November 7, 2013

Subject: Request Exemption from Regulation 14 CFR Part 45.13(a)(4)

Hartzell Propeller Inc. is reque sting an exemption from regulation 14 CFR Part 45.13(a)(4). The following discussion supports this request, but fi rst, here are the applicable regulations of

interest.

Regulation 45.11(c) amendment 45-27 requires: (c) Propellers and propeller blades and hubs. Each person who produces a propeller, propeller blade, or propeller hub under a type certificate or production certificate must mark each product or part using an approved fire proof method. The marking must-- (1) Be placed on a non-critical surface; (2) Contain the information specified in Sec. 45.13 ; (3) Not likely be defaced or removed during normal service; and (4) Not likely be lost or destroyed in an accident.

Regulation 45.13(a) amendment 45-28 requires: (a) The identification re quired by § 45.11 (a) through (c) must in clude the following information: (1) Builder's name. (2) Model designation. (3) Builder's serial number. (4) Type certificate number, if any

. (5) Production certificate number, if any. (6) For aircraft engines, the established rating.

Hartzell Propeller Inc. manufacturers a wide variet y of propeller models that fit a numerous and identical blade models. Table 1 provides a summa ry of the various blad e model series and the number of Type Certificates in to which they could be installe d. (Note: A specific blade design may or may not have been certifi ed for use in each of the eligible hub designs due to workload and lack of a customer request, but th ey could be if and when needed.) Hartzell Propeller Inc. One Propeller Place Piqua, OH 45356-2634 USA

Tel: +1-937-778-4200

Fax: +1-937-778-4271 www.hartzellprop.comTable 1

From table 1, you can see that “Y-shank” propeller blades are capable of being installed into 17 different type-certificated prope llers. Furthermore, all but 3 of our 56 Type Certificated propellers specify propeller blades that fit mu ltiple propellers. The attached spreadsheet provides more detail.

Attached is a photo of a typical “Y-shank” propeller blad e butt, showing the current markings. As you can see, there may not be enough room to squeeze in 17 different TC numbers and even if we could, the blade butt would probably ha ve a crowded and confusing appearance.

We agree there is sufficient space to add one TC designation, but which one should we choose if more than one possibility exists? Since a blad e can be removed from a propeller having one TC number, and installed into a propeller having a nother TC number, the a ppropriate TC number may not be stamped on the blade when it is installe d into the other propelle r type. Interestingly, this does not violate the regulati on since the regulation does not spec ifically require that the TC number on the blade match the TC of the propelle r assembly. However, we probably all agree that such a practice may cause sign ificant confusion in the field.

These regulations and their pred ecessors have for many years required the propeller blade be stamped with the “Type Certificate number, if any” . I believe this topic has been discussed with FAA several times over the decades, but that it ha s never been resolved by issuance of an exemption. Evidence of several di scussions with FAA is containe d in two attached documents:

PDF attachment “FAA correspondence 9-15-2000” FAA e-mail correspondence “Marking Email 11 28 2000 e-mail to Jerry Seay.msg” FAA e-mail correspondence “Re Fw 45.11 and 45.13.msg”

Since this issue continues to peri odically resurface, we request that it be dealt with by issuance of an exemption to the regulation.

Given that there is no known safety of flight concern with the presence or absence of this particular marking, we also question the valu e of marking the TC number on the blade.

Consequently, we request an exemption to regulation 14 CFR Part 45.13(a)(4).

Until FAA advises otherwise, Hartzell wishes to continue our current practice of not marking a TC Number on the blade butt in the expect ation that FAA will grant this exemption. Blade Series No. TC's

A shank 1
D,E shank 4

M shank 3

P shank 2

R shank 1

T shank 2

U shank 1

V shank 8

X shank 10

Y shank 17

Z shank 4Regards,

Richard Edinger (Dick) VP Certification and Flight Safety

Lead ODA administrator Hartzell Propeller Inc 937-214-6544 (Cell)