AC 29.1363. § 29.1363 ELECTRICAL SYSTEMS TESTS.
a. Explanation. Most of this rule is self-explanatory. Since other regulatory paragraphs also contain requirements regarding functioning and malfunctioning of the electrical system, a recommended test procedure has been included in paragraph AC 29 MG 2 instead of being made a part of this paragraph.
b. Procedures.
(1) Reference paragraph AC 29 MG 2 for a recommended test procedure.
(2) When simulating the electrical characteristics of the distribution system wiring, emphasis should be placed on duplicating the type, gage, and length of the wiring being evaluated. As much as possible, cable bundling and grounding considerations should also be duplicated.
(3) Most laboratory test connected loads would normally be in the form of load banks rather than providing the actual aircraft system. If load banks are used during laboratory testing, additional consideration should be given to these loads when an actual aircraft installation is available.
(4) Limited aircraft testing should also be accomplished to verify that the response of the laboratory drives does adequately simulate the response of the rotorcraft engines under normal and malfunction conditions.
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SUBPART F - EQUIPMENT LIGHTS AC 29.1381. § 29.1381 INSTRUMENT LIGHTS.
a. Explanation. This section provi des minimum performance standards for the instrument lighting system. Section 29.1309( b) is used to evaluate the malfunction aspects of the system. If appropriate, § 29. 1309(a) is used to evaluate the equipment under environmental considerations.
b. Procedures.
(1) The overall instrument lighting system should be designed and installed such that single failures that occur will not result in the loss of both primary and secondary (backup) lighting for any instrument or area of the cockpit. In some instances, the system is divided such that the controls for the pilot’s panel are separate from the copilot’s panel and both of these are separate from the center panel. The ideal is to divide the system such that the impact of single failures will be minimized.
(2) Secondary (backup) instrument lighting should be provided, and this is accomplished in some instances by eyebrow lights. A system that provides general cockpit lighting from a source in the aft area of the cockpit is normally not acceptable since normal positioning and movement of the crew will block this type of light.
(3) The standard does not specify any color requirements for instrument lighting. White is normally provided. The color provided should ensure that the color coding of the instruments is readily identifiable.
(4) The final installed system should be evaluated by a flight test pilot. An actual night flight should be conducted for initial certification of an aircraft. In some instances the vibration characteristics and other flight-induced factors have been demonstrated to seriously affect the pilot’s ability to see in the cockpit environment at night. Evaluations following modifications may be conducted with a darkened cockpit on the ground. It should be verified that direct rays are shielded from the pilot’s eyes, and that objectionable reflections do not exist. The pilot should also assume failures of various controls, electrical busses, etc., to account for all appropriate failures.
(5) In some instances manufacturers have provided high intensity instrument lighting systems as an option associated with IFR approvals. If provided, this capability should be included in the overall evaluation of the instrument lighting system.
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AC 29.1383. § 29.1383 LANDING LIGHTS.
a. Explanation. This section provides minimum performance standards for the installation and normal operation of the landing lights. Certification to this standard is all that is required for approval of the rotorcraft; however, the different operating rules should also be reviewed since they may contain additional requirements. The malfunction considerations are based on the provisions of § 29.1309(b).
b. Procedures.
(1) The performance requirements of this standard are normally evaluated by a flight test pilot, and usually are included in the Type Inspection Authorization as part of the evaluation to be conducted at night.
(2) The installation of the landing light unit(s) should be very carefully evaluated. Many of the units provided are stowed until needed and then driven to their operating position by an electric motor. If this type of light unit is provided, the possibility of its contact with fuel fumes should be considered. Installations that have this problem normally require the use of light units qualified as explosion proof. The installation should also be reviewed to determine if a single failure can cause the light to be on in the stowed position. If the light can be on, the potential for overheating or fire in the adjacent area should be considered.
AC 29.1385. § 29.1385 POSITION LIGHT SYSTEM INSTALLATION. Refer to AC 20-74, Aircraft Position and Anticollision Light Measurements, July 29, 1971.
AC 29.1387. § 29.1387 (Amendment 29-9) POSITION LIGHT SYSTEM DIHEDRAL ANGLES. Refer to AC 20-74.
AC 29.1389. § 29.1389 POSITION LIGHT DISTRIBUTION AND INTENSITIES. Refer to AC 20-74.
AC 29.1391. § 29.1391 MINIMUM INTENSITIES IN THE HORIZONTAL PLANE OF FORWARD AND REAR POSITION LIGHTS. Refer to AC 20 -74.
AC 29.1393. § 29.1393 MINIMUM INTENSITIES IN ANY VERTICAL PLANE OF FORWARD AND REAR POSITION LIGHTS. Refer to AC 20-74.
AC 29.1395. § 29.1395 MAXIMUM INTENSITIES IN OVERLAPPING BEAMS OF FORWARD AND REAR POSITION LIGHTS. Refer to AC 20 -74.
AC 29.1397. § 29.1397 (Amendment 29-7) COLOR SPECIFICATIONS. Refer to AC 20-74.
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AC 29.1399. § 29.1399 RIDING LIGHT.
a. Explanation. The riding light is an amphibious operation requirement. The function of this light is to make the rotorcraft visible at night to other vessels when the rotorcraft has landed on water. A very important point which should be remembered is that when a rotorcraft has landed on the water and is not in flight, it is considered a vessel in accordance with the United States Coast Guard (USCG) navigation rules (Inland Navigation Rules Act of 1980). If water operations are contemplated, one should acquire the USCG Navigation Rules, COMDTINST M16672.2A, which are for sale from Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402.
b. Procedures. A white light should be installed in a position where it will show the maximum unbroken light for a horizontal arc of 360° around the rotorcraft. If possible, this light should not be obscured by sectors of more than 6°. The light should be installed to meet the malfunction requirements of § 29.1309(b) (reference paragraph AC 29.1309). For the purpose of this light, the following definition found in the Inland Navigation Rules, 33 CFR 84.13, Color specification of lights, and 33 CFR 84.15, Intensity of lights, applies:
(1) The chromaticity of white lights shall conform to the following standards, which lie within the boundaries of the area of the diagram specified for each color by the International Commission on Illumination (CIE), in the “Colors of Light Signals,” which is incorporated by reference. It is Publ ication CIE No. 2.2 (TC-1.6), 1975, and is available from the Illumination Engineering Society, 345 East 47th Street, New York, NY 10017.
It is also available for inspection at the Office of the Federal Register, Room 8401, 1100 L Street NW., Washington, D.C. 20408.
(2) The boundaries of the area for white are given by indicating the corner coordinates, which are as follows:
X 0.525 0.525 0.452 0.310 0.310 0.443 Y 0.382 0.440 0.440 0.348 0.283 0.382 and 33 CFR 84.15 defines the required luminosity to be visible on a clear night for 2 nautical miles. The minimum luminosity of the light is given by the formula:
l = 3.43 x 106 x T x D2 x K-D where: l is luminous intensity in candelas under service conditions, T is threshold factor 2 x 10-7 lux, D is range of visibility (luminous range) of the light in nautical miles, and K is atmospheric transmissivity. For the prescribed lights the value of K shall be 0.8, corresponding to a meteorological visibility of approximately 13 nautical miles.
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(3) Solving this formula indicates a minimum intensity of 4.3 candelas is required for this light.
NOTE: The FAR and the USCG navigation rules may be satisfied by an externally hung light(s). One method of compliance woul d be to use USCG approved all-around lights which are of the appropriate luminosity and externally hung.
AC 29.1401. § 29.1401 (Amendment 29-11) ANTICOLLISION LIGHT SYSTEM.
a. Explanation. Certification for night operations requires an approved aviation red anticollision light. Determination of t he location and how many anticollision lights are required to satisfy the regulations are functions of aircraft shape and the ability to obtain the required area coverage and light intensity. A deta iled explanation of how to calculate the measured area coverage required by § 29.1401(b) is given in AC 20-30B.
An explanation of the methods used to measure and calculate the light intensity and color required by § 29.1401(e) are explained in AC 20-74.
b. Procedure. The anticollision light(s ) should be located to obtain the required coverage and to prevent cockpit reflections that would affect the crew’s vision. The anticollision lights are required to be red to reduce cockpit reflections and objectionable effect of rotor blade strobing. Duri ng the period of August 11, 1971, through February 4, 1976, white lights were permitted by the rules; however, white lights resulted in undesirable cockpit reflections at night and in close proximity to clouds. For these reasons, white lights are not considered to be satisfactory in all operating conditions. Section 29.1401(b) was changed in 1976 to require a red anticollision light.
White lights have been approved for installation on rotorcraft when they were installed in addition to the required red lights, if an independent control for the white light was provided that allowed the pilot to eliminate any adverse cockpit reflections.
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SUBPART F - EQUIPMENT
SAFETY EQUIPMENT AC 29.1411. § 29.1411 SAFETY EQUIPMENT - GENERAL.
a. Explanation.
(1) This section contains requirements for the accessibility and stowage of required safety equipment. Compliance with this section should assure that:
(i) Locations for stowage of all required safety equipment have been provided.
(ii) Safety equipment is read ily accessible to both crewmembers and passengers, as appropriate, during any reasonably probable emergency situation.
(iii) Stowage locations for a ll required safety equipment will adequately protect such equipment from inadvertent damage during normal operations.
(iv) Safety equipment stowage prov isions will protect the equipment from damage during emergency landings when subjected to the inertia loads specified in § 29.561.
(2) It is a frequent practice for the rotorcraft manufacturer to provide the substantiation for only those portions of the ditching requirements relating to aircraft flotation and ditching emergency exits. Completion of the ditching certification to include the safety equipment installation and stowage provisions is then left to the affected operator so that those aspects can best be adopted to the selected cabin interior. In such cases, the “Limitations” section of the Rotorcraft Flight Manual should identify the substantiations yet to be accomplished in order to justify the full ditching approval. The operator (or modifier) perfo rming these final installations is then concerned directly with the details of this paragraph. Any aspects of the basic rotorcraft flotation and emergency exits approval that are not compatible with the modifier’s proposed safety equipment provisions should be resolved between the type certificate holder and the modifier prior to FAA/AUTHORITY approval for ditching.
(See paragraphs AC 29.801a(9) and AC 29.1415a(3).)
b. Procedures.
(1) A cockpit evaluation should be conducted to demonstrate that all required emergency safety equipment to be used by the crew will be readily accessible during any probable emergency situation. This evaluation should include, for example, emergency flotation equipment actuation devices, remote life raft releases, hand fire extinguishers, and protective breathing equipment.
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(2) Stowage provisions for safety equipment shown to be compatible with the vehicle configuration presented for certification should be provided and identified so that:
(i) Equipment is readily accessible regardless of operational configuration.
(ii) Stored equipment is free from inadvertent damage from passengers and handling.
(iii) Stored equipment is adequately restrained to withstand the inertia forces specified in § 29.561(b)(3) without sustaining damage.
(3) For rotorcraft required to have an emergency descent slide or rope according to § 29.809(f), the stowage provisions for these devices must be located at the exits where they are intended to be used.
(4) Life raft stowage provisions should be sufficient to accommodate rafts for the maximum number of occupants for which certification for ditching is requested.
(i) Life rafts stowed inside the rotorcraft should be located near the ditching emergency exits so that:
(A) Life rafts are readily accessible and deployment through ditching emergency exits by passengers and crew may be accomplished without unreasonable effort and training.
(B) Deployment of life rafts can be accomplished without damage (i.e., punctures, tears, etc.).
(ii) Life rafts stowed outside of the rotorcraft should have-- (A) A readily accessible deployment device; and (B) A secondary method of deployment near the stowed area.
(iii) Rotorcraft fuselage attachments for the life raft static lines required by § 29.1415(b)(2) must be provided.
(A) Static line fuselage attachments should not be susceptible to damage when the rotorcraft is subjected to the maximum emergency ditching water entry loads established by § 29.801. (See paragraph AC 29.801b(1).)
(B) Static line fuselage attachments should be structurally adequate to restrain a fully loaded raft of the maximum capacity required for ditching certification.
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AC 29-2C, Chg 2 4/25/06 (C) Life rafts that are remotely or automatically deployed must be attached to the rotorcraft by the required static line after deployment without further action from the crew or passengers.
(5) Stowage provisions for the emergency locator transmitter (ELT) required by § 29.1415 must be located near a designated ditching emergency exit. The TSO under which most life rafts are approved and the operating regulations (e.g., 135.167(b)) require that the ELT be actually attached to an approved life raft. Configurations supplying an ELT as a part of an approved life raft package have been accepted as meeting the intent of § 29.1411(e).
(6) If stowage provisions for life preservers are included in an interior configuration, each life preserver when stowed must be within easy reach of each occupant while seated.
(7) Service experience has shown that following deployment, life rafts are susceptible to damage while in the water adjacent to the helicopter due to projections on the exterior of the helicopter such as antennas, overboard vents, guttering, etc.
Projections likely to cause damage to a deployed life raft should be modified or suitably protected to minimize the likelihood of their causing damage to a deployed life raft.
Relevant maintenance information should also provide procedures for maintaining such protection for rotorcraft equipped with life rafts.
AC 29.1413. § 29.1413 (Amendment 29-16) SAFETY BELTS: PASSENGER WARNING DEVICE.
a. Explanation. A safety belt design feature and a design feature for the belt warning or signal device are stated in the standard.
(1) Belts must have metal-to-metal latches (Amendment 29-16).
Section 29.785(c), (f), and (g) of Amendment 29-24 concern design and installation standards for belts.
(2) Whenever a “fasten” seat belt sign or equivalent symbol is used, each pilot shall be able to control or operate the sign.
(3) Section 29.853(c) of Amendment 29-18 concerns illuminated “no smoking” information signs which are typically adjacent to any seat belt information sign.
Whenever the crew and passenger compartments are separated, illuminated signs are required. However, a placard ma y be used to prohibit any smoking.
(4) TSO-C22, Safety Belts, contains acceptable aircraft belt standards. Also, TSO-C114, Torso Restraint Systems, dated March 27, 1987, contains acceptable aircraft standards, provided there is compliance with § 29.785.
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b. Procedures.
(1) A TSO-C22 or TSO-C114 approved seat belt or seat belt/harness should be used. The rated load shall not be exceeded. During an interior compliance inspection, the belt shall be checked for proper label, rating, and metal-to-metal latches. Other features are required by § 29.785(c) and (g) of Amendment 29-24.
(2) A placard, legible to each passenger seated in the cabin, stating “fasten seat belts” (and harness if appropriate) may be used. This is similar to the “no smoking” placard standard.
(3) If an illuminated “fasten seat belt” sign or symbol is used, it should be legible to each seated passenger and must be controllable from each pilot seat.
AC 29.1415. § 29.1415 (Amendment 29-30) DITCHING EQUIPMENT.
a. Explanation.
(1) overw ater operations. However, if such equipment is required by an operating rule
(e.g., § 135.167), the equipment supplied for compliance with the operating rule must meet the requirements of this section.
(2) Compliance with the provisions of § 29.801 for rotorcraft ditching requires compliance with the safety equipment stowage requirements and ditching equipment requirements of §§ 29.1411 and 29.1415, respectively.
(i) Emergency flotation and signaling equipment installed to complete certification for ditching or required by any operating rule must be compatible with the basic rotorcraft configuration presented for ditching certification. It is satisfactory if operating equipment is not incorporated at the time of original type certification of the rotorcraft provided suitable information is included in the “Limitations” section of the Rotorcraft Flight Manual to identify the extent of ditching certification not yet completed.
(ii) When the ditching equipment required by § 29.1415 is being installed by a person other than the applicant who provided the rotorcraft flotation system and ditching emergency exits, special care must be taken to avoid degrading the functioning of the aircraft devices and to make the ditching equipment compatible with them. (See paragraphs AC 29.801a(9) and AC 29.1411a(2).)
b. Procedures.
Emergenc y flotation and signaling equipment is not required for all rotorcraft
(1) Life rafts and life preservers used to show compliance with the ditching requirements must be of an approved type. Compliance with the requirements of TSO-C12 for life rafts and TSO-C13 for life preservers will satisfy regulatory requirements for approval of this equipment.
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(i) Life preservers.
(A) Life preservers should comply with the requirements of the applicable operating regulations (FAR Parts 91, 135, 121, etc.). For extended overwater operations each life preserver is required to have an approved survivor locator light by the operating rules.
(B) Protective covers for life preservers should be compatible with the TSO requirements under which the basic life preserver was approved.
(ii) Life rafts.
(A) Life rafts are rated during their approval to the number of people that can be carried under normal conditions and the number that can be accommodated in an overload condition. Only the normal rating may be used in relationship to the number of occupants permitted to fly in the rotorcraft.
(B) The life raft configuration (i.e., number of life rafts and capacity of each raft) presented for ditching certification must be adequate to accommodate all rotorcraft occupants using the overload rating of the remaining raft(s) after the loss of one raft of the largest rated capacity. Thus, at least two rafts are required for any transport category rotorcraft extended overwater operation.
(C) Each life raft must be equipped with both a trailing line and a static line to be used for securing the life raft close to the rotorcraft for occupant egress. The static line should be of adequate strength to restrain the life raft under any reasonably probable sea state condition but must be designed to release before submerging the empty raft to which it is attached if the rotorcraft sinks.
(iii) Survival Equipment. Approved survival equipment if required by any operating rule must be attached to each life raft. Provisions for the attachment and stowage of the appropriate survival equipment should be addressed during the ditching equipment segment of the basic ditching certification.
(2) One emergency locator transmitter (ELT) meeting the applicable requirements of TSO-C91 must be provided for use in one life raft. The ELT provided for this purpose should be attached to one of the rafts or included in the survival equipment which is attached to one of the life rafts. If not attached to a life raft, the ELT must be located near an emergency ditching exit for compliance with § 29.1411(e).
(See paragraph AC 29.1411b(5).)
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AC 29.1419. § 29.1419 (Amendment 29-21) ICE PROTECTION.
NOTE: Section 29.877 was removed and replaced by § 29.1419 in Amendment 29- 21.
Guidance material for Ice Protection prior to Amendment 29-21 is retained in AC paragraph 29.877 (Subpart D).
a. Background.
(1) In March 1984, the FAA/AUTHORITY for the first time certificated a rotorcraft for flight into known icing conditions. Several other manufacturers are pursuing designs for icing flight capability.
(2) Most rotorcraft icing technology has been developed for military rotorcraft.
The only U.S. military rotorcraft equipped and approved for flight into icing conditions is the UH-60A (Blackhawk). The UH -60A is limited to supercooled cloud conditions where liquid water content (LWC) does not exceed 1.0°gm/m3 and outside air temperature (OAT) is not below -20° C.
(3) Many rotorcraft operators have voiced a high priority on obtaining rotorcraft approved for operation in icing conditions.
(4) The icing characteristics envelope of FAR Part 25, Appendix C, has served as a satisfactory design criteria for fixed-wing operations for two decades. The envelope, as presented, extends to 22,000 feet with possible extension to 30,000 feet but does not present icing severity as a function of altitude. At the time the envelope was derived, it was assumed that all transport category airplanes would operate to at least 22,000 feet. For present state- of-the-art rotorcraft, this assumption is not valid. As such, an altitude-limited icing envelope based on the same data used to derive the Part 25, Appendix C, and the Part 29, Appendix C, envelopes is presented as an alternate to the full icing envelope.
b. Explanation .
(1) General.
(i) The discussion in this paragraph pertains generally to certifications to the full icing envelope of Part 29, Appendix C, within the altitude limitations of the rotorcraft or to the altitude-limited icing envelope based on a 10,000-foot pressure altitude limit. The actual icing envelope considered may be further restricted based on the actual pressure altitude envelope for which certification is requested. It envisions certification with full ice protection systems (rotor blades, windshields, engine inlets, stabilizer surfaces, etc.). With the exception of pilot controllable variables such as altitude and airspeed, limited certification (either in terms of icing envelope or protection capability) is not envisaged at this time due to the difficulty in forecasting the severity of icing conditions, relating the effects of the forecasted conditions to the type of aircraft, and the effects of reported icing among various types of aircraft, particularly between Page F – 93
fixed- and rotary-wing aircraft. In addition, with a limited protection capability, viable escape options may not be operationally available if limitations are exceeded.
(ii) The discussion in this paragraph, regarding rotor blade ice protection, is oriented primarily toward electrothermal rotor deicing systems, since these have the most widespread acceptance and projected use within the industry. Also, most of the testing and research into rotorcraft ice protection to date has been conducted with these types of systems. Research is continuing with other types of systems such as anti -icing fluid systems, and information will be added to address certification of these as necessary. It should also be noted that most of the rotorcraft icing experience accumulated to date has been on rotorcraft with symmetrical airfoil sections. The application of this experience to rotorcraft with asymmetrical airfoils should be carefully evaluated. Limited experience has been gained during development and qualification testing of the Army Blackhawk on asymmetrical airfoil icing characteristics. The most prominent difference appears to be a more rapid degradation of airfoil performance.
Rapidity of performance degradation is also dependent upon severity of the icing condition (primarily a function of liquid water content) and ice shape (primarily a function of OAT and median volumetric droplet diameter (MVD)).
(iii) The effects of ice can vary considerably from rotorcraft to rotorcraft.
Experience gained for a rotor system with an identical blade profile could provide valuable information but should be used cautiously when applied to another rotorcraft.
Assumptions cannot necessarily be made based on icing test results from another rotorcraft. Particular care should be exercised when drawing from fixed- wing icing experience as the widely different and varying conditions seen by the rotor blades make many comparisons with fixed-wing results invalid. Likewise, icing effects on rotor blades vary significantly from those on other parts of the rotorcraft. This is due to changing blade velocity as compared with the constant velocity of the remaining parts.
(2) Reference Material. Prior to commencement of efforts to design and certify a rotorcraft, the references listed in paragraph d should be reviewed. FAA Technical Report ADS-4, Engineering Summary of Airframe Icing Technical Data, December 1963, although somewhat dated, is recommended for basic aircraft icing protection system design information.
(3) Objective. The objective of icing certification is to verify that throughout the approved envelope, the rotorcraft can operate safely in icing conditions expected to be encountered in service (i.e., Appendix C of Part 29 or the altitude-limited icing envelope presented herein). This will entail determining that no icing limitations exist or defining what the limitations are, as well as establishing the adequacy of the ice warning means (or system) and the ice protection system. A limiting condition may manifest itself in one of several areas such as handling qualities, performance, autorotation, asymmetric shedding from the rotors, visibility through the windshield, etc. Prior to flight tests in icing conditions, sufficient analyses should have been conducted to determine the design points for the particular item of the rotorcraft being analyzed (windshield, engine inlet, rotor blades, etc.). After the analyses are reviewed and found adequate, tests Page F – 94