AC 27-1A

Historical

Advisory circular · Certification of Normal Category Rotorcraft

A newer version is currentThis is a historical version. AC 27-1B CHG 1-9 is the version in force, approved June 23, 2023.
Approved
July 30, 1997
Last reviewed
January 23, 2001
Cancelled by
AC27-1B
Family
AC 27-1 · 10 versions
Revision
A
14 CFR parts
27
Cited by
1 AD

Guidance, not mandatory unless a rule or AD requires it. DRS record last changed November 22, 2025.

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7/30/97 АС 27-1A

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.

990 (thru 1000) Par 751

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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

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include other "unapproved" data in a separate and distinctively identified portion within the same document.

The RFM is considered necessary for safe operation of the rotorcraft and care should therefore be taken to produce a manual that is consistent with the need for completeness and clarity of the required information. Also, since the RFM is necessary for operation of the rotorcraft in accordance with the certificate limitations, it is considered to be public information.

(3) The page size for the RFM will be left to the discretion of the manufacturer.

In this regard, operational compliance with § 91.31 should be considered. A cover should be provided and should indicate the nature of the contents by means of the title, "Rotorcraft Flight Manual." Each page of the approved portion should bear the notation "FAA/AUTHORITY approved," an indication of the approval sequence of that particular page (e.g., a date of approval, a revision number suitably supported by an amendment log which contains the appropriate date, etc.) the rotorcraft model number as it appears on the type data sheet, and any appropriate document identification number. Pages of the unapproved portion of the flight manual would use the issue date in lieu of the FAA/AUTHORITY-approved date. The material should be bound in semipermanent fashion so that the pages will be protected and retained in proper sequence. In selecting the form of binding, consideration should be given to the necessity for amendment and the ease with which amendments can be accomplished.

(4) Amendments may take the form of revisions or supplements.

A revision is a change to the RFM or its supplement made by the holder of the type certificate (TC) or supplemental type certificate (STC) involved.

(ії) A supplement is an addition to the RFM. If the rotorcraft manufacturer (holder of the TC) adds optional equipment or specific operations (such as Category "A" vertical operation or IFR operations), then the rotorcraft manufacturer is responsible for preparing any necessary RFM supplement. If someone other than the rotorcraft manufacturer applies for an STC to install equipment or modify the rotorcraft such that an RFM supplement is necessary, then the person who applies for the STC is responsible for the preparation of the RFM supplement.

(5) "Revision" may be incorporated by inserting new pages which embody the amended text and, where applicable, by removing superseded pages. A vertical amendment bar or data processing symbol should be inserted in the outer margin, where practicable, to indicate those parts of the text that have been changed. Each amended page should be identified in the same manner as pages of the basic manual and, in addition, should carry the assigned revision number and the FAA/AUTHORITY-approved revision date.

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(6) Supplements are incorporated in the manual by inserting the applicable pages which contain the information associated with the particular change. Each supplemental page should also identify the rotorcraft type and model flight manual for which the supplement was issued, the name of the issuer, and the FAA/AUTHORITY approval date. The following statement is an example of a note which would be included on the title page of a flight manual supplement: "For rotorcraft approved to operate in accordance with the provisions of this rotorcraft flight manual supplement, the information contained herein supplements the information of the basic flight manual.

For limitations, procedures, and performance data not contained in this supplement, consult the basic flight manual."

(7) Supplements should contain as much of the flight manual contents outlined below as considered appropriate for the particular change in type design, including title page and index of contents. It is suggested that these be prepared with a view to insertion in the FAA/AUTHORITY-approved portion of the flight manual as a complete and self-contained unit.

(8) The RFM should contain as much of the information required in Part 27 as is applicable to the individual type and model. For the purpose of standardization, it is recommended that the sequence of sections and of items within sections follow the format presented at the end of this paragraph if practicable.

(9) The following information would normally be included in the introduction section of the flight manual.

Title Page. This page should include the manufacturer's name and address and the rotorcraft model number as it appears on the type certificate data sheet. If desired, include a trade name or trade model number in quotes, provisions for rotorcraft serial number and registration number, approval date of the basic document, and title and signature of the FAA/AUTHORITY approving official.

(ii) Table of Contents. An index should be located at the front of each section or at the front part of the manual.

(iii) Amendment Log. This log should be in the form of a table with provisions to record each amendment, an identifying number, title or description, the page numbers involved, the issue date, the identification of the FAA/AUTHORITY approving official, and the FAA/AUTHORITY approval date.

(iv) Separate amendment logs should be provided for each type of amendment issued; i.e., Log of Revisions, Log of Supplements, etc. Amendments issued by other than the holder of the basic type certificate should include a separate amendment log which, in addition to the issue date, should also identify the issuer and the STC number or other approval basis for the associated modification.

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(v) List of Current Pages. This table should list, for each approved page of the manual, the issue date and any other appropriate identification necessary to establish that the manual is complete and current.

(10) The following flight manual format would be acceptable. The format recommends a sequence of sections and suggests items which would be included in those sections.

FLIGHT MANUAL FORMAT

INTRODUCTION

PART I, FAA/AUTHORITY APPROVED Section 1 Limitations Section 2 Normal Procedures Section 3 Emergency Malfunction Procedures Section 4 Performance Data Section 5 Optional Equipment Supplements

PART II, MANUFACTURER'S DATA Section 6 Weight and Balance Section 7 Systems Description Section 8 Handling, Servicing, and Maintenance Section 9 Supplemental Performance Information INTRODUCTION: This section would include any signature pages, list of approved pages, the log of revisions, and any additional introductory information desired. For each section, it is suggested that the following major titles be utilized and that the recommended information listed under each title be incorporated. Each section should include a table of contents and a list of figures applicable to that particular section.

Section 1 - Limitations:

a. Kinds of Operation.

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Under this heading, the certification basis, crew requirements, VFR and/or IFR flight authorizations, and any operational restrictions would be presented.

b. Flight Limitations.

This section would include limitations with respect to airspeed, altitude, ambient temperatures, wind, slope, prohibited maneuvers, and any other flight limitations associated with a particular rotorcraft.

c. Weight Limitations.

This section would contain all gross weight, center of gravity (both longitudinal and lateral) limitations, and any other weight limitations unique to the rotorcraft (i.e., crew, passenger and/or cargo loadings).

d. Powerplant Limitations.

This section would include the temperature and pressure limits associated with powerplant operation (i.e., torque, RPM, TOT, etc.). This section would also include approved fuels and oils and their temperature and pressure limits. Any accessories attached to the powerplant (l.e., starters, generators, etc.), to which limitations in starting or operation are applicable, would be included herein.

e. Rotor Limitations.

This would include the power-on and power-off RPM limits, the effect of altitude on these parameters, and any other limitations associated with the rotor systems).

f. Drive System Limitations.

This section would include all limitations associated with the drive system (i.e., main transmission, any adapter gearboxes, tail rotor gearbox, and any other drive system component applicable to a particular rotorcraft).

g. System Limitations.

This section would include any particular system limitations unique to the rotorcraft (i.e., battery limitations, hydraulic system limitations) and any limitations associated with the various types of stability augmentation and/or automatic flight control systems.

h. Instrument Markings.

All instrument markings would appear in this section. The significance of each limitation and of the color coding would be explained in this paragraph.

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i. Placards.

The exact wording and general location of all placards would appear in this section.

Section 2 - Normal Procedures:

a. Preflight Checks.

This paragraph would include any exterior, interior, and any system checks prior to starting the engine(s).

b. Engine Start.

This paragraph would include any procedures associated with the engine start.

c. System Checks.

This paragraph would include any system check procedures such as hydraulic, stability augmentation, electrical, flight control, etc., which should be accomplished prior to takeoff.

d. Takeoff.

This paragraph would include any procedures associated with the takeoff and any procedures unique or applicable to the takeoff profile.

e. Cruise and/or Level Flight.

This paragraph would include any procedures applicable to cruise and/or level flight operation.

f. Approach and Landing.

This paragraph would include any procedures required or recommended for the approach and landing operation of the rotorcraft.

g. Engine/Rotor Shutdown.

This paragraph would include any procedures applicable to the engine and/or rotor shutdown and any procedures applicable upon completion of the rotorcraft operation.

h. Miscellaneous Procedures.

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