Which is the larger risk:

1. That a plane will crash due to pilot error
2. That a plane will crash due to mechanical failure
3. That a plane will crash due to inclement weather
4. That a plane will crash from hitting a Model Aircraft

And I submit that the order of cause of the crash is the same for both full scale and model aircraft.

Causes of Fatal Accidents by Decade (percentage)

[TABLE="width: 550, align: center"]
[TR]
[TD="width: 550, align: left"][TABLE="width: 554"]
[TR]
[TD="class: style14, width: 208, align: center"]Cause[/TD]
[TD="class: style14, width: 44, align: center"]1950s[/TD]
[TD="class: style14, width: 44, align: center"]1960s[/TD]
[TD="class: style14, width: 44, align: center"]1970s[/TD]
[TD="class: style14, width: 44, align: center"]1980s[/TD]
[TD="class: style14, width: 47, align: center"]1990s[/TD]
[TD="class: style14, width: 44, align: center"]2000s[/TD]
[TD="class: style14, width: 45, align: center"]All[/TD]
[/TR]
[TR]
[TD="class: style3, width: 208, align: center"]Total Pilot Error[/TD]
[TD="class: style3, align: center"]58[/TD]
[TD="class: style3, align: center"]63[/TD]
[TD="class: style3, align: center"]44[/TD]
[TD="class: style3, align: center"]57[/TD]
[TD="class: style3, align: center"]55[/TD]
[TD="class: style3, align: center"]57[/TD]
[TD="class: style77, align: center"]53[/TD]
[/TR]
[TR]
[TD="class: style14, align: center"]Pilot Error[/TD]
[TD="class: style14, align: center"]42[/TD]
[TD="class: style14, align: center"]36[/TD]
[TD="class: style14, align: center"]25[/TD]
[TD="class: style14, align: center"]29[/TD]
[TD="class: style14, align: center"]29[/TD]
[TD="class: style14, align: center"]34[/TD]
[TD="class: style77, align: center"]32[/TD]
[/TR]
[TR]
[TD="class: style14, width: 208, align: center"] Pilot Error (weather related)[/TD]
[TD="class: style14, width: 44, align: center"]10[/TD]
[TD="class: style14, width: 44, align: center"]18[/TD]
[TD="class: style14, width: 44, align: center"]14[/TD]
[TD="class: style14, width: 44, align: center"]16[/TD]
[TD="class: style14, width: 47, align: center"]21[/TD]
[TD="class: style14, width: 44, align: center"]18[/TD]
[TD="class: style77, width: 45, align: center"]16[/TD]
[/TR]
[TR]
[TD="class: style14, width: 208, align: center"] Pilot Error (mechanical related)[/TD]
[TD="class: style14, width: 44, align: center"]6[/TD]
[TD="class: style14, width: 44, align: center"]9[/TD]
[TD="class: style14, width: 44, align: center"]5[/TD]
[TD="class: style14, width: 44, align: center"]2[/TD]
[TD="class: style14, width: 47, align: center"]5[/TD]
[TD="class: style14, width: 44, align: center"]5[/TD]
[TD="class: style77, width: 45, align: center"]5[/TD]
[/TR]
[TR]
[TD="class: style14, width: 208, align: center"] Other Human Error[/TD]
[TD="class: style14, width: 44, align: center"]3[/TD]
[TD="class: style14, width: 44, align: center"]8[/TD]
[TD="class: style14, width: 44, align: center"]9[/TD]
[TD="class: style14, width: 44, align: center"]5[/TD]
[TD="class: style14, width: 47, align: center"]8[/TD]
[TD="class: style14, width: 44, align: center"]6[/TD]
[TD="class: style77, width: 45, align: center"]6[/TD]
[/TR]
[TR]
[TD="class: style14, width: 208, align: center"] Weather[/TD]
[TD="class: style14, width: 44, align: center"]16[/TD]
[TD="class: style14, width: 44, align: center"]9[/TD]
[TD="class: style14, width: 44, align: center"]14[/TD]
[TD="class: style14, width: 44, align: center"]14[/TD]
[TD="class: style14, width: 47, align: center"]8[/TD]
[TD="class: style14, width: 44, align: center"]6[/TD]
[TD="class: style77, width: 45, align: center"]12[/TD]
[/TR]
[TR]
[TD="class: style14, width: 208, align: center"] Mechanical Failure[/TD]
[TD="class: style14, width: 44, align: center"]21[/TD]
[TD="class: style14, width: 44, align: center"]19[/TD]
[TD="class: style14, width: 44, align: center"]20[/TD]
[TD="class: style14, width: 44, align: center"]21[/TD]
[TD="class: style14, width: 47, align: center"]18[/TD]
[TD="class: style14, width: 44, align: center"]22[/TD]
[TD="class: style77, width: 45, align: center"]20[/TD]
[/TR]
[TR]
[TD="class: style14, width: 208, align: center"] Sabotage[/TD]
[TD="class: style14, width: 44, align: center"]3[/TD]
[TD="class: style14, width: 44, align: center"]5[/TD]
[TD="class: style14, width: 44, align: center"]11[/TD]
[TD="class: style14, width: 44, align: center"]12[/TD]
[TD="class: style14, width: 47, align: center"]10[/TD]
[TD="class: style14, width: 44, align: center"]9[/TD]
[TD="class: style77, width: 45, align: center"]8[/TD]
[/TR]
[TR]
[TD="class: style14, width: 208, align: center"] Other Cause[/TD]
[TD="class: style14, width: 44, align: center"]0[/TD]
[TD="class: style14, width: 44, align: center"]2[/TD]
[TD="class: style14, width: 44, align: center"]2[/TD]
[TD="class: style14, width: 44, align: center"]1[/TD]
[TD="class: style14, width: 47, align: center"]1[/TD]
[TD="class: style14, width: 44, align: center"]0[/TD]
[TD="class: style77, width: 45, align: center"]1
[/TD]
[/TR]
[/TABLE]
[/TD]
[/TR]
[/TABLE]

I was unable to find any evidence of a plane crash attributed to a collision with a model airplane. There was a incident at a RC fly in a few years ago the full scale was damaged but did not crash.