I think the safety argument is somewhat more complex.
- There seems to be very strong evidence that GA in the UK is significantly safer than in most other European countries.
(based on fatal accident rates/100k hrs. Note the number of GA hours flown in Spain is likely much lower than the UK but results in a similar total number of deaths)
.
- There are many factors which might influence accident rates and are significantly different between the UK and other European countries.
.
- There is no study which in anyway tries to quantify these differences, hence argument is based on 'logic' rather than statistics. In this context it seems more reasonable to attribute significance to the IMCr rather than for instance the CAA's approach to GPS
)
.
- The people seeking to retain the IMCr are, in general, coming from a safety vs utility perspective. In that IMCr trained pilots are clearly safer undertaking ILS approaches in IMC than people with only a PPL. Some people argue this as improved safety and some as improved utility.
.
- There is a reasonable body of anecdotes with regards to IMCr 'saves'.
.
- IMHO it is more objective to say 'the IMCr greatly increases utility with no observed decline in safety'.
In summary, I think AOPA's document is 'reasonable' in the context of a lobbying letter (where after all you are presenting as positive a picture as possible) and a substantial improvement on the factually untrue statements they have made in recent magazine articles.