HomeCompanies that hold design approvals – like type certificate and supplemental type certificates (STCs) – will have to prepare and make available damage tolerance data for repairs and alterations to fatigue critical airplane structure.
The purpose of this new rule is to support compliance with the Aging Airplane Safety rules. The FAA adopted the Aging Airplane Safety rule in the February 2, 2005 edition of the Federal Register. That rule requires that maintenance programs belonging to airline operators include Damage Tolerance inspection programs. Air carriers’ programs must take into account the adverse effects that repairs, alterations, and modifications could have on fatigue cracking and the inspection of this airplane structure.
In order to be able to meet their obligations under the Aging Aircraft Safety Rules, air carriers needs some baseline information about the aircraft design, and about the design of the repairs and alterations that are implemented in the aircraft.
In order to support the air carriers’ damage tolerance inspection obligations, design approval holders will be required to develop and make available the following four types of documents to operators:
(1) Lists of fatigue critical structure (to aid operators in identifying repairs and alterations that need to be addressed for DT).
(2) Damage tolerance inspections to provide operators with the necessary inspection times and methods for the following:
• Repair data published by type certificate (TC) holders (repair manuals and service bulletins).
• TC holder's future repair data not published for general use.
• Repair data developed by supplemental type certificate (STC) holders.
• Alteration data developed by TC and STC holders.
(3) Damage tolerance evaluation guidelines for all other repairs (to enable operators to obtain the necessary damage tolerance inspections).
(4) Implementation schedules (to define the necessary timing for performing damage tolerance evaluations and developing damage tolerance inspections and for incorporating the DT data into the operator's maintenance program).
This final rule transfers the responsibility for developing Damage Tolerance-based data from operators to design approval holders.
The intent of this new rule is to ensure the continued airworthiness of fatigue critical airplane structures by requiring design approval holders to support operator compliance with specified damage tolerance requirements. The rule change becomes effective January 11, 2008 and applies to all approved repairs and alterations. The implementation schedule is phased based on the type of data involved but the first round of damage tolerance information for existing fatigue critical structures will be due July 11, 2008. PAMA members with STCs (or TCs) should be certain that they are in compliance with the requirements to produce damage tolerance data.
EASA Part 66 Guidance
EASA publishes a list of specific aircraft types in the appendix to their mechanics’ certification rule. Under that rule (EASA Part 66), mechanics must be type-rated to work on any type of aircraft that is listed in the appendix to the rule.
EASA has proposed to add a number of new aircraft to the type rating list, and has also chosen to group together certain similar aircraft (so that the type rating for those similar aircraft will cover both). Certain other aircraft have been removed from the list of type ratings and redefined as annex II aircraft. These types are not subject to EASA regulation, although they are subject to regulation by national aviation authorities within Europe (for example, in the United Kingdom, Annex II aircraft may be maintained under a BCAR section L license).
The proposed rule is identified as NPA 2007-18. Comments may be sent by email to [email protected]. The comment period remains open until January 18, 2008.
Comments