[Federal Register Volume 81, Number 28 (Thursday, February 11, 2016)]
[Rules and Regulations]
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
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.
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
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
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-
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.
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
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.
This action affects only certain novel or unusual design features
on Boeing Model 737-8 series airplanes. It is not a rule of general
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
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 Boeing Model 737-8 series
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
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.
Acting Manager, Transport Airplane Directorate, Aircraft Certification
[FR Doc. 2016-02762 Filed 2-10-16; 8:45 am]
BILLING CODE 4910-13-P