Appendix 1 49
5. Stall Warning Installation of the artificial Stall Warning System on the PA-18 is optional. Most of the PA-18's in Alaska do not have the system installed. The airplane tested did have the artificial Stall Warning System, and a number of test points were obtained with the system deactivated. The airplane as tested does not have an aerodynamic stall warning.
Appendix 2 50 APPENDIX 2 A "COMPLIANCE CHECKLIST" TO CAR PART 3, AS AMENDED TO NOVEMBER 1, 1949 Subpart B—Flight Requirements Weight Range and Center of Gravity Section Subject
3.71 Weight and balance
3.72 Use of ballast
3.73 Empty weight
3.74 Maximum weight
3.75 Minimum weight
3.76 Center of gravity position Performance Requirements—General
3.81 Performance*
3.82 Definition of stalling speeds*
3.83 Stalling speed* Takeoff
3.84 Takeoff* Climb
3.85 Climb* Landing
3.86 Landing* Flight Characteristics
3.105 Requirements* (exclude § 3.117) Ground and Water Characteristics
3.143 Requirements*
Appendix 2 51 Flutter and Vibration Section Subject
3.159 Flutter and vibration (vibration only) * Indicates topics identified by NTSB Safety Recommendation A-95-13 Subpart C—Strength Requirements Symmetrical Flight Conditions (Flaps Retracted)
3.189 Airplane equilibrium Flaps Extended Flight Conditions
3.190 Flaps extended flight conditions Unsymmetrical Flight Conditions
3.191 Unsymmetrical flight conditions Control Surface Loads
3.211 General
3.212 Pilot effort
3.213 Trim tab effects Horizontal Tail Surfaces
3.214 Horizontal tail surfaces Vertical Tail Surfaces
3.219 Maneuvering loads Control System Loads
3.231 Primary flight controls and systems Ground Loads
3.241 Ground loads
3.242 Design weight
3.243 Load factor for landing conditions
Appendix 2 52 Landing Cases and Attitudes Section Subject
3.244 Landing cases and attitudes Ground Roll Conditions
3.248 Braked roll
3.249 Side load Subpart D—Design and Construction Control Systems
3.342 Proof of strength Landing Gear
3.351 Tests
3.352 Shock absorption tests
3.353 Limit drop tests
3.354 Limit load factor determination
3.355 Reserve energy absorption drop tests Wheels and Tires
3.361 Wheels
3.362 Tires Brakes
3.363 Brakes Subpart E- Propulsion Systems
3.429 Fuel System General
3.437 Unusable Fuel
3.444 Fuel Tank Sump
3.553 Fuel Tank Drains
3.583 Cooling Tests
3.605 Induction System General
3.606 Induction Systems de-icing and anti-icing provisions
Appendix 2 53 Subpart F—EQUIPMENT Landing Lights
3.699 Landing light installation Subpart G—OPERATING LIMITATIONS AND INFORMATION
3.735 General Limitations
3.737 Limitations
23.735 Brakes Original Issue and Subsequent Brake Replacement and Modified Parts
1. Related regulations and documents are:
a. Regulations Acceptable means of compliance are found in 14 CFR part 23. Additional specific information is listed below, including other regulatory material and advisory information. Part 23 sections may be used in showing compliance with the corresponding sections of the former Civil Air Regulations (CAR) for airplanes where the CAR regulations are applicable.
For convenience, the former CAR section reference is also shown in parenthesis following the part 23 section reference:
Part 21, § 21.15 Application for type certificate Part 21, § 21.93 Classification of changes in type design (TC) Part 21, § 21.113 Requirement of supplemental type certificate Part 21, § 21.303 Replacement and modification parts Part 21, § 21.611 Design changes (TSO) Part 23, § 23.55 Accelerate-stop distance Part 23, § 23.75 (3.86) Landing Part 23, § 23.143 (3.106) Controllability and maneuverability:
General Part 23, § 23.231 (3.144) Longitudinal stability and control Part 23, § 23.233 (3.145) Directional stability and control Part 23, § 23.493 (3.248) Braked roll conditions
Appendix 2AC 23-17A 55 Part 23, § 23.731 (3.361) Wheels Part 23, § 23.735 (3.363) Brakes Part 23, § 23.1301 (3.652) Function and installations Part 23, § 23.1309 Equipment, systems, and installations Part 23, Appendix D Wheel spin-up and spring back loads Part 23, § 23.1529 and Instructions for Continued Airworthiness Appendix G to Part 23 Part 135, Appendix. A Additional airworthiness standards for 10 or more passenger airplanes Part 45, § 45.14 Identification of critical components Part 45, § 45.15 Replacement and modification parts
b. Advisory Circulars (AC's) AC 21.303-2H Announcement of Availability: Parts Manufacturer Approvals1992 (Microfiche) AC 23-8A Flight Test Guide for Certification of Part 23 Airplanes
c. Technical Standard Order (TSO) TSO-C26c Aircraft Wheels and Wheel-Brakes Assemblies, with Addendum I
d. Industry Documents ARP 597C Wheels and Brakes, Supplementary Criteria Design for Endurance-Civil Transport Aircraft ARP 813A Maintainability Recommendations for Aircraft Wheels and Brakes AIR 1064B Brake Dynamics AS 1145A Aircraft Brake Temperature Monitor System
56 ARP 1619A Replacement and Modified Brakes and Wheels
2. BACKGROUND A review of recent replacement and modification wheel/brake system and installation approvals on part 23 airplanes has resulted in the need to provide FAA guidelines that clearly describe the changes and associated substantiation procedures involved. As contained herein, these guidelines will reflect upon issues that have been identified by industry under Aerospace Recommended Practice (ARP) 1619, revision A, which, in part, concerns the variance in compliance provisions associated with original equipment manufacturers (OEM) and non-OEM applicants. The guidelines will include a description of replacement or modified wheel, wheel/brake parts or assembly changes, a description and examples of associated "major" and "minor" changes, and a description of corresponding laboratory and airplane flight tests needed to ensure that requested changes will result in a continued level of airplane safety and performance.
3. CLASSIFICATION OF REPLACEMENT AND MODIFIED WHEEL/BRAKE
CHANGES
a. Replacement of Wheel, Wheel/Brake Parts, or Assembly Changes A replacement wheel, wheel/brake part, or an assembly change is classified as one in which either the included parts or assemblies that are being changed are of equivalent design that will result in an equivalent level of certified type performance and safety to that exhibited by either the originally approved parts or assemblies. The change may be approved under a Parts Manufacturer Approval (PMA) by the provisions of part 21. Under part 21, § 21.303, an applicant may be eligible for approval of either PMA replacement parts or assemblies, or both, by demonstrating compliance in accordance with the following methods, as applicable:
(1) Licensing Agreement Applicant should provide evidence of a licensing agreement or equivalent with the holder of a Technical Standard Order Authorization (TSOA), Type Certificate (TC), or a Supplemental Type Certificate (STC) together with the submission of any design data covered by the licensing agreement, as determined by the FAA.
(2) Identicalness Applicant should provide evidence that the parts he produces will be identical in all respects to the corresponding parts of an approved 14 CFR type design, Technical Standard Order, or Parts Manufacture Approval. Data submitted should include all applicable design, material, and process specifications: that is, technical data that would specify all dimensions, tolerances, materials, processes, and specifications to the design of the corresponding part of an approved design.
Appendix 2AC 23-17A 57
(3) Airworthiness Requirements (Tests and Analyses) Applicant should provide evidence—in the form of drawings, test reports, computations, and other substantiating data—showing that the part meets either the applicable part 23 airworthiness requirements or the certification basis under which the airplane was approved.
Compliance to applicable part 23 airworthiness requirements may include the following:
(a) Part 23, § 23.55 and Accelerate-stop distance for Part 135, Appendix A commuter category airplanes and other airplanes that have accelerate-stop distance requirements, including airplanes that have published data such as stopping distances and brake energy/cooling charts in the Airplane Flight Manual.
(b) Part 23, § 23.75 Landing.
(c) Part 23, § 23.143 Controllability and maneuverability: General.
(d) Part 23, § 23.231 Longitudinal stability and control.
(e) Part 23, § 23.233 Directional stability and control.
(f) Part 23, § 23.493 Braked roll conditions.
(g) Part 23, § 23.731 Wheels.
(h) Part 23, § 23.735 Brakes.
(i) Part 23, § 23.1301 Function and installation.
(j) Part 23, § 23.1309 Equipment, systems, and installations.
(k) Part 23, § 23.1529 and Instructions for Continued Appendix G to Part 23 Airworthiness.
(l) TSO-C26c Aircraft Wheels and Wheel-Brakes Assemblies, with Addendum 1.
[Note: A description of the certification basis in which an airplane was approved can be obtained from the FAA.]
b. Identical Wheel, Wheel/Brake Parts, or Assembly An identical wheel, wheel/brake part, or assembly is classified as a replacement in which either the included parts or assemblies being changed are of an identical design and will result in an equivalent level of demonstrated performance to that exhibited by either the originally approved parts or assemblies.
c. Modified Wheel, Wheel/Brake Parts, or Assemblies May Be Approved Under a Provision of Part 21 Under part 21, § 21.303, an applicant may be eligible for approval of modified wheel, wheel/brake parts, or assemblies by demonstrating compliance to methods identified under the above paragraph 3(a)(3) “Airworthiness Requirements (Tests and Analysis)”.
d. Major and Minor Wheel, Wheel/Brake Parts, or Assembly Changes Since design changes appropriate to replacement and modified wheels, wheel/brake parts, or assemblies may involve changes to the original TSO wheel or wheel/brake assembly approval basis under an STC or TC in which the wheel or wheel/brake was installed, compliance to applicable provisions for "major" and "minor" design changes under part 21, § 21.93 or § 21.611, or both, should also be complied with per the following:
(1) Major Design Changes A major design change to an existing TSO approved assembly is one that would require a substantially complete investigation of change for compliance to requirements under the TSO, and would result in a new type or model designation. A major design change to an airplane's type design or certification basis is one that could appreciably affect the weight, balance, structural strength, reliability, operational characteristics or other characteristics affecting the airworthiness of the airplane. Examples of such major design changes involving the wheel, wheel/brake parts, or assemblies include, but are not limited to, the following:
(a) Structural material changes and friction material composition changes of heat sink elements that result in changes to FAA-approved performance data.
(b) Reduction of original heat sink mass.
(c) Change in the total brake actuation load or area.
(d) Changes in the friction radius, the total number, or the area of friction faces or elements.
(e) Fuse plug relocation in the wheels, change in release temperature, or a fuse plug redesign where a minor change has not been substantiated.
Appendix 2AC 23-17A 59
(f) Changes that would adversely affect the temperature-time profile of either a wheel or fuse plug, or both.
(g) Relocation of "overpressure release" or "inflation valve."
(h) Redesign of the wheel in a wheel/brake assembly, including a reduction in the wheel or brake structure that could adversely affect wheel strength or fatigue life.
(i) Reduction in the wheel tie-bolt diameter or material strength of bolt and nut.
(j) Change in the wheel bearing size that could or would adversely affect the wheel or bearing load capacity.
(k) Changes in the wheel structural strength, deflection, fatigue life, or weight.
(2) Minor Design Changes A minor design change to the TSO assembly (or airplane once the assembly is installed) is one that would have no appreciable affect on either the performance of the original TSO assembly or the certification basis (as identified above for major change) of the airplane in which the assembly is to be installed. Investigation into further compliance and FAA approval would normally be limited to minimal functional and compatibility tests. Original model numbers would be retained while part numbers could be used to identify minor changes for TSOA. See paragraph 6.b. “Part Numbering.” of this AC in § 23.735 Brakes, for PMA part numbering requirements. Examples of potential minor design changes involving wheel, wheel/brake parts or assemblies might include but are not limited to the following:
(a) Brake friction material changes or heavier heat sink elements that do not result in a change of FAA-approved performance data.
(b) Structural improvements to improve fatigue life.
(c) Paint/corrosion protection changes.
(d) Changes to bleed ports or tube and service fittings.
(e) Revised over-inflation devices.
4. SUBSTANTIATION PROCEDURES Replacement and modified wheels, wheel/brake parts or assembly changes should be substantiated by conducting the necessary analytical investigations, laboratory testing, or airplane testing, or all of these, to ensure that the change can be made without adversely affecting aircraft safety and associated braking and rolling performance. A substantiation plan should first be proposed by the applicant for FAA approval followed by the applicant's implementation of the plan.
a. Substantiation Plan A proposed substantiation plan may be presented to the FAA for approval that identifies the applicant's requested change and intended approach in substantiating the change in accordance with the methods addressed under this section. The plan should include the following:
(1) A description of the replacement or modified part or assembly, or both.
(2) An assessment covering the applicable airworthiness requirements involved.
(3) A statement of change that is determined to be either "major" or "minor" along with the basis for the classification relative to the applicable requirements of part 21.
(4) An assembly drawing reflecting the replacement or modified part or assembly, or both.
(5) Aircraft installation drawings/instructions.
(6) The substantiation method, which includes an analysis/test protocol.
(7) The method of identification and maintenance procedures that will be utilized.
(8) The quality management and quality assurance system under which either the part or assembly, or both, will be produced.
b. Substantiation Requirements As contained herein, the recommended substantiation requirements for replacement and modified wheels, wheel/brake parts or assemblies are based upon changes for which approval is requested, and the impact a new part or assembly will have on prior certification. If the replacement and modified wheel, wheel/brake part or assembly meets the minimum applicable airworthiness requirements to the product (airplane) on which either the part or assembly, or both, is to be installed, but not the Airplane Flight Manual (AFM) performance data, then the applicant should provide the applicable performance data in an FAA approved AFM or AFM supplement.
Depending upon the type and extent of change (as defined under “Section 3, CLASSIFICATION OF REPLACEMENT AND MODIFIED WHEEL/BRAKE CHANGES”) and either engineering or pilot judgment, or both, FAA approval will be determined on the basis of compliance with the following substantiation requirements: