SENSENICH COMPOSITES, INC. 

AREA CODE 813 

fireproof-exemption-r4.doc 

PHONE - 752-3711 

FAX - 752-2818 

 

2008 WOOD COURT 

PLANT CITY,FL USA 

 33563

See us on the Web @ www.sensenichprop.com

November 16, 2000 

Mr. Jay Pardee 

Manager, Engine and Propeller Directorate 

Federal Aviation Administration 

12 New England Executive Park 

Burlington, MA 01803 

Dear Mr. Pardee, 

 Sensenich Wood Propeller Company, Inc. submits a petition for exemption from 

Title 14 CFR Part 45.11 b (fire proof markings for TCed products) using Sec. 11.81 

Petition for Exemption form. This requested exemption is for all Sensenich wooden 

propellers, as detailed in Type Certificate Data Sheet P-170 and also Type Certificate 

P00001NY. I have written this letter in a question / answer format, please see below: 

Sec. 11.81 Petition for Exemption

(a) Your name and mailing address and, if you wish, other contact information such as a 

fax number, telephone number, or e-mail address; 

Steve Boser 

Engineering Manager 

Sensenich Wood Propeller Co., Inc. 

2008 Wood Court 

Plant City, FL 33567 

813.752.3711 phone 

813.752.2818 fax 

steveb@sensenichprop.com

 (b) The specific section or sections of 14 CFR from which you seek an exemption; 

Title 14 CFR Part 45.11 b 

 (c) The extent of relief you seek, and the reason you seek the relief; 
Sensenich Wood Propeller Co., Inc. requests an exemption from the requirement for 

fireproof identification on propellers. This requested exemption is for all Sensenich 

wooden propellers, as detailed in Type Certificate Data Sheet P-170 and also Type 

Certificate P00001NY. Sensenich manufactures wooden fixed pitch propellers for small 

aircraft using conventional methods of construction and identification. With a few 

exceptions, the population of aircraft that use fixed pitch wooden propellers is limited to 

antique small aircraft. The method of stamping the required part marking information 

into the propeller hub was developed to meet the original permanent identification 

certification requirements of CAM 14.20 prior to the existence of §45.11 b. This 

identification practice has proven satisfactory in over 68 years of Sensenich production, 

in addition to being the industry standard procedure of marking identification for wooden 

propellers within the United States and Europe. When fixed pitch wooden propellers 

are typically damaged, the hub portion remains intact, providing all the required 

information. 

The only means of providing fireproof identification requires mounting a metal tag on the 

propeller hub. Attaching a metal tag to the propeller hub could have detrimental effects 

on propeller safety and identification. The attachment of a metal tag would break the 

moisture seal and increase the potential for cracking and deterioration and would 

increase the difficulty in attaining propeller vertical balance. A metal tag could come 

loose leaving a propeller with no identification. Also, a metal tag would detract from the 

authenticity and historical value of antique small aircraft, the primary users of wooden 

fixed pitch propellers. 

 (d) The reasons why granting your request would be in the public interest; that is, 

how it would benefit the public as a whole; 

The exemption would retain the service proven method of propeller identification while 

preserving the historical value of antique small aircraft without adversely affecting 

safety. 

 (e) The reasons why granting the exemption would not adversely affect safety, or 

how the exemption would provide a level of safety at least equal to that provided by the 

rule from which you seek the exemption; 

When wooden propellers are typically damaged, the hub remains intact, thus preserving 

the stamped required information. This method has proven satisfactory and safe for 

over 68 years of Sensenich production. A change to add a metal tag could adversely 

affect propeller safety 

 

fireproof-exemption-r4.doc 
fireproof-exemption-r4.doc 

 (f) A summary we can publish in the Federal 

 Register, stating: (1) The rule from which you seek the exemption; and (2) A brief 

description of the nature of the exemption you seek; 

Title 14 CFR Part 11 b, states a requirement for fireproof identification on propellers. 

Sensenich requests an exemption from this requirement for wooden fixed pitch 

propellers for the following reasons: 

1. Original intent was for identification means which was not likely to be defaced or 

removed during normal service or destroyed in an accident. The current method of 

directly stamping into the wooden hub has proven satisfactory for over 68 years of 

Sensenich production. Typical damage to a wooden fixed pitch propeller leaves the 

hub intact, thus preserving required information. 

2. Incorporation of metal identification tag would affect environmental resistance (due 

to screws breaking the moisture seal) and also make vertical balancing of the 

propeller more difficult. . 

3. A metal tag could come loose leaving a propeller with no identification. 

4. A metal identification tag would detract from the authenticity and historical value of 

antique small aircraft, the primary users of wooden fixed pitch propellers. 

This requested exemption is for all Sensenich wooden propellers, as detailed in Type 

Certificate Data Sheet P-170 and also Type Certificate P00001NY. 

 (g) Any additional information, views or arguments available to support your request; 

and 

None. 

 (h) If you want to exercise the privileges of your exemption outside the United States, 

the reason why you need to do so. 

No. 

Thank you for your attention to this matter. Please contact me with any questions. 

Sincerely, 

Steve Boser 

Engineering Manager Fireproof-exemption-r4.doc