Originally Posted by
bradpaul
My question is concerning the full scale, if the drone was 200' below the airliner is 1200' AGL a usual altitude when 3 to 4 miles from the runway?
Yes.
See link for approach plate to Birmingham, AL.
http://155.178.201.160/d-tpp/1504/00050IL6.PDF
The final approach fix is at 2200 MSL, or 1550 ft above the ground at 4.1 nm (4.7 statute miles). The descent begins there, so at 3 to 4 statute miles 1200 AGL is quite a normal altitude.
This is a very normal ILS instrument approach profile so it would apply at many airports. Many smaller airports without instrument approaches have a light system (VASI) that allows/encourages aircraft to fly the same descent profile as an ILS so the same altitude/distances can apply at most any airport.
Many non-precision approaches include a descent earlier than this - arriving at minimum descent altitude (400 to 600 AGL typically) earlier than a continuous descent to the runway as in an ILS so below 1200 AGL at 3 miles is quite common.
We had an issue here (KBHM) recently with a "drone" reported at 3400 MSL five miles from the airport a while back right on the route to intercept the final approach course. While I am a long time modeler - 40 years - I also fly airplanes for a living, I would like to keep doing both.
Something to think about
: Pilots don't spend a lot of time deciding how big a rock we can throw at someone without hurting them. Perhaps the discussion about how big a model aircraft can hit us without hurting is a bit out of bounds.
Bryan