Expert: Paul Soderman - 1/18/2009

Question
Hello: After the recent U.S.Airways near disaster,and assuming ingestion of large birds into the engine intakes was to blame,an idea to mitigate the effects of these types of incidents came to mind.Please keep in mind I have no training in aeronautical engineering,but like to imagine solutions.
Would an offset air intake help here? Similar to the middle engine intake on an L1011? Of course,it would probably only work in a design with rear mounted engines like the MD80 Or DC10.
The idea would be that the intake would curve towards the engine.If a large bird was encountered,inertia would tend to keep it traveling in a straight line,where it would meet a portion of the air intake path engineered to shatter on impact. After punching a hole at the engineered weak spot,it would exit the intake,bypassing the engine turbine blades. Even with the hole thus created,the engine would still get plenty of air to function.Would this be feasible?
Thanks!

Answer
Well Michael - I like your imagination but there are a few problems with your idea.  First, there is a very strong flow field entering the engine; even if the path were curved the bird would likely follow the streamlines into the fan.  If the bird did manage to strike the side of the inlet, it would be a glancing blow - I don't see how it could punch a hole and exit in one clean operation.  Any debris from this collision might also get drawn into the fan with potentially disastrous results. So designers would be loathe to build a weak spot in the inlet.

I think it is time for you to study engineering Michael.  Maybe some of your ideas could be made feasible with a little science behind them.
Paul