[Federal Register Volume 81, Number 28 (Thursday, February 11, 2016)]
[Rules and Regulations]
[Pages 7198-7200]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-02762]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2015-5877; Special Conditions No. 25-610-SC]


Special Conditions: The Boeing Company, Model 737-8 Airplanes; 
Design Roll-Maneuver Requirements

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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

SUMMARY: These special conditions are issued for Boeing Model 737-8 
airplanes. These airplanes will have a novel or unusual design feature 
associated with an electronic flight-control system that provides roll 
control of the airplane through pilot inputs to the flight computers. 
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: This action is effective on the Boeing Company on February 11, 
2016. We must receive your comments by March 28, 2016.

ADDRESSES: Send comments identified by docket no. FAA-2015-5877 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 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, 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

[[Page 7199]]

would significantly delay issuance of the design approval and thus 
delivery of the affected airplane.
    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 
publication in the Federal Register.

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 January 27, 2012, The Boeing Company applied for an amendment to 
Type Certificate No. A16WE to include a new Model 737-8 airplane. The 
Model 737-8 airplane is a narrow-body, transport-category airplane that 
is a derivative of the Model 737-800 airplane with two CFM LEAP-1B 
wing-mounted engines.
    The Model 737-8 airplane will include electronic flight controls 
that affect maneuvering.
    The current design roll-maneuver requirements in Title 14, Code of 
Federal Regulations (14 CFR) part 25 are inadequate for addressing an 
airplane with electronic flight controls that affect maneuvering. These 
special conditions adjust the current roll-maneuver requirement, Sec.  
25.349, to take into account the effects of an electronic flight-
control system.

Type Certification Basis

    Under the provisions of Sec.  21.101, The Boeing Company must show 
that the Model 737-8 series airplanes meet the applicable provisions of 
the regulations listed in type certificate no. A16WE, or the applicable 
regulations in effect on the date of application for the change except 
for earlier amendments as agreed upon by the FAA.
    The regulations listed in the type certificate are commonly 
referred to as the ``original type-certification basis.'' The 
regulations listed in type certificate no. A16WE are as follows:
    14 CFR part 25, effective February 1, 1965, including Amendments 
25-1 through 25-134. In addition, the certification basis includes 
certain special conditions, exemptions, or later amended sections of 
the applicable part that are not relevant to these special conditions.
    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 737-8 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 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 Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, the Model 737-8 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.
    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.  21.101.

Novel or Unusual Design Features

    The Model 737-8 series airplanes will incorporate the following 
novel or unusual design features:

    The airplanes are equipped with an electronic flight-control 
system that provides control through pilot inputs to the flight 
computer. Current part 25 airworthiness regulations account for 
control laws for which aileron deflection is proportional to 
control-stick deflection. They do not address nonlinearities or 
other effects on aileron actuation that electronic flight controls 
may cause. Because this type of system may affect flight loads, and 
therefore the structural capability of the airplanes, special 
conditions are needed to address these effects.

Discussion

    These special conditions differ from current requirements in that 
they require that the roll maneuver is based on defined actuation of 
the cockpit roll control as opposed to defined deflections of the 
aileron itself. Also, the special conditions require an additional load 
condition at VA, in which the cockpit roll control is 
returned to neutral following the initial roll input.
    These special conditions differ from similar special conditions 
applied on previous programs. These special conditions are limited to 
the roll axis only, whereas previous special conditions also included 
the pitch and yaw axes. Special conditions are no longer needed for the 
pitch or yaw axes, because Amendment 25-91 takes into account the 
effects of an electronic flight-control system in those axes (Sec.  
25.331 for pitch and Sec.  25.351 for yaw). On the Model 737-8 series 
airplanes, only the flight spoilers are fly-by-wire.
    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 
Boeing Model 737-8 series 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 certain novel or unusual design features 
on Boeing Model 737-8 series 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, 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.

[[Page 7200]]

The Special Conditions

0
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 Boeing Model 737-8 series 
airplanes.

Design Roll Maneuver Condition

    In lieu of compliance to Sec.  25.349(a):

    The following conditions, speeds, and cockpit roll-control 
motions (except as the motions may be limited by pilot effort) must 
be considered in combination with an airplane load factor of zero 
and of two-thirds of the positive maneuvering factor used in design. 
In determining the resulting control-surface deflections, the 
torsional flexibility of the wing must be considered in accordance 
with Sec.  25.301(b):
    1. The applicant must investigate conditions corresponding to 
steady rolling velocities. In addition, conditions corresponding to 
maximum angular acceleration must be investigated for airplanes with 
engines or other weight concentrations outboard of the fuselage. For 
the angular acceleration conditions, zero rolling velocity may be 
assumed in the absence of a rational time-history investigation of 
the maneuver.
    2. At VA, sudden movement of the cockpit roll control 
up to the limit is assumed. The position of the cockpit roll control 
must be maintained until a steady roll rate is achieved and then 
must be returned suddenly to the neutral position.
    3. At VC, the cockpit roll control must be moved 
suddenly and maintained so as to achieve a roll rate not less than 
that obtained in Special Condition 2, above.
    4. At VD, the cockpit roll control must be moved 
suddenly and maintained so as to achieve a roll rate not less than 
one third of that obtained in Special Condition 2, above.

    Issued in Renton, Washington, on January 20, 2016.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2016-02762 Filed 2-10-16; 8:45 am]
 BILLING CODE 4910-13-P