaximum certificated weights shall aply for an amendment of the airworthiness ertificate of the airplane and shall show hat the weights sought have been estab

lished, and the appropriate manual material obtained, as provided in this section.

NOTE: Transport category performance requirements result in the establishment of maximum certificated weights for various altitudes.

(a) Weights-25,200 to 26,900 for the DC-3 and 18,500 to 19,500 for the L-18. New maximum certificated weights of more than 25,200 but not more than 26,900 pounds for DC-3 and more than 18,500 but not more than 19.500 pounds for L-18 airplanes may be established in accordance with the transport category performance requirements of either Part 4a or Part 4b, if the airplane at the new maximum weights can meet the structural requirements of the elected part.

(b) Weights of more than 26,900 for the DC-3 and 19,500 for the L-18. New maximum certificated weights of more than 26,900 pounds for DC-3 and 19,500 pounds for L-18 airplanes shall be established in accordance with the structural performance, flight characteristics, and ground handling requirements of Part 4b: Provided, That where literal compliance with the structural requirements of Part 4b is extremely difficult to accomplish and would not contribute materially to the objective sought, and the Administrator finds that the experience with the DC-3 or L-18 airplanes justifies it. he is authorized to accept such measures of compliance as he finds will effectively accomplish the basic objective.

(c) Airplane flight manual-performance operating information. An approved airplane flight manual shall be provided for each DC-3 and L-18 airplane which has had new maximum certificated weights established under this section. The airplane flight manual shall contain the applicable performance information prescribed in that part of the regulations under which the new certificated weights were established and such additional information as may be necessary to enable the application of the takeoff, en route, and landing limitations prescribed for transport category airplanes in the operating parts of the Civil Air Regulations.

(d) Performance operating limitations. Each airplane for which new maximum certificated weights are established in accordance with paragraphs (a) or (b) of this section shall be considered a transport category airplane for the purpose of complying with the performance operating limitations applicable to the operations in which it is utilized.

5. Reference: Unless otherwise provided, all references in this regulation to Part 4a and Part 4b are those parts of the Civil Air Regulations in effect on September 1. 1953

This regulation supersedes Special Civil Air Regulation SR-398 and shall remain effective until superseded or rescinded by the Board.

19 F.R. 5039, Aug. 11, 1954. Redesignated at 29 F.R. 19099, Dec. 30, 1964]