July 24, 2013

U.S. Department of Transportation

Docket Operations

West Building, Room W12-140

1200 New Jersey Avenue, S.E.

Washington, D.C. 20590

Subject: Petition for Exemption,

Delta Engineering for Project ODA-2265-02

Title 14 CFR § 25.869 (a)(4), amendment 25-113

Subject: Request for immediate exemption from Title 14 CFR §25.869(a)(4) for the wire and cable located 

within certain metal electronic articles.

Introduction:

In accordance with Title 14 CFR Part 11, Delta Engineering is petitioning for an immediate exemption from Title 

14 CFR § 25.869 (a)(4) for the wire and cable located within certain metal electronic articles, where the electronic 

article is located in a non-fire zone. Delta Engineering’s STC project, ODA-2265-02 is for the installation of 

various electronic articles in the fuselage, in the cabin, in the Electronics Rack, and under the floor, of an ATR42 

aircraft. Many of the electronic articles are commercial off the shelf articles and/or are government furnished 

equipment (GFE). 

Title 14 CFR § 25.869 (a)(4) amendment 25-113 states, “ Insulation on electrical wire and electrical cable 

installed in any area of the airplane must be self-extinguishing when tested in accordance with the applicable 

portions of Part I, Appendix F of this part.” This regulation does not provide relief if the wire or cable is located 

within a non-flammable metal case, electronic article or when raped within a non-flammable material. 

Based upon requirements of Title 14 CFR § 25.869 (a)(4) even the electrical wire and cable located within a metal 

case electronic article must be tested per Appendix F. 

Supporting data for the requested exemption:

As provided in FAA Advisory Circular 21-16G the FAA finds the criteria in RTCA DO-160G sufficient for 

compliance with Title 14 CFR Part 25. Within RTCA DO-160G, Section 26.3.3 it is establishes two conditions 

wherein flammability testing is NOT required. As worded the wire and cable within an electronic article that 

meets those conditions would not require flammability testing, even though this would be contrary to the wording 

provided in Title 14 CFR § 25.869(a)(4) amendment 25-113. 
Proposed Requirements for Equivalent level of safety:

To ensure an equivalent level of safety as provided by Title 14 CFR 25.869 (a)(4) amendment 25-113, Delta 

Engineering is proposing the following:

Wire and cable located internal to the electronic articles/ metal cased articles located in non-fire zones if 

any of the following conditions are met:

1) The enclosure is constructed of metal (metal finish that is non-flammable), on all sides, and has no 

vent holes.

2) The enclosure is constructed of metal (metal finish that is non-flammable) on five sides and one side is 

constructed of a material that has met 12 second vertical test, and has no vent holes

3) The enclosure is constructed of metal (metal finish that is non-flammable) on all sides and has vent 

holes, provided test and/or analysis substantiates an external fire event cannot propagate to the inside 

of the metal case and subject any of the wire or cable to the flame. The test and/or analysis 

substantiates an internal fire event cannot propagate out of the metal case and subject any external item 

to a fire that would be located within three inches (3”) of the electronic article.

4) The enclosure is constructed of metal (metal finish that is non-flammable) on five sides with vent 

holes and one side is constructed of a material that has met 12 second vertical test, provided test and/or 

analysis substantiates an external fire event cannot propagate to the inside of the metal case and 

subject any of the wire or cable to the flame. The test and/or analysis substantiates an internal fire 

event cannot propagate out of the metal case and subject any external item to a fire that would be 

located within three inches (3”) of the electronic article.

Public Interest:

Granting this request for exemption would benefit the public by not requiring additional articles to be purchased 

by the government to support flammability testing of the wire and cable that is used on the internal of the 

electronic articles.

Sincerely,

John A. Moritz

President

Phone (302) 325-9337

E Mail jamoritz@delta-engineering.com