Headquarters Office 1933 Dover Road,  Epsom, New Hampshire 03234 Phone:  603-736-4892           Fax: 603-763-3323   Engineering Office 150 High Street,  Canton, Massachusetts 02021-3611 Phone:  781-828-0451            Fax:  781-821-4091

April 27, 1999 (date written)

October 15, 2001 (date revised)

TO: Turbo Products / Northstar Turbine Customers.

Gentlemen:

Turbo Products holds FAA PMA on a large number of parts. Six of them contain design changes (i.e. improvements) which make them different from the PWC parts they replace. They are: CT blades P/N T023401, T102401-01, T102401-100, T102401-792, CT vane rings P/N T032651, and CT vanes P/N T019551. Since these parts are NOT identical to the PWC parts they replace, the FAA has required us to provide field inspection criteria.

Today I spoke with Mr. Ben Granatek, FAA Engine Certification Office, Burlington MA. Since he had reviewed the above mentioned procedures, I asked him if similar procedures were necessary for the Turbo Products FAA PMA parts which were made from the same material and which were as close to dimensionally identical as reverse engineering would allow. Mr. Granatek's response was that FAA policy was NOT to require procedures for FAA PMA parts which were either exactly identical or essentially identical to the parts they replaced.

Based on the above conversation, I will NOT write, approve or distribute corresponding field inspection procedures for the following Turbo Products FAA PMA parts: segment P/N T019438, segment P/N T018503, heat shield P/N T006888, clamp P/N T017860, inner support P/N T028229, housing P/N T020259, segment P/N T020484, segment P/N T020485, cover P/N T011438, lock plate P/N T012057, housing P/N T020258, ring P/N T024979, shroud P/N T010231, and cover P/N T016058, because they are unnecessary.

HOWEVER, Dean Machine Products and Connecticut Turbine Technologies remain the only facilities authorized to perform overhaul inspection and repair on these above listed parts.

Sincerely,

Ralph Hawkins

Chief Engineer

Northstar Turbine LLC