Federal Register / Vol. 79, No. 109 / Friday, June 6, 2014 / Rules and Regulations 32637 

The normal load factor limit on the 

CSeries airplanes is unique in that 

traditional airplanes with conventional 

flight control systems (mechanical 

linkages) are limited in the pitch axis 

only by the elevator surface area and 

deflection limit. The elevator control 

power is normally derived for adequate 

controllability and maneuverability at 

the most critical longitudinal pitching 

moment. The result is that traditional 

airplanes have a significant portion of 

the flight envelope wherein 

maneuverability in excess of limit 

structural design values is possible. 

These special conditions for the 

CSeries airplanes supplement the 

applicable regulations, including 

§ 25.143, to accommodate the unique 

features of the flight envelope limiting 

systems, and establish an equivalent 

level of safety to the existing 

regulations. 

Discussion of Comments 

Notice of proposed special conditions 

No. 25–13–38–SC for the Bombardier 

CSeries airplanes was published in the 

Federal Register on December 11, 2013 

(78 FR 75285). No comments were 

received, and the special conditions are 

adopted as proposed. 

Applicability 

As discussed above, these special 

conditions are applicable to the Models 

BD–500–1A10 and BD–500–1A11 series 

airplanes. Should Bombardier 

Aerospace 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 

model series of airplanes. It is not a rule 

of general applicability. 

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 the Bombardier 

Aerospace Models BD–500–1A10 and 

BD–500–1A11 series airplanes. 

Flight Envelope Protection: Normal 

Load Factor (g) Limiting 

■ 1. To meet the intent of adequate 

maneuverability and controllability 

required by § 25.143(a), and in addition 

to the requirements of § 25.143(a) and in 

the absence of other limiting factors, the 

following special conditions based on 

§ 25.333(b) apply: 

a. The positive limiting load factor 

must not be less than: 

(1) 2.5g for the normal state of the 

electronic flight control system with the 

high lift devices retracted. 

(2) 2.0g for the normal state of the 

electronic flight control system with the 

high lift devices extended. 

b. The negative limiting load factor 

must be equal to or more negative than: 

(1) Minus 1.0g for the normal state of 

the electronic flight control system with 

the high lift devices retracted. 

(2) 0.0g for the normal state of the 

electronic flight control system with 

high lift devices extended. 

c. Maximum reachable positive load 

factor wings level may be limited by the 

characteristics of the electronic flight 

control system or flight envelope 

protections (other than load factor 

protection) provided that: 

(1) The required values are readily 

achievable in turns, and 

(2) That wings level pitch up is 

satisfactory. 

d. Maximum achievable negative load 

factor may be limited by the 

characteristics of the electronic flight 

control system or flight envelope 

protections (other than load factor 

protection) provided that: 

(1) Pitch down responsiveness is 

satisfactory, and 

(2) From level flight, 0g is readily 

achievable or alternatively, a 

satisfactory trajectory change is readily 

achievable at operational speeds. For 

the FAA to consider a trajectory change 

as satisfactory, the applicant should 

propose and justify a pitch rate that 

provides sufficient maneuvering 

capability in the most critical scenarios. 

e. Compliance demonstration with the 

above requirements may be performed 

without ice accretion on the airframe. 

These special conditions do not 

impose an upper bound for the normal 

load factor limit, nor do they require 

that the limit exist. If the limit is set at 

a value beyond the structural design 

limit maneuvering load factor ‘‘n’’ of 

§§ 25.333(b) and 25.337(b) and (c), there 

should be a very obvious positive tactile 

feel built into the controller so that it 

serves as a deterrent to inadvertently 

exceeding the structural limit. 

Issued in Renton, Washington, on April 22, 

2014. 

Jeffrey E. Duven, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. 2014–13241 Filed 6–5–14; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 25 

[Docket No. FAA–2013–1040; Notice No. 25– 

548–SC] 

Special Conditions: Bombardier 

Aerospace, Models BD–500–1A10 and 

BD–500–1A11 Series Airplanes; Flight 

Envelope Protection: General Limiting 

Requirements 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final Special Conditions. 

SUMMARY: These special conditions are 

issued for the Bombardier Aerospace 

Models BD–500–1A10 and BD–500– 

1A11 series airplanes. These airplanes 

will have a novel or unusual design 

feature associated with a new control 

architecture and a full digital flight 

control system that provides flight 

envelope protections. The applicable 

airworthiness regulations do not contain 

adequate or appropriate safety standards 

for this design feature. 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: Effective Date: July 7, 2014. 

FOR FURTHER INFORMATION CONTACT: Joe 

Jacobsen, FAA, Airplane and Flight 

Crew Interface Branch, ANM–111, 

Transport Airplane Directorate, Aircraft 

Certification Service, 1601 Lind Avenue 

SW., Renton, Washington 98057–3356; 

telephone 425–227–2011; facsimile 

425–227–1149. 

SUPPLEMENTARY INFORMATION: 

Background 

On December 10, 2009, Bombardier 

Aerospace applied for a type certificate 

for their new Models BD–500–1A10 and 

BD–500–1A11 series airplanes (hereafter 

collectively referred to as ‘‘CSeries’’). 

The CSeries airplanes are swept-wing 

monoplanes with an aluminum alloy 

fuselage sized for 5-abreast seating. 

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 

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32638 Federal Register / Vol. 79, No. 109 / Friday, June 6, 2014 / Rules and Regulations 

Model BD–500–1A10 and 144,000 

pounds for the Model BD–500–1A11. 

Bombardier has developed 

comprehensive flight envelope 

protection features integral to the 

CSeries electronic flight control system 

(EFCS) design. These flight envelope 

protection features include limitations 

on angle-of-attack, normal load factor, 

bank angle, pitch angle, and speed. To 

accomplish this flight envelope limiting, 

a significant change (or multiple 

changes) occurs in the EFCS control 

laws as the limit is approached or 

exceeded. When EFCS failure states 

occur, flight envelope protection 

features can likewise either be modified, 

or in some cases, eliminated. The 

current regulations were not written 

with these comprehensive flight 

envelope limiting systems in mind. 

Type Certification Basis 

Under the provisions of Title 14, Code 

of Federal Regulations (14 CFR) 21.17, 

Bombardier Aerospace must show that 

the CSeries airplanes meet the 

applicable provisions of 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 CSeries 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 under § 21.101. 

In addition to the applicable 

airworthiness regulations and special 

conditions, the CSeries 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 CSeries airplanes will incorporate 

the following novel or unusual design 

features: New control architecture and a 

full digital flight control system that 

provides comprehensive flight envelope 

protections. 

Discussion 

The applicable airworthiness 

regulation is 14 CFR 25.143. The 

purpose of § 25.143 is to verify that any 

operational maneuvers conducted 

within the operational envelope can be 

accomplished smoothly with average 

piloting skill and without exceeding any 

structural limits. The pilot should be 

able to predict the airplane response to 

any control input. During the course of 

the flight test program, the pilot 

determines compliance with § 25.143 

primarily through qualitative methods. 

During flight test, the pilot should 

evaluate all of the following: 

• The interface between each 

protection function; 

• Transitions from one mode to 

another; 

• Airplane response to intentional 

dynamic maneuvering, whenever 

applicable, through dedicated 

maneuvers; 

• General controllability assessment; 

• High speed characteristics; and 

• High angle-of-attack. 

Section 25.143, however, does not 

adequately ensure that the novel or 

unusual features of the CSeries 

airplanes will have a level of safety 

equivalent to that of existing standards. 

These special conditions are therefore 

required to accommodate the flight 

envelope limiting systems in the CSeries 

airplanes. The additional safety 

standards in these special conditions 

will ensure a level of safety equivalent 

to that of existing standards. 

Discussion of Comments 

Notice of proposed special conditions 

No. 25–13–39–SC for the Bombardier 

CSeries airplanes was published in the 

Federal Register on December 11, 2013 

(78 FR 75287). No comments were 

received, and the special conditions are 

adopted as proposed. 

Applicability 

As discussed above, these special 

conditions are applicable to the Models 

BD–500–1A10 and BD–500–1A11 series 

airplanes. Should Bombardier 

Aerospace 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 

model series of airplanes. It is not a rule 

of general applicability. 

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 the Bombardier 

Aerospace Models BD–500–1A10 and 

BD–500–1A11 series airplanes. 

1. General Limiting Requirements: 

a. Onset characteristics of each 

envelope protection feature must be 

smooth, appropriate to the phase of 

flight and type of maneuver, and not in 

conflict with the ability of the pilot to 

satisfactorily change airplane flight 

path, speed, or attitude as needed. 

b. Limit values of protected flight 

parameters (and, if applicable, 

associated warning thresholds) must be 

compatible with the following: 

i. Airplane structural limits; 

ii. Required safe and controllable 

maneuvering of the airplane; and 

iii. Margins to critical conditions. 

Unsafe flight characteristics/conditions 

must not result if dynamic 

maneuvering, airframe and system 

tolerances (both manufacturing and inservice), and non-steady atmospheric 

conditions, in any appropriate 

combination and phase of flight, can 

produce a limited flight parameter 

beyond the nominal design limit value. 

c. The airplane must be responsive to 

intentional dynamic maneuvering to 

within a suitable range of the parameter 

limit. Dynamic characteristics such as 

damping and overshoot must also be 

appropriate for the flight maneuver and 

limit parameter in question. 

d. When simultaneous envelope 

limiting is engaged, adverse coupling or 

adverse priority must not result. 

2. Failure States: Electronic flight 

control system failures (including 

sensor) must not result in a condition 

where a parameter is limited to such a 

reduced value that safe and controllable 

maneuvering is no longer available. The 

crew must be alerted by suitable means 

if any change in envelope limiting or 

maneuverability is produced by single 

or multiple failures of the electronic 

flight control system not shown to be 

extremely improbable. 

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Federal Register / Vol. 79, No. 109 / Friday, June 6, 2014 / Rules and Regulations 32639 

Issued in Renton, Washington, April 22, 

2014. 

Jeffrey E. Duven, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. 2014–13242 Filed 6–5–14; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 25 

[Docket No. FAA–2013–1038; Special 

Conditions No. 25–549–SC] 

Special Conditions: Bombardier 

Aerospace, Models BD–500–1A10 and 

BD–500–1A11 Series Airplanes; Flight 

Envelope Protection: High-Speed 

Limiting 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final Special Conditions. 

SUMMARY: These special conditions are 

issued for the Bombardier Aerospace 

Models BD–500–1A10 and BD–500– 

1A11 series airplanes. These airplanes 

will have a novel or unusual design 

feature associated with an electronic 

flight control system that contains flyby-wire control laws, including 

envelope protections, for the overspeed 

protection and roll-limiting function. 

The applicable airworthiness 

regulations do not contain adequate or 

appropriate safety standards for this 

design feature. 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: Effective Date: July 7, 2014. 

FOR FURTHER INFORMATION CONTACT: Joe 

Jacobsen, FAA, Airplane and Flight 

Crew Interface Branch, ANM–111, 

Transport Airplane Directorate, Aircraft 

Certification Service, 1601 Lind Avenue 

SW., Renton, Washington 98057–3356; 

telephone 425–227–2011; facsimile 

425–227–1149. 

SUPPLEMENTARY INFORMATION:

Background 

On December 10, 2009, Bombardier 

Aerospace applied for a type certificate 

for their new Models BD–500–1A10 and 

BD–500–1A11 series airplanes (hereafter 

collectively referred to as ‘‘CSeries’’). 

The CSeries airplanes are swept-wing 

monoplanes with an aluminum alloy 

fuselage sized for 5-abreast seating. 

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. 

The longitudinal control law design of 

the Bombardier CSeries airplanes 

incorporates an overspeed protection 

system in the normal mode. This mode 

prevents the pilot from inadvertently or 

intentionally exceeding a speed 

approximately equivalent to the 

maximum speed for stability 

characteristics (VFC) or attaining 

demonstrated flight diving speed (VDF). 

Current Title 14, Code of Federal 

Regulations (14 CFR) part 25 standards 

did not envision a high-speed limiter 

that might preclude or modify flying 

qualities assessments in the overspeed 

region. 

Type Certification Basis 

Under the provisions of 14 CFR 21.17, 

Bombardier Aerospace must show that 

the CSeries airplanes meet the 

applicable provisions of 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 CSeries 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 under § 21.101. 

In addition to the applicable 

airworthiness regulations and special 

conditions, the CSeries 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 CSeries airplanes will incorporate 

the following novel or unusual design 

features: An electronic flight control 

system that contains fly-by-wire control 

laws, including envelope protections, 

for the overspeed protection and rolllimiting function. Current part 25 

requirements do not contain appropriate 

standards for high-speed protection 

systems. 

Discussion 

The overspeed protection 

functionality includes multifunction 

spoilers (MFS) that will automatically 

deploy as speed brakes once the 

airspeed exceeds a small tolerance 

above maximum operating limit speed 

(Vmo/Mmo); the MFS will retract 

automatically when speed is 

subsequently reduced. Special 

conditions are necessary in addition to 

the requirements of § 25.143 for the 

operation of the high-speed protection. 

The general intent is that the overspeed 

protection does not impede normal 

maneuvering and speed control, and 

that the overspeed protection does not 

restrict or prevent emergency 

maneuvering. 

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. 

Discussion of Comments 

Notice of proposed special conditions 

No. 25–13–38–SC for the Bombardier 

CSeries airplanes was published in the 

Federal Register on December 11, 2013 

(78 FR 75284). We received one 

comment in favor of the proposed 

special conditions as written. 

Applicability 

As discussed above, these special 

conditions are applicable to the Models 

BD–500–1A10 and BD–500–1A11 series 

airplanes. Should Bombardier 

Aerospace 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 

model series of airplanes. It is not a rule 

of general applicability. 

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 

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