CS 25 – Criteria for Special Cabin Features

Sofema Online (SOL) www.sofemaonline.com Considers the process for managing Special Cabin Elements

Introduction - Role of the DOA Holder

>> Classify the changes
>> Approval of minor changes and repairs (Without EASA Involvement)

Examples of major changes for cabin safety include the following:

>> New cabin layout affecting pax & crew safety or requiring changes in emergency evacuation.
>> Introduction of dynamically tested seats.
>> Pitch between seat rows.
>> Distance between the seat and adjacent obstacle (For example a Cabin divider).
>> Cabin layouts that affect evacuation path or access to exits.
>> Installation of new galleys, toilets, wardrobes, etc.
>> Installation of a new type of electrically powered galley insert.

Modification – Key Events

Any modification program contains a number of key events consider the following:

>> Concept
>> Definition
>> Design
>> Adjustment
>> Certification

Concept Element

>> What do we want to achieve – goals, targets & aspirations
>> What is the budget – does it support the above
>> What certification issues will we face
>> Feasibility Study
>> Design Considerations – Methods & Alternatives
>> Organizing the workflows
>> Development of the Preliminary Design
>> Developing the Test Plan including verification methodology

Definition Element

>> Definition of the certification basis
>> Construct the Means of Compliance (MOC) – EASA LOI
>> Detailed Definition of Process Steps
>> Engineering Team Manpower Selection (Project Lead)
>> Mechanical and Electrical Load Considerations
>> Potential impact on other elements
>> Testing & Validation of the Design

Design Element

>> Action the Design to comply with the previously defined plan & objective
>> Engineering Verification of the Design
>> Provide Detailed Feedback to Project Lead

Adjustment Element

During the adjustment element, it is possible to deliver design improvements and resolve conflicts or constraints. Issues identified during Design Verification are addressed during this aspect of the program.

>> Actioning of the defect Reports from the Design Verification Engineer
>> Understanding the various options available and choosing the most appropriate
>> Adjusting the Design
>> Validation of the Final Design

Certification CS 25.21 Proof of compliance

>> Each requirement of this Subpart must be met at each appropriate combination of weight and centre of gravity within the range of loading conditions for which certification is requested. This must be shown:

o By tests upon an aeroplane of the type for which certification is requested, or by calculations based on, and equal in accuracy to, the results of testing; and
o By systematic investigation of each probable combination of weight and centre of gravity, if compliance cannot be reasonably inferred from combinations investigated.

Notes Regarding Certification 

>> The process should start from the earliest elements and run in parallel with the design development activities.
>> The certification process is under the responsibility of the Office of Airworthiness. Primary steps include:

o Establishing contact with the authorities
o Developing the means of compliance (tests and corresponding documentation)
o Creating and approving the certification documentation, under DOA privileges
o Signing the declaration of compliance (head of DO)

Next Steps

Sofema Aviation Services (SAS) Provides Classroom or Webinar Training, including the following course: EASA CS 25 Compliant Cabin Certification & Mods Training Program – 5 Days

Please see our websites www.sassofia.com and www.sofemaonline.com or email team@sassofia.com