Page 29 - UK Regulation Part 21 Initial Airworthiness Annex I (consolidated) March 2022

PART 21 - INITIAL AIRWORTHINESS (ANNEX I)

(RTC)
Point 21.A.15(e) establishes a maximum period of validity for an application for a TC or an RTC.
During this period, the type-certification basis, operational suitability data (OSD) certification basis, and
the environmental protection requirements (hereinafter referred to as the ‘certification basis’),
established and notified by the CAA in accordance with points 21.B.80, 21.B.82 and 21.B.85, remain
effective. However, the period of validity of the certification basis is limited so that the standards
notified as part of the certification basis at the time of application do not become outdated.
For various reasons (e.g. development, business, commercial, etc.), the applicant may not be able to
complete the certification within the established time limit. In this case, the applicant has the following
two options (see 21.A.15(f)(1) and (2)):
1. Submit a new application In this case, the CAA establishes and notifies a new certification
basis in accordance with points 2B.80, 2B.82 and 2B.85, considering the standards that
are available at the date of the new application.
In accordance with point 21.A.15(e), the new application has a maximum period of validity
that is equal to the first one, corresponding to the product category. Beyond this period of
validity, the applicant may need to choose again between the two options of either
submitting a new application or applying for an extension of the initial application.
2. Apply for an extension of the initial application
In this case, the applicant proposes a ‘new target date’ to the CAA for the issuance of the
certificate, and selects a date that becomes the reference date for the establishment of the
certification basis by the CAA. For the purposes of this GM, the selected reference date is
referred to as the ‘new effectivity date’ of the initial application.
The ‘new effectivity date’ of the initial application may be any date in the past between the
following time limits:
- the ‘new target date’ for a TC proposed by the applicant minus the time limit used
under 21.A.15(e) (e.g. 5 years for large aeroplanes and large rotorcraft, 3 years for
the other products); and
- the date on which the applicant applies for the extension of the initial application.
This calculation is visualised in Figure 1 below:
This ensures that the standards used to establish the certification basis are never older
than the ones available at the start of the period of validity required by point 21.A.15(e).
If the applicant is not able to complete the product certification by the new target date, the
applicant may choose again between the two options of either submitting a new application
or applying for a new extension of the initial application.

21.A.19 Changes requiring a new type-certificate
Any natural or legal person proposing to change a product shall apply for a new type-certificate if the
CAA finds that the change in design, power, thrust, or mass is so extensive that a substantially
complete investigation of compliance with the applicable type-certification basis is required.
21.A.20 Demonstration of compliance with the type certification basis, operational suitability data certification basis
and environmental protection requirements
(a) Following the acceptance of the certification programme by the CAA, the applicant shall
demonstrate compliance with the type certification basis, operational suitability data
certification basis and environmental protection requirements, as established and notified
to the applicant by the CAA in accordance with points 21.B.80, 21.B.82, 21.B.85, and shall
provide the CAA with the means by which such compliance has been demonstrated.
(b) The applicant shall report to the CAA any difficulty or event encountered during the process
of demonstration of compliance that may have an appreciable effect on the risk
assessment under point 21.A.15(b)(6) or on the certification programme, or may otherwise
necessitate a change to the level of involvement of the CAA previously notified to the
applicant in accordance with point 21.B.100(c).
(c) The applicant shall record justifications of compliance within the compliance documents
as referred to in the certification programme.
(d) After completion of all demonstrations of compliance in accordance with the certification
programme, including any inspections and tests in accordance with point 21.A.33, and
after all flight tests in accordance with point 21.A.35, the applicant shall declare that:
1. it has demonstrated compliance with the type-certification basis, operational
suitability data certification basis and environmental protection requirements, as
established and notified by the CAA, following the certification programme as
accepted by the CAA; and
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