I have read NASA and FAA reports citing the benefits that greater speed flexibility below 10,000' has on traffic flow management and airport capacity. The FAA's much talked about "Freeflight" concept also makes reference to this practice possibly being expanded in the US to include many more terminal areas in addition to KIAH. I also read ALPA's birdstrike/wildlife hazard commitee reccomendations. They take the position that speed should remain limited to 250 KIAS below 10,000 in view of the birdstrike hazard and make several reccomendations to mitigate the hazards. With flight safety and economic interests in apparent conflict, I expect debate on this issue to continue far into the future. I tend to believe that more accurate real-time bird tracking would be useful in making a proper threat assessment. I have been lucky in that my three birdstrikes were small birds hit at low airspeed and did no damage to airframe of engines. In consideration of some past accident reports, I realize it could easily have been otherwise. Earlier posts have cited the kinetic energy involved. One more thing to consider!
Best regards,
Westhawk