November 7, 2013 

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

Hartzell Propeller Inc. is requesting an exemption from regulation 14 CFR Part 45.13(a)(4). The 

following discussion supports this request, but first, 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 fireproof 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 required by § 45.11 (a) through (c) must include 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 variety of propeller models that fit a numerous and 

identical blade models. Table 1 provides a summary of the various blade model series and the 

number of Type Certificates into which they could be installed. (Note: A specific blade design 

may or may not have been certified for use in each of the eligible hub designs due to workload 

and lack of a customer request, but they 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.com
Table 1 

From table 1, you can see that “Y-shank” propeller blades are capable of being installed into 17 

different type-certificated propellers. Furthermore, all but 3 of our 56 Type Certificated 

propellers specify propeller blades that fit multiple propellers. The attached spreadsheet 

provides more detail. 

Attached is a photo of a typical “Y-shank” propeller blade 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 have 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 blade can be removed from a propeller having one TC 

number, and installed into a propeller having another TC number, the appropriate TC number 

may not be stamped on the blade when it is installed into the other propeller type. Interestingly, 

this does not violate the regulation since the regulation does not specifically require that the TC 

number on the blade match the TC of the propeller assembly. However, we probably all agree 

that such a practice may cause significant confusion in the field. 

These regulations and their predecessors 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 has never been resolved by issuance of an 

exemption. Evidence of several discussions with FAA is contained 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 periodically 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 value 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 expectation 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 4
Regards, 

Richard Edinger (Dick) 

VP Certification and Flight Safety 

Lead ODA administrator 

Hartzell Propeller Inc 

937-214-6544 (Cell)