5. instructions for Continued Airworthiness A PMA applicant may be required to provide instructions for continued airworthiness if the article on which the part is eligible for installation has an existing set of instructions for continued airworthiness that are not considered acceptable for the applicants PMA part (reference part 23, § 23.1529).
6. Identification of PMA Parts
a. General Under part 45, § 45.15, parts produced under a PMA should be permanently and legibly marked in a manner that will enable people to identify the following:
It is a PMA part.
The manufacturer.
The part number.
The type certificated product(s) or TSOA article(s) on which it may be installed.
For a part based on an STC, identifying installation eligible type certified products should include reference to the STC. Under part 45, § 45.14, parts that have been identified as critical components should be marked with a part number, or equivalent, and serial number or equivalent. If the TC or TSOA holder applies serial numbers to a critical part, the PMA holder should also "permanently mark" their parts with serial numbers.
NOTE: Because of the harsh environments that wheels and brakes experience, decals or adhesive backed "metalcals" are not considered permanent forms of marking. Metal stamping, etching or permanently affixing a data plate with rivets or drive screws in a non-critical area is satisfactory. Laser marking is also acceptable if it can be read under 2X magnification. Ink stamping is allowed only if more permanent means are not possible.
b. Part Numbering The PMA holders' part should be numbered so it is sufficiently different from the OEM holders' part number to be distinguishable. The OEM holders' part number with a prefix/suffix is enough for this purpose. The requirements of part 45, § 45.15(a)(2), to mark with name, trademark, or symbol of the PMA holder may be satisfied by the prefix/suffix if the prefix/suffix is done consistently across the PMA holders product line. The FAA-PMA letter should show the type approved part number with which the PMA holders' part is interchangeable.
c. Parts Manufactured Under License When the PMA is issued by showing evidence of a license agreement or equivalent, the PMA part number may be identical with that on the type certificated part providing the PMA holder also meets the requirements of part 45, § 45.15(a)(1) and (2) to permanently mark the part with the letters "FAA-PMA" and the name, trademark, or symbol of the PMA holder.
d. Parts that are Impractical to Mark
Where the part is found by the FAA to be too small (or to have other characteristics that make it impractical) to mark all (or any) of the information on the part, the information not marked on the part should be put on the tag that is attached to the part or marked on the container for the part. If the number of certificated products or TSOA articles on which the part is eligible for installation is too long to be practicable to include with the part, the tag or container may refer to a readily available manual or catalog made available by the PMA holder for part eligibility information.
Amendment 23-7 and Subsequent
Amendment 7 was a major change in the standard. The following explanation in NPRM 67-14 is stated as follows: “Part 23 does not provide for the determination of the energy absorption requirements of brakes. The present requirement in Sec.
23.735 (b) may not ensure the design of wheel brake combinations adequate for safe operation of the airplane. Proposed Sec. 23.735 (a) would therefore provide standards similar to the energy absorption determination requirements for transport category airplanes (Sec. 25.735 (f)). Proposed Sec. 23.735(b) would reflect the fact that, for aircraft with high power-to-weight ratios, it may be impossible to prevent motion, with locked wheels, when takeoff power is applied to the critical engine.
Some question has arisen as to whether such motion constitutes "rolling" of the airplane within the meaning of present (a). It is not the intent of present (a) to prevent this motion, but only to ensure that the brakes can prevent the wheels themselves from rolling. The proposed energy absorption requirements reflect current industry practice in the design of small airplanes.”
Amendment 23-42 and Subsequent
Guidance for 14 CFR part 23, § 23.735, Brakes, and Specific Sections versus § 23.1309; Equipment, Systems and Installations
Brake systems are approved based on compliance to the specific standard, § 23.735, not the general standard, § 23.1309. This is true for any installations where there are specific standards in 14 CFR, part 23 (that is, brakes, autopilots, and ice protection systems).
79 In the past, the Small Airplane Directorate has not considered brake failures catastrophic or severe-major because of mitigating factors, which include: low stall speeds, minimum field lengths for landing, and propeller feathering or reverse thrust.
For commuter category airplanes where loss of the brakes is catastrophic or severemajor, FAA will accept an emergency brake system or a single failure in the primary system that meets the following requirements (based on § 25.735(b)):
In the following circumstances, the brake system and associated systems must be designed and constructed so the airplane may be brought to rest under conditions specified in § 23.75:
If any electrical, pneumatic, hydraulic, or mechanical connecting or transmitting element (excluding the operating pedal or handle) fails, or
If any single source of hydraulic or other brake operating energy supply is lost.
The airplane can be brought to rest with a mean deceleration during the landing roll of at least 50 percent of that obtained in determining the landing distance as prescribed in that section. Subcomponents in a brake assembly such as brake drums, shoes and actuators (or their equivalents), should be considered as connecting or transmitting elements unless it is shown that leakage of hydraulic fluid from a failure of sealing elements in these subcomponents would not reduce the braking effectiveness below that specified in this paragraph.
FAA agrees that requiring an emergency brake system is not desirable for small single-engine airplanes. FAA cannot agree that brake system failure for commuter category and jet powered airplanes can automatically be classified as severe-major.
Mitigating factors must always be considered for any part 23 airplanes.
Change 1 AC 23-17C 7/16/2012
80 Amendment 23-49 and Subsequent
The intent of the proposed revision in NPRM 94-21 is given as follows: “Section
23.735(a) would be revised to state plainly that wheel brakes must be provided. A proposed new Sec. 23.735(c) would require the brake system to be designed so that the brake manufacturer's specified brake pressures are not exceeded during the landing distance determination required by Sec. 23.75. Proposed new Sec. 23.735(e), applicable to commuter category airplanes, would require establishing the minimum rejected takeoff brake kinetic energy capacity rating of each main wheel brake assembly. Section 23.45 provides that the determination of the accelerate-stop distance for commuter category airplanes be made in accordance with the applicant's procedures for operation in service. The proposed requirement is needed to ensure that the brakes will perform safely under accelerate-stop conditions.”
EASA AMC effective February 12, 2009, AMC 23.735(c) is acceptable for FAA certification.
Amendment 23-62 and Subsequent
In Docket No. FAA-2009-0738, the Discussion of the Regulatory Amendments stated: FAA revised the commuter category rejected takeoff requirements for all multiengine jet airplanes over 6,000 pounds. The higher takeoff speeds and distances for these aircraft make the ability to stop in a specified distance a safety issue.
Therefore, FAA revised the requirements in § 23.735(e) to apply to all multiengine jet airplanes over 6,000 pounds as well as all commuter category airplanes.”
This amendment changes the requirement for the wheel/brakes to meet § 23.735(e) if the airplane must comply with § 23.55. That section requires the accelerate-stop distance be determined and is applicable to normal, utility, and acrobatic category multiengine jet airplanes of more than 6,000 pounds maximum weight as well as commuter category airplanes.
The Final Rule adopted Section 23.735 as proposed.
23.737 Skis
The corresponding rule in CAR 3 is CAR 3.364.
There is no corresponding airworthiness criteria in the Airship Design Criteria.
Amendment 23-45 and Subsequent
See § 23.505, Supplementary conditions for ski-planes, for additional guidance about aircraft skis.
23.745 Nose/tail wheel steering
No policy available as of December 31, 2007.
There are no corresponding rule or airworthiness criteria in CAR 3 or the Airship Design Criteria.
83 Section 3. Floats And Hulls
23.751 Main float buoyancy
The corresponding rule in CAR 3 is CAR 3.371.
There is no corresponding airworthiness criteria in the Airship Design Criteria.
Original Issue and Subsequent
For a twin float seaplane or amphibian aircraft, the 80 percent excess buoyancy requirement should be applied to both rather than each float.
The rules for twin float aircraft do not address water stability or capsizing. They only require the aircraft remain afloat with any two compartments of the main floats flooded. The history does not support the position the aircraft will remain afloat indefinitely without capsizing with two compartments flooded. However, if an unsafe condition exists, certification should be denied under part 21, § 21.21(b)(2).
An example of an unsafe condition could be capsizing so rapidly the occupants could not safely exit. Capsizing that is delayed long enough to permit taxi to the shore or dock is not an unsafe condition. The time to capsize should be listed in the Emergency Procedures Section of the AFM.
Amendment 23-45 and Subsequent
This amendment adopted a proposed revision to NPRM 90-18 that stated: “This proposal revises Section 23.751 to clarify the buoyancy requirements for main floats in paragraph (a)(1) by specifying an 80 percent excess in buoyancy for each main float above the buoyancy required by that float to support the maximum weight of the seaplane. Additionally, the words "without capsizing" are added to paragraph (a)(2) to clarify the extent of flotation necessary after main float compartment flooding.
A strict interpretation of existing Section 23.751(a)(1) results in a buoyancy excess of 80 percent of the maximum weight of the seaplane when the design consists of only one main float, or a total of 180 percent of the maximum weight. However, on seaplanes having two main floats, each float would be required to have buoyancy of 80 percent in excess of that necessary to support the seaplane, or 180 percent of the maximum weight of the seaplane; for a total of 360 percent of the maximum weight.
For designs having three floats, each float would be required to support 180 percent of the maximum weight for a total of 440 percent. This is neither the intent of the rule nor the practice of industry.
The change to paragraph (a)(2) is intended to clarify the fact that the seaplane be afloat in the upright condition.”
23.753 Main float design
There is no policy available as of December 31, 2007.
There are no corresponding rule or airworthiness criteria in CAR 3 or the Airship Design Criteria.
23.755 Hulls
The corresponding rule in CAR 3 is CAR 3.372.
There is no corresponding airworthiness criteria in the Airship Design Criteria.
Original Issue
The discussion on capsizing and unsafe conditions in § 23.751 applies to this rule also.
Amendment 23-45 and Subsequent
This amendment changed the rule to prohibit capsizing in fresh water for planes over 5,000 pounds with two adjacent compartments flooded, and those between 1,500 and 5,000 pounds with any single compartment flooded.
23.757 Auxiliary floats
There is no policy available as of December 31, 2007.
This rule was adopted on February 1, 1965 as a recodification of CAR 3.373.
There is no corresponding airworthiness criteria in the Airship Design Criteria.
87 Section 4. Personnel And Cargo Accommodations
23.771 Pilot compartment
There is no policy available as of December 31, 2007.
The corresponding rule in CAR 3 is CAR 3.381.
The corresponding airworthiness criteria is section 4.28, Airship Design Criteria, FAA-P-8110-2, Change 2.
23.773 Pilot compartment view
The corresponding rule in CAR 3 is CAR 3.382.
The corresponding airworthiness criteria is section 4.29, Airship Design Criteria, FAA-P-8110-2, Change 2.
Amendment 23-14 and Subsequent
See AC 23-8C, “Flight Test Guide for Certification of Part 23 Airplanes,” for guidance on this regulation. EASA AMC effective February 12, 2009, AMC
23.773 references the CS-23 Flight Test Guide.
Amendment 23-45 and Subsequent
A proposed revision in NPRM 90-18 explains the rewrite of this section as follows:
“This proposal is based in part on conference recommendation 272, on conference comments, and on a post conference review of the adequacy of previous certifications, which establishes a precedent for compliance with existing Section
23.773. It is not the intent of this proposal to require windshield heat on all small airplanes, to preclude open cockpit designs or to prohibit the pilot from using a cloth to wipe the windows. It does, however, define requirements to assure that a means exists to remove or prevent the formation of fog or frost on the inside of the windshield, specifies the extent of credit to be given to pilot actions and defines the area of windshield and windows to be kept clear.
Paragraph (a)(1) of this proposal requires an extensive, clear, and undistorted view sufficient to enable the pilot to perform any maneuvers within the operating limitations of the airplane, and specifies particular operations, such as taxi, takeoff, approach and landing to clarify the extent of view necessary for safe operation.
Paragraph (b) of this proposal is included to address the condition where an airplane is operated at high altitudes, becomes cold-soaked, and is then descended into warm, moist air. Such conditions have resulted in the formation of frost on the inside surface of the windshield and crew compartment windows, which resulted in a limited or completely obscured view. Since, in such cases, compliance has been shown for the current Section 23.773(a)(3), a rule change is appropriate to address this condition. The FAA proposes to revise Section 23.773 to identify this condition and to clarify the extent of actions taken by the pilot to remove such moisture.”
The Final Rule 26269 for Amendment 23-45 states as follows: “The FAA proposed to revise the 23.773 requirements for the pilot compartment view to address the environment expected in all the operations requested for certification. The JAA states that it will consider this change for JAR 23 but that it proposes to retain present paragraph (b) relating to night flight tests. The GAMA contends that the words "must