Expert: Paul Soderman - 1/22/2009

Question
Hello Paul,
Turning now again to the problem of the presence of birds near the airports, could it be reasonable to consider placing a carefully designed mesh or grill in front of the turbine intake? An alternative embodiment could consider being able to automatically move the mesh out of the intake path once the aircraft has reached a safe height, or after a bird crash.
Thanks for your time.
Alfredo

Answer
Alfredo
Yes, an intake grill could solve the problem of bird strikes to an engine.  But you have introduced several new problems.  The grill will introduce a drag or pressure loss to the intake flow along with turbulence, hence a performance hit.  Stowing the grill sounds nice, but would be very complicated mechanically because everything has to be aerodynamically faired (reliably) when stowed.  Most importantly, you have added weight to the aircraft.  I wish I could convey how aircraft designers and managers hate adding weight to an aircraft.  They look at it as X number of passengers denied.  All these penalties occur each flight, whereas bird strikes are very rare and seldom fatal.  I guess it boils down to the cost of eliminating all risks in life.  Elimination of all risk to aircraft may mean that we can't fly.
Paul