91.101—Applicability.
(a)
The requirements of this subpart B are applicable to all engines subject to the provisions of subpart A of this part.
(b)
In a given model year, you may ask us to approve the use of procedures for certification, labeling, reporting and recordkeeping, or other administrative requirements specified in 40 CFR part 1045 or 1068 instead of the comparable procedures specified in this part 91. We may approve the request as long as it does not prevent us from ensuring that you fully comply with the intent of this part.