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| ![           | Federal Aviation                                      |
| ](media/imag |                                                       |
| e1.png){widt | Administration                                        |
| h="1.0569444 |                                                       |
| 444444445in" |                                                       |
| height       |                                                       |
| ="1.05694444 |                                                       |
| 44444445in"} |                                                       |
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| **           |                                                       |
| Memorandum** |                                                       |
+--------------+-------------------------------------------------------+

Date: October 15, 2007

To: See Distribution

From: Manager, Small Airplane Directorate

Prepared by: Leslie B. Taylor, ACE-111

Subject: PS-ACE100-2007-002; Policy Statement; 14 CFR Part 23,
§§ 23.853, 23.855, 23.863 and 23.1359, Flammability of MIL-C-17/60, /93,
/94, /113, /127, and /128 Coaxial Cable

> **Summary**

This policy memorandum clarifies Federal Aviation Administration (FAA)
certification policy on 14 CFR part 23 and the Airship Design Criteria
(ADC). Coaxial cables with Type IX jackets, MIL-C-17/60, /93, /94, /113,
/127, and /128, have been tested and found to comply with 14 CFR part
25, § 25.869(a)(4) and applicable section of Appendix F, part I (a)(3)
for self-extinguishing. The self-extinguishing requirements in part 23
for the average burn length and the average flame time of the insulation
and droppings are the same as part 25. Therefore, this coaxial cable
meets or exceeds the part 23 requirements in Subparts D & F and may be
installed in part 23 aircraft and airships without further flammability
testing.

Applicability

This policy statement clarifies part 23, §§ 23.853, 23.855, 23.863 and
23.1359 for installing coaxial cable in part 23 aircraft. It applies to
normal, utility, acrobatic, and commuter category airplanes. It also
applies to non-rigid airships (ADC sections 4.39, 4.40 and 6.21)
certificated in the normal category (14 CFR part 21, § 21.17(b)) with
nine passenger seats or less.

**References**

§ 23.853 Passenger and crew compartment interiors

§ 23.855 Cargo and baggage compartment fire protection

§ 23.863 Flammable fluid fire protection

§ 23.1359 Electrical system fire protection

**Policy**

This policy applies to the coaxial cables with Type IX jackets (extruded
fluorinated ethylene propylene (FEP)) listed below:

MIL-C-17/60 (RG142)

MIL-C-17/93 (RG178)

MIL-C-17/94 (RG179)

MIL-C-17/113 (RG316)

MIL-C-17/127 (RG393)

MIL-C-17/128 (RG400)

These coaxial cables can be installed in part 23 aircraft and airships
without further flammability testing. The coaxial cables have been
tested and found to comply with part 25, § 25.869(a)(4) and applicable
section of Appendix F, part I (a)(3) for self-extinguishing. Part 25,
Appendix F, part I (a)(3) requires insulation on electrical wire or
cables be self-extinguishing when subjected to the 60 degree test. The
average burn length may not exceed 3 inches, and the average flame time
after removal of the flame source may not exceed 30 seconds. Droppings
from the test specimen may not continue to flame for more than the
average of 3 seconds after falling.

The self-extinguishing requirements in part 23 for the average burn
length and the average flame time of insulation and droppings are the
same as part 25. Therefore, this coaxial cable meets or exceeds the part
23 requirements for self-extinguishing flammability for electrical wire
and cables in Subparts D & F of part 23.

Other MIL-C-17 coaxial cable not listed in this policy must be
flammability tested per the applicable part 23 or ADC requirement.

MIL-C-17 includes some cables with Polyvinyl Chloride (PVC) jackets.
These cables should not be used in new installations due to the
toxicity, corrosiveness, and flammability characteristics of PVC
by-products from burning.

## Effect of Policy

The general policy stated in this document does not constitute a new
regulation or create what the courts refer to as a \"binding norm.\" The
FAA Aircraft Certification Offices (ACOs) should implement this policy
when applicable to the specific project. Whenever an applicant\'s
proposed method of compliance is outside this established policy, it
must be coordinated with the policy issuing office, for example, through
the issue paper process or equivalent. Similarly, if the implementing
office becomes aware of reasons that an applicant\'s proposal that meets
this policy should not be approved, the office must coordinate its
response with the policy issuing office.

Applicants should expect that the certificating officials will consider
this information when making findings of compliance relevant to new
certificate actions. Also, as with all advisory material, this policy
statement identifies one means, but not the only means, of compliance.

For questions about this policy, please contact Mr. Leslie Taylor by
telephone at (816) 329‑4134, by fax at (816) 329-4090, or by e-mail at
leslie.b.taylor@faa.gov.

Distribution:

Manager, Anchorage Aircraft Certification Office, ACE-115N

Manager, Atlanta Aircraft Certification Office, ACE-115A

Manager, Chicago Aircraft Certification Office, ACE-115C

Manager, Wichita Aircraft Certification Office, ACE-115W

Manager, Military Certification Office, ACE-115M

Manager, Boston Aircraft Certification Office, ANE-150

Manager, New York Aircraft Certification Office, ANE-170

Manager, Denver Aircraft Certification Office, ANM-100D

Manager, Los Angeles Aircraft Certification Office, ANM-100L

Manager, Seattle Aircraft Certification Office, ANM-100S

Manager, Ft. Worth Aircraft Certification Office, ASW-150

Manager, Ft. Worth Special Certification Office, ASW-190

Manager, Transport Airplane Directorate, ANM-100

Manager, Engine & Propeller Directorate, ANE-100

Manager, Rotorcraft Directorate, ASW-100

Manager, Brussels Aircraft Certification Staff, AEU-100

Manager, Aircraft Engineering Division, AIR-100