I was president of an airport for 10 years and am a Flight Instructor/Commercial Pilot. I don't normally like to comment on stuff like this with those not familiar with flying, aircraft, airspace and the FAA but I think you will find most pilots will push for clear airspace where aircraft take off and land for safety. The smallest of foreign materials ingested in an engine or even hitting a leading edge of an aircraft can cause serious damage or possibly the loss of life. Airports, at least most, have instrument approaches in which aircraft are becoming close to the ground in lower visibility and cielings not to mention that in the air it is very very difficult so even see an object of this size before it is to late to 'see and avoid'. We used to have an 2 seat exemption ultralight (now LSA) dealer and even though their speed wasn't great they could climb and descend quickly and we had several incidents reported close to the runway with faster, less maneuverable aircraft. Remember an aircraft can not see from the nose down and what is directly overhead (many blind spots). The big problem is many people fly remote control aircraft with an "it can't happen to me" attitude and will irresponsibly fly their RC plane as they are the only one in the sky.
I have had a lot of dealings with the FAA. This is just like the 2 seat ultralights...they sucked them in and eventually created the LSA (light sport aircraft) so the operators ended up having to get a pilots liscense and regist er their aircraft. The FAA is one, if not the most powerful agencies in the US. I think you will see, once registration is in place, they will make an examples out of some.
Also, NO pilot can fly anymore near DC without logged training and follow procedures. Instructors must also have Flight Training on procedures. This has been in place for several years.
