[Code of Federal Regulations]
[Title 14, Volume 1]
[Revised as of January 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 14CFR21.99]

[Page 130]
 
                     TITLE 14--AERONAUTICS AND SPACE
 
CHAPTER I--FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION
 
PART 21--CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS--Table of Contents
 
                 Subpart D--Changes to Type Certificates
 
Sec. 21.99  Required design changes.

    (a) When an Airworthiness Directive is issued under Part 39 the 
holder of the type certificate for the product concerned must--
    (1) If the Administrator finds that design changes are necessary to 
correct the unsafe condition of the product, and upon his request, 
submit appropriate design changes for approval; and
    (2) Upon approval of the design changes, make available the 
descriptive data covering the changes to all operators of products 
previously certificated under the type certificate.
    (b) In a case where there are no current unsafe conditions, but the 
Administrator or the holder of the type certificate finds through 
service experience that changes in type design will contribute to the 
safety of the product, the holder of the type certificate may submit 
appropriate design changes for approval. Upon approval of the changes, 
the manufacturer shall make information on the design changes available 
to all operators of the same type of product.

[Doc. No. 5085, 29 FR 14567, Oct. 24, 1964, as amended by Amdt. 21-3, 30 
FR 8826, July 24, 1965]