Special Conditions: Bombardier Inc., Models BD-500-1A10 and BD-500-1A11 Series Airplanes; Interactions of Systems and Structures, 65156-65161 [2013-25448]

Download as PDF 65156 Federal Register / Vol. 78, No. 211 / Thursday, October 31, 2013 / Rules and Regulations CFR part 36 and the FAA must issue a finding of regulatory adequacy under § 611 of Public Law 92–574, the ‘‘Noise Control Act of 1972.’’ The FAA issues special conditions, as defined in 14 CFR 11.19, under § 11.38, and they become part of the typecertification basis under § 21.17(a)(2). wreier-aviles on DSK5TPTVN1PROD with RULES Novel or Unusual Design Features The Learjet Model 45 series airplanes will incorporate the following novel or unusual design features: The proposed architecture and network configuration may be used for, or interfaced with, a diverse set of functions, including: 1. Flight-safety related control, communication, and navigation systems (aircraft control domain); 2. Operator business and administrative support (operator information domain); and 3. Passenger information and entertainment systems (passenger entertainment domain). In addition, the operating systems (OS) for current aircraft systems are usually and historically proprietary. Therefore, they are not as susceptible to corruption from worms, viruses, and other malicious actions as more widely used commercial operating systems, such as Microsoft Windows NT, because access to the design details of these proprietary OS is limited to the system developer and aircraft integrator. Some systems installed on the Learjet Model 45 series airplanes will use operating systems that are widely used and commercially available from third party software suppliers. The security vulnerabilities of these operating systems may be more widely known than proprietary operating systems currently used by avionics manufacturers. Discussion The integrated network configurations in the Learjet Model 45 series airplanes may allow increased connectivity with external network sources and will have more interconnected networks and systems, such as passenger entertainment and information services than previous airplane models. This may allow the exploitation of network security vulnerabilities and increased risks potentially resulting in unsafe conditions for the airplanes and occupants. This potential exploitation of security vulnerabilities may result in intentional or unintentional destruction, disruption, degradation, or exploitation of data and systems critical to the safety and maintenance of the airplane. The existing regulations and guidance material did not anticipate these types of system architectures. Furthermore, 14 VerDate Mar<15>2010 15:19 Oct 30, 2013 Jkt 232001 CFR regulations and current system safety assessment policy and techniques do not address potential security vulnerabilities which could be exploited by unauthorized access to airplane networks and servers. Therefore, these special conditions are being issued to ensure that the security (i.e., confidentiality, integrity, and availability) of airplane systems is not compromised by unauthorized wired or wireless electronic connections between airplane systems and the passenger entertainment services. For the reasons discussed above, these special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards. Applicability As discussed above, these special conditions are applicable to the Learjet Model 45 series airplanes. Should Learjet apply at a later date for a change to the type certificate to include another model incorporating the same novel or unusual design feature, the special conditions would apply to that model as well. Conclusion This action affects only certain novel or unusual design features on one model series of airplanes. It is not a rule of general applicability. The substance of these special conditions has been subjected to the notice and comment period in several prior instances and has been derived without substantive change from those previously issued. It is unlikely that prior public comment would result in a significant change from the substance contained herein. Therefore, because a delay would significantly affect the certification of the airplane, which is imminent, the FAA has determined that prior public notice and comment are unnecessary and impracticable, and good cause exists for adopting these special conditions upon publication in the Federal Register. 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 described above. List of Subjects in 14 CFR Part 25 Aircraft, Aviation safety, Reporting and recordkeeping requirements. The authority citation for these special conditions is as follows: Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704. PO 00000 Frm 00012 Fmt 4700 Sfmt 4700 The Special Conditions 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 Learjet Model 45 series airplanes. Isolation or Security Protection of the Aircraft Control Domain and the Airline Information Services Domain From the Passenger Services Domain 1. The applicant must ensure that the design provides isolation from, or airplane electronic system security protection against, access by unauthorized sources internal to the airplane. The design must prevent inadvertent and malicious changes to, and all adverse impacts upon, airplane equipment, systems, networks, or other assets required for safe flight and operations. 2. The applicant must establish appropriate procedures to allow the operator to ensure that continued airworthiness of the aircraft is maintained, including all post-typecertification modifications that may have an impact on the approved electronic system security safeguards. Issued in Renton, Washington, on October 22, 2013. Stephen P. Boyd, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 2013–25851 Filed 10–30–13; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 25 [Docket No. FAA–2013–0820; Notice No. 25–499–SC] Special Conditions: Bombardier Inc., Models BD–500–1A10 and BD–500– 1A11 Series Airplanes; Interactions of Systems and Structures Federal Aviation Administration (FAA), DOT. ACTION: Final special conditions; request for comments. AGENCY: These special conditions are issued for the Bombardier Inc. Models BD–500–1A10 and BD–500–1A11 series airplanes. These airplanes will have novel or unusual features when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. These design features include systems that, directly or as a result of SUMMARY: E:\FR\FM\31OCR1.SGM 31OCR1 wreier-aviles on DSK5TPTVN1PROD with RULES Federal Register / Vol. 78, No. 211 / Thursday, October 31, 2013 / Rules and Regulations failure or malfunction, affect structural performance. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for these design features. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards. DATES: The effective date of these special conditions is October 31, 2013. We must receive your comments by December 16, 2013. ADDRESSES: Send comments identified by docket number FAA–2013–0820 using any of the following methods: • Federal eRegulations Portal: Go to http://www.regulations.gov/ and follow the online instructions for sending your comments electronically. • Mail: Send comments to Docket Operations, M–30, U.S. Department of Transportation (DOT), 1200 New Jersey Avenue SE., Room W12–140, West Building Ground Floor, Washington, DC 20590–0001. • Hand Delivery or Courier: Take comments to 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. • Fax: Fax comments to Docket Operations at 202–493–2251. Privacy: The FAA will post all comments it receives, without change, to http://www.regulations.gov/, including any personal information the commenter provides. Using the search function of the docket Web site, anyone can find and read the electronic form of all comments received into any FAA docket, including the name of the individual sending the comment (or signing the comment for an association, business, labor union, etc.). DOT’s complete Privacy Act Statement can be found in the Federal Register published on April 11, 2000 (65 FR 19477–19478), as well as at http://DocketsInfo .dot.gov/. Docket: Background documents or comments received may be read at http://www.regulations.gov/ at any time. 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. FOR FURTHER INFORMATION CONTACT: Mark Freisthler, FAA, Airframe and Cabin Safety Branch, ANM–115, Transport Airplane Directorate, Aircraft Certification Service, 1601 Lind Avenue VerDate Mar<15>2010 15:19 Oct 30, 2013 Jkt 232001 SW., Renton, Washington 98057–3356; telephone 425–227–1119; facsimile 425–227–1232. SUPPLEMENTARY INFORMATION: The FAA has determined that notice of, and opportunity for prior public comment on, these special conditions is impracticable because these procedures would significantly delay issuance of the design approval and thus delivery of the affected aircraft. In addition, the substance of these special conditions has been subject to the public comment process in several prior instances with no substantive comments received. The FAA therefore finds that good cause exists for making these special conditions effective upon issuance. Comments Invited We invite interested people to take part in this rulemaking by sending written comments, data, or views. The most helpful comments reference a specific portion of the special conditions, explain the reason for any recommended change, and include supporting data. We will consider all comments we receive on or before the closing date for comments. We may change these special conditions based on the comments we receive. Background On December 10, 2009, Bombardier Inc. applied for a type certificate for their new Models BD–500–1A10 and BD–500–1A11 series airplanes. The Models BD–500–1A10 and BD–500– 1A11 series airplanes are swept-wing monoplanes with a pressurized cabin, and they share an identical supplier base and significant common design elements. The fuselage is aluminum alloy material, blended double-bubble design, sized for nominal 5-abreast seating. Each airplane’s powerplant includes two under-wing Pratt and Whitney PW1524G ultra high-bypass, geared turbofan engines. Flight controls are fly-by-wire systems with two passive/uncoupled side sticks. Avionics include five landscape primary cockpit displays. The dimensions of the airplanes encompass a wingspan of 115 feet; a height of 37.75 feet; and a length of 114.75 feet for the Model BD–500– 1A10 and 127 feet for the Model BD– 500–1A11. Passenger capacity is designated as 110 for the Model BD– 500–1A10 and 125 for the Model BD– 500–1A11. Maximum takeoff weight is 131,000 pounds for the Model BD–500– 1A10 and 144,000 pounds for the Model BD–500–1A11. Maximum takeoff thrust is 21,000 pounds for the Model BD– 500–1A10 and 23,300 pounds for the Model BD–500–1A11. The range is PO 00000 Frm 00013 Fmt 4700 Sfmt 4700 65157 3,394 miles (5,463 kilometres) for both models of airplanes. The maximum operating altitude is 41,000 feet for both models of airplanes. Type Certification Basis Under the provisions of Title 14, Code of Federal Regulations (14 CFR) 21.17, Bombardier Inc. must show that the Model BD–500–1A10 and BD–500– 1A11 series airplanes meet the applicable provisions of 14 CFR part 25 as amended by Amendments 25–1 through 25–129 thereto. If the Administrator finds that the applicable airworthiness regulations (i.e., 14 CFR part 25) do not contain adequate or appropriate safety standards for the Models BD–500–1A10 and BD– 500–1A11 series airplanes because of a novel or unusual design feature, special conditions are prescribed under the provisions of § 21.16. Special conditions are initially applicable to the model for which they are issued. Should the type certificate for that model be amended later to include any other model that incorporates the same or similar novel or unusual design feature, the special conditions would also apply to the other model. In addition to the applicable airworthiness regulations and special conditions, the Model BD–500–1A10 and BD–500–1A11 series airplanes must comply with the fuel vent and exhaust emission requirements of 14 CFR part 34 and the noise certification requirements of 14 CFR part 36, and the FAA must issue a finding of regulatory adequacy under § 611 of Public Law 92– 574, the ‘‘Noise Control Act of 1972.’’ The FAA issues special conditions, as defined in 14 CFR 11.19, in accordance with § 11.38, and they become part of the type-certification basis under § 21.17(a)(2). Novel or Unusual Design Features The Models BD–500–1A10 and BD– 500–1A11 series airplanes will incorporate the following novel or unusual design features: Systems that affect the airplane’s structural performance, either directly or as a result of failure or malfunction. That is, the airplane’s systems affect how it responds in maneuver and gust conditions, and thereby affect its structural capability. These systems may also affect the aeroelastic stability of the airplane. Such systems include flight control systems, autopilots, stability augmentation systems, load alleviation systems, and fuel management systems. These systems represent novel and unusual features when compared to the E:\FR\FM\31OCR1.SGM 31OCR1 65158 Federal Register / Vol. 78, No. 211 / Thursday, October 31, 2013 / Rules and Regulations wreier-aviles on DSK5TPTVN1PROD with RULES technology envisioned in the current airworthiness standards. Discussion The flight control system of the Models BD–500–1A10 and BD–500– 1A11 series airplanes will consist of a full authority fly-by-wire system with normal and direct modes of operation. Special conditions have been applied on past airplane programs, with similar systems, in order to require consideration of the effects of those systems on structures. The regulatory authorities and industry developed standardized criteria in the Aviation Rulemaking Advisory Committee (ARAC) forum based on the criteria defined in Advisory Circular 25.672, dated November 11, 1983. The ARAC recommendations have been incorporated in European Aviation Safety Agency (EASA) Certification Specifications (CS) 25.302 and CS–25 Appendix K. FAA rulemaking on this subject is not complete, thus the need for special conditions. These special conditions are similar to those previously applied to other airplane models and to EASA CS 25.302. Transport Canada Civil Aviation (TCCA) plans to apply the CS 25.302 version of the special conditions. The differences between FAA special conditions and the current CS 25.302, which the FAA regards as minor, are shown below. (1) Both these special conditions and CS 25.302 specify the design load conditions to be considered. Paragraphs 2a(1) and 2b(2)(i) of these special conditions clarify that, in some cases, different load conditions are to be considered due to other special conditions or equivalent level of safety findings. (2) Both these special conditions and CS 25.302 allow consideration of the probability of being in a dispatched configuration when assessing subsequent failures and potential ‘‘continuation of flight’’ loads (see paragraph 2d below). These special conditions, however, also allow using probability when assessing failures that induce loads at the ‘‘time of occurrence,’’ whereas CS 25.302 does not. The FAA provision is relieving. The FAA chooses to preserve these minor differences and go forward with this version of the special conditions. Applicability As discussed above, these special conditions are applicable to the Models BD–500–1A10 and BD–500–1A11 series airplanes. Should Bombardier Inc. apply at a later date for a change to the type certificate to include another model VerDate Mar<15>2010 15:19 Oct 30, 2013 Jkt 232001 incorporating the same novel or unusual design feature, the special conditions would apply to that model as well. Conclusion This action affects only certain novel or unusual design features on two models of airplanes. It is not a rule of general applicability. The substance of these special conditions has been subjected to the notice and comment period in several prior instances and has been derived without substantive change from those previously issued. It is unlikely that prior public comment would result in a significant change from the substance contained herein. Therefore, because a delay would significantly affect the certification of the airplane, which is imminent, the FAA has determined that prior public notice and comment are unnecessary and impracticable, and good cause exists for adopting these special conditions upon publication in the Federal Register. 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 described above. List of Subjects in 14 CFR Part 25 Aircraft, Aviation safety, Reporting and recordkeeping requirements. The authority citation for these special conditions is as follows: Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704. The Special Conditions 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 Bombardier Inc. Models BD–500–1A10 and BD–500– 1A11 series airplanes. 1. Interaction of Systems and Structures. General. a. For airplanes equipped with systems that affect structural performance, either directly or as a result of a failure or malfunction, the influence of these systems and their failure conditions must be taken into account when showing compliance with the requirements of Title 14, Code of Federal Regulations (14 CFR) part 25 subparts C and D. b. The following criteria must be used for showing compliance with these special conditions for airplanes equipped with flight control systems, autopilots, stability augmentation systems, load alleviation systems, flutter control systems, fuel management systems, and other systems that either directly or as a result of failure or PO 00000 Frm 00014 Fmt 4700 Sfmt 4700 malfunction affect structural performance. If these special conditions are used for other systems, it may be necessary to adapt the criteria to the specific system. c. The criteria defined herein only address the direct structural consequences of the system responses and performances and cannot be considered in isolation but should be included in the overall safety evaluation of the airplane. These criteria may in some instances duplicate standards already established for this evaluation. These criteria are only applicable to structure whose failure could prevent continued safe flight and landing. Specific criteria that define acceptable limits on handling characteristics or stability requirements when operating in the system degraded or inoperative mode are not provided in these special conditions. d. Depending upon the specific characteristics of the airplane, additional studies may be required that go beyond the criteria provided in these special conditions in order to demonstrate the capability of the airplanes to meet other realistic conditions such as alternative gust or maneuver descriptions for an airplane equipped with a load alleviation system. e. The following definitions are applicable to these special conditions: (1) Structural performance: Capability of the airplane to meet the structural requirements of 14 CFR part 25. (2) Flight limitations: Limitations that can be applied to the airplane flight conditions following an in-flight occurrence and that are included in the flight manual (e.g., speed limitations and avoidance of severe weather conditions). (3) Operational limitations: Limitations, including flight limitations, that can be applied to the airplane operating conditions before dispatch (e.g., fuel, payload and Master Minimum Equipment List limitations). (4) Probabilistic terms: The probabilistic terms (probable, improbable, extremely improbable) used in these special conditions are the same as those used in § 25.1309. (5) Failure condition: The term ‘‘failure condition’’ is the same as that used in § 25.1309. However, these special conditions apply only to system failure conditions that affect the structural performance of the airplane (e.g., system failure conditions that induce loads, change the response of the airplane to inputs such as gusts or pilot actions, or lower flutter margins). 2. Effect on Systems and Structures. The following criteria will be used in determining the influence of a system E:\FR\FM\31OCR1.SGM 31OCR1 Federal Register / Vol. 78, No. 211 / Thursday, October 31, 2013 / Rules and Regulations 65159 b. System in the failure condition. For any system failure condition not shown to be extremely improbable, the following apply: (1) At the time of occurrence. Starting from 1-g level flight conditions, a realistic scenario, including pilot corrective actions, must be established to determine the loads occurring at the time of failure and immediately after failure. (i) For static strength substantiation, these loads, multiplied by an appropriate factor of safety that is related to the probability of occurrence of the failure, are ultimate loads to be considered for design. The factor of safety (FS) is defined in Figure 1. loads that could result in detrimental deformation of primary structure. (2) For the continuation of the flight. For the airplane, in the system-failed state and considering any appropriate reconfiguration and flight limitations, the following apply: (i) The loads derived from the following conditions (or defined by special conditions or equivalent level of safety in lieu of the following conditions) at speeds up to VC/MC, or the speed limitation prescribed for the remainder of the flight, must be determined: (A) The limit symmetrical maneuvering conditions specified in § 25.331 and in § 25.345. (B) The limit gust and turbulence conditions specified in § 25.341 and in § 25.345. (C) The limit rolling conditions specified in § 25.349 and the limit unsymmetrical conditions specified in § 25.367 and § 25.427(b) and (c). (D) The limit yaw maneuvering conditions specified in § 25.351. (E) The limit ground loading conditions specified in §§ 25.473, 25.491, 25.493(d) and 25.503. (ii) For static strength substantiation, each part of the structure must be able to withstand the loads in paragraph 2b(2)(i) of these special conditions multiplied by a factor of safety depending on the probability of being in this failure state. The factor of safety (FS) is defined in Figure 2. VerDate Mar<15>2010 15:19 Oct 30, 2013 Jkt 232001 PO 00000 Frm 00015 Fmt 4700 Sfmt 4700 E:\FR\FM\31OCR1.SGM 31OCR1 ER31OC13.001</GPH> deriving limit loads from limit conditions. (2) The airplane must meet the strength requirements of part 25 (static strength, residual strength) using the specified factors to derive ultimate loads from the limit loads defined above. The effect of nonlinearities must be investigated beyond limit conditions to ensure the behavior of the system presents no anomaly compared to the behavior below limit conditions. However, conditions beyond limit conditions need not be considered when it can be shown that the airplane has design features that will not allow it to exceed those limit conditions. (3) The airplane must meet the aeroelastic stability requirements of § 25.629. (ii) For residual strength substantiation, the airplane must be able to withstand two thirds of the ultimate loads defined in subparagraph 2b(1)(i). For pressurized cabins, these loads must be combined with the normal operating differential pressure. (iii) Freedom from aeroelastic instability must be shown up to the speeds defined in § 25.629(b)(2). For failure conditions that result in speeds beyond VC/MC, freedom from aeroelastic instability must be shown to increased speeds, so that the margins intended by § 25.629(b)(2) are maintained. (iv) Failures of the system that result in forced structural vibrations (e.g., oscillatory failures) must not produce wreier-aviles on DSK5TPTVN1PROD with RULES and its failure conditions on the airplane structure. a. System fully operative. With the system fully operative, the following apply: (1) Limit loads must be derived in all normal operating configurations of the system from all the limit conditions specified in subpart C (or defined by special conditions or equivalent level of safety in lieu of those specified in subpart C), taking into account any special behavior of such a system or associated functions or any effect on the structural performance of the airplane that may occur up to the limit loads. In particular, any significant nonlinearity (rate of displacement of control surface, thresholds, or any other system nonlinearities) must be accounted for in a realistic or conservative way when 65160 Federal Register / Vol. 78, No. 211 / Thursday, October 31, 2013 / Rules and Regulations (v) Freedom from aeroelastic instability must be shown up to a speed determined from Figure 3. Flutter clearance speeds V′ and V″ may be based on the speed limitation specified for the remainder of the flight using the margins defined by § 25.629(b). (vi) Freedom from aeroelastic instability must also be shown up to V′ in Figure 3 above, for any probable system failure condition combined with any damage required or selected for investigation by § 25.571(b). (3) Consideration of certain failure conditions may be required by other sections of 14 CFR part 25 regardless of calculated system reliability. Where analysis shows the probability of these failure conditions to be less than 10¥9, criteria other than those specified in this paragraph may be used for structural substantiation to show continued safe flight and landing. c. Failure indications. For system failure detection and indication, the following apply: (1) The system must be checked for failure conditions, not extremely improbable, that degrade the structural capability below the level required by part 25 or significantly reduce the VerDate Mar<15>2010 15:19 Oct 30, 2013 Jkt 232001 PO 00000 Frm 00016 Fmt 4700 Sfmt 4700 E:\FR\FM\31OCR1.SGM 31OCR1 ER31OC13.003</GPH> combined with the normal operating differential pressure. (iv) If the loads induced by the failure condition have a significant effect on fatigue or damage tolerance, then their effects must be taken into account. ER31OC13.002</GPH> wreier-aviles on DSK5TPTVN1PROD with RULES (iii) For residual strength substantiation, the airplane must be able to withstand two thirds of the ultimate loads defined in paragraph 2b(2)(ii) of these special conditions. For pressurized cabins, these loads must be wreier-aviles on DSK5TPTVN1PROD with RULES Federal Register / Vol. 78, No. 211 / Thursday, October 31, 2013 / Rules and Regulations reliability of the remaining system. As far as reasonably practicable, the flight crew must be made aware of these failures before flight. Certain elements of the control system, such as mechanical and hydraulic components, may use special periodic inspections, and electronic components may use daily checks, in lieu of detection and indication systems to achieve the objective of this requirement. These certification maintenance requirements must be limited to components that are not readily detectable by normal detection and indication systems and where service history shows that inspections will provide an adequate level of safety. (2) The existence of any failure condition, not extremely improbable, during flight that could significantly affect the structural capability of the airplane and for which the associated reduction in airworthiness can be minimized by suitable flight limitations, must be signaled to the flight crew. For example, failure conditions that result in a factor of safety between the airplane strength and the loads of subpart C below 1.25, or flutter margins below V″, must be signaled to the crew during flight. d. Dispatch with known failure conditions. If the airplane is to be dispatched in a known system failure condition that affects structural performance, or affects the reliability of the remaining system to maintain structural performance, then the provisions of these special conditions must be met, including the provisions of paragraph 2a for the dispatched condition, and paragraph 2b for subsequent failures. Expected operational limitations may be taken into account in establishing Pj as the probability of failure occurrence for determining the safety margin in Figure 1. Flight limitations and expected operational limitations may be taken into account in establishing Qj as the combined probability of being in the dispatched failure condition and the subsequent failure condition for the safety margins in Figures 2 and 3. These limitations must be such that the probability of being in this combined failure state and then subsequently encountering limit load conditions is extremely improbable. No reduction in these safety margins is allowed if the subsequent system failure rate is greater than 10¥3 per hour. VerDate Mar<15>2010 15:19 Oct 30, 2013 Jkt 232001 Issued in Renton, Washington, on September 12, 2013. Jeffrey E. Duven, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. 65161 Federal Aviation Administration (FAA), DOT. ACTION: Final rule. Examining the AD Docket You may examine the AD docket on the Internet at http:// www.regulations.gov or in person at the Docket Operations Office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the foreign authority’s AD, any incorporated-byreference service information, the economic evaluation, any comments received, and other information. The street address for the Docket Operations Office (phone: 800–647–5527) is U.S. Department of Transportation, Docket Operations Office, M–30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue SE., Washington, DC 20590. FOR FURTHER INFORMATION CONTACT: Chinh Vuong, Aviation Safety Engineer, Safety Management Group, Rotorcraft Directorate, FAA, 2601 Meacham Blvd., Fort Worth, Texas 76137; telephone (817) 222–5110; email chinh.vuong@ faa.gov. SUPPLEMENTARY INFORMATION: We are adopting a new airworthiness directive (AD) for Agusta Model A109A, A109AII, and A109C helicopters with a certain third stage turbine wheel installed. This AD requires installing a placard on the instrument panel and revising the limitations section of the rotorcraft flight manual (RFM). This AD was prompted by several incidents of third stage engine turbine wheel failures, which were caused by excessive vibrations at certain engine speeds during steady-state operations. These actions are intended to alert pilots to avoid certain engine speeds during steady-state operations, prevent failure of the third stage engine turbine, engine power loss, and subsequent loss of control of the helicopter. DATES: This AD is effective December 5, 2013. The Director of the Federal Register approved the incorporation by reference of a certain document listed in this AD as of December 5, 2013. ADDRESSES: For service information identified in this AD, contact Agusta Westland, Customer Support & Services, Via Per Tornavento 15, 21019 Somma Lombardo (VA) Italy, ATTN: Giovanni Cecchelli; telephone 39 0331 711133; fax 39 0331 711180; or at http:// www.agustawestland.com/technicalbullettins. You may review the referenced service information at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. Discussion On June 20, 2013, at 78 FR 37162, the Federal Register published our notice of proposed rulemaking (NPRM), which proposed to amend 14 CFR part 39 by adding an AD that would apply to Agusta Model A109A, A109AII, and A109C helicopters with a third stage turbine wheel, part number (P/N) 23065833, installed. The NPRM proposed to require installing a placard on the instrument panel adjacent to the engine and rotor RPM power turbine (N2) indicator and revising the Operating Limitations sections of the Model A109A, A109AII, and A109C RFMs to limit steady-state operations between speeds of 95% and 97%. The proposed requirements were intended to alert pilots to avoid certain engine speeds during steady-state operations, prevent failure of the third stage engine turbine, engine power loss, and subsequent loss of control of the helicopter. The NPRM was prompted by AD No. 2009–0037–E, dated February 19, 2009, issued by the European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union. EASA issued AD No. 2009–0037–E to correct an unsafe condition for Agusta Model A109A, A109AII, and A109C helicopters with a Rolls Royce Corporation (RRC) engine Model 250–C20B or 250–C20R/1 having a third stage turbine wheel P/N 23065833 installed. EASA advises that following several third stage turbine wheel failures, the engine type [FR Doc. 2013–25448 Filed 10–30–13; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2013–0518; Directorate Identifier 2009–SW–021–AD; Amendment 39–17607; AD 2013–20–01] RIN 2120–AA64 Airworthiness Directives; Agusta S.p.A. (Type Certificate Currently Held by AgustaWestland S.p.A) (Agusta) Helicopters AGENCY: SUMMARY: PO 00000 Frm 00017 Fmt 4700 Sfmt 4700 E:\FR\FM\31OCR1.SGM 31OCR1

Agencies

[Federal Register Volume 78, Number 211 (Thursday, October 31, 2013)]
[Rules and Regulations]
[Pages 65156-65161]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-25448]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2013-0820; Notice No. 25-499-SC]


Special Conditions: Bombardier Inc., Models BD-500-1A10 and BD-
500-1A11 Series Airplanes; Interactions of Systems and Structures

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

-----------------------------------------------------------------------

SUMMARY: These special conditions are issued for the Bombardier Inc. 
Models BD-500-1A10 and BD-500-1A11 series airplanes. These airplanes 
will have novel or unusual features when compared to the state of 
technology envisioned in the airworthiness standards for transport 
category airplanes. These design features include systems that, 
directly or as a result of

[[Page 65157]]

failure or malfunction, affect structural performance. The applicable 
airworthiness regulations do not contain adequate or appropriate safety 
standards for these design features. These special conditions contain 
the additional safety standards that the Administrator considers 
necessary to establish a level of safety equivalent to that established 
by the existing airworthiness standards.

DATES: The effective date of these special conditions is October 31, 
2013. We must receive your comments by December 16, 2013.

ADDRESSES: Send comments identified by docket number FAA-2013-0820 
using any of the following methods:
     Federal eRegulations Portal: Go to http://www.regulations.gov/ and follow the online instructions for sending 
your comments electronically.
     Mail: Send comments to Docket Operations, M-30, U.S. 
Department of Transportation (DOT), 1200 New Jersey Avenue SE., Room 
W12-140, West Building Ground Floor, Washington, DC 20590-0001.
     Hand Delivery or Courier: Take comments to 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.
     Fax: Fax comments to Docket Operations at 202-493-2251.
    Privacy: The FAA will post all comments it receives, without 
change, to http://www.regulations.gov/, including any personal 
information the commenter provides. Using the search function of the 
docket Web site, anyone can find and read the electronic form of all 
comments received into any FAA docket, including the name of the 
individual sending the comment (or signing the comment for an 
association, business, labor union, etc.). DOT's complete Privacy Act 
Statement can be found in the Federal Register published on April 11, 
2000 (65 FR 19477-19478), as well as at http://DocketsInfo.dot.gov/.
    Docket: Background documents or comments received may be read at 
http://www.regulations.gov/ at any time. 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.

FOR FURTHER INFORMATION CONTACT: Mark Freisthler, FAA, Airframe and 
Cabin Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Avenue SW., Renton, Washington 98057-
3356; telephone 425-227-1119; facsimile 425-227-1232.

SUPPLEMENTARY INFORMATION: The FAA has determined that notice of, and 
opportunity for prior public comment on, these special conditions is 
impracticable because these procedures would significantly delay 
issuance of the design approval and thus delivery of the affected 
aircraft. In addition, the substance of these special conditions has 
been subject to the public comment process in several prior instances 
with no substantive comments received. The FAA therefore finds that 
good cause exists for making these special conditions effective upon 
issuance.

Comments Invited

    We invite interested people to take part in this rulemaking by 
sending written comments, data, or views. The most helpful comments 
reference a specific portion of the special conditions, explain the 
reason for any recommended change, and include supporting data.
    We will consider all comments we receive on or before the closing 
date for comments. We may change these special conditions based on the 
comments we receive.

Background

    On December 10, 2009, Bombardier Inc. applied for a type 
certificate for their new Models BD-500-1A10 and BD-500-1A11 series 
airplanes. The Models BD-500-1A10 and BD-500-1A11 series airplanes are 
swept-wing monoplanes with a pressurized cabin, and they share an 
identical supplier base and significant common design elements. The 
fuselage is aluminum alloy material, blended double-bubble design, 
sized for nominal 5-abreast seating. Each airplane's powerplant 
includes two under-wing Pratt and Whitney PW1524G ultra high-bypass, 
geared turbofan engines. Flight controls are fly-by-wire systems with 
two passive/uncoupled side sticks. Avionics include five landscape 
primary cockpit displays. The dimensions of the airplanes encompass a 
wingspan of 115 feet; a height of 37.75 feet; and a length of 114.75 
feet for the Model BD-500-1A10 and 127 feet for the Model BD-500-1A11. 
Passenger capacity is designated as 110 for the Model BD-500-1A10 and 
125 for the Model BD-500-1A11. Maximum takeoff weight is 131,000 pounds 
for the Model BD-500-1A10 and 144,000 pounds for the Model BD-500-1A11. 
Maximum takeoff thrust is 21,000 pounds for the Model BD-500-1A10 and 
23,300 pounds for the Model BD-500-1A11. The range is 3,394 miles 
(5,463 kilometres) for both models of airplanes. The maximum operating 
altitude is 41,000 feet for both models of airplanes.

Type Certification Basis

    Under the provisions of Title 14, Code of Federal Regulations (14 
CFR) 21.17, Bombardier Inc. must show that the Model BD-500-1A10 and 
BD-500-1A11 series airplanes meet the applicable provisions of 14 CFR 
part 25 as amended by Amendments 25-1 through 25-129 thereto.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., 14 CFR part 25) do not contain adequate or 
appropriate safety standards for the Models BD-500-1A10 and BD-500-1A11 
series airplanes because of a novel or unusual design feature, special 
conditions are prescribed under the provisions of Sec.  21.16.
    Special conditions are initially applicable to the model for which 
they are issued. Should the type certificate for that model be amended 
later to include any other model that incorporates the same or similar 
novel or unusual design feature, the special conditions would also 
apply to the other model.
    In addition to the applicable airworthiness regulations and special 
conditions, the Model BD-500-1A10 and BD-500-1A11 series airplanes must 
comply with the fuel vent and exhaust emission requirements of 14 CFR 
part 34 and the noise certification requirements of 14 CFR part 36, and 
the FAA must issue a finding of regulatory adequacy under Sec.  611 of 
Public Law 92-574, the ``Noise Control Act of 1972.''
    The FAA issues special conditions, as defined in 14 CFR 11.19, in 
accordance with Sec.  11.38, and they become part of the type-
certification basis under Sec.  21.17(a)(2).

Novel or Unusual Design Features

    The Models BD-500-1A10 and BD-500-1A11 series airplanes will 
incorporate the following novel or unusual design features: Systems 
that affect the airplane's structural performance, either directly or 
as a result of failure or malfunction. That is, the airplane's systems 
affect how it responds in maneuver and gust conditions, and thereby 
affect its structural capability. These systems may also affect the 
aeroelastic stability of the airplane. Such systems include flight 
control systems, autopilots, stability augmentation systems, load 
alleviation systems, and fuel management systems. These systems 
represent novel and unusual features when compared to the

[[Page 65158]]

technology envisioned in the current airworthiness standards.

Discussion

    The flight control system of the Models BD-500-1A10 and BD-500-1A11 
series airplanes will consist of a full authority fly-by-wire system 
with normal and direct modes of operation. Special conditions have been 
applied on past airplane programs, with similar systems, in order to 
require consideration of the effects of those systems on structures. 
The regulatory authorities and industry developed standardized criteria 
in the Aviation Rulemaking Advisory Committee (ARAC) forum based on the 
criteria defined in Advisory Circular 25.672, dated November 11, 1983. 
The ARAC recommendations have been incorporated in European Aviation 
Safety Agency (EASA) Certification Specifications (CS) 25.302 and CS-25 
Appendix K. FAA rulemaking on this subject is not complete, thus the 
need for special conditions.
    These special conditions are similar to those previously applied to 
other airplane models and to EASA CS 25.302. Transport Canada Civil 
Aviation (TCCA) plans to apply the CS 25.302 version of the special 
conditions. The differences between FAA special conditions and the 
current CS 25.302, which the FAA regards as minor, are shown below.
    (1) Both these special conditions and CS 25.302 specify the design 
load conditions to be considered. Paragraphs 2a(1) and 2b(2)(i) of 
these special conditions clarify that, in some cases, different load 
conditions are to be considered due to other special conditions or 
equivalent level of safety findings.
    (2) Both these special conditions and CS 25.302 allow consideration 
of the probability of being in a dispatched configuration when 
assessing subsequent failures and potential ``continuation of flight'' 
loads (see paragraph 2d below). These special conditions, however, also 
allow using probability when assessing failures that induce loads at 
the ``time of occurrence,'' whereas CS 25.302 does not. The FAA 
provision is relieving. The FAA chooses to preserve these minor 
differences and go forward with this version of the special conditions.

Applicability

    As discussed above, these special conditions are applicable to the 
Models BD-500-1A10 and BD-500-1A11 series airplanes. Should Bombardier 
Inc. apply at a later date for a change to the type certificate to 
include another model incorporating the same novel or unusual design 
feature, the special conditions would apply to that model as well.

Conclusion

    This action affects only certain novel or unusual design features 
on two models of airplanes. It is not a rule of general applicability.
    The substance of these special conditions has been subjected to the 
notice and comment period in several prior instances and has been 
derived without substantive change from those previously issued. It is 
unlikely that prior public comment would result in a significant change 
from the substance contained herein. Therefore, because a delay would 
significantly affect the certification of the airplane, which is 
imminent, the FAA has determined that prior public notice and comment 
are unnecessary and impracticable, and good cause exists for adopting 
these special conditions upon publication in the Federal Register. 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 described above.

List of Subjects in 14 CFR Part 25

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.

    The authority citation for these special conditions is as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701, 44702, 44704.

The Special Conditions

    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 Bombardier Inc. Models BD-500-1A10 and 
BD-500-1A11 series airplanes.
    1. Interaction of Systems and Structures. General.
    a. For airplanes equipped with systems that affect structural 
performance, either directly or as a result of a failure or 
malfunction, the influence of these systems and their failure 
conditions must be taken into account when showing compliance with the 
requirements of Title 14, Code of Federal Regulations (14 CFR) part 25 
subparts C and D.
    b. The following criteria must be used for showing compliance with 
these special conditions for airplanes equipped with flight control 
systems, autopilots, stability augmentation systems, load alleviation 
systems, flutter control systems, fuel management systems, and other 
systems that either directly or as a result of failure or malfunction 
affect structural performance. If these special conditions are used for 
other systems, it may be necessary to adapt the criteria to the 
specific system.
    c. The criteria defined herein only address the direct structural 
consequences of the system responses and performances and cannot be 
considered in isolation but should be included in the overall safety 
evaluation of the airplane. These criteria may in some instances 
duplicate standards already established for this evaluation. These 
criteria are only applicable to structure whose failure could prevent 
continued safe flight and landing. Specific criteria that define 
acceptable limits on handling characteristics or stability requirements 
when operating in the system degraded or inoperative mode are not 
provided in these special conditions.
    d. Depending upon the specific characteristics of the airplane, 
additional studies may be required that go beyond the criteria provided 
in these special conditions in order to demonstrate the capability of 
the airplanes to meet other realistic conditions such as alternative 
gust or maneuver descriptions for an airplane equipped with a load 
alleviation system.
    e. The following definitions are applicable to these special 
conditions:
    (1) Structural performance: Capability of the airplane to meet the 
structural requirements of 14 CFR part 25.
    (2) Flight limitations: Limitations that can be applied to the 
airplane flight conditions following an in-flight occurrence and that 
are included in the flight manual (e.g., speed limitations and 
avoidance of severe weather conditions).
    (3) Operational limitations: Limitations, including flight 
limitations, that can be applied to the airplane operating conditions 
before dispatch (e.g., fuel, payload and Master Minimum Equipment List 
limitations).
    (4) Probabilistic terms: The probabilistic terms (probable, 
improbable, extremely improbable) used in these special conditions are 
the same as those used in Sec.  25.1309.
    (5) Failure condition: The term ``failure condition'' is the same 
as that used in Sec.  25.1309. However, these special conditions apply 
only to system failure conditions that affect the structural 
performance of the airplane (e.g., system failure conditions that 
induce loads, change the response of the airplane to inputs such as 
gusts or pilot actions, or lower flutter margins).
    2. Effect on Systems and Structures. The following criteria will be 
used in determining the influence of a system

[[Page 65159]]

and its failure conditions on the airplane structure.
    a. System fully operative. With the system fully operative, the 
following apply:
    (1) Limit loads must be derived in all normal operating 
configurations of the system from all the limit conditions specified in 
subpart C (or defined by special conditions or equivalent level of 
safety in lieu of those specified in subpart C), taking into account 
any special behavior of such a system or associated functions or any 
effect on the structural performance of the airplane that may occur up 
to the limit loads. In particular, any significant nonlinearity (rate 
of displacement of control surface, thresholds, or any other system 
nonlinearities) must be accounted for in a realistic or conservative 
way when deriving limit loads from limit conditions.
    (2) The airplane must meet the strength requirements of part 25 
(static strength, residual strength) using the specified factors to 
derive ultimate loads from the limit loads defined above. The effect of 
nonlinearities must be investigated beyond limit conditions to ensure 
the behavior of the system presents no anomaly compared to the behavior 
below limit conditions. However, conditions beyond limit conditions 
need not be considered when it can be shown that the airplane has 
design features that will not allow it to exceed those limit 
conditions.
    (3) The airplane must meet the aeroelastic stability requirements 
of Sec.  25.629.
    b. System in the failure condition. For any system failure 
condition not shown to be extremely improbable, the following apply:
    (1) At the time of occurrence. Starting from 1-g level flight 
conditions, a realistic scenario, including pilot corrective actions, 
must be established to determine the loads occurring at the time of 
failure and immediately after failure.
    (i) For static strength substantiation, these loads, multiplied by 
an appropriate factor of safety that is related to the probability of 
occurrence of the failure, are ultimate loads to be considered for 
design. The factor of safety (FS) is defined in Figure 1.
[GRAPHIC] [TIFF OMITTED] TR31OC13.001

    (ii) For residual strength substantiation, the airplane must be 
able to withstand two thirds of the ultimate loads defined in 
subparagraph 2b(1)(i). For pressurized cabins, these loads must be 
combined with the normal operating differential pressure.
    (iii) Freedom from aeroelastic instability must be shown up to the 
speeds defined in Sec.  25.629(b)(2). For failure conditions that 
result in speeds beyond VC/MC, freedom from 
aeroelastic instability must be shown to increased speeds, so that the 
margins intended by Sec.  25.629(b)(2) are maintained.
    (iv) Failures of the system that result in forced structural 
vibrations (e.g., oscillatory failures) must not produce loads that 
could result in detrimental deformation of primary structure.
    (2) For the continuation of the flight. For the airplane, in the 
system-failed state and considering any appropriate reconfiguration and 
flight limitations, the following apply:
    (i) The loads derived from the following conditions (or defined by 
special conditions or equivalent level of safety in lieu of the 
following conditions) at speeds up to VC/MC, or 
the speed limitation prescribed for the remainder of the flight, must 
be determined:
    (A) The limit symmetrical maneuvering conditions specified in Sec.  
25.331 and in Sec.  25.345.
    (B) The limit gust and turbulence conditions specified in Sec.  
25.341 and in Sec.  25.345.
    (C) The limit rolling conditions specified in Sec.  25.349 and the 
limit unsymmetrical conditions specified in Sec.  25.367 and Sec.  
25.427(b) and (c).
    (D) The limit yaw maneuvering conditions specified in Sec.  25.351.
    (E) The limit ground loading conditions specified in Sec. Sec.  
25.473, 25.491, 25.493(d) and 25.503.
    (ii) For static strength substantiation, each part of the structure 
must be able to withstand the loads in paragraph 2b(2)(i) of these 
special conditions multiplied by a factor of safety depending on the 
probability of being in this failure state. The factor of safety (FS) 
is defined in Figure 2.

[[Page 65160]]

[GRAPHIC] [TIFF OMITTED] TR31OC13.002

    (iii) For residual strength substantiation, the airplane must be 
able to withstand two thirds of the ultimate loads defined in paragraph 
2b(2)(ii) of these special conditions. For pressurized cabins, these 
loads must be combined with the normal operating differential pressure.
    (iv) If the loads induced by the failure condition have a 
significant effect on fatigue or damage tolerance, then their effects 
must be taken into account.
    (v) Freedom from aeroelastic instability must be shown up to a 
speed determined from Figure 3. Flutter clearance speeds V' and V'' may 
be based on the speed limitation specified for the remainder of the 
flight using the margins defined by Sec.  25.629(b).
[GRAPHIC] [TIFF OMITTED] TR31OC13.003

    (vi) Freedom from aeroelastic instability must also be shown up to 
V' in Figure 3 above, for any probable system failure condition 
combined with any damage required or selected for investigation by 
Sec.  25.571(b).
    (3) Consideration of certain failure conditions may be required by 
other sections of 14 CFR part 25 regardless of calculated system 
reliability. Where analysis shows the probability of these failure 
conditions to be less than 10-9, criteria other than those 
specified in this paragraph may be used for structural substantiation 
to show continued safe flight and landing.
    c. Failure indications. For system failure detection and 
indication, the following apply:
    (1) The system must be checked for failure conditions, not 
extremely improbable, that degrade the structural capability below the 
level required by part 25 or significantly reduce the

[[Page 65161]]

reliability of the remaining system. As far as reasonably practicable, 
the flight crew must be made aware of these failures before flight. 
Certain elements of the control system, such as mechanical and 
hydraulic components, may use special periodic inspections, and 
electronic components may use daily checks, in lieu of detection and 
indication systems to achieve the objective of this requirement. These 
certification maintenance requirements must be limited to components 
that are not readily detectable by normal detection and indication 
systems and where service history shows that inspections will provide 
an adequate level of safety.
    (2) The existence of any failure condition, not extremely 
improbable, during flight that could significantly affect the 
structural capability of the airplane and for which the associated 
reduction in airworthiness can be minimized by suitable flight 
limitations, must be signaled to the flight crew. For example, failure 
conditions that result in a factor of safety between the airplane 
strength and the loads of subpart C below 1.25, or flutter margins 
below V'', must be signaled to the crew during flight.
    d. Dispatch with known failure conditions. If the airplane is to be 
dispatched in a known system failure condition that affects structural 
performance, or affects the reliability of the remaining system to 
maintain structural performance, then the provisions of these special 
conditions must be met, including the provisions of paragraph 2a for 
the dispatched condition, and paragraph 2b for subsequent failures. 
Expected operational limitations may be taken into account in 
establishing Pj as the probability of failure occurrence for 
determining the safety margin in Figure 1. Flight limitations and 
expected operational limitations may be taken into account in 
establishing Qj as the combined probability of being in the 
dispatched failure condition and the subsequent failure condition for 
the safety margins in Figures 2 and 3. These limitations must be such 
that the probability of being in this combined failure state and then 
subsequently encountering limit load conditions is extremely 
improbable. No reduction in these safety margins is allowed if the 
subsequent system failure rate is greater than 10-3 per 
hour.

    Issued in Renton, Washington, on September 12, 2013.
Jeffrey E. Duven,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-25448 Filed 10-30-13; 8:45 am]
BILLING CODE 4910-13-P