credit to : http://voices.yahoo.com/plane-crashes-pitot-tubes-2447529.html Most of us are aware of the devastation a bird strike can have on an aircrafts structure or engines. But what about an insect? Or a few ice crystals? A surprisingly trivial substance can bring down even the largest aircraft. All avionics systems rely on devices called "pitot tubes." These measure the force (impact) of oncoming air. The "pitot-static" system compares this impact pressure to the neutral (static) air pressure. The information is fed to three of the most critical instruments: Airspeed, Altitude and Rate of Climb. A blocked static port affects all three instruments, while the pitot tube itself will only involve airspeed. The simplicity of the pitot tubes makes them vulnerable to blockages. The elaborite system of avionics, gauges and computers can be deceived by any number of blockages. Dead insects, mud wasp nests, and ice are the most common. The most hideou