4-1 CHAPTER 4. AIRWORTHINESS REQUIREMENTS
4.1 Operations Flight Characteristic Demonstration. Title 14 CFR part 133, § 133.41(a) pertains to airworthiness requirements and refers to the flight characteristics as it relates to each rotorcraft-load combination (RLC) for a specific rotorcraft type. Approval of each RLC requires a demonstration flight showing satisfactory flight characteristics for that RLC. For the purposes of this demonstration, the external-load weight, including the external-load attaching means, must be the maximum weight for which authorization is sought.
4.1.1 Documentation of Previous RLC Demonstrations. Documentation of any approved RLC demonstrations that were obtained from manufacturer’s data in the Rotorcraft Flight Manual (RFM) or documentation showing satisfactory results issued to another operator by the Administrator for that specific RLC satisfy the requirements of § 133.41(a).
Therefore, operators need not comply with the requirements for a demonstration flight if the manufacturer has already performed this demonstration. The RFM for each rotorcraft contains this information.
4.1.2 Unsatisfactory Documentation. If the RLC flight characteristic check has not been satisfactorily documented as described above, then the applicant must demonstrate the flight characteristic checks to the Administrator to meet this requirement. When the applicant conducts the demonstration, they must use their direct employees or agents.
4.1.3 Demonstration of Quick-Release Device. In addition, the external-load attaching means must be appropriately certificated and a satisfactory demonstration must be performed in accordance with §§ 133.41 and 133.43. The flight characteristics demonstration should evaluate the pilot actuating each quick-release device under simulated emergency conditions. Whenever the quick-release switch location or function is modified, operators should ensure that their pilots re-demonstrate their ability to actuate the switch in normal and simulated emergency operation without inducing unwanted control inputs.
4.2 Rotorcraft Type Certification Requirements. All rotorcraft external-load operations conducted in the United States by any person must comply with the operating and airworthiness rules of part 133. Most operations, with the exception of those listed in § 133.1(c), must also comply with the certification rules of part 133 and hold a Rotorcraft External-Load Operating Certificate. Certificates issued under part 133 are valid for a period of 24 calendar-months per § 133.13.
4.2.1 Airworthiness Certification Rules. Part 133 prescribes airworthiness certification rules for rotorcraft used in rotorcraft external-load operations in the United States. This part further provides that an applicant must have the exclusive use of a rotorcraft type certificated (TC) under 14 CFR part 27, part 29, or part 21, § 21.25.
4.2.2 Background.
1. Under previous regulations, rotorcraft could not be operated with external loads for compensation or hire unless the RLC has been approved under the provision of Civil Air Regulations (CAR) part 6, Rotorcraft Airworthiness:
4-2 Normal Category, and part 7, Rotorcraft Airworthiness: Transport Category, or in not-for-hire operations under § 21.25(b). It was pointed out that the burden and expense of obtaining such approval may be unnecessarily severe and that safety would not be compromised if less restrictive airworthiness requirements were established.
2. Recognizing that the type certification rules prescribed in CAR parts 6 and 7 might be unduly restrictive when applied to rotorcraft with external-load provisions, part 133 was adopted containing airworthiness standards for the approval of rotorcraft external-load operations and appropriate operating limitations for such rotorcraft. Part 133 requires an applicant to demonstrate satisfactory flight characteristics with various external-load combinations that are usually in addition to demonstrations required by parts 27 and 29.
4.2.3 Standard Category Aircraft. Upon successful completion of all applicable requirements of part 133, an applicant is eligible for a Rotorcraft External-Load Operating Certificate.
This certificate becomes a current and valid airworthiness certificate for each standard category rotorcraft listed in that certificate when the rotorcraft is used in operations under part 133.
4.2.4 Restricted Category Aircraft. In accordance with § 21.25, an applicant is entitled to a TC for an aircraft in the restricted category for special purpose operations if he or she shows compliance with the applicable noise requirements of 14 CFR part 36; the applicant shows that no feature or characteristic of the aircraft makes it unsafe when it is operated under the limitations prescribed for its intended use; and the aircraft meets the airworthiness requirements for the special purpose(s) for which the aircraft is to be used or has been manufactured in accordance with the requirements of, and accepted for use by, a branch of the Armed Forces of the United States, and has been later modified for a special purpose.
4.2.4.1 Special Purpose Operations. As authorized under the provisions of § 21.25, special purpose operations for restricted category aircraft include the following:
1. Agricultural use (includes the special purpose operations of crop spraying, dusting, and seeding; livestock and predatory animal control; insect control; dust control; and protection of crops).
2. Forest and wildlife conservation (includes the special purpose operations of aerial dispensing of liquids, heli-logging, fish spotting, wild animal survey, and oil spill response).
3. Aerial surveying (includes the special purpose operations of photography, mapping, oil and mineral exploration, atmospheric survey and research, geophysical and electromagnetic survey, oceanic survey, and airborne measurement of navigation signals).
4. Patrolling (includes patrolling pipelines, power lines, and canals).
5. Weather control (includes cloud seeding).
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6. Aerial advertising (includes the special purpose operations of skywriting, banner towing, airborne signs, and public address systems).
7. Any other operation specified by the FAA. The following purposes are approved under § 21.25(b)(7):
• Rotorcraft external-load operations (part 133).
• Carriage of cargo (incidental).
• Target towing.
• Search and Rescue (SAR) (nontransport).
• Space vehicle (SV) launch.
• Glider towing.
• Alaskan fuel hauling.
• Alaskan Fixed-Wing External Loads (FWEL).
Note: Rotorcraft certificated in the restricted category for the special purpose of external-load operations under § 21.25(b)(7) are issued restricted category airworthiness certificates.
4.3 External-Load Attaching Means.
4.3.1 Definition. External-load attaching means are the structural components used to attach an external load to an aircraft, including external-load containers, the backup structure at the attachment points, and any quick-release device used to jettison the external load.
This includes any structure, mounts, hooks, hoists, and lines used to connect the external load.
4.3.2 Certification. Rotorcraft external-load attaching means must meet the requirements outlined in § 133.43(a). While conducting external-load operations, the aircraft must have on board a facsimile of the approved Rotorcraft External-Load Operating Certificate (FAA Form 8430-21, Operating Certificate). This certificate constitutes a valid airworthiness certificate while the operator conducts external-load operations. It in no way invalidates the airworthiness certificate issued at certification. The facsimile, carried in the aircraft, is only valid while an external load is attached to the aircraft. The standard airworthiness certificate issued at certification must be displayed in accordance with 14 CFR part 91, § 91.203. Each external-load attaching means must have been approved under one of the following:
• CAR part 8 on or before January 17, 1964;
• Part 133, before February 1977;
• Part 27 or 29, as applicable, irrespective of the date of approval;
• Section 21.25;
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• Supplemental Type Certificate (STC); or
• FAA Form 337, Major Repair and Alteration (Airframe, Powerplant, Propeller, or Appliance).
4.4 Quick-Release Devices.
4.4.1 Background. The rotorcraft operator must be able to jettison the load quickly in an emergency condition. A quick-release mechanism is installed to meet this requirement.
By rule, the quick release requires the operator to perform two distinct movements or operations to release the load.
4.4.2 Certification. A quick-release device must be approved under one of the following:
• Part 27 or 29, as applicable;
• Part 133, before February 1, 1977; or
• Section 21.25, except the device must comply with part 27, § 27.865(b) or part 29, § 29.865(b), as applicable.
Note: A control for quick release must be installed in accordance with § 27.865 or § 29.865. In addition, a manual mechanical control for the quick-release device must be readily accessible to either the pilot or another crewmember.
4.5 Portable Safety Devices (PSD)/Belly Bands.
4.5.1 Development of Belly Bands. The primary attaching means must be capable of securely retaining the load, and must also be able to jettison the load very quickly in an emergency condition. Inadvertent release of the load, especially a human external cargo (HEC) load, is an obvious safety problem. At the same time, an inability to release the load in an emergency is also an obvious safety problem. To overcome the inadvertent release problem, external-load operators began using a device in addition the primary attaching means, commonly called a belly band. This device is similar to a belt or strap. It goes through the cabin, wraps around the fuselage, and hangs below the aircraft between the landing gear. The cable that attaches the external load to the rotorcraft is called a long line. In HEC operations, the long line is attached to both the cargo hook and the belly band. Should the cargo hook release inadvertently, the HEC is retained by the belly band.
4.5.2 Use of Belly Bands. The belly band is authorized to be used in addition to the primary attaching means for HEC external load operations. A belly band system, also known as an emergency anchor, is classified as a PSD. The PSD is intended to improve HEC safety by reducing the chance of an accidental death in case the primary attaching means release system fails. The PSD is not TC’d and an STC is not required since PSDs are not permanently installed. The use of a PSD is at the operator’s discretion in addition to the attaching means and quick-release certification requirements as an option to mitigate risk.
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4.5.2.1 Use of a PSD is not required for HEC operations. However, if you choose to use a PSD, the operator must ensure that it does not endanger the safe operation of the aircraft. This would include an evaluation to show that the load is transportable and releasable, when necessary, without hazard to the helicopter during both normal and emergency flight conditions. This evaluation would be conducted as part of the flight characteristics demonstration flight required by § 133.41(c)(6).
4.5.2.2 However, along with the jettison requirements of the primary attaching means, a PSD should also be evaluated by the operator to ensure:
• The materials meet the accepted industry standard of National Fire Protection Association (NFPA) 1983, Standard on Life Safety Rope and Equipment for Emergency Services, or equivalent;
• The system includes installation requirements and instructions necessary for continued serviceability;
• There are provisions for a quick release;
• There is an ability to jettison without endangering the helicopter; and
• There is no sudden and/or unacceptable shift in the center of gravity (CG).
4.5.2.3 To fully realize the safety benefits of the PSD, it must be adequately maintained.
4.5.2.4 The crews utilizing the device must be trained. In addition, operators should apply the additional equipment upgrades associated with HEC.
1. Inspect and maintain the PSD. The operator should inspect and maintain PSDs as necessary to ensure they function properly and safely to protect crewmembers. This also ensures that the PSDs will not adversely affect the safe operation of the helicopter.
2. Develop operational training procedures for use of the PSD.
The operator should develop operational training procedures that include procedures for emergency release of the PSD and the primary attaching means in case either system fails to release.
3. Additional cargo hook equipment upgrades (see § 27.865):
• Substantiate a higher static limit load (3.5 load limit) for the external-load attaching means and corresponding personnel carrying device system;
• Incorporate separate dual actuation devices in both the primary and backup quick-release systems in the aircraft;
• Substantiate more stringent electromagnetic interference and lightning protection for the quick-release system in the aircraft;
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• Use a personnel carrying device system with improved structural integrity and personnel safety features.
• Conduct a fatigue evaluation of the aircraft quick-release system, attaching means, and personnel carrying device system.
4.6 Airworthiness Regulations and Limitations. The aircraft must be Airworthy, including the certification requirements of parts 27 and/or 29, for the operations conducted.
Sections 27.865 and 29.865 prescribe rules that must be complied with for external loads.
AC 27-1, Certification of Normal Category Rotorcraft, and AC 29-2, Certification of Transport Category Rotorcraft, explain in greater detail the requirements of §§ 27.865 and 29.865. Additionally, the aircraft is required to be operated in accordance with the limitations section of the RFM including any RFM Supplements (RFMS). Operations of an aircraft when the aircraft is not Airworthy or equipped for the operation, or when not in compliance with the RFMS limitations, may be a violation of FAA regulations.
Appendix A A-1 APPENDIX A. SAMPLE ROTORCRAFT-LOAD COMBINATION FLIGHT MANUAL
CONTENTS SECTION 1. OPERATING LIMITATIONS
1. Certification
2. Persons Aboard
3. Congested Area Operations
4. Knowledge and Skills
5. Required Documentation
6. Weight and Load Combination
7. Center of Gravity (CG)
8. Other Limitations SECTION 2. LOAD-COMBINATION OPERATING INFORMATION
1. Information Specific to the Load Combination
2. Required Inspections
3. Static Electricity Discharges
4. Other Information Essential to Operational Safety
5. Ground-to-Air Hand Signals
6. External-Load Securing Procedures
7. Fuel Burnoff/Center of Gravity (CG)
8. Required Placards
9. Operating Procedures
10. Safety Precautions SECTION 3. INFORMATION
1. General
2. Flight and Non-Flightcrew Personnel
3. Safety Around Helicopters
Appendix A A-2 Sample Rotorcraft-Load Combination Flight Manual Section 1. Operating Limitations In addition to the operating limitations set forth in the approved Rotorcraft Flight Manual (RFM), operate this rotorcraft in accordance with the following operating limitations.
1. Certification. No person may operate this rotorcraft with an external load unless that person holds an FAA Rotorcraft External-Load Operating Certificate and has a letter of competency or an entry in his or her logbook, as required by Title 14 of the Code of Federal Regulations (14 CFR) part 133, § 133.37(a)(2). The letter of competency or the knowledge and skill test logbook endorsement must be in that person’s possession while conducting operations under part 133.
Note: For Public Aircraft Operations (PAO), see paragraph 3.5, Public Aircraft Operations (PAO).
2. Persons Aboard. No person who is not a required crewmember may fly aboard the rotorcraft unless that person performs an essential function in connection with the external-load operation.
When the rotorcraft used requires a hoist operator, the air crewmember must wear an approved hoist operator’s safety harness while not seated with a seatbelt fastened.
3. Congested Area Operations. Do not conduct operations over congested areas unless approved by the FAA Flight Standards District Office (FSDO) in accordance with a congested area plan (CAP) developed in compliance with § 133.33(d)(1) and (2) (refer to AC 133-1, Figure 3-1, Sample Congested Area Plan).
4. Knowledge and Skills. No person may serve as a pilot of this rotorcraft during external-load operations unless that person has passed the knowledge and skill tests required by § 133.23 for the class of operation being conducted.
5. Required Documentation. A copy of the Rotorcraft External-Load Operating Certificate and Rotorcraft-Load Combination Flight Manual (RLCFM) will be on board this rotorcraft during all external-load operations.
Appendix A A-3
6. Weight and Load Combination. The total weight of this rotorcraft and load combination may not exceed:
Make and model N-number Class A load max weight # not to exceed maximum gross weight Maximum forward airspeed knots Other Make and model N-number Class B load max weight # not to exceed maximum gross weight Maximum forward airspeed knots Other Exercise extreme caution when carrying Class B external loads because the size and shape of the cargo can affect controllability.
Make and model N-number Class C load max weight # not to exceed maximum gross weight Maximum forward airspeed knots Other
7. Center of Gravity (CG). The location of the CG for this rotorcraft and load combination must be within the CG range established during type certification under 14 CFR part 27 or 29 or special purpose certification of the rotorcraft.
8. Other Limitations. Other limitations deemed necessary by the operator or contained in the RFM or the RFM Supplements (RFMS).
Appendix A A-4 Section 2. Load-Combination Information
1. Information Specific to the Load Combination. Th e operator will list information pertaining to the peculiarities of the load combination, such as the following:
• Oscillating tendencies,
• Spinning loads and the appropriate use of swivels,
• Ground effect,
• Density altitude,
• Strong or gusty winds,
• Abrupt control movements,
• Acceleration limitation,
• Maximum Class A lateral load imbalance, and
• Lateral CG calculation procedure.
This is an example of information that may be applicable to some types of cargo attach devices:
“Lift the cargo load to a hover, then check the remaining power to determine if there is enough to carry the load safely. While hovering, verify that directional control is adequate. When moving into horizontal flight, use smooth, slow control movements to minimize settling and to prevent the load from swinging.
In climbing forward flight, check for hazardous oscillations of the external load.
When approaching a landing area with a load, identify the delivery point and come in slowly, into the wind, at the shallowest possible angle, ensuring that the load clears all obstructions safely. Start bringing in power early to slow your descent and forward airspeed, ending in a hover short of the release point and in view of any ground crew personnel. Follow ground signal instructions to hover over the release point. Place the load on the ground without any movement of the load. When the helicopter is stabilized over the load and has slack in the sling, open the cargo hook by normal means. In the event of electrical failure, use the manual release to drop the cargo load. If any difficulties arise during the flight that warrant an emergency landing, release the load immediately. If for some reason the load will not release, do not drag the load on the ground before touchdown. This may cause the rotorcraft to nose over with inadequate aft cyclic control to compensate.”
2. Required Inspections. Inspect the cargo sling or basket for proper installation and overall condition. Check the load to ensure proper and safe rigging. For Class B and C loads, check the electrical release and the manual release on the ground before flight. Arm the circuit by pushing the cargo release circuit breaker in.
3. Static Electricity Discharges. Before attaching the cargo hook to the load, make sure to ground the rotorcraft to dissipate charges of static electricity that may have built up during flight.
Appendix A A-5
4. Other Information Essential to Operational Safety. The operator must set forth any other information essential for safe operation with external loads, such as:
1. Class B Human External Cargo (HEC) operations.
2. Class B HEC training:
• Pilot training.
• Crewmember training.
• Recurrent training.
• Recent experience.
3. Personnel qualifications:
• Pilot qualifications.
• Crewmember qualifications.
4. Class B HEC briefings.
5. Operational safety considerations.
6. Communications.
7. Precautions to avoid high-tension wires.
8. Lightning (Class C loads).
9. Radio communications procedures.
10. Crossing over main highways.
11. Procedures for the placement of cargo at delivery (may vary according to a specific operation class).
12. Night operation considerations, limitations, training, and risk mitigation procedures (if applicable).
Note: An example of the HEC essential information to be included in the RLCFM may be found in AC 133-1, paragraph 3.4. Additional information regarding night operations may be found in AC 133-1, paragraph 3.5.
5. Ground-to-Air Hand Signals. All personnel engaged in the external-load operation will be familiar with and use the hand signals found in AC 133-1, Appendix B. (List the procedures used to ensure familiarity.)
6. External-Load Securing Procedures. Use the company procedures to make precautionary landings in the event the securing devices become disconnected or loose.
7. Fuel Burnoff/Center of Gravity (CG). Fuel burnoff and how it may affect the CG en route.
Appendix A A-6
8. Required Placards.
a. Place a placard for the maximum weight of external load on each side of the fuselage near the external-load hook or basket if a Class A load.
b. Install an instrument panel placard describing load class approval and passenger occupancy limitations.
9. Operating Procedures. After directing the helicopter into position, one ground crewmember should remain within sight of the pilot to give positive direction with hand signals, or remain in direct radio contact with the pilot, while an appropriate number of other crewmembers attend to the cargo hookup. Hasten all hookups made to the helicopter while it is in a hover to minimize the time the hookup personnel spend underneath the helicopter.
a. If performing a hookup without the aid of a ground guide and without using direct visual operational contact, an air crewmember should lie prone on the floor and look downward from the main entrance doorway to observe the actions of the ground crewmembers; this crewmember can direct the pilot via the intercom.
b. It is relatively common, however, for a pilot to hover while ground personnel hook the line to the cargo hook. Regardless of whether there are extra crewmembers to act as observers, a thorough briefing between the pilot and the hookup person is extremely important. The hookup person should approach and proceed beneath the helicopter directly from the front, between the skids or landing gear. Should the helicopter experience catastrophic failure and be forced to land, the hookup person should retreat directly to the front. This technique avoids the confusion of “you go right, and I will go left.”
c. Crewmembers should wear approved safety harnesses and be attached to an aircraft’s approved attachment point when not seated with seatbelts fastened.
d. When giving hand signals to the pilot, a ground crewmember must stand in front of and to the pilot’s side of the helicopter, within sight of the pilot. (Refer to AC 133-1, Appendix B for hand signals.)
10. Safety Precautions. Conduct all Class D operations using only FAA-approved personnel lifting devices. The crew must calculate one-engine-inoperative hover capability at the operating weight and altitude prior to each Class D operation. Conduct each operation with a minimum of two crewmembers onboard the helicopter. Maintain intercom communication between the pilot and other crewmember. This second crewmember must be able to advise the pilot of the status of the lift device and be able to release the empty device should it become necessary. This release must require two separate and distinct actions: arming the system and depressing the release button. Where possible, a third person associated with the lift will be in position on the surface and communicating by radio with the pilot. This person’s purpose is to advise the pilot of any safety-related item and to supervise the loading or unloading of the personnel lifting device.
Further, this person should ensure not to exceed the pilot-determined maximum weight appropriate for this operation.