Thursday, April 23, 2009

Response to a Bird Strike Protection Idea

A reader responded to comment I made to a 23 April 2009 Washington Post article about the FAA opening up the bird strike database. A reader made a suggestion for a screen or grate that could be placed in front of engine intakes. My response will likely generate additional feedback from the visitors to this site.

Question: Couldn't you engineer a conical grate in front of the jet intake, like this:

      / ||
     / || intake
air flow --> \ ||
      \ ||

That way if a bird struck it wouldn't stay on the grate but roll off due to the air pressure.

Response: The kind of design you have may in fact be effective. However, one must look at the effect that this kind of system in place on an aircraft. Weight, extra maintenance, and design costs are only the beginning. On the other hand, look at what this system would prevent. It may avert the rare serious accident that causes serious injury or death. For US airlines, in the last half century the number of passenger airliners involved in bird strikes that caused serious injury or death has been exactly two (assuming the system worked as designed), and that includes the US Airways ditching in January. Given the rarity of a fatal bird strike event, and especially in the absence of a relatively recent and spectacular fatal event, any suggested change that involves a new design for the entire airliner fleet would not likely be accepted by the FAA.

Any suggested change in aircraft design or procedures would have to survive the regulatory process, which includes the kinds of cost effectiveness issues like the one I just implied. It wouldn't be a situation of a change being rejected because of costs, but rather a rejection based on whether it were not as cost effective as other alternatives.