This AC paragraph is final and will be included in the upcoming Change 2 update.
AC 29.75A. (AC's 29.77, 29.79, 29.81, & 29.83) §§ 29.75, 29.77, 29.79, 29.81, and
29.83 (Amendment 29-39) LANDING.
(For § 29.77 and § 29.79 prior to Amendment 39, see paragraphs AC 29.77 and AC 29.79 respectively.)
a. Explanation.
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b. Procedures - Category A Requirements.
(1) Explanation. The Category A certification concept limits landing weight to a value that will allow the rotorcraft, following an engine failure at the landing decision point (LDP), to land within the available area or to execute a balked landing descending no lower than 15 feet (or higher depending on rotorcraft geometry and performance characteristics) above the landing surface. For elevated heliports the rotorcraft may descend below the landing surface, but all parts of the rotorcraft must clear the heliport and other obstacles by not less than 15 feet. These minimum heights should be demonstrated with variations in piloting techniques and with pilot recognition and reaction times for engine failures occurring before and after the LDP. See figure AC 29.75A-1. For additional information addressing the OEI landing case at night, refer to AC 29.59A.b(12).
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(2) Procedures.
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(iii) Power. Power used for demonstrating performance should be limited to minimum specification values on the operating engine(s). This may be accomplished by adjustment of the engine topping to minimum specification values including consideration of temperature effects on engine power. If the management of engine power at topping is beyond normal pilot capability, the validity of the Cat A procedure must also be established with representative in-service characteristics. The method used for simulating engine failure must be representative of the power decay characteristics that will occur during a real, sudden engine failure and acceleration of the remaining engine(s). In order to cushion the OEI landing, it is acceptable for the engine and transmission transient range in order to droop the rotor provided performance credit is not taken for this additional power above the maximum permitted rating and it can be shown that the engine(s) will remain within these limits in all conditions requested by the applicant. Any excursion beyond established transient Page 5
This AC paragraph is final and will be included in the upcoming Change 2 update.
limits in this flight phase should be substantiated to the extent that it does not constitute an immediate hazard to the rotorcraft.
(iv) * * * * * Page 6
This AC paragraph is final and will be included in the upcoming Change 2 update.
AC 29.337. § 29.337 (Amendment 29-30) LIMIT MANEUVERING LOAD FACTOR.
a. Explanation. The rotorcraft must be designed and substantiated to load factors as specified to provide a minimum level of structural integrity of the rotorcraft airframe and rotors.
(1) A range of design positive load factors from +3.5 to +2.0 may be used.
(2) A range of design negative load factors from -1.0 to -0.5 may be used.
(3) Load factors inside the range of +3.5 to -1.0 may be used provided the probability of exceeding the design load factors is shown by analysis and flight tests to be extremely remote, and the selected load factors are appropriate to each weight condition between design maximum and minimum weights.
(4) Load factors exceeding these “minimums” may be used.
b. Procedures.
(1) The applicant may elect to substantiate the rotorcraft for a design maneuvering load factor less than +3.5 and more than -1.0. Whenever this option is used, an analytical study and flight demonstration are required. Maximum available rotor lift with both power on and power off must be considered when substantiating maneuver load factors less than the specified values.
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This AC paragraph is final and will be included in the upcoming Change 2 update.
AC 29.631. § 29.631 (Amendment 29-40) BIRD STRIKE.
a. Explanation. Amendment 40 adds requirements for continued safe flight and landing after a bird strike. Compliance with § 29.631 must be shown for a 2.2 lb (1.0 kg) bird at a relative velocity equal to the lesser of VNE or VH at altitudes up to 8,000 feet.
For Category A certification, the rotorcraft must be capable of continued safe flight and landing after the described bird strike. For Category B certification, the rotorcraft must be capable of a safe landing after the bird strike.
b. Procedures. For compliance with FAR 29.631, it should be demonstrated by test or analysis supported by test evidence that,
(1) The windshields will withstand the bird strike, without penetration, and,
(2) The rotorcraft is capable of continued safe flight and landing following impact with a 2.2-lb (1.0 kg) bird at VNE or VH (whichever is the lesser) at altitudes up to 8,000 feet. Areas of impact that are of particular interest include flight control surfaces (which includes main and tail rotors) and exposed flight control system components.
This AC paragraph is final and will be included in the upcoming Change 2 update.
AC 29.672. § 29.672 (Amendment 29-24) STABILITY AUGMENTATION, AUTOMATIC, AND POWER-OPERATED SYSTEMS.
a. Explanation.
(1) This rule requires that the pilot be made aware of stability augmentation, automatic, or power-operated system failures which could lead to an unsafe condition.
It should be understood that this requirement applies to stability augmentation and supplementary controls and not the primary flight control system, which is dealt with under § 29.695 and associated advisory material. Examples of clearly distinguishable warnings include, but are not limited to, an obvious aircraft attitude change following the failure or an audio warning tone. A visual indication itself may not be adequate since detection of a visual warning would normally require special pilot attention. The use of devices such as stick pushers or shakers is not acceptable as a warning means since the automatic flight control systems (AFCS) may provide a hands-off capability or normal helicopter vibrations could mask a control shaker. However, this rule is not intended to eliminate the use of such devices for other purposes. Examples of automatic control systems other than a stability augmentation system would be a pitch axis actuator used for the purpose of demonstrating compliance with longitudinal static stability requirements or a fly-by-wire elevator. The design of such systems must not interfere with completion of the control checks described in § 29.671(c). Further, for control systems where a series actuator malfunction could degrade control authority, a means should be provided to the pilot to determine actuator alignment (see § 29.1329(b)).
(2) The corrective flight control input following a system failure should be in the logical direction. For example, a malfunction resulting in a nosedown pitch of the aircraft should require a corrective cyclic control input in the aft direction. The system deactivating means does not have to be located on the primary flight control grips;
however, it should be easily accessible to the pilot. Consideration should be given to the consequences of inadvertent de-selection of the automatic stabilization system, especially if the deactivation control is mounted on a primary control grip. Malfunctions and subsequent recoveries must be shown throughout the operating envelope of the aircraft. In a case where control authority is decreased following a malfunction, a practical flight envelope must be defined wherein compliance with controllability and maneuverability requirements can be demonstrated. This practical flight envelope must be presented in the flight manual. Compliance with trim and stability characteristics is not required following a malfunction; however, a pilot workload assessment should be made to show that these characteristics are not impaired below that needed for continued safe flight and landing.
This AC paragraph is final and will be included in the upcoming Change 2 update.
AC 29.683. § 29.683 OPERATION TESTS.
a. Explanation. The rule requires that the control system be free from jamming, excessive friction, and excessive deflection. An operational test is required in which specified loads are applied at the pilot controls and carried through an operating control system.
b. Procedures.
(1) Compliance with the requirements of this rule is obtained by use of a test setup similar to that used for the limit load tests of § 29.681, except the load reactions at the blades (or surfaces) must allow for movement of the blades (or surfaces) as the system is operated through its operating range.
(2) Fixtures are normally affixed to the surfaces (or replace the surfaces) to allow pulley arrangements which provide for movement under load. These fixtures should be evaluated to assure that system loads up to limit will be applied during the full range of operations of each system.
(3) Each flight control system should be operated through its entire range under a light load and under limit load. As the controls are being operated, the system should be checked for jamming, excessive friction, and excessive deflection. Excessive deflection includes deflection sufficient to contact other systems or structure. Also, if under these limit load conditions the components deflect, the deflection would be considered excessive if there is permanent deformation of any component or supporting structure. Also any deflection that results in an uncorrected condition when the load is released, e.g., if a bellcrank is forced off-center or over-center during load and does not return to the normal position after load release is excessive deflection. Floor panels, wall panels, and other access panels may have to be removed to permit visual checks of the entire control system. However, care should be taken when removing panels so that airframe structure is not weakened enough to deflect from its normal position when test loads are applied to the control system.
This AC paragraph is final and will be included in the upcoming Change 2 update.
AC 29.777. § 29.777 COCKPIT CONTROLS.
a. Explanation. This section defines the general cockpit control requirements.
Cockpit control location and arrangement, with respect to the pilot’s seat, must be designed to accommodate pilots from 5’2” to 6’0” in height. Pilots within this range should be able to reach and operate all required controls and have sufficient clearance with the structure, panels, etc.
b. * * * * * Page 11
This AC paragraph is final and will be included in the upcoming Change 2 update.
AC 29.1321. § 29.1321 (Amendment 29-21) ARRANGEMENT AND VISIBILITY.
a. Background. This section is the first in a series that concerns the installation of instruments. Specific requirements for individual instruments are addressed in other paragraphs. The instruments should be arranged in a manner so that the pilot may avail himself of the information displayed by the instruments without undue distraction.
Additionally, for instrument flight, the rule requires that the attitude, altitude, airspeed, and compass indicators be grouped in the so-called standard “T.” Instrument location and arrangement, with respect to the pilot’s seat, should be designed to accommodate pilots from 5’2” to 6’0” in height. Pilots within this range should be able to see and, where necessary, reach and operate all of the displays.
b. * * * * * Page 12
This AC paragraph is final and will be included in the upcoming Change 2 update.
AC 29.1333. § 29.1333 (Amendment 29-24) INSTRUMENT SYSTEMS.
a. Explanation.
(1) Electromechanical Displays. Prior to Amendment 29-24, this requirement was titled “Duplicate Instrument Systems,” and its provisions were intended to apply when duplicate flight instruments were required by any operating rule. Due to the increased complexity of instrumentation that was available and being used, it was considered appropriate to amend the provisions of this requirement by adopting §
29.1333 in Amendment 29-24 to more appropriately consider the extreme range of operational environments to which rotorcraft were being routinely exposed. It is the intent of § 29.1333 to prevent degrading the first pilot’s instrument system, or the only pilot’s instrument system in a single-pilot-approved rotorcraft, by not permitting peripheral systems to be connected to it. In addition, equipment must not be connected to operating systems for the second pilot’s required instruments unless it is extremely improbable that failure of such additional equipment would affect that operating system.
Similar provisions are also included in VIII.(b)(5)(i) through (iii) of Appendix B to Part 29, Airworthiness Criteria for Helicopter Instrument Flight.
(2) Advanced Display Systems. The increased use of microprocessor technology in avionic systems has resulted in the use of computer-generated graphics to replace conventional electromechanical instruments. These displays may replace individual instruments or may integrate several flight critical parameters into single displays. For display of redundant information, “crosstalk” between the pilot and copilot displays and supporting systems has been allowed to provide detection and annunciation of faults or “miscompare” of critical flight information. A level of safety finding equivalent to that level of safety provided by § 29.1333 may be possible through the implementation of integration technology that will assure that failure of one system does not and can not adversely affect the other system.
b. Procedures.
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(4) For those installation designs that employ integration technology and seek to obtain approval of those designs through an equivalent level of safety finding, applicants should perform adequate system testing and any analysis necessary to assure that failure of one system will not adversely affect the other system in order to demonstrate that the design meets or exceeds the minimum safety level established by § 29.1333 and VIII.(b)(5)(i) through (iii) of Appendix B to Part 29, Airworthiness Criteria for Helicopter Instrument Flight.
This AC paragraph is final and will be included in the upcoming Change 2 update.
AC 29.1351. § 29.1351 (Amendment 29-40) ELECTRICAL SYSTEMS AND EQUIPMENT -GENERAL.
a. Explanation. * * * * *
b. Procedures. * * * * *
c. * * * * *
(3) Category A rotorcraft (See FAR 29.1351(d)(2) Amendment 29-40).
(i) FAR 29.1351(d)(2) is applicable to Category A rotorcraft and requires that provision be made to ensure adequate electrical supplies to those systems which are necessary for continued safe flight and landing in the event of a failure of all normal generated electrical power. All components and wiring of the alternate supplies should be physically and electrically segregated from the normal system and should be such that no single failure, including the effects of fire, the cutting of a cable bundle, or the loss of a junction box or control panel will affect both normal and alternate supplies.
(ii) * * * * *
(iii) The systems required by FAR 29.1351(d)(2) may differ between rotorcraft types and roles and should be agreed with the Authority. They should normally include:
(A) Attitude information;
(B) Radio communication and flight crew intercommunication;
(C) Navigation;
(D) Cockpit and instrument lighting;
(E) Heading, airspeed and altitude information, including appropriate pitot head and static vent heating;
Note: Where the aircraft is to be approved for IFR, pitot heat and, where appropriate, static vent heating specified in paragraph (E) above (relating to required air data for airspeed information while operating in an emergency configuration) should be provided for the complete duration (at least 30 minutes) while operating on emergency power. A minimum 5-minute “landing” time for the landing light operation specified in paragraph (3)(i) above should be provided.
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This AC paragraph is final and will be included in the upcoming Change 2 update.
AC 29.1585. § 29.1585 (Amendment 29-24) OPERATING PROCEDURES.
a. * * * * *
b. Procedures. Procedural information should be presented in substantial accord with the categories described below:
(1) Normal Procedures. Normal procedures are concerned with peculiarities of the rotorcraft design and operating features encountered in connection with routine operations, including malfunction cases not considered in the other procedures section
(i.e., not considered to degrade safety). Material conforming to the above should be presented for each phase of flight, following in sequence from preflight through engine shutdown, and should include, but not be limited to, systems operation (including fuel system information prescribed in § 29.1585(b)), missed approaches, etc.
(2) Malfunction or Abnormal Procedures (Optional). Malfunction or abnormal procedures are included in many flight manuals to provide corrective crew actions that are not as urgent as those in the Emergency Procedures sections. These procedures are concerned with foreseeable situations, usually entailing a failure condition, in which the use of special systems, or the alternate use of regular systems, may be expected to maintain an acceptable level of safety. Typical examples of events considered to entail abnormal procedures are engine failure and or conditions that require an engine shutdown (under flight conditions where the failure is not critical), stopping and restarting engines in flight, extending landing gear or flaps by alternate means, approach in multiengine aircraft with inoperative engine(s), etc.
(3) Emergency Procedures. Emergency procedures are concerned with foreseeable but unusual situations in which immediate and precise action by the crew, as detailed in the recommended procedures, may be expected to reduce substantially the risk of disaster. Typical examples of incidents considered to be emergencies are fire, ditching, loss of tail rotor thrust or control, etc. It is expected that, in the case of tail rotor failure, the emergency procedures will have been validated by analysis, simulation, or any relevant service experience. The analysis or simulation of the tail rotor control failure procedures may be validated where practical by limited flight test.
(4) * * * * *
This AC paragraph is final and will be included in the upcoming Change 2 update.
(AC 29-2C, Appendix A, A29.3(b)(2), Instructions for Continued Airworthiness)
(MANUAL IDENTIFICATION)
REQUIREMENTS (Continued)
13. WORK RECOMMENDED
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14. APPLICABLE WEAR TOLERANCES
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15. TROUBLESHOOTING
Troubleshooting information describing:
a. Probable malfunctions.
b. How to recognize those malfunctions. (Probable Cause). Some malfunctions could be identified on the basis of a baseline vibration signature provided as follows in the maintenance manual:
The baseline vibration characteristics of the basic aircraft configuration to be used for maintenance or trouble shooting purposes should be provided as the vibratory aircraft reference in the maintenance manual. These characteristics should be given for specified loading and flight conditions (speed, altitude) with vibration pickups at specified airframe locations decided by the manufacturer. The characteristics should be given as a typical range of vibration levels at these locations and for the most representative frequencies and directions for the rotorcraft concerned (N omega main rotor and n omega tail rotor...). The manufacturers and operators should keep the basic vibration data updated from field/service experience.
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