David Anderson

Dear Sirs While reviewing the proposed AD, I noted that the Applicability section includes model LTS101-600A-2, but this model is not included in the Compliance or Installation Prohibitions section of the AD. Also, while reviewing the Preamble Cost Of Compliance, the FAA estimates only one hour of work per engine with an estimated cost of $8000.00 per engine. To change the GP Disc will require a minimum of 3 hours to access the GP Rotor after engine removal. This does not include balancing or reassembly. The cost of a new replacement disc is list price $22,352.00 with a possibility of scraping the GP Blades at access. This has potential of a $77,000.00 not to exceed exchange price for the GP Rotor assembly. The FAA's assessment of cost is well below what any operator will pay to have the disc replaced.