June 10, 2022


Sofema Aviation Services (SAS) www.sassofia.com looks at the Declaration of Design and Performance (DDP) process and the information which is required to support the process.

Introduction – What is a DDP and what information should it contain?

DDP stands for Declaration of Design and Performance. It is the central summary document containing the definition and all relevant references of the article.

  • Its informational content could be compared to the one of a Type Certificate Data Sheet for products.
  • In the DDP the applicant is required to state that the article is designed, tested, and manufactured in compliance with the applicable sections of Part 21 and CS-ETSO.

21.A.608 Declaration of Design and Performance (DDP) (Regulation (EU) No 748/2012)

The DDP shall contain at least the following information:

  • Information corresponding to points 21.A.31(a) and (b), identifying the article and its design and testing standard;
  • The rated performance of the article, where appropriate, either directly or by reference to other supplementary documents;
  • A statement of compliance certifying that the article has met the appropriate ETSO;
  • Reference to relevant test reports;
  • Reference to the appropriate Maintenance, Overhaul and Repair Manuals;
  • The levels of compliance, where various levels of compliance are allowed by the ETSO;
  • List of deviations accepted in accordance with point 21.A.610.

The DDP shall be endorsed with the date and signature of the holder of the ETSO authorisation, or its authorised representative.

Information Required Includes:

  • Name and address of the manufacturer.
  • Description and identification of article including:

o Type No
o Modification Standard
o Master drawing record
o Weight and overall dimensions

  • Specification reference, i.e., ETSO No. and Manufacturer’s design specification.
  • The rated performance of the article directly or by reference to other documents.
  • Particulars of approvals held for the equipment.
  • Reference to the qualification test report.
  • Service and Instruction Manual reference number.
  • Statement of compliance with the appropriate ETSO and any deviations therefrom.
  • A statement of the level of compliance with the ETSO in respect of the ability of the article to withstand various ambient conditions or to exhibit various properties.

The following are examples of information to be given under this heading depending on the nature of the article and the specifications of the ETSO:

  • Environmental Qualification

o Temperature and Altitude
o Temperature Variation
o Humidity

  • Operational Shocks and Crash Safety
  • Vibration
  • Explosion Proofness
  • Waterproofness
  • Fluids Susceptibility
  • Sand and Dust
  • Fungus Resistance
  • Salt Spray
  • Magnetic Effect
  • Power Input
  • Voltage Spike
  • Audio Frequency Conducted Susceptibility – Power Inputs
  • Induced Signal Susceptibility
  • Radio Frequency Susceptibility (Radiated and Conducted)
  • Emission of Radio Frequency Energy
  • Lightning Induced Transient Susceptibility
  • Lightning Direct Effects
  • Icing
  • Electrostatic Discharge
  • Fire, Flammability

(Note: The manufacturer should list environmental categories for each of the sections of the issue of EUROCAE ED-14/RTCA DO-160 that was used to qualify the article.) For radio transmitters the transmitting frequency band, maximum transmitting power, and emission designator.

  • Working and ultimate pressure or loads
  • Time rating (e.g., continuous, intermittent) or duty cycle
  • Limits of the accuracy of measuring instruments
  • Any other known limitations which may limit the application in the aircraft e.g., restrictions in mounting attitude

A statement of the software level(s) used or ‘None’ if not applicable.

(Note: Software levels (software development assurance levels (DAL)) are those defined in the industry document referred to in the latest edition of AMC 20-115)

A statement of design assurance level for complex hardware or a statement indicating whether complex hardware is embedded or not in the product.

(Note: Complex hardware design assurance levels are those defined in the applicable issue of EUROCAE ED–80/RTCA DO-254.)

The declaration in this document is made under the authority of (name of manufacturer)

(Manufacturer’s name) cannot accept responsibility for equipment used outside the limiting conditions stated above without their agreement.

Signed Manufacturer’s authorised representative)

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