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 - 226 5 - 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: Ina ccordance with Title 14 CFR Part 11, Delta Engineering is petitio ning for an immediate exemption from Title 14 CFR § 25.869 (a)(4 ) for the wire and cable located within certain metal electronic article s , where the electronic article is located in a non - fire zone. Delta Engineering’s STC project , ODA - 226 5 - 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. M any 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. W ithin RTCA DO - 160G, Section 26.3.3 it is establishes two conditions wherein flammability

testing is NOT required. A s worded the wire and cable within an electronic article that meets those conditions would not require flammability t esting, 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 e lectronic articles/ metal cased articles located in non - fire zone s if any of the f ollowing 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 anal ys is substantiates an external fire event cann ot propagate to the inside of the metal case and subject any of the wire or cable to the flame. The test and/or anal ys is substantiates an internal fire event cannot propa gate out of the metal case and subject any external item to a fire that would be loc ated within three inches (3”) of the electronic article . 4) The enclosure is constructed of m etal (metal finish that is non - f lammable) 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 anal ys is substantiates an external fire event cannot prop a gate 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 go vernment to support flammability testing of the wire and cable that is used on the internal of the electronic article s . Sincerel y, John A. Moritz President Phone (302) 325 - 9337 E Mail jamoritz@delta - engineering.com