729. § 27.1529 (Amendment 27-18) INSTRUCTIONS FOR CONTINUED AIRWORTHINESS (MAINTENANCE MANUAL).
a. Explanation. The FAA/AUTHORITY has long recognized the necessity to have a maintenance manual for rotorcraft due to the unique and generally complicated and critical design features.
(1) Amendment 27-3, in 1968, established the requirement for a specific airworthiness limitations section. Amendment 27-18, in 1980, revised the rule and added Appendix A containing requirements for preparation of instructions for continued airworthiness, including the airworthiness limitations section. The operating and maintenance rules require compliance with the airworthiness limitations section. The maintenance rules §§ 43.15 and 43.16 and § 91.163(c) of the operating rules also refer to or require compliance with certain parts of the instructions for continued airworthiness. The limitations were intended toidefine the limits of this type certification approval of the fatigue characteristics of critical flight structure.i Refer to FAA Order 8620.2, Applicability and Enforcement of Manufacturer's Data, November 2, 1978, for further information.
(2) Critical components must be identified by part number (or equivalent) and serial number (or equivalent). Section 29.1529(a)(1) and (2) of Amendment 27-3 and/or § 45.14 list the requirements. The part numbers of parts and/or components requiring inspections and/or replacement as a result of § 27.571 must be listed in the airworthiness limitations section of the manual or another separate, segregated section of the manual appropriate to the rules.
(3) Control rigging procedures are included in the manuals. Since rotorcraft are generally difficult to rig properly, it is important that these procedures be correct and complete.
(4) Rotorcraft type designs are unique in comparison to airplane designs in that transmissions and rotors have critical components that may be adversely affected by operating conditions and time in service. The FAA/AUTHORITY-approved airworthiness limitations section may include such items as gear sets, bearings, etc., of the rotorcraft type design if a finite life was established during the type certification program and if the FAA/AUTHORITY determined that mandatory inspections and/or replacement of the component (part) was necessary to maintain airworthiness of the rotorcraft. For example, a drive spline, gear, or bearing was serviceable after concluding the ground endurance test and/or FAA/AUTHORITY flight test program.
However, an FAA/AUTHORITY-mandated inspection or replacement of the component was considered essential for airworthiness of the rotorcraft type design and necessary for type certification. Time between overhaul (TBO) of components is not part of the airworthiness limitations but is a recommendation from the manufacturer (See Part 27, Appendix A, A27.3(b)(1)). If an inspection or replacement of a part in an assembly is required, the inspection interval or replacement time and the part number should be 970 Par 729
included in the limitations. The inspection interval or replacement time may or may not coincide with the recommended overhaul interval of the assembly. (See the comments for Proposal 8-25, § XX.4 in the preamble of Amendment 29-20 (45 FR 60154), September 11, 1980). Note that parts considered unserviceable at the conclusion of the ground endurance test of § 29.923 are not acceptable for type certification.
b. Procedures.
(1) General.
The rule states that the manual must contain all information that the applicant considers essential for proper maintenance. Amendment 27-3 added the requirement for an airworthiness limitations section and Amendment 27-18 revised § 27.1529 and added Appendix A that contains the requirements for preparation of the manual. The airworthiness limitations section of the manual, and any revisions thereto, must be FAA/AUTHORITY approved. The manufacturer's recommendations for continued airworthiness are not FAA/AUTHORITY approved.
The airworthiness limitations section contains information derived primarily from the data approved under § 27.571. Approval of this section of the manual (draft form is acceptable) must be accomplished before type certification. See Part 27, Appendix A, Paragraph A27.4 of Amendment 27-17. (For further information, see comments for Proposal 8-25, § XX.4, in the preamble of Amendment 27-18 (45 FR 60154, September 11, 1980).)
(iii) Part 27, Appendix A, Paragraphs A27.3(a) and (b) pertain to the content of the instructions for continued airworthiness. For example, scheduling and servicing information is included in this section of the manual.
(2) Identifying and Serializing Fatigue Critical Components.
(i) Part numbers and serial numbers must be applied to fatigue critical components as noted in § 45.14 and § 27.1529(a)(1) and (2). Electric arc marking method should not be used due to possible internal arcing, pitting of surfaces, and changes in physical or chemical characteristics due to the local high temperature at the arcs.
(ii) Vibrating pencils, name plates, or permanent inks may be used.
However, serial numbers should be applied on each part such that material is upset or displaced on the part, thereby attaining a more permanent number. This is not a requirement, however. When material is upset or displaced, the least critical or lowest stressed area should be used.
(iii) For small parts, the rule (§ 45.14) allows markings that are equivalent to part and serial numbers. Markings or symbols may be used to enable the Par 729 971
identification of a part as one for which a replacement time, inspection interval, or related procedure is specified in the airworthiness limitations section. The FAA/AUTHORITY-stated identification of such small parts is clearly essential for safety and may not be relieved. With adoption of Amendment 27-18, the marking requirements are contained in § 45.14, Amendment 45-12.
(3) The FAA/AUTHORITY inspector should witness the rigging of the controls of a test rotorcraft. This is imperative for a new rotorcraft design to ensure the practicality and feasibility of the procedure stated in the design data and/or the maintenance manual. The type design data information should be used; and the FAA/AUTHORITY should ensure the manual includes the proper information. Rigging procedures are not included in the airworthiness limitations section.
(4) A draft copy of the manual should be available to the FAA/AUTHORITY for use during the F&R program if such a program is conducted under § 21.35(b). The manual must be completed and furnished with each aircraft receiving an airworthiness certificate, § 21.50(a) and (b).
(5) Service experience may dictate additional and subsequent (to type certification) changes to the airworthiness limitations section. ADs may be used to revise the limitations. (The relationship between ADs and the process of changing the limitations is covered in the preamble of Amendment 29-4 (33 FR 14104;
September 18, 1968).) Whenever the revised limitations are made restrictive for aircraft in service, the Administrative Procedures Act requires "notice and public procedure" to persons that may be affected and to satisfy the requirement for notification of the changes and identification of the correct issue of the airworthiness limitations, if appropriate. This procedure is also used for restrictive or reduced operation limitations in the RFM.
729A. § 27.1529 (Amendment 27-23) INSTRUCTIONS FOR CONTINUED AIRWORTHINESS (MAINTENANCE MANUAL).
a. Explanation. Amendment 91-21, 54 FR 41211, October 5, 1989, recodified certain paragraphs in FAR Part 91. This revision corrects a reference from FAR § 91.163 to FAR § 91.403.
b. Procedures. Correct the references in Paragraph 729a(1) from §§ 43.15,
43.16, and 91.163(c) to §§ 43.15, 43.16, and 91.403 of the operating rules.
730.-739. RESERVED.
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SECTION 41. MARKINGS AND PLAÇARDS
740. § 27.1541 GENERAL. See Paragraph 781.
741. § 27.1543 INSTRUMENT MARKINGS: GENERAL. See Paragraph 781.
742. § 27.1545 (Amendment 27-16) AIRSPEED INDICATOR. See Paragraph 781.
743. § 27.1547 (Amendment 27-13) MAGNETIC DIRECTION INDICATOR.
a. Explanation. This section identifies the requirement and location for a calibration placard for the magnetic direction indicator.
b. Procedures. One means of accomplishing the requirements of this regulation is commonly known as swinging the compass. A surveyed compass rose is laid out on an appropriate surface. The compass rose location should be free from the influence of steel structures, underground pipes and cables, reinforced concrete, and other aircraft.
The aircraft should be in an attitude which permits an accurate result. Normally the engines are in operation; however, if the aircraft is equipped with an auxiliary power unit which can supply electrical power for all electrical/electronic equipment or systems, this can be used instead of engine driven generators. Turn the aircraft on successive headings through 360°. It is recommended that the increments be every 30°; however, the increments should not exceed 45°. Prepare a placard to show the correction to be applied at each of the selected headings. When deviations of more than 10° are introduced by operation of any electrical/electronic equipment or systems, the placard should also be marked at each calibration heading showing the correction to be applied when such equipment or systems are turned on or energized. The placard resulting from this calibration should be installed on or near the magnetic direction indicator and identify which electrical loads, or combination of loads, are the cause of the excessive deviations.
744. § 27.1549 POWERPLANT INSTRUMENTS. See Paragraph 781.
745. § 27.1551 OIL QUANTITY INDICATORS.
a. Background. This section states that each oil quantity indicator must be marked with enough increments to indicate readily and accurately the quantity of oil.
b. Procedures. There are several different ways in which the oil quantity indicator may be presented. Some of the ones more prevalent in the industry are:
(1) Oil quantity indicator. (Generally used when large amounts of reserve oil are required.)
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(2) Oil quantity dip stick. (Most common method of measuring engine oil.)
(3) Oil quantity sight indicator. (Generally used for measuring transmission and gearbox oil quantities.)
c. No matter what method of oil quantity indicator is used, the indicator should be marked so that the oil quantity can be accurately determined. This can range from increments marked in gallons, such as oil quantity indicators for large amounts of oil, to oil quantity indicators marked in quarts with full and add marks, such as engine dip sticks. Sight indicators with full and add marks have been used successfully for gearboxes. Sight indicators normally do not reflect quantities. These are some of the methods currently in use to indicate the oil quantity. In all cases, those methods identified above have proved to be acceptable methods of showing compliance with the § 27.1551.
746. § 27.1553 FUEL QUANTITY INDICATOR.
a. Explanation. This section describes the markings necessary to identify the portion of unusable fuel that cannot be used in level flight. Unusable fuel may be present in a design due to the relative configuration of the fuel tank to the fuel tank outlet (e.g., sumps, unusual elevations and/or configurations dictated by aircraft contours, etc.). If the unusable fuel supply for any tank is less than or equal to 1 gallon or is less than or equal to 5 percent of the tank capacity, whichever is greater, this section does not apply.
b. Procedures. For each fuel tank which has an unusable fuel capacity exceeding 1 gallon or 5 percent of the tank capacity, whichever is greater, the following should be accomplished.
(1) Calibration computations, measurements, and/or tests should determine the zero (empty) position on the fuel quantity indicator. (reference § 27.1337).
(2) The lowest reading obtainable in level flight must be determined by computation, measurement, and/or testing.
(3) Once the instrument readings defined by Paragraphs b(1) and (2) above have been determined, a red arc should be placed between the readings on the fuel quantity indicator.
(4) Appropriate notations should be made in the flight manual to define the intent of the red arc to the flightcrew (reference § 27.1585(e)).
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747. § 27.1555 (Amendment 27-21) CONTROL MARKINGS.
a. Explanation. Section 27.1301(b) requires that all installed equipment be labeled to identify its function and operations; however, this section provides more detailed requirements for control markings. Specific criteria are given for powerplant fuel controls, fuel quantity markings, and landing gear controls. The requirement to color emergency controls red is in this section.
b. Procedures.
(1) Section 27.1555(a) requires each cockpit control, other than flight controls whose function is not obvious, to be appropriately labeled. The primary flight controls are the cyclic, collective, and the directional control (tail rotor) pedals. For the control to be appropriately labeled, the rule requires that there should be an obvious and clear demarcation of the function and operation of the control. When performing the evaluation to determine the adequacy of markings, remember that only those controls which are quite traditional should be judged to be obvious in their operation. An example of this has been the navigation/communication (NAV/COMM) control heads.
The more traditional control units had concentric knobs of decreasing size for the selection of frequency. Because this system was so common for such a period of time, the finding was generally made that the function of this control was obvious and thus did not require a specific marking. However, as more current technology digital electronic controls were used, the frequency selectors were judged not to be obvious in their operation, and their function and operation were required to be labeled.
(2) Review design data and available hardware to ensure the powerplant fuel controls are clearly and permanently marked such that:
Selector valve control clearly shows each position for each tank and each crossfeed configuration.
(ii) Tank selection sequences required for safe operation are clearly and permanently marked on or adjacent to the required selector.
(iii) Each control valve is clearly marked to show the position of the controls for each engine on multiengine rotorcraft.
(3) Review design data and available hardware to ensure that usable fuel capacity is clearly marked as follows:
(i) If the fuel system has no selector controls, usable fuel capacity must be shown on the fuel quantity indicator (reference Paragraph 746).
If the system has selector controls, the usable fuel capacity at each selector position must be clearly shown near the selector position.
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(4) Markings of essential visual position indicators must be obvious and within view of required crewmembers. Landing gear markings normally include indications for down, intermediate/unsafe, and up. Accepted symbology has included arrows for up/down indications, crosshatching of intermediate/unsafe, various combinations of colored lights, and combinations of all of the above. Cockpit presentation is further discussed in Paragraph 301. Emergency controls which should be marked in red include those used for firewal/emergency fuel shutoff, landing gear blowdown/emergency release, fire extinguishers, float activation, cargo hook release and fuel dump. The method of operation of emergency controls must be clearly marked. In the case of switches and buttons, the method of operation is often inherently obvious without dedicated labeling.
(5) The two most obvious means of displaying landing gear operating speed are use of a placard or an appropriate mark in the airspeed indicator.
748. § 27.1557 (Amendment 27-11) MISCELLANEOUS MARKINGS AND PLACARDS.
a. Explanation. Placards or equivalent markings that are conspicuous and durable are required to identify design/operational limits or information for certain seats, baggage/cargo compartments, ballast, fuel and oil tanks, and emergency exits. The color red is specified for exit placards.
(1) Baggage, cargo and ballast markings must state the allowable maximum weight and the distributed (floor) loading, where appropriate. The markings should prevent overloading the compartment and its floor or the ballast installation.
(2) Seats must be permanently marked as prescribed with the design allowable occupant weight if the seat is designed for less than a 170-pound occupant. The placard specified here is not related to a rotorcraft operating weight or loading limitation.
(3) Fuel and oil tank filler openings must be marked as prescribed to provide essential information for proper fluids and to provide limitation data for pressures in refueling/defueling systems if installed.
(4) Emergency exit placards or markings, inside and outside, shall be red (red with white background for visibility or reversed colors). Locating signs and operating signs or placards are required. See Paragraph 335, § 27.783 of this AC for door marking requirements.
(5) Markings must be conspicuous and durable as prescribed in § 27.1541(b).
b. Procedures.
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(1) The type design drawings such as general "markings" drawing should be reviewed for compliance. During an interior/exterior compliance inspection, usually conducted prior to issuing the TIA, compliance with the standard should be confirmed or ensured. If an FAA/AUTHORITY conducted F&R program is prescribed, complete "production" aircraft markings should be installed prior to beginning the program. As a continuation of the FAA/AUTHORITY evaluation, the markings shall be checked during the F&R program. Contrasting colors are essential. Various paint schemes should be checked for compliance.
(2) Allowable maximum weight and floor distributed loading and possibly baggage tiedown and security instructions are generally included in the cargo compartment markings. A placard, stencil, or equivalent that is conspicuous and durable may be placed on the compartment door, wall, etc.
(3) For fuel and oil filler markings, contrasting colors between letters and background are essential. The visibility of the markings should not be affected by changing paint schemes or colors. This may be accomplished by decals having a contrasting background. Stencil markings should be discouraged for fuel and oil markings.
(4) Emergency exit marking performance standards are also contained in Paragraph 340, § 27.807 (b)(3), of this AC. It is recommended that the exit locating sign (interior) be readable from the farthest seat in the cabin and that the identification of the operating handle or device and the operating instructions be readable from a distance of 30 inches. It is further recommended that external exit instructions or markings have contrasting colors that comply with § 29.811 and have at least 30 percent difference in reflectance. Advisory Circular 20-47, Exterior Colored Band Around Exits on Transport Airplanes, provides information about measuring reflectance of colors. The standard concerns a qualitative or objective standard, however.
(5) Advisory Circular 20-116, Marking Aircraft Fuel Filler Openings with Color-Coded Decals, concerns color-coded decals for fuel filler openings. These decals generally supplement the markings required by the certification standards.
749. § 27.1559 (Amendment 27-21) LIMITATIONS PLACARD.
a. Explanation.
(1) The content of and information on the placard has been changed significantly as a result of associated and complementary changes in the airworthiness standards and the maintenance and operating rules. Regardless of content, the placard must be in clear view of the pilot (or pilots).
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(2) By adoption of FAR Part 27 in 1965, the standard and its predecessor CAR Part 6, required compliance with the operating limitations in the approved Rotorcraft Flight Manual.
(3) In conjunction with the adoption of an Airworthiness Limitations Section for the maintenance manual as stated in § 27.1529 of Amendment 27-3, the content of the placard was changed significantly to require compliance with the requirements in that section. The maintenance rule (§ 43.16) was also adopted in 1968.
(4) Amendment 27-8 adopted standards to allow use of a combination of manual material, markings, and placards rather than mandate a Rotorcraft Flight Manual. The requirement for the placard content was revised accordingly.
(5) Amendment 27-18, issued in 1980, adopted standards requiring "Instructions for Continued Airworthiness" (maintenance manual). This manual may include an Airworthiness Limitations Section which is a segregated and approved part of the manual. The maintenance and operating rules, §§ 43.15, 43.16, 91.163(c) and other operating rules require compliance with the Airworthiness Limitations Section.
Similarly, other airworthiness standards were adopted for airplanes, engines, and propellers to require Instructions for Continued Airworthiness and an Airworthiness Limitations Section. See Paragraph 729 of this AC for further information.
(6) Amendment 27-21 adopted a significant change for the placard. The placard must be in clear view of the pilot and must provide a convenient cockpit presentation of the approved types of operation for each aircraft. Other operating and maintenance rules referenced in the previous paragraph provided the basis for much of this reduction in the placard content.
b. Procedures.
(1) The placard must specify the kinds of operations, such as VFR, FR, day, night, or icing for which the rotorcraft is equipped and approved.
(2) A placard (or durable decal) must be legible to the pilot and located in clear view of the pilot. If two pilots are required, a single placard may satisfy the standard.
This aspect will be evaluated by a test pilot. The TIR should contain a compliance check entry for this section.
(3) The placard content for older rotorcraft designs is directly related to the rotorcraft certification basis. If the rotorcraft type design has an "FAA/AUTHORITY approved and segregated Airworthiness Limitations Section of the maintenance manual, the limitations placard may be revised to comply with the new standard. The certification basis should be changed in conjunction with the placard change.
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750. § 27.1561 SAFETY EQUIPMENT.
a. Explanation. This standard requires identification or location markings for each item of safety equipment and operating information for crew-operated controls.
b. Procedures.
(1) Release devices, such as levers or latch handles for liferafts and other satety equipment, should be plainly marked. The method of operation should be marked also. Stencils, permanent decals, placards, or other permanent labels or instructions may be used.
(2) Lockers, compartments, or pouches used to house safety equipment, such as life vests, should be marked to identify the equipment therein and to also identify, if not obvious, the method or means of getting to or releasing the equipment.
(3) Safety equipment labels and instructions should be used.
Section 27.1555(d)(2) concerns emergency control markings. White letters and red background (or reverse) should be used.
(4) Locating signs for equipment should be legible in daylight from the furthest-seated point in the cabin or should be recognizable from a distance equal to the width of the cabin. Letters, 1 inch high, should be acceptable to satisfy the recommendation. Operating instructions should be legible from a distance of 30 inches. These are recommendations based on exit standards of § 29.811(b) and
(e) (1).
(5) Easily recognized or identified and easily accessible safety equipment located in view of the occupants may not require locating signs, stencils, or decals.
Passenger compartment fire extinguisher in view of the passengers is an example.
751. §27. 1565 (Amendment 27-2) TAIL ROTOR.
a. Explanation.
(1) This standard concerns tail rotor disc visibility in normal daylight ground conditions. Amendment 27-2 added "daylight" to the standard. A personnel guard is not required. The tail rotor shall be marked to achieve a conspicuous disc whenever the blades are rotating.
(2) Completely shrouded or protected blades may not require contrasting color segments if the shroud provides equivalent protection for personnel on the ground. A simple tubular guard does not alleviate this standard.
b. Procedures.
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(1) Each tail rotor blade shall be marked with contrasting colors.
(2) During FAA/AUTHORITY compliance inspections or during the flight test program, the tail rotor will be evaluated, qualitatively, in daylight for a conspicuous disc.
(3) As an aid to select proper colors for conspicuousness, see AC 20-47, Exterior Colored Band around Exits on Transport Airplanes. This AC concerns, in part, methods for measuring reflectance (3:1 factor) and contrast colors for transport aircraft.
Section 29.811(b)(2) requires contrast colors for transport rotorcraft. This AC also contains suggestions for chromatic contrast. A 3:1 reflectance factor between rotor blade segment colors is acceptable. It is recommended that a few combinations of colors be approved to provide a selection of color combinations. The type design drawings will include the necessary information and data for design control.
752.-761. RESERVED.
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SECTION 42. ROTORCRAFT FLIGHT MANUAL
762. § 27.1581 (Amendment 27-14) GENERAL.
a. Explanation.
(1) The primary purpose of the Rotorcraft Flight Manual (RFM) is to provide an authoritative source of information considered to be necessary for or likely to promote safe operation of the rotorcraft.
(2) Since the flightcrew is most directly concerned with operation of the rotorcraft, the language and presentation of the flight manual shall be directed principally to the needs and convenience of the flightcrew but should not ignore the needs of other contributors to safe operation. As used with respect to the RFM, safe operation is construed to include, but not be limited to, operation of the rotorcraft in the manner that is mandatory for, or recommended for, compliance with applicable airworthiness requirements and with the particular provisions of the operating regulations relating to the rotorcraft's approved performance capabilities.
(3) To serve its intended purpose, therefore, the RFM must include the certificate limitations established for the design as a consequence to the type certification evaluation, the performance information necessary to establish the operating limitations imposed through application to the operating regulations (FAR Parts 91, 127, and 135), and the procedures and other information necessary to enable the flightcrew to safely operate the rotorcraft within the envelope of limitations thus delineated. The outline presented in this circular is directed toward those objectives.
(4) Information and data that are mandatory for an acceptable RFM are prescribed in §§ 27.1581 through 27.1589, and nothing contained in these sections should be construed as amending those requirements. Certain additional elements of flight manuals, however, have been shown by experience to be practical necessities if the document is to serve effectively its intended purpose.
b. Procedures.
(1) The following criteria do not affect the status of RFMs which are presently approved. When such manuals are amended in the future, however, it is recommended that the concepts of this section be incorporated wherever uniformity or clarity will result.
(2) Only the material required by FAR Part 27, or that considered necessary to implement the operating regulation, should be included in the portion of the manual that is approved by the FAA/AUTHORITY. However, the manufacturer or operator may Par 762 1001