Statistical Assessment of Changes in Bird Certification Rules for Aero-Engines Through Time

Overview 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 growt