Farha Ahmed

NOISE CERTIFICATION

INTRODUCTION

Aircraft noise was already of concern during the formative years of ICAO, but it was then limited to the noise caused by propellers whose tips rotated at speeds approaching that of sound. This concern increased with the introduction of the first generation jet aeroplanes in the early 1960s and accelerated with the growth in the number of jet aircraft in international operations.

Aircraft noise is a function, among other things, of the power of the engines that propel aeroplanes through the atmosphere. Reduce the power and you reduce noise, but at the same time you may affect the safety characteristics of the jet aircraft

Aircraft built today have to meet noise certification requirements as set by the certificating authorities. For most states they are based on Certification Standards adopted by the Council of ICAO. These are contained in Annex 16, Environmental Protection, Volume 1, Aircraft Noise to the Convention on International Civil Aviation. 

The prime purpose of noise certification is to ensure that the latest available noise reduction technology is incorporated into aircraft design demonstrated by procedures which are relevant to day to day operations, to ensure that noise reduction offered by technology is reflected in reductions around airport.

HISTORY

In 1968, the ICAO Assembly adopted a resolution which conceded the seriousness of noise in the vicinity of airports, and instructed the ICAO Council to establish international specifications and associated guidance material to control aircraft noise. In 1971, the Assembly adopted another resolution recognizing the adverse environmental impact that may be related to aircraft activity. This resolution placed on ICAO the responsibility to guide the development of international civil aviation in such a manner as to benefit the people of the world and to achieve maximum compatibility between the safe and orderly development of civil aviation and the quality of the human environment. Annex 16 dealing with various aspects of aircraft noise problems was adopted in 1971 on the basis of recommendations of the 1969 Special Meeting on Aircraft Noise in the Vicinity of Aerodromes.


These aspects included: procedures for describing and measuring aircraft noise; human tolerance to aircraft noise; aircraft noise certification; criteria for establishment of aircraft noise abatement procedures; land use control; and ground run-up noise abatement procedures. Shortly after this meeting, the Committee on Aircraft Noise (CAN) was established to assist ICAO in the development of noise certification requirements for different classes of aircraft. The first meeting of this committee developed the first amendment to Annex 16, which became applicable in 1973 and included noise certification of future production and derived versions of subsonic jet aeroplanes.

During subsequent meetings, the Committee on Aircraft Noise developed noise certification standards for future subsonic jet aeroplanes and propeller-driven aeroplanes, and for future production of existing supersonic transport aeroplane types and helicopters. It also developed guidelines for noise certification of future supersonic and propellerdriven STOL (short take-off and landing) aeroplanes as well as installed APUs (auxiliary power-units) and associated aircraft systems when operating on the ground. A resolution adopted by the ICAO Assembly in 1971 led to specific action on the question of engine emissions and detailed proposals for ICAO Standards for the control of engine emissions from certain types of aircraft engines. 

WHO IS IN CHARGE?

• Noise certification shall be granted or validated by the State of Registry of an aircraft on the basis of satisfactory evidence that the aircraft complies with requirements that are atleast equal to applicable Standards in this Annex.
• If noise re-certification is requested, it shall be granted or validated by the State of Registry.
• The documents showing noise certifications shall be approved by the State of Registry and shall be required by that State to be carried on the Aircraft. 

INFORMATION SHOWN IN CERTIFICATION

 The documents attesting noise certification for an aircraft shall provide at least the following information:

• Item 1. Name of State
  
• Item 2. Title of the noise document. 
  
• Item 3. Number of the document.
   
• Item 4. Nationality or common mark and registration marks. 
  
• Item 5. Manufacturer and manufacturer’s designation of aircraft. 
• Item 6. Aircraft serial number. 
  
• Item 7. Engine manufacturer, type and model. 
  
• Item 8. Propeller type and model for propeller-driven aeroplanes. 
  
• Item 9. Maximum take-off mass in kilograms. 
  
• Item 10. Maximum landing mass, in kilograms, for certificates issued under Chapters 2, 3, 4, 5 and 12 of this Annex.
   
• Item 11. The chapter and section of this Annex according to which the aircraft was certificated.
  
• Item 12. Additional modifications incorporated for the purpose of compliance with the applicable noise certification Standards. 
  
• Item 13. The lateral/full-power noise level in the corresponding unit for documents issued under Chapters 2, 3, 4, 5 and 12 of this Annex. 
• Item 14. The approach noise level in the corresponding unit for documents issued under Chapters 2, 3, 4, 5, 8 and 12 of this Annex. 
  
• Item 15. The flyover noise level in the corresponding unit for documents issued under Chapters 2, 3, 4, 5 and 12 of this Annex. 
• Item 16. The overflight noise level in the corresponding unit for documents issued under Chapters 6, 8 and 11 of this Annex. 
• Item 17. The take-off noise level in the corresponding unit for documents issued under Chapters 8 and 10 of this Annex. 
  
• Item 18. Statement of compliance, including a reference to Annex 16, Volume I. 
  
• Item 19. Date of issuance of the noise certification document.
   
• Item 20. Signature of the officer issuing it. 

CANCEL THE NOISE CERTIFICATION

Contracting States shall recognize as valid a noise certification granted by another Contracting State provided that the requirements under which such certification was granted are at least equal to the applicable Standards specified in this Annex.  

A Contracting State shall suspend or revoke the noise certification of an aircraft on its register if the aircraft ceases to comply with the applicable noise Standards. The State of Registry shall not remove the suspension of a noise certification or grant a new noise certification unless the aircraft is found, on reassessment, to comply with the applicable noise Standards.  

The amendment of this volume of the Annex to be used by a Contracting State shall be that which is applicable on the date of submission to that Contracting State for:  

•  a Type Certificate in the case of a new type; or
  
•  approval of a change in type design in the case of a derived version; or
  
•  in either case, under an equivalent application procedure prescribed by the certificating authority of that Contracting State.  

 As each new edition and amendment of this Annex becomes applicable (according to Table A of the Foreword) it supersedes all previous editions and amendments.

The Standards of this chapter shall be applicable to all subsonic jet aeroplanes.