The applicable simple answer to your question is contained in the AD
i.e.
3. Will not have a significant
economic impact, positive or negative,
on a substantial number of small entities
under the criteria of the Regulatory
Flexibility Act.
We prepared a summary of the costs
to comply with this AD and placed it in
the AD Docket. You may get a copy of
this summary at the address listed
under ADDRESSES.
Typically it's initally an inspection cost and all large operators have a pretty good handle on this.
In some cases operators may have left their engines on wing too long to pass the initial evaluation and if so it's catch up time on their cost management ouija boards