AC 29-2C, Chg 4 9/17/2009
(i) General. Include all descriptive information necessary to identify the configuration and conditions for which the performance data are applicable. Such information may include the complete model designations of rotorcraft and engines, definition of installed rotorcraft features, and equipment that affects performance together with the operative status thereof. This section should also include definitions or terms used in the performance section (i.e., indicated airspeed (IAS), calibrated airspeed (CAS), international standard atmosphere (ISA), configuration, critical decision point (CDP), VTOSS, Category A, Category B, landing decision point (LDP), etc.) plus calibration data for airspeed, altimeter, ambient air temperature, and other information of a general nature.
(ii) Performance Procedures. The procedures, techniques, and other conditions associated with obtainment of the flight manual performance should be included. The procedures may be presented as a performance subsection or in connection with a particular performance graph. In the latter case, a comprehensive listing of the conditions associated with the particular performance may serve the objective of "procedures" if sufficiently complete. Performance figures are based on the installed minimum specification engine, unless normally depreciated engine performance is approved.
(iii) Wind Accountability. Wind a ccountability may be utilized for determining takeoff and landing field lengths. This accountability may be up to 100 percent of the minimum wind component along the takeoff or landing path opposite to the direction of takeoff. Wind accountability data presented in the RFM should be labeled "UNFACTORED" (if 100 percent accountability is taken) and should be accompanied by the following note: "Unless otherwise authoriz ed by operating regulations, the pilot is not authorized to credit more than 50 percent of the performance increase resulting from the actual headwind component and must reduce performance by 150 percent of the performance decrement resulting from the actual tail wind component." In some rotorcraft, it may be necessary to discount the beneficial aid to takeoff performance for winds from zero to 10 knots. This should be done if it is evident that the winds from zero to 10 knots have resulted in a significant degradation to the takeoff performance due to flight through the main rotor vortex. Degradation may be determined by ascertaining the power required to fly, by reference to a calibrated pace vehicle, at speeds of 10 knots or less.
(iv) The following list is illustrative of the information that should be provided for a transport Category "A" and "B" rotorcraft.
(A) Density altitude chart for converting from pressure to density altitude.
(B) Temperature conversion chart (°C to °F to °C).
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(C) Airspeed calibration (calibrated vs. indicated airspeed) for both pilot and copilot systems for level flight, climb, autorotation, and recommended approach rate of descent.
(D) Altimeter correction for pilot and copilot instruments showing the correction factor vs. indicated airspeed at sea level and altitude.
(E) Hover performance charts both (IGE) and OGE with instructions for their use.
(F) A series of climb performance charts for various weights showing rate of climb vs. pressure altitude for a range of temperatures and showing the variation of best rate of climb speed with pressure altitude. The conditions should appear on each chart (i.e., power, weight, single, or multiengine, etc.). The one-engine-inoperative (OEI) climb performance charts at 30-minute power and maximum continuous power (MCP) or at continuous OEI power should provide rate of climb performance down to a minimum of -500 feet/min. The effect of engine air bleed, particle separators, or other devices, on the rate of climb/descent performance must be provided.
(G) A chart showing the takeoff flight path for Category A presented in height vs. distance from the hover wheel height to the point at which VTOSS and not less than 35 feet is reached, and the rejected takeoff distance. The chart should identify the critical decision point and VTOSS.
(H) Charts to allow calculation of distance to climb at VTOSS from the point at which VTOSS and not less than 35 feet is reached (or from the lowest point of the takeoff profile for elevated heliport) to 200 feet with one engine inoperative and other engines within approved operating limitations. If conservative, providing charts to allow calculation of the total distance from VTOSS and 35 feet to VY and 200 feet is allowed.
(I) A series of charts to allow calculation of any additional distance which may be required to accelerate to best rate of climb speed from VTOSS with one engine inoperative and other engines within approved operating limitations. If conservative, providing charts to allow calculation of the total distance from VTOSS and 35 feet to VY and 200 feet is allowed.
(J) Charts to allow calculation of distance to climb at VY from 200 feet to 1000 feet above the takeoff surface (or from the lowest point of the takeoff profile for elevated heliport) with one engine inoperative and other engines at 30-minutes OEI power or maximum continuous OEI power. If conservative, providing charts to allow calculation of the total distance from VTOSS and 35 feet to VY and 1000 feet is allowed.
(K) Landing distance chart for Category A showing the landing distance from a 50-foot height (25-foot for VTOL operations from an elevated heliport) to a stop with one engine inoperative vs. pressure altitude over the range of temperatures being Page G - 53
AC 29-2C, Chg 4 9/17/2009 certified. This chart should identify the bal ked landing decision point (LDP) so the pilot will know how to achieve this performance.
(L) For Category B, a series of charts at various weights showing takeoff distance from hover to 50 feet vs. pressure altitude over the range of temperatures being certified.
(M) For Category B, a landing distance chart similar to the one for Category A from a 50-foot height to stop with one engine inoperative.
(N) For turbine-powered rotorcraft in all categories, a power assurance check chart.
(O) For Category B, a statement of the maximum crosswind and downwind components that have been demonstrated as safe for operation near the ground unless this information is incorporated as an operating limitation. (See AC
29.1583.)
(P) For Category B, the height-velocity (HV) envelope except for rotorcraft which must incorporate the HV diagram as an operating limitation.
(Q) For Category B, the autorotative glide distance as a function of altitude if required by § 29.71. (See AC 29.71.)
(v) Miscellaneous Performance Data. Any performance information or data not covered in items (A) through (Q) above, but considered necessary to enhance safety or to enable application of the operating regulations, should be included.
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AC 29.1587C. § 29.1587 (AMENDMENT 29-59) PERFORMANCE INFORMATION.
a. Explanation. Amendment 29-59 changed the term “height-speed” to “heightvelocity” in paragraph (b)(6) of § 29.1587 to be consistent with the title nomenclature of § 29.87, which was changed from “Limiting height-speed envelope” to “Height-velocity envelope” at amendment 29-39.
b. Procedures. The policy pertaining to the procedures in this section remains in effect. For purposes of this AC, the terms “height-velocity” and “height-speed” are equivalent.
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AC 29.1589. § 29.1589 LOADING INFORMATION.
a. Explanation. Control of the roto rcraft weight and balance is an operational function, and is the responsibility of the operator. However, instructions necessary to enable loading of the rotorcraft within the established limits of weight and center of gravity, and to maintain the loading within such limits are required by the operating regulations, and inclusion of such loading instructions in the Rotorcraft Flight Manual is required by § 29.1583(c). Approved loading inst ructions, therefore, must be presented in the Rotorcraft Flight Manual, and at the option of the applicant, may be included in the approved portion or may be included in the unapproved portion.
b. Procedures.
(1) For the purpose of the flight manual, distinction is made here between the loading instructions required by the certification requirements of Part 29, and the weight and balance data required by the operating requirements. The former prescribed information is applicable to the rotorcraft type, and is subject to FAA/AUTHORITY approval as flight manual material.
(2) For compliance with the noted requirements, it is necessary for the applicant to develop weight and balance data and loading instructions as necessary to satisfy the needs of both certification and operation. In order to consolidate in one document information on rotorcraft loading, however, it is recommended that the weight and balance data be developed to include appropriate loading instructions, and that both be included in the Rotorcraft Flight Manual as an “unapproved” section entitled, “Weight and Balance.” Such a section should include the following statement as a note:
“In accordance with FAA/AUTHORITY procedures, the detail weight and balance data of this section are not subject to FAA/AUTHORITY approval. The loading instructions of this section, however, have been approved by FAA/AUTHORITY as satisfying all requirements for instructions on loading of the rotorcraft within approved limits of weight and center of gravity, and on maintaining the loading within such limits.”
(3) An actual or specimen weight and balance section should be included in the initial submittal of the manual. Weight and balance data for each particular rotorcraft need not be submitted as flight manual material.
(4) The weight and balance material outlined below is believed to be adequate for rotorcraft with conventional loading and fuel-management techniques. For rotorcraft which necessitate redistribution of fuel (other than normal consumption) to maintain loading within prescribed limits, the material should be amplified as necessary.
(i) Weight Limits. Contained in limitations section of the flight manual.
(ii) Center of Gravity Limits. C ontained in the limitations section of the flight manual.
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AC 29-2C, Chg 4 5/1/2014
(iii) Dimensions and Datum Line Locations. The dimensions and relative location of rotorcraft features associated with weighing and loading of the rotorcraft and with weight and balance computations should be described and/or illustrated.
(iv) Equipment List. The rotorcraft should be defined or described sufficiently to identify the presence or absence of optional systems, features, or installations that are not readily apparent. In addition, all other items of fixed and removable equipment included in the empty weight should be listed.
(v) Fuel and Other Liquids. Fuel and other liquids, including passengerservice liquids that are included in the empty weight, should be identified and listed together with information necessary to enable ready duplication of the particular condition.
(vi) Weight Computations. Com putations of the empty weight and emptyweight CG location should be included.
(vii) Empty Weight and Empty-Weight Center of Gravity Location.
Statement of these values should be included.
(viii) Loading Schedule. Loading schedule should be included, if appropriate.
(ix) Loading Instructions. Complete instructions relative to the loading procedure, or to use the loading schedule, must be included.
(x) Special Consideration. Consideration should be given to the lateral center-of-gravity loading instructions when various kits such as a side mounted hoist are installed.
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CHAPTER 3
AIRWORTHINESS STANDARDS
TRANSPORT CATEGORY ROTORCRAFT
MISCELLANEOUS GUIDANCE (MG) AC 29 MG 1. CERTIFICATION PROCEDURE FOR ROTORCRAFT AVIONICS EQUIPMENT.
a. Pre-Test Requirements.
(1) General. This test guideline has been prepared as an aid in the evaluation of rotorcraft avionics (aviation electronics) equipment installations. The criteria presented are not exclusive, but are offered as one method of evaluating design practice and performance. The testing and qualification of an electronic installation should consist of three phases: pre-installation, ground, and flight. The amount of testing necessary during each phase will vary with the amount of testing performed on previous phases.
For example, if a system is TSO approved, there has probably been substantiation of the pre-installation performance and therefore ground and flight testing may be reduced accordingly. In addition, a thorough ground testing program should result in a reduction in necessary flight testing. When the operating or airworthiness regulations require a system to perform its intended function, we strongly recommend the use of TSO- approved equipment or the submission of data substantiating the equipment performance.
(2) Regulatory References. Sections 29.1301, 29.1309, 29.1329, 29.1331,
29.1333, 29.1355, 29.1431, and 29.1457.
(3) System Design. Sufficient data should accompany systems or equipment presented for installation approval, when not qualified by TSO or other approval means, to substantiate the design acceptability.
(i) Operation of Controls. The operation of controls intended for use during flight, in all possible position combinations and sequences, should not result in a condition that would be detrimental to the continued safe performance of the system.
(ii) Electrical Shock. Design systems to minimize the risk of dangerous electrical shock under all probable conditions.
(iii) Fire Hazard. The design of the system should be such that all components meet the applicable fire and smoke protection requirements of §§ 29.853 and 29.863. Cables and equipment for installation in designated fire zones used during emergency procedures should be fire resistant.
(iv) Plugs and Cables. Connector pins for sensitive signal circuits should not be adjacent to pins used for ac power circuits. When redundant wiring is used to Page MG 1 - 1
AC 29-2C, Chg 7 2/4/2016 comply with the systems independence regulations such as §§ 29.1331, 29.1333, or
29.1355, the wires should be routed through separate plugs or cables with as much physical separation as practicable. The system design should eliminate possible incorrect mating of plugs. Minimize electromagnetic interference by using cable grounding and shielding techniques.
(4) System Performance. Where the operating or airworthiness regulations require a system to perform its intended function, and when the equipment is not qualified by TSO or other approval means, performance data furnished to the FAA can reduce the installed performance testing. The appropriate TSO minimum performance standard may be useful as a guide.
(i) Environment. An appropriate means for environmental testing is set forth in Radio Technical Commission for Aeronautics (RTCA) Document DO-160. Applicants should submit test reports showing that the laboratory tested categories, such as temperature, vibration, altitude, etc., are compatible with the environmental demands placed on the rotorcraft.
(ii) Failure Analysis. Procedures are contained in section 29.1309 of this AC.
(5) Installation Design.
(i) Mechanical Installation. Installations should ensure compliance with airworthiness regulations and comply with the equipment manufacturer’s recommendations. The designer should observe good engineering practices in specifying material type, thickness, fastener type, edge distance, and attachment to the equipment rack. By analysis or static tests the mounted equipment should be shown to withstand the inertia forces of §§ 29.561(b)(3) and 29.337. Refer to AC 43.13-2 (current version) for static test procedures.
(ii) Arrangement and Visibility. The mounting position of all instruments, switches, position labels, and control heads should make them plainly visible to the pilot while in his normal, panel-facing position and under all cockpit lighting conditions likely to occur. TSO approval does not assure instruments will be acceptable in a particular cockpit installation or for all lighting conditions. The instruments, switches, and placarding must be free from reflections. Malfunction annunciation devices should be conspicuous and clearly visible to the pilot. (See §§ 29.1321, 29.771, 29.1381,
29.1555(a) and AC 20-69.)
(iii) Load Analysis.
(A) Power sources. I t should be determined whether the electrical power source capacity is adequate for the system installation under all foreseeable operating conditions including engine failure on multiengine rotorcraft. Apply system load reductions or increase power source capacity, if necessary, to assure compatibility between load and source. If duplicate systems are required, they should be powered Page MG 1 -2
from separate buses and independent sources. (See §§ 29.1309, 29.1331, 29.1333,
29.1351, and 29.1355.)
(B) Navigation course deviation circuit loading. It should be determined that the impedance of the deviation circuit source matches its load and does not exceed the source capacity. Consider the transfer loads when the system is capable of transfer (§ 29.1301).
(C) Malfunction indicator circuit loading. It should be determined that the impedance of the malfunction indicator source matches its load and does not exceed the source capacity. Consider the transfer loads when the system is capable of transfer (§ 29.1301).
(D) Synchro signal loading. When adding parallel loads to synchros, review the manufacturers’ specifications to assure that the additional loads do not result in an overloaded synchro.
(iv) Interface. In many cases, different manufacturers design the mating units of a system. For example, a brand-X gyro may be designed for operation with a brand-X flight director, but later a modifier decides to operate a brand-Y autopilot with the brand-X gyro. This applies just as well to navigational (NAV) receivers, Area NAV (RNAV) units, course indicators, omni bearing selectors, tachometer indicators, transmitters and many other equipment items. When this is the case, the applicant should provide data, in summarized form, describing those characteristics such as impedance, volts, etc., that are necessary to assure a compatible and reliable system.
The data should also reference the source of the interface data (§ 29.1301).
(v) Flight Tests. An FAA engineering flight test is required during type certification or after modification that changes the established limitations, flight characteristics or performance of a rotorcraft or any of its required systems or operating procedures. Appropriate flight test personnel should evaluate new installations of equipment in the cockpit or modifications that affect existing equipment in the cockpit if it is necessary to evaluate operational aspects of the change. If the applicant opts to darken the windows, evaluate the cockpit arrangement, placards, markings, instrument visibility, and light reflections on the ground, where possible. Electromagnetic compatibility functional checks, windshield glare, and pilot workload evaluations may be conducted in flight at the FAA flight test pilot’s option.
(vi) Radio Master Switches. Some installations incorporate radio master switches to control special busses for the avionics systems. If providing this capability, evaluate it to ensure failure modes that result in excessive or even total loss of all required avionics are not introduced. One switch that controls all required avionics is unacceptable for instrument flight rules (IFR) installations. The evaluation should include an assessment of the loss of the systems to be included on the radio master switches and the subsequent effect on continued safe flight.
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AC 29-2C, Chg 7 2/4/2016
b. Test Procedures. Where the airworthiness or operating regulations require a system to perform its intended function and not create a hazard to other required systems, accomplish sufficient testing to ensure satisfactory performance. When ground testing is not sufficient to properly evaluate a system’s performance, flight testing should be accomplished. Acceptable flight test criteria for specific navigation and communication equipment are contained herein. If seeking IFR operational approval for the rotorcraft, the additional criteria of Appendix B of this AC should be satisfied.
(1) VHF Systems.
(i) General. Intelligible communications should be provided between the rotorcraft and ground facilities throughout the airspace within 100 NM of an FAA ground facility from radio line of sight altitude to the maximum altitude for which the rotorcraft is certificated. Communication should be provided with the rotorcraft at or above line of sight altitude in right and left bank up to 10° and on all headings.
(ii) Electromagnetic Compatibility (EMC). With all systems operating in flight, verify by observation that no adverse effects are present in the flight systems.
Complete a qualitative evaluation of VHF radio navigation and communication equipment operation. Further guidance may be found in AC 43.13-2B, Chapter 2, paragraph 209.
(iii) Antenna Measurement. If satisfactory antenna measurement data are provided, the following flight test may be reduced to checks in right and left turns near the predicted bearings of worst performance. If antenna locations are symmetrical, tests may be conducted using only one turn direction.
(A) Long range reception. Starting at a distance of at least 100 NM from the ground facility antenna, perform a right or left 360° turn at a bank angle of at least 10°. Communicate with the ground facility every 10° of turn to test the intelligibility of the signals received at the ground station and in the rotorcraft. For 100 NM, the minimum line of sight altitude is approximately 7,000 feet.
(B) Approach configuration. With the landing gear down and with the rotorcraft in the approach configuration (at a distance of 10 NM from the ground station and in an idle power descent toward the station), demonstrate intelligible communications between the rotorcraft and the ground facility.
(2) HF Systems.
(i) Acceptable communications should be demonstrated by contacting a ground facility at a distance of at least 100 nautical miles. Single sideband equipment should also perform acceptably in the amplitude modulation mode of operation.
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(ii) Demonstrate that precipitation static is not excessive when the aircraft is flying at cruise speed (in areas of high electrical activity, including clouds and rain if possible). Use the minimum number of installed dischargers for which approval is sought.
(3) Very High Frequency Omnidirectional Range (VOR) Systems.
(i) These flight tests may be reduced if adequate studies of antenna radiation pattern have shown no significant holes in the patterns with the rotorcraft configurations used in flight (i.e., landing gear retracted en route and extended for approach).
Particularly note that certain rotor RPM settings may cause modulation of the course deviation indication (rotor modulation). VOR performance should be checked for rotor modulation in both approach and en route operation while varying rotor RPM throughout its normal range.
(ii) The airborne VOR system should operate normally with warning flags out of view at all headings of the rotorcraft (in level flight) throughout the airspace within 100 NM of the VOR facility while flying above the radio line of sight altitude to within 90 to 100 percent of the maximum altitude for which the rotorcraft is certified.
(iii) The indicated reciprocals accuracy determination should agree to within 2°. Tests should be conducted over at least two known points on the ground to obtain data in each quadrant. Data should correlate with the ground calibration with no absolute error exceeding ±6°. Fluctuation of the course deviation indication should not be excessive.
(A) Enroute reception. Fly from a VOR facility, rated for high altitude, along a radial to a range of 100 NM. The VOR warning flag should not come into view, nor should the station identification signal deteriorate. The course width should be 20° (±5° tolerance, 10° either side at the selected radial). If practical, perform en route segment on a doppler VOR station to verify the compatibility of the airborne unit. Large errors have been found when incompatibility exists.
(B) Long range reception. Perform a 360° right and a 360° left turn at a bank angle of at least 10° at an altitude just above radio line of sight (see paragraph
b.(1)(iii)(A) above for line of sight altitude) and at a distance of at least 100 NM from the VOR facility. Signal dropout should not occur as evidenced by the malfunction indicator appearance. Dropouts that are relieved by a reduction of bank angle at the same relative heading to the station are satisfactory. The VOR identification should be satisfactory during the left and right turns.
(C) Enroute station passage. Verify that the To -From indicator correctly changes as the rotorcraft passes through the cone of confusion above a VOR facility.
(4) Localizer Systems.
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AC 29-2C, Chg 7 2/4/2016
(i) Flight test requirements may be modified to allow for adequate antenna radiation pattern measurements as discussed under VOR systems, paragraph b.(3)(i) above.
(ii) The signal input to the receiver presented by the antenna system should be of sufficient strength to keep the malfunction indicator out of view when the rotorcraft is in the approach configuration and at least 10 NM from the station. This signal should be received for 360° of rotorcraft heading at all bank angles up to 10° left or right at all normal pitch altitudes, and at an altitude of approximately 2,000 feet.
(iii) The deviation indicator should properly direct the aircraft back to course when the rotorcraft is right or left of course.
(iv) The station identification signal should be of adequate strength and sufficiently free from interference to positive station identification, and voice signals should be intelligible with all electric equipment operating and pulse equipment transmitting.
(v) Localizer performance should be checked for rotor modulation in approach while varying rotor RPM throughout its normal range.
(A) Localizer intercept. In the approach configuration and a distance of at least 10 NM from the localizer facility, fly toward the localizer front course, inbound, at an angle of at least 50°. Perform this maneuver from both left and right of the localizer beam. No flags should appear during the time the deviation indicator moves from full deflection to on course. If the total antenna pattern has not been shown to be adequate by ground checks or by VOR flight evaluation, additional intercepts should be made.
(B) Localizer tracking. While flying the localizer inbound and not more than 5 miles before reaching the outer marker, change the heading of the rotorcraft to obtain full needle deflection. Then fly the rotorcraft to establish localizer on course operation. The localizer deviation indicators should direct the rotorcraft to the localizer on course. Perform this maneuver with both a left and a right needle deflection.
Continue tracking the localizer until over the transmitter. At least three acceptable front course and back course flights should be conducted to 200 feet or less above threshold.
(5) Glide Slope Systems.
(i) Flight Test. The signal input to the receiver should be of sufficient strength to keep the warning flags out of view at all distances to 10 NM from the facility. This performance should be demonstrated at all aircraft headings from 30° left to 30° right of the localizer course. The deviation indicator should properly direct the aircraft back to path when the aircraft is above or below path. Interference with the navigation operation should not occur with all rotorcraft equipment operating and all pulse equipment transmitting. There should be no interference with other equipment because of glide slope operation.
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