Page 211 - UK Regulation Part 21 Initial Airworthiness Annex I (consolidated) March 2022

PART 21 - INITIAL AIRWORTHINESS (ANNEX I)

- High reduced
The CAA assesses all the compliance data; sampling/checking is significant
and adapted to the likelihood of an unidentified noncompliance. The sampling
rate may be reduced if the content of the life cycle data provides confidence in
compliance and is focused in the area where confidence needs to be gained.
The CAA assesses the DDP and general compliance with Part 21 Subpart O.
The CAA performs desktop reviews, as well as an onsite assessment of the
applicant’s compliance demonstration. This occurs when design and
verification evidence is available.
- Medium
The CAA assesses all the compliance data, but for some compliance data, it
performs no or limited sampling/checking. The CAA adapts its sampling and
focuses on the likelihood of an unidentified noncompliance, taking into
account the level of complexity and novelty of the project. The CAA assesses
the DDP and general compliance with Part 21 Subpart O. The CAA performs
desktop reviews and may perform an onsite assessment of the applicant’s
compliance demonstration.
- Basic
The CAA assesses the DDP and general compliance with Part 21 Subpart O,
and verifies the completeness of the data package.
Generally, the CAA performs a desktop assessment.
3. The process of determining CAA’s LoI
The determination of the CAA's LoI is captured as a process. This process is performed
mainly in three steps and is illustrated in the following figure:
Figure 1: Process of determination of CAA’s LoI in UKTSO certification projects
Step 1 consists of the initial LoI determination which the CAA evaluates by assessing:
- the applicant’s experience in the UKTSOA process and scope of work according to
Section 1.1 above, and
- the UKTSOA applicant’s performance within its scope of work according to Section
1.2 above.
The result of this determination of the CAA's initial LoI is either high or high reduced.
Step 2 consists of reassessing the CAA's LoI. Throughout the UKTSO project, the CAA
receives project deliverables (e.g. plans, reports), means of compliance, requests for
deviations, limitations, etc., and interacts with the applicant.
If the CAA's LoI has been initially set to high reduced, CAA reevaluates it considering:
- the novelty in the technology or in the means of compliance according to Section 1.3
above, and
- the complexity of the UKTSO project according to Section 1.4 above.
The result of this reassessment may vary from high to medium according to the following
table:
- ¹It refers to deviations from UKTSO minimum operational performance standards
(MOPSs), excluding deviations for requesting compliance with a new revision of an
industry MOPS standard.
- ²When CAA agrees that a major change only requires a straightforward
redemonstration of the UKTSO compliance using previous methods, without any
identified risk, then the CAA's LoI is reduced to basic. Please note that this may only
be defined after a minimum assessment of the applicant’s compliance
demonstration methods.
Note: For a minor change, this process does not apply; in that case, the CAA's LoI
consists of an assessment of the minor change classification, an update of the certificate,
and, when needed, an assessment of the DDP.

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