Source: https://www.federalregister.gov/documents/2017/03/16/2017-05268/special-conditions-robinson-helicopter-company-model-r22-beta-helicopter-installation-of-helitrak
Timestamp: 2017-10-24 10:00:20
Document Index: 449787292

Matched Legal Cases: ['art 27', '§\u200927', '§\u200927', 'art 27', 'art 27', 'art 36', 'art 27', '§\u200921', '§\u200911', '§\u200911', '§\u200921', '§\u200927', '§\u200927', '§\u200927', '§\u200927']

Federal Register :: Special Conditions: Robinson Helicopter Company Model R22 BETA Helicopter; Installation of Helitrak Autopilot System
Special Conditions: Robinson Helicopter Company Model R22 BETA Helicopter; Installation of Helitrak Autopilot System
82 FR 13962
13962-13965 (4 pages)
2017-05268
FAA-2017-0167
https://www.federalregister.gov/d/2017-05268 https://www.federalregister.gov/d/2017-05268
These special conditions are issued for the Robinson Helicopter Company (Robinson) Model R22 BETA helicopter. This helicopter as modified Start Printed Page 13963by Helitrak, Incorporated (Helitrak) will have a novel or unusual design feature associated with an autopilot (AP) system. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards the Administrator considers necessary to establish a level of safety equivalent to that ensured by the existing airworthiness standards.
Send comments identified by docket number [FAA-2017-0167] using any of the following methods:
Hand Delivery of Courier: Deliver comments to the Docket Operations, in Room W12-140 of the West Building Ground Floor at 1200 New Jersey Avenue SE., Washington, DC, between 9 a.m., and 5 p.m., Monday through Friday, except federal holidays.
Docket: You can read the background documents or comments received at http://www.regulations.gov. Follow the online instructions for accessing the docket or go to the Docket Operations in Room W12-140 of the West Building Ground Floor at 1200 New Jersey Avenue SE., Washington, DC, between 9 a.m., and 5 p.m., Monday through Friday, except Federal holidays.
Mark Wiley, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Regulations and Policy Group (ASW-111), 10101 Hillwood Parkway, Fort Worth, TX 76177; telephone (817) 222-5134; or email to Mark.Wiley@faa.gov.
The FAA considers prior notice to be unnecessary as we have provided previous opportunities to comment on substantially identical proposed special conditions, and we are satisfied that new comments are unlikely. Therefore, the FAA has determined that prior public notice and comment are unnecessary and finds that good cause exists for adopting these special conditions effective upon issuance. The FAA is requesting comments to allow interested persons to submit views that may not have been submitted in response to the prior opportunities for comment.
On January 27, 2012, Helitrak applied for a supplemental type certificate (STC) to install an AP system on the Robinson Model R22 BETA helicopter. The Robinson Model R22 BETA helicopter, currently approved under Type Certificate No. H10WE, is a 14 CFR part 27 normal category, single reciprocating engine, conventional helicopter designed for civil operation. This helicopter model is capable of carrying one passenger with one pilot, and has a maximum gross weight of up to 1,370 pounds. The major design features include a two-blade teetering main rotor, an anti-torque tail rotor system, a skid landing gear, and a visual flight rule basic avionics configuration. Helitrak proposes to modify this model helicopter by installing a two-axis Helitrak AP.
The present § 27.1309(c) regulation does not adequately address the safety requirements for systems whose failures could result in “catastrophic” or “hazardous/severe-major” failure conditions, or for complex systems whose failures could result in “major” failure conditions. When § 27.1309(c) was promulgated, it was not envisioned that a normal category rotorcraft would use systems that are complex or whose failure could result in “catastrophic” or “hazardous/severe-major” effects on the rotorcraft. The Helitrak AP controls rotorcraft flight control surfaces. Possible failure modes exhibited by this system could result in a catastrophic event.
Under 14 CFR 21.101 and 21.115, Helitrak must show that the Robinson Model R22 BETA helicopter, as modified by the installed Helitrak AP, continues to meet the applicable provisions of the regulations incorporated by reference in Type Certificate No. H10WE or the applicable regulations in effect on the date of application for the change. Additionally, Helitrak must comply with the following equivalent level of safety findings, exemptions, and special conditions prescribed by the Administrator as part of the certification basis:
14 CFR part 27 dated February 1, 1965, including Amendments 27-1 through 27-10
National Environmental Act of 1969
Equivalent Safety Finding: Number TD10352LA-R/S-1
14 CFR part 27.1401(d), Anticollision Light System
In addition, Helitrak must show the Helitrak AP STC-altered Robinson Model R22 BETA helicopter complies with the noise certification requirements of 14 CFR part 36.
If the Administrator finds the applicable airworthiness regulations (that is, 14 CFR part 27) do not contain adequate or appropriate safety standards for the Robinson Model R22 BETA helicopter because of a novel or unusual design feature, special conditions are prescribed under § 21.16.
The FAA issues special conditions, as defined in § 11.19, in accordance with § 11.38 and they become part of the type certification basis under § 21.101.
Special conditions are initially applicable to the model for which they are issued. Should Helitrak apply for an STC to modify any other model included on the H10WE type certificate to incorporate the same novel or unusual design feature, the special conditions would also apply to the other model.Start Printed Page 13964
The Robinson Model R22 BETA will incorporate the following novel or unusual design features: A Helitrak AP. This AP system performs non-required flight control functions. The Helitrak AP is a two-axis system with two operational flight control modes: Heading and airspeed hold or heading and altitude hold. Other flight control functions include unusual attitude recovery, collective pulldown, and an autorotation function.
The effect on safety is not adequately covered under § 27.1309 for the application of new technology and new application of standard technology. Specifically, the provisions of § 27.1309(c) do not adequately address the safety requirements for systems whose failures could result in catastrophic or hazardous/severe-major failure conditions and for complex systems whose failures could result in major failure conditions.
To comply with these special conditions, we require that Helitrak provide the FAA with a systems safety assessment (SSA) for the final Helitrak AP installation configuration that will adequately address the safety objectives established by a functional hazard assessment (FHA) and a preliminary system safety assessment (PSSA), including the fault tree analysis (FTA). This will ensure that all failure conditions and their resulting effects are adequately addressed for the installed Helitrak AP. The SSA process, FHA, PSSA, and FTA are all parts of the overall safety assessment process discussed in FAA Advisory Circular 27-1B, Certification of Normal Category Rotorcraft, and Society of Automotive Engineers document Aerospace Recommended Practice 4761, Guidelines and Methods for Conducting the Safety Assessment Process on Civil Airborne Systems and Equipment.
These special conditions require that the Helitrak AP installed on a Robinson Model R22 BETA helicopter meets the requirements to adequately address the failure effects identified by the FHA, and subsequently verified by the SSA, within the defined design integrity requirements.
These special conditions are applicable to the Robinson Model R22 BETA helicopter. Should Helitrak apply at a later date for an STC to modify any other model included on Type Certificate No. H10WE to incorporate the same novel or unusual design feature, the special conditions would apply to that model as well.
This action affects only certain novel or unusual design features on one model helicopter. It is not a rule of general applicability and affects only the applicant who applied to the FAA for approval of these features on the helicopter.
Under standard practice, the effective date of final special conditions would be 30 days after the date of publication in the Federal Register; however, the substance of these special conditions has been subjected to the notice and comment period previously and has been derived without substantive change from those previously issued. As it is unlikely that prior public comment would result in a significant change from the substance contained herein, the FAA considers prior notice to be unnecessary and finds that good cause exists to make these special conditions effective upon issuance.
Authority: 42 U.S.C. 7572; 49 U.S.C. 106(g), 40113, 44701-44702, 44704.
Accordingly, pursuant to the authority delegated to me by the Administrator, the following special conditions are issued as part of the type certification basis for Robinson Helicopter Company (Robinson) Model R22 BETA helicopters as modified by Helitrak, Incorporated.
In addition to the requirement of § 27.1309(c), the Helitrak autopilot (AP) system installation on Robinson Model R22 BETA helicopters must be designed and installed so that the failure conditions identified in the functional hazard assessment (FHA) and verified by the system safety assessment (SSA) are adequately addressed in accordance with the following requirements.
Helitrak, Incorporated must provide the FAA with a SSA for the final Helitrak AP installation configuration that will adequately address the safety objectives established by the FHA and the preliminary system safety assessment (PSSA), including the fault tree analysis (FTA). This will show that all failure conditions and their resulting effects are adequately addressed for the installed Helitrak AP.
Note 1: The SSA process, FHA, PSSA, and FTA are all parts of the overall safety assessment (SA) process discussed in FAA Advisory Circular (AC) 27-1B (Certification of Normal Category Rotorcraft) and Society of Automotive Engineers (SAE) document Aerospace Recommended Practice (ARP) 4761 (Guidelines and Methods for Conducting the Safety Assessment Process on civil airborne Systems and Equipment).
1. No Effect. Failure conditions have no effect on safety. These failure conditions would not affect the operational capability of the rotorcraft or increase crew workload; however, could result in an inconvenience to the occupants, excluding the flight crew.
2. Minor. Failure conditions do not significantly reduce rotorcraft safety, and involve crew actions that are well within their capabilities. Minor failure conditions would include, for example, a slight reduction in safety margins or functional capabilities, a slight increase in crew workload, such as, routine flight plan changes, or result in some physical discomfort to occupants.
3. Major. Failure conditions reduce the capability of the rotorcraft or the ability of the crew to cope with adverse operating conditions to the extent that there would be, for example, a significant reduction in safety margins or functional capabilities, a significant increase in crew workload or result in impairing crew efficiency, physical distress to occupants, including injuries, or physical discomfort to the flight crew. The potential for a failure to result in a condition characterized as major should be remote with a probability of occurrence between 1 × 10−3 to 1 × 10−5 failures/flight hour.
a. Failure conditions reduce the capability of the rotorcraft or the ability of the crew to cope with adverse operating conditions to the extent that there would be:
(3) possible serious or fatal injury to a passenger or a cabin crewmember, excluding the flight crew. The potential that a failure results in a condition characterized as hazardous/severe-major should be extremely remote with a probability of occurrence between 1 × 10−5 to 1 × 10−7 failures/flight hour.Start Printed Page 13965
5. Catastrophic. Failure conditions result in multiple fatalities to occupants, fatalities or incapacitation to the flight crew, or result in loss of the rotorcraft. The potential that a failure results in a condition characterized as catastrophic should be extremely improbable with probability of occurrence 1 × 10−9 failures/flight hour or less.
Helitrak must comply with the existing requirements of § 27.1309 for all applicable design and operational aspects of the Helitrak AP with the failure condition categories of “no effect” and “minor,” and for non-complex systems whose failure condition category is classified as “major.” Helitrak must comply with the requirements of these special conditions for all applicable design and operational aspects of the Helitrak AP with the failure condition categories of “catastrophic” and “hazardous severe/major,” and for complex systems whose failure condition category is classified as “major.” A complex system is a system whose operations, failure conditions, or failure effects are difficult to comprehend without the aid of analytical methods (for example, FTA, Failure Modes and Effect Analysis, FHA).
Each of the failure condition categories defined in these special conditions relate to the corresponding aircraft system integrity requirements. The system design integrity requirements for the Helitrak AP, as they relate to the allowed probability of occurrence for each failure condition category and the proposed software design assurance level, are as follows:
Systems with failures that may result in a “major” effect must be shown to be remote and develop software to the Radio Technical Commission for Aeronautics (RTCA) Document DO-178B, Software Considerations in Airborne Systems and Equipment Certification, Level C software design assurance level and must develop complex hardware to the Radio Technical Commission for Aeronautics (RTCA) Document DO-254, Design Assurance Guidance for Airborne Electronic Hardware, Level C hardware design assurance level.
Systems with failures that may result in “hazardous/severe-major” effects must be shown to be extremely remote must develop software to the RTCA Document DO-178B, Software Considerations in Airborne Systems and Equipment Certification, Level B software design assurance level and must develop complex hardware to the Radio Technical Commission for Aeronautics (RTCA) Document DO-254, Design Assurance Guidance for Airborne Electronic Hardware, Level B hardware design assurance level.
Systems with failures that may result in “catastrophic” effects must be shown to be extremely improbable, and develop software to the RTCA Document DO-178B, Software Considerations in Airborne Systems and Equipment Certification, Level A design assurance level and must develop complex hardware to the Radio Technical Commission for Aeronautics (RTCA) Document DO-254, Design Assurance Guidance for Airborne Electronic Hardware, Level A hardware design assurance level.
The AP system equipment must be qualified to the appropriate environmental level per RTCA Document DO-160F, Environmental Conditions and Test Procedures for Airborne Equipment, for all relevant aspects. This is to show that the AP system performs its intended function under any foreseeable operating condition, including the expected environment in which the AP is intended to operate. Some of the main considerations for environmental concerns are installation locations and the resulting exposure to environmental conditions for the AP system equipment, including considerations for other equipment that may be affected environmentally by the AP equipment installation. The level of environmental qualification must be related to the severity of the considered failure conditions and effects on the rotorcraft.
Compliance with the requirements of these special conditions may be shown by a variety of methods, which typically consist of analysis, flight tests, ground tests, and simulation, at a minimum. Compliance methodology is related to the associated failure condition category. If the AP is a complex system, compliance with the requirements for failure conditions classified as “major” may be shown by analysis, in combination with appropriate testing, to validate the analysis. Compliance with the requirements for failure conditions classified as “hazardous/severe-major” may be shown by flight-testing in combination with analysis and simulation, and the appropriate testing to validate the analysis. Flight tests may be limited for “hazardous/severe-major” failure conditions and effects due to safety considerations. Compliance with the requirements for failure conditions classified as “catastrophic” may be shown by analysis and appropriate testing in combination with simulation to validate the analysis. Very limited flight tests in combination with simulation are used as a part of a showing of compliance for “catastrophic” failure conditions. Flight tests are performed only in circumstances that use operational variations, or extrapolations from other flight performance aspects to address flight safety.
These special conditions require that the Helitrak AP system installed on a Robinson Model R22 BETA helicopter, Type Certificate No. H10WE, meet these requirements to adequately address the failure effects identified by the FHA, and subsequently verified by the SSA, within the defined design system integrity requirements.
Issued in Fort Worth, Texas, on March 10, 2017.
Manager Rotorcraft Standard Staff, Aircraft Certification Service.
[FR Doc. 2017-05268 Filed 3-15-17; 8:45 am]