Bird Strike Committee Proceedings


Date of this Version


Document Type



Presented at 2011 Bird Strike North America Conference, September 12-15, 2011, Niagara Falls, Ontario, Canada.


Copyright 2011 Reed.



  • Aim: to develop a means of assessing potential benefit of engine certification rule changes
  • Fleet cycles past and future
  • Bird rule changes through time
  • Bird strike distribution considerations
  • Monte-Carlo method
  • engine capability for different rules
  • Fleet risk through time
  • Rate of introduction of new products
  • Fleet risk in the future
  • Conclusions and recommendations
  • Note: predictions made regarding future fleet mix are solely the judgement of the author

Fleet Aircraft Cycles Per Year

  • Increase is sustained through time and predictable
  • Trend seems to recover from major setbacks

Fleet Cycles Per Year –Looking Forward

  • 40 million flights per year by 2030
  • Will have doubled since start of century
  • But what lies behind the curve?

Bird Ingestion Certification Rule History

Section 33.13/19 –Feb 1965

  • Original Rule
  • Small, medium, large birds defined

Section 33.77 A6 –Oct 1974

  • Concept of critical areas on engine introduced for large bird
  • Run-on after ingestion mandated

Section 33.77 A10 –Mar 1984

  • Critical areas expanded to all bird sizes

Section 33.76 A20 –Dec 2000

  • Medium bird increased to 2½lb
  • Ingestion at critical conditions
  • Very significant increase in capability

Section 33.76 A24 –Nov 2007

  • Large Flocking Bird added to address Goose population growth