6. FIRE CONTAINMENT BY SIMILARITY REPORT. A unit that is similar in construction, materials, and volume to a unit previously approved by the FAA may be approved without a fire containment test, with a similarity report that satisfactorily demonstrates the similarity.
6.1 PURPOSE. The similarity report should state the purpose, which is to show by similarity to previously approved units, that waste containers, waste compartments, and carts containing combustible materials contain a fire in compliance with this document and the fire containment requirements of § 25.853. The report should also include:
a. Identification by part and drawing number of items to be approved by similarity to previously approved items.
b. Identification of airplane(s) in which the item will be installed as well as the airplane and airline customer for which the original test was conducted. A copy of the original test report should also be attached or referenced.
c. Identify the fire containment requirements of § 25.853 for which compliance will be demonstrated by similarity.
6.2 DESCRIPTION OF SIMILARITY SPECIMEN. Drawing numbers, photographs, etc., for items to be approved by similarity, and previously approved unit to which they are being compared should be provided.
6.3 SIMILARITY REQUIREMENTS.
a. Configuration should be adequately defined by production drawings or equivalent sketches and layouts.
b. Construction or fabrication of the subject unit should be similar to previously approved unit as shown by drawing or sketches with part numbers.
c. Ventilation or air leakage paths (length or area) should be equal to or less than previously approved unit. Air gap dimensions between waste compartment access or chute doors and sill should be shown on sketches or drawings.
d. Compartment volume should be equal to or less than previously approved unit, and tabulated for both units. Include dimensions and volume comparisons of the unit tested and of the unit to be approved by similarity.
e. A statement should be made in the report verifying that the design permits no waste material to fall out of the stowage or waste compartments as installed in the airplane.
6.4 CONCLUSION.
a. A statement should be made in the report verifying that the design confines a fire within the waste compartment and does not present a hazard to personnel or other compartments.
b. A statement should be made in the report that the galley or lavatory waste container and compartments are qualified to the fire containment requirements of § 25.853 based on the attached comparison analysis that shows these units to have equivalent fire containment capabilities of the previously approved test unit documented in the referenced report.
7. PARAGRAPH (e) and (f). Refer to AC 20-42C, dated 3/7/84, “Hand Fire Extinguishers for Use in Aircraft,” for guidance on acceptable fire extinguishers.
THIS PAGE INTENTIONALLY LEFT BLANK
813 APPENDIX 9
ACRONYMS AC Aircraft Certification AC Advisory Circular ACO Aircraft Certification Office AFM Airplane Flight Manual ASTM American Society of Testing and Materials AWG American Gage Size Conductor BTU British Thermal Unit CFR Code of Federal Regulations ELT Emergency Locator Transmitter FAA Federal Aviation Administration FSSR Flight Standards Service Releases
g. G ravity GPH Gallons Per Hour Hg Mercury HIC Head Injury Criterion NACA National Advisory Committee for Aeronautics NASA National Aeronautics and Space Administration PSI Pounds per Square- inch RTO Rejected Takeoff SAE Society of Automotive Engineers SRP Seat Reference Point STC Supplemental Type Certificate TSO Technical Standard Order TT & L Taxi, Takeoff, and Landing
THIS PAGE INTENTIONALLY LEFT BLANK
815 APPENDIX 10 CROSS REFERENCE FOR PRE-AMENDMENT 25-72 AND POST AMENDMENT 25-72
RELOCATION AND REWORDING OF PERTINENT CRASHWORTHINESS SECTIONS BY AMENDMENT 25-72 NOTE: Only those sections, paragraphs or sub-paragraphs that have been relocated are listed here. If the section, paragraph or sub-paragraph is exactly the same between pre and post amendment 25-72, that section, paragraph or sub-paragraph will not appear in the list below. Minor rewording or revisions will also be listed below.
Pre-amendment 25-72 Post-Amendment 25-72
(b) rewritten (content the same)
25.783(g) minor revision (correct previous error)
25.785(a), relocated from § 25.1307(a), Refer to below
25.785(a) (b)
(b) (c)
(c) (d)
(d) (j)
(e) (k)
(f) (e)
(c) rewritten and part moved to (h)(1), part moved to (h)(6)
(h)(1) (h)(2)
(h)(2)(i) (h)(5)
(h)(2)(ii) (h)(3)
(i) (f) & (f) (1)
(i)(1) (f)(1)
(i)(2) (f)(2)
(i)(3) (f)(3)
(j) (h)(4)
25.785(k) (l)
25.791 separated into 25.791(a) and (b)
25.801(a) revised reference from § 25.807(d) to 25.807(f)
25.803(a) minor rewording
(a) 25.807(d)(6)(ii) and (iii)
(b) minor rewording, added content of 25.803(d), Refer to below
(c)(1) Appendix. J (a)
(c)(2) “ (b)
(c)(3) “ (c)
(c)(4) “ (d)
(c)(5) “ (e)
(c)(6) “ (f) Pre-amendment 25-72 Post-Amendment 25-72
25.803(c)(7) Appendix J (g) with minor rewording
(c)(8) “ (h)
(c)(9) “ (i)
(c)(10) “ (j)
(c)(11) “ (k)
(c)(12) deleted, already in Appendix J, (g)
(c)(13) Appendix J (l)
(c)(14) “ (m)
(c)(15) “ (n)
(c)(16) “ (o)
(c)(17) “ (p)
(c)(18) “ (q)
(c)(19) “ (r)
(c)(20) “ (s)
25.803(d) added to 25.803(c)
25.803(d) is reserved in Amendment 25-72
25.803(e) 25.810(c)
25.803(e) is reserved in Amendment 25-72
25.805 25.807(f) with minor rewording
25.807(a),(a)(1),(a)(2),(a)(3),(a)(4) minor rewording
(a)(7),(a)(7)(i),(a)(7)(ii) (a)(7) with minor rewording
(a)(7)(iii),(a)(7)(iv),(a)(7)(v) 25.813(a)
(a)(7)(vi) 25.785(h)(1)
(a)(7)(vii) 25.813(b),(b)(1),(b)(2)
(a)(7)(viii) 25.810(a),(a)(1)
(a)(7)(ix) 25.810(b) and 25.807(b)
(b) 25.813 and 25.807(c)
(b)(1),(b)(2) 25.807(c)
(c) 25.813 with minor rewording
(c)(1),(c)(2) 25.807(d),(d)(1)
(c)(3) (d)(2)
(c)(4) (d)(3)
(c)(5) (d)(4)
(c)(6) (d)(6)(i)
(c)(7) (d)(7)
(d) (e) with minor rewording
817 Pre-amendment 25-72 Post-Amendment 25-72
25.809(d) 25.809(f)
(e) (g)
(f) 25.810(a)
(g) 25.809(e)
(h) 25.810(d) with minor rewording
(i) 25.809(d)
(j) (h)
25.813(a) revised with additional wording
(b) (b),(b)(1),(b)(2)
25.851(a)(1) 25.851(a)(4)
(a)(2) (a)(5)
(a)(3) (a)(6)
(a)(4) (a)(3)
(a)(5) (a)(1) with minor rewording
(a)(6) (a)(2)
(b),(b)(1) minor rewording
25.853 minor rewording
(d) Appendix F, Part I, (a)(1)(i), with minor rewording (a-1) 25.853©
(b) Appendix F, Part I, (a)(1)(ii), with minor rewording (b-1) Appendix F, Part I, (a)(1)(iii), with minor rewording (b-2) Appendix F, Part I, (a)(1)(iv), with minor rewording (b-3) Appendix F, Part I, (a)(1)(v), with minor rewording
(c) 25.853(b)
(d) part (placard requirement) moved to 25.791(a)
(d)(1) 25.853(d)
(d)(2) 25.791(a)
(e) 25.853(f) plus part (placard requirement) moved to 25.791(c)
(f)* 25.853(e) plus part (placard requirement) moved to
25.791(d) and 25.791(e)* NOTE: * last sentence on lettering size and color has been dropped.
25.855(a) 25.855(d) and Appendix F, Part I (a)(2)(i) with liner requirements moving to 25.855(b) and (c)
818 Pre-amendment 25-72 Post-Amendment 25-72
25.855(a-1) 25.855(b) (a-1)(1) (c) (a-1)(2) (d) and Appendix F, Part I (a)(2)(iii) (a-2) (d) and Appendix F, Part I (a)(2)(iv)
(b) (e)
(c) (f)
(d) (g)
(e) (a), (h) and (i) (Note: first sentence of (e) to (a), second sentence of (e) and (e)(1), (e)(2), (e)(3) to (h), and last sentence of (e) to (i)
25.1307(a) 25.785(a) with minor revision and clarification
25.1359(a) 25.869(a)(1)
(e) (a)(2)
(f) (a)(3)
(g) (a)(4) and Appendix F, Part I (a)(4)
25.1413 (removed by amendment 25-72)
(a) unnecessary duplication of 25.791
(b) and (c) transferred and combined with the same requirements for seats
(d) 25.785(i)
25.1415(a) minor revision Some errors created by Amendment 25-72
25.812(g)(1)(ii) references 25.803(e), should be 25.810(c)
25.812(g)(2) references 25.809(f), should be 25.810(a)
25.812(h) references 25.809(f)(1) and (h), should be 25.810(a) and (d)
25.1411(c) references 25.809(f), should be 25.810(a)
819 APPENDIX 11 FAA MEMORANDUM (latest revision) Certification of Strengthened Flightdeck Doors on Transport Category Airplanes U.S. Department of Transportation Federal Aviation Administration
Subject: INFORMATION: Certification of Strengthened Flightdeck Doors on Transport Category Airplanes Date: Original Release:
November 6, 2001 Revised:
December 3, 2002
From: Manager, Transport Airplane Directorate, ANM-100 Reply to Attn. of: Jeff Gardlin 01-115-11 To: Refer to Distribution This memorandum has been revised to include additional information on § 25.772(b) and information contained in the airplane flight manual.
The events of September 11, 2001, have highlighted the importance of expediting the installation of strengthened flightdeck doors to prevent, or at least delay, entry of unauthorized persons into the flightdeck. To accomplish this goal in a very short time, the Federal Aviation Administration (FAA) promulgated Special Federal Aviation Regulation (SFAR) 92, effective October 9, 2001, and subsequent amendments, SFAR 92-1 through SFAR 92-4, the latest being effective March 19, 2002. While earlier versions of the SFAR only encouraged entities operating under part 121 of 14 CFR to install internal locking devices on their flightdeck compartment doors to resist intrusion by unwanted persons, the latest version requires the installation of these devices. To facilitate rapid improvements to security, all versions of the SFAR allow installations that do not meet all of the airworthiness requirements of Title 14 CFR part 25. At this time, most U.S. operators have installed bars and/or bolts on their flightdeck doors.
These installations have usually resulted in a non-compliance with one or more of the part 25 requirements, typically, the decompression requirements of § 25.365, the egress from the flightdeck requirements of § 25.772, and the entry into the flightdeck requirements of §§ 25.807 and 25.809.
On November 19, 2001, the United States Congress enacted Public Law 107-71, the Aviation and Transportation Security Act, henceforth referred to as the Act. Section 104 of the Act required the FAA to issue requirements to improve flightdeck integrity, specifically the strengthening of the flightdeck door. On January 15, 2002, the FAA
820 issued Amendment 25-106 which adds new intrusion resistance and ballistic penetration requirements to part 25. Concurrently, the FAA also issued Amendment 121-288 that requires part 121 passenger operators that are required to have flightdeck doors, and part 121 cargo operators with flightdeck doors installed on that date, to strengthen these doors. Flightdeck doors on these airplanes must meet these new requirements of part 25 by April 9, 2003.
Supplemental Type Certificate (STC) applications involving flightdeck door modification must address all affected regulatory requirements, including, but not limited to: §§ 25.301, 25.303, 25.305, 25.307, 25.365, 25.571, 25.601, 25.605,
25.607, 25.609, 25.611, 25.613, 25.619, 25.625, 25.771, 25.772, 25.777, 25.789,
25.803, 25.807, 25.809, 25.831, 23.853, 25.855, 25.857, 25.1301, 25.1309, and
25.1581. Final determination of the affected regulatory sections is dependent on the complexity and scope of the modification, and the agreed certification basis of the design change. As stated earlier, all the applicable regulatory sections must be addressed and complied with in order for an applicant to be issued an STC.
The regulations that have been most commonly excepted under SFAR 92-4 (§§ 25.365, 25.772, 25.807, 25. 795, and 25.809) will typically pose the greatest challenge for STC applicants. Additionally, other significant requirements that must be addressed by an STC applicant include the ventilation and smoke requirements of § 25.831, § 25.855, § 25.857, and the flammability requirements of § 25.853.
Information about these requirements and possible acceptable design approaches are discussed in the following paragraphs.
Pressurized Compartment Loads:
Background: Changes in decompression venting integral to the flightdeck door, and in the surrounding flightdeck barrier, must be reviewed to ensure compliance with § 25.365. Airplane decompression requirements include both minimum effective vent areas and maximum opening times for blowout panels or similar decompression venting devices. In cases where the entire flightdeck door functions as a large decompression blowout panel, applicants should consider the impact of additional door locking features on the release time, the reliability of the latching system to release under decompression loads, as well as any increases in opening time due to an increase in door mass, special or additional door hinges, etc. Some of these same concerns apply to smaller decompression blowout panels. Applicants must also address reduced decompression venting area due to the addition of grilles, louvers, or similar features, as well as the direction of the required venting (e.g., from the main cabin to the flightdeck or from the flightdeck to the main cabin).
Failure of a decompression mechanism to function could result in a catastrophic failure of the flightdeck structure. Therefore, if the decompression venting relies on an electrically or mechanically actuated release or opening mechanism, the applicant should
821 conduct qualitative and/or quantitative assessments in accordance with Figure 2, "Depth of Analysis Flowchart," in AC (AC) 25.1309-1A, "System Design and Analysis."
FAQ:
Q: Should the effects of loose articles (e.g., newspapers, magazines, blankets, etc.)
blocking the available flightdeck door flow area through grilles, louvers, grates, or similar features be considered?
A: The intent of CFR 25.365(e) is to establish a minimum design level of strength for floors, bulkheads, partitions and other structure to be able to withstand prescribed decompression scenarios. In particular, CFR 25.365(e)(2) currently establishes a hole size based on fuselage cross-sectional area and is intended to cover different decompression scenarios through one simple and conservative criterion.
Since loose articles are not part of the type design, and their effect cannot be quantified with any certainty, loose articles such as newspapers, magazines, or blankets need not be considered in a decompression analysis. However, if there is something inherent to the airplane design that would become detached or would otherwise be free to block a vent
(e.g., a curtain or a lavatory door), then this should be considered in the analysis.
While the intent of the decompression criteria is to establish a simple and conservative level of strength, certain rational assumptions, such as the use of a discharge coefficient, have historically been accepted and will continue to be accepted. Other assumptions may also be accepted. For example, the flow area restriction formed by the flightdeck glareshield and overhead panel, as would occur in the event of a windshield blowout, may be considered, provided that it is shown that these components will remain intact.
Reliability:
The primary purpose of the door systems is to deter and delay unauthorized entry into the flightdeck without compromising aircraft safety. The flightdeck door systems that are developed to comply with the new § 25.795 requirements must have a reliability level commensurate with the security function intended to support the operational strategies for intruder mitigation. Although the conditional probability of an intruder is not considered extremely high (i.e., this probability is less than one), there should be reasonable confidence that the door will deter and delay any intrusion attempt. Systems used to meet flightdeck intrusion, decompression or other safety related criteria, must meet the applicable requirements of § 25.1309. Guidance on compliance to § 25.1309 is provided in AC 25.1309-1A. Reliability guidance is based on section § 25.1309(b) which states:
The airplane systems and associated components, considered separately and in relation to other systems, must be designed so that:
(1) The occurrence of any failure condition which would prevent the continued safe flight and landing of the airplane is extremely improbable, and