My Cessna turns 60 this year.
I started on the SID's journey when they first came out and was doing them one step at a time.
When I got to the wings my LAME and I decided that we remove them and have a good look in the area as to do the Spar carry through, the wing attach blocks it cannot be done thoroughly with the wings in place.
Spar carry through, corrosion between the doublers. Replacement parts $1400 USD.
Wing attach blocks OK.
Wings looked OK but thought I would change the bag and do a fuel vent mod while the wings were off. Easiest way to do that is unzip the end rib with the wing off. Not good, signs of corrosion at the spar skin join.
I elected to dig a little further and the more I dig the worse it got. End result both wings require total rebuild. The spars had significant cx in the laminate that could not be seen until the strip down. The bill so far for the wings alone is 30K and they have yet to be put back together.
I am guessing that I will have her back in the air in two years time and about 100K poorer. However I will know exactly what I have.
My experience is that only a fool would not do the SID program, my old girl looked OK but I was quite shocked with what we found under the hood. The life of my family is worth more that what I am paying to fix the old girl.
You cannot do the inspection properly with removing the wings and getting into the tank bays and the spar carry through. My engineers have all remarked that factory corrosion proofed Cessnas' are mostly getting through OK but the failure rate on high time and non cx proof machines is about 50/50.
High time Cessna restart machines are starting to enter the SID program and are starting to show problems in the landing gear, vertical fin and hori stab. The landing gear fix for one R model is going to be in excess of 28K.