This section of the FEDERAL REGISTER

contains notices to the public of the proposed

issuance of rules and regulations. The

purpose of these notices is to give interested

persons an opportunity to participate in the

rule making prior to the adoption of the final

rules.

Proposed Rules Federal Register

50581 

Vol. 82, No. 210 

Wednesday, November 1, 2017 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 25 

[Docket No. FAA–2017–0636; Notice No. 25– 

17–02–SC] 

Special Conditions: The Boeing 

Company Model 777–8 and 777–9 

Airplanes; Folding Wingtips 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed special 

conditions. 

SUMMARY: This action proposes special 

conditions for Boeing Model 777–8 and 

777–9 airplanes. These airplanes will 

have a novel or unusual design feature 

when compared to the state of 

technology envisioned in the 

airworthiness standards for transportcategory airplanes. This design feature 

is folding wingtips. The applicable 

airworthiness regulations do not contain 

adequate or appropriate safety standards 

for this design feature. These proposed 

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: Send your comments on or 

before December 18, 2017. 

ADDRESSES: Send comments identified 

by docket number FAA–2017–0636 

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). 

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 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: Ian 

Won, FAA, Airframe and Cabin Safety 

Section, AIR–675, Policy and 

Innovation Division, Transport 

Standards Branch, Aircraft Certification 

Service, 1601 Lind Avenue SW., 

Renton, Washington 98057–3356; 

telephone 425–227–2145; facsimile 

425–227–1360. 

SUPPLEMENTARY INFORMATION: 

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 by the closing date for 

comments. We may change these special 

conditions based on the comments we 

receive. 

Background 

On April 19, 2017 (for the Model 777– 

8 airplane), and May 12, 2015 (for the 

777–9 airplane), Boeing applied for an 

amendment to Type Certificate (TC) No. 

T00001SE to include the new Model 

777–8 and 777–9 airplanes. These 

airplanes are constructed with new 

carbon-fiber-reinforced plastic (CFRP) 

wings with folding wingtips. 

The Model 777–9 airplane, a 

derivative of the Model 777–300ER 

airplane currently approved under TC 

No. T00001SE, is a stretched-fuselage, 

large, twin-engine airplane with seating 

for 408 passengers and a maximum 

takeoff weight of 775,000 pounds. 

The Model 777–8 airplane, a 

shortened-body derivative of the Model 

777–9 airplane, is a large, twin-engine 

airplane with seating for 359 passengers 

and a maximum takeoff weight of 

775,000 pounds. 

Type Certification Basis 

Under the provisions of title 14, Code 

of Federal Regulations (14 CFR) 21.101, 

Boeing must show that the Model 777– 

8 and 777–9 airplanes meet the 

applicable provisions of the regulations 

listed in TC No. T00001SE, or the 

applicable regulations in effect on the 

date of application for the change, 

except for earlier amendments as agreed 

upon by the FAA. 

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 Model 777–8 and 777–9 

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 novel or unusual 

design feature, or should any other 

model already included on the same 

type certificate be modified to 

incorporate the same novel or unusual 

design feature, these special conditions 

would also apply to the other model 

under § 21.101. 

In addition to the applicable 

airworthiness regulations and special 

conditions, the Model 777–8 and 777– 

9 airplanes must comply with the fuelvent and exhaust-emission requirements 

of 14 CFR part 34, and the noisecertification requirements of 14 CFR 

part 36. 

The FAA issues special conditions, as 

defined in 14 CFR 11.19, in accordance 

with § 11.38, and they become part of 


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50582 Federal Register / Vol. 82, No. 210 / Wednesday, November 1, 2017 / Proposed Rules 

1A Code E gate is designed to accommodate 

aircraft wingspans between 170.6 ft. (52m) and 

213.3 ft. (65m), and outer main-gear wheel spans 

between 29.5 ft. (9m) and 45.9 ft. (14m). Boeing 777 

airplanes are in this gate-code category. 

the type certification basis under 

§ 21.101. 

Novel or Unusual Design Features 

The Model 777–8 and 777–9 airplanes 

will incorporate the following novel or 

unusual design features: CFRP wings 

with folding wingtips. 

Boeing proposes to incorporate this 

on-ground wingtip-fold capability to 

reduce the wingspan from 235 to 212 

feet when folded. These folding 

wingtips, when extended into the flightdeployed position, provide improved 

aerodynamic performance and 

efficiency, and comply with Code E 1

gate compatibility when folded during 

ground operations. 

Discussion 

Boeing proposes adding folding 

wingtips to their Model 777–8 and 777– 

9 airplane wings to improve 

aerodynamic performance and 

efficiency when the wingtips are 

extended into the flight-deployed 

position, while maintaining Code E gate 

compatibility when folded during 

ground operations. This wing-folding 

feature will be operable on the ground 

only. Boeing has no plan to carry fuel 

in the folding sections of the wings. 

Boeing has determined that a 

catastrophic event could occur if the 

777–8 and 777–9 airplane wingtips are 

not properly positioned and secured for 

takeoff and during flight. In service, 

numerous takeoff operations with 

improper airplane configurations have 

occurred due to failures of the takeoff 

warning systems, or inadvertent crew 

actions. For these proposed special 

conditions, a parallel is drawn between 

taking off with gust locks engaged and 

taking off with the wingtips folded, as 

either condition could result in a 

catastrophic event. Consequently, the 

FAA has determined that the level of 

safety in protecting a misconfigured 

airplane from takeoff with wingtips 

folded should be the same as taking off 

with the gust locks engaged. Therefore, 

condition 2 of these proposed special 

conditions has the same intent as 

§ 25.679(a)(2). Per § 25.1309, the 

applicant must show that such an event 

is extremely improbable, must not result 

from a single failure, and that 

appropriate alerting must be provided 

for the crew to manage unsafe systemoperating conditions. In addition, the 

applicant must ensure that the wingtips 

are properly secured during ground 

operations to protect ground personnel 

against bodily injury. 

Factors to be considered when 

showing compliance to these proposed 

special conditions include, but are not 

limited to: 

• With wingtips in the folded 

position, the conventional airplanewingtip-position lights may have 

reduced visibility due to the upward 

position of the wingtips, possibly 

impacting ground-operation safety. 

Light placement may require special 

consideration to retain the current 

ground-operation safety, and mitigate 

any adverse impact this light position 

may have on pilot visibility during 

night-lighting conditions. 

• Due to upward wingtip positioning 

on the ground, significant loads may be 

imposed by wind gusts combined with 

taxi speed during the transition from the 

unfolded to the folded position. 

• The FAA issued Policy Statement 

No. PS–ANM–25–12, ‘‘Certification of 

Structural Elements in Flight Control 

Systems,’’ to address structural elements 

in systems that act as both structure and 

as part of a system. This policy provides 

additional guidance on the appropriate 

application of the fatigue and damagetolerance requirements of § 25.571, and 

the system-safety requirements of 

§§ 25.671 and 25.1309. 

These proposed 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 Boeing 

Model 777–8 and 777–9 airplanes. 

Should Boeing apply at a later date for 

a change to the type certificate to 

include another model incorporating the 

same novel or unusual design feature, 

these special conditions would apply to 

that model as well. 

Conclusion 

This action affects only a certain 

novel or unusual design feature on one 

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 Proposed 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 Boeing Model 

777–8 and 777–9 airplanes. 

Note: The term ‘‘latch’’ refers to the 

mechanism that allows the wingtip to carry 

flight loads in the down (flight-deployed) 

position. The term ‘‘lock’’ refers to the 

mechanism that prevents disconnection of 

the latch when the wing tip is down. 

1. More than one means must be 

available to alert the flightcrew that the 

wingtips are not properly positioned 

and secured prior to takeoff. Each of 

these means must be unique in their 

wingtip-monitoring function. When 

meeting this condition, the applicant 

must add a function to the takeoff 

warning system, as required by 

§ 25.703(a)(1) and (2), to warn of an 

unlocked or improperly positioned 

wingtip, including indication to the 

flightcrew when a wingtip is in the 

folded position during taxi. 

2. In addition to a takeoff warning in 

accordance with § 25.703, a means must 

be provided to prevent airplane takeoff 

if a wingtip is not properly positioned 

and secured for flight. 

3. The applicant must consider the 

effects of folding-wingtip freeplay when 

evaluating compliance to the design 

load requirements of 14 CFR subpart C, 

and the aeroelastic stability (including 

flutter, divergence, control reversal, and 

any undue loss of stability and control 

as a result of structural deformation) 

requirements of § 25.629. Thus, the 

effects of normal wear, and other longterm durability conditions (such as 

corrosion) of the folding-wingtip 

operating mechanism on freeplay, and 

its impact on loads and aeroelastic 

stability, must be considered. Where 

freeplay limitations are required to 

ensure aeroelastic stability, acceptable 

freeplay limits and freeplay check 

procedures must be established. If 

lubrication is required to control 

excessive wear, lubrication intervals 

must be established. These procedures 

and limitations must be documented in 

accordance with § 25.1529. The 

freeplay-check and mechanismlubrication intervals, if required, must 

be documented as a certification 

maintenance requirement (CMR). 

Guidance for CMRs can be found in 

Advisory Circular 25–19A, 

‘‘Certification Maintenance 

Requirements.’’ The effects of freeplay 

on wing-joint torsional and bending 

stiffness, as well as wing frequencies, 

must be evaluated when showing 

compliance to loads and aeroelastic 

stability requirements. Also, the effects 

of freeplay on fatigue and damage 


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Federal Register / Vol. 82, No. 210 / Wednesday, November 1, 2017 / Proposed Rules 50583 

tolerance must be considered when 

showing compliance with § 25.571. 

4. The folding wingtips and their 

operating mechanism must be designed 

for 65 knot, horizontal, ground-gust 

conditions in any direction as specified 

in § 25.415(a). Relevant design 

conditions must be defined using 

combinations of steady wind and taxi 

speeds determined by rational analysis 

utilizing airport wind data. The folding 

wingtip is not a control surface as 

specified in § 25.415(b)(c). Therefore, in 

lieu of the equation provided in 

§ 25.415(b), the hinge moment may be 

calculated from rational wind-tunnel 

data. The 1.25 factor specified in 

§ 25.415(d) need not be applied to the 

portion of the system that is isolated in 

flight and is not critical for safe flight 

and landing. The folding-wingtip 

system must be designed for the 

conditions specified in § 25.415(e), (f), 

and (g). Runway roughness, as specified 

in § 25.491, must be evaluated 

separately up to the maximum relevant 

airplane ground speeds. All of the above 

conditions must be applied to the 

folding wingtips in the extended (flightdeployed), folded, and transient 

positions. 

5. The airplane must demonstrate 

acceptable handling qualities during 

rollout in a crosswind environment, as 

wingtips transition from the flightdeployed to folded position, as well as 

during the unlikely event of asymmetric 

wingtip folding. 

6. The wingtip-fold operating 

mechanism must have stops that 

positively limit the range of motion of 

the wingtips. Each stop must be 

designed to the requirements of 

§ 25.675. 

7. The wingtip hinge structure must 

be designed for inertia loads acting 

parallel to the hinge line. In the absence 

of more rational data, the inertia loads 

may be assumed to be equal to KW as 

referenced in § 25.393. Hinge design 

must meet the requirements of § 25.657. 

8. In lieu of § 25.1385(b): The forward 

position lights must be installed such 

that they consist of a red and a green 

light spaced laterally as far apart as 

practicable, and installed forward on the 

airplane, so that, with the airplane in 

the normal flying position and with the 

wingtips in the folded position for 

ground operations, the red light is on 

the left side and the green light is on the 

right side at approximately the level of 

the wingtips in the takeoff 

configuration. Each light must be 

approved and must meet the 

requirements of § 25.1385(a) and (d). 

The lights must not impair the vision of 

the flightcrew when the wingtips are in 

the folded and transient positions. 

9. The applicant must include design 

features that ensure the wingtips are 

properly secured during ground 

operations, to protect ground personnel 

from bodily injury as well as to prevent 

damage to the airframe, ground 

structure, and ground support 

equipment. 

10. The wingtips must have means to 

safeguard against unlocking from the 

extended, flight-deployed position in 

flight, as a result of failures, including 

the failure of any single structural 

element. All sources of airplane power 

that could initiate unlocking of the 

wingtips must be automatically isolated 

from the wingtip-fold operating system 

(including the latching and locking 

system) prior to flight, and it must not 

be possible to restore power to the 

system during flight. The wingtip 

latching and locking mechanisms must 

be designed so that, under all airplane 

flight-load conditions, no force or torque 

can unlatch or unlock the mechanisms. 

The latching system must include a 

means to secure the latches in the 

latched position, independent of the 

locking system. It must not be possible 

to position the lock in the locked 

position if the latches and the latching 

mechanisms are not in the latched 

position, and it must not be possible to 

unlatch the latches with the locks in the 

locked position. 

Issued in Renton, Washington, on October 

25, 2017. 

Victor Wicklund, 

Manager, Transport Airplane Directorate, 

Policy and Innovation Division, Aircraft 

Certification Service. 

[FR Doc. 2017–23698 Filed 10–31–17; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Parts 27 and 29 

[Docket No.: FAA–2017–0990] 

RIN 2120–AK80 

Normal and Transport Category 

Rotorcraft Certification 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to amend 

the certification standards of normal 

and transport category helicopters. The 

proposed changes are necessary to 

address modern designs currently used 

in the rotorcraft industry and would 

reduce the burden on applicants for 

certification of new rotorcraft designs. 

The proposed changes would reduce or 

eliminate the need for certain special 

conditions currently required to obtain 

certification of modern rotorcraft. The 

proposed changes would also 

incorporate the requirements of 

equivalent level of safety findings that 

the FAA has imposed as conditions for 

approving certain design features. 

DATES: Send comments on or before 

January 30, 2018. 

ADDRESSES: Send comments identified 

by docket number FAA–2017–0990 

using any of the following methods: 

• Federal eRulemaking 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: In accordance with 5 U.S.C. 

553(c), DOT solicits comments from the 

public to better inform its rulemaking 

process. DOT posts these comments, 

without edit, including any personal 

information the commenter provides, to 

www.regulations.gov, as described in 

the system of records notice (DOT/ALL– 

14 FDMS), which can be reviewed at 

www.dot.gov/privacy. 

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: For 

questions concerning this action, 

contact Sandra Shelley, Aviation Safety 

Engineer, Safety Management Group, 

FAA, 10101 Hillwood Pkwy., Fort 

Worth, TX 76177; telephone (817) 222– 

5110; email sandra.shelley@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Authority for This Rulemaking 

The FAA’s authority to issue rules on 

aviation safety is found in Title 49 of the 

United States Code. Subtitle I, Section 

106 describes the authority of the FAA 


sradovich on DSK3GMQ082PROD with PROPOSALS