[Federal Register Volume 81, Number 178 (Wednesday, September 14, 2016)]
[Rules and Regulations]
[Pages 63051-63053]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-22048]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2016-8832; Special Conditions No. 25-638-SC]


Special Conditions: Lufthansa Technik, AG, Boeing Model 737-700 
Airplanes; Large, Non-Structural Glass in the Passenger Compartment

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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

SUMMARY: These special conditions are issued for Boeing Model 737-700 
airplanes. This airplane, as modified by Lufthansa Technik, AG 
(Lufthansa), will have a novel or unusual design feature when compared 
to the state of technology envisioned in the airworthiness standards 
for transport-category airplanes. This design feature is large, non-
structural glass panels in the passenger compartment of Very Important 
Person (VIP) interiors of Model 737-700 airplanes modified by 
Lufthansa. 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 Lufthansa on September 14, 2016. We 
must receive your comments by October 31, 2016.

ADDRESSES: Send comments identified by docket number FAA-2016-8832 
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: John Shelden, Airframe and Cabin 
Safety, ANM-115, Transport Airplane Directorate, Aircraft Certification 
Service, 1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone 
425-227-2785; facsimile 425-227-1320.

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 
airplanes.
    In addition, the substance of these special conditions has been 
subjected to the notice and comment period in several prior instances, 
and has been

[[Page 63052]]

derived without substantive change from those previously issued. The 
FAA made changes for clarity in response to one recent comment on 
similar special conditions. 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.

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 October 15, 2015, Lufthansa applied for a supplemental type 
certificate to install a VIP interior and cabin system, which includes 
installation of large, non-structural glass panels in the passenger 
compartment of Boeing Model 737-700 airplanes. This airplane is a twin-
jet engine, transport-category airplane. The airplane seating 
accommodates 34 passengers, 5 cabin crewmembers, and 4 flightcrew 
members. Maximum takeoff weight is 171,000 lbs.

Type Certification Basis

    Under the provisions of title 14, Code of Federal Regulations (14 
CFR) 21.101, Lufthansa must show that the Boeing Model 737-700 
airplane, as changed, continues to 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.
    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 Boeing Model 737-700 airplane 
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 applicant apply for a supplemental type 
certificate to modify any other model included on the same type 
certificate 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 Boeing Model 737-700 airplane 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 Boeing Model 737-700 airplane, as modified by Lufthansa, will 
incorporate a novel or unusual design feature associated with a VIP 
interior and cabin system, which is the installation of large, non-
structural glass panels in the passenger compartment.

Discussion

    No specific regulations address the design and installation of 
large glass components in airplane passenger cabins. Existing 
requirements, such as Sec. Sec.  25.561, 25.562, 25.601, 25.603, 
25.613, 25.775, and 25.789, provide some design standards appropriate 
for large glass component installations. However, additional design 
standards for non-structural glass augmenting the existing design are 
needed to complement the existing requirements. The addition of glass 
involved in this installation, and the potentially unsafe conditions 
caused by damage to such components from external sources, necessitate 
assuring that adequate safety standards are applied to the design and 
installation of the feature in Boeing Model 737-700 airplanes.
    For purposes of these special conditions, a large glass component 
is defined as a glass component weighing 4 kg (9 lbs) or more. 
Groupings of glass items that individually weigh less than 4 kg, but 
collectively weigh 4 kg or more, also would need to be included. These 
special conditions also apply when showing compliance with the 
applicable performance standards in the regulations for the 
installation of these components. For example, heat-release and smoke-
density testing must not result in fragmentation of the component.
    The use of glass has resulted in trade-offs between the one unique 
characteristic of glass--its capability for undistorted or controlled 
light transmittance, or transparency--and the negative aspects of the 
material, such as extreme notch-sensitivity, low fracture resistance, 
low modulus of elasticity, and highly variable properties. While 
reasonably strong, glass is nonetheless not a desirable material for 
traditional airplane applications because it is heavy (about the same 
density as aluminum), and when it fails, it breaks into extremely sharp 
fragments that have the potential for injury and have been known to be 
lethal. Likewise, the use of glass traditionally has been limited to 
windshields, and instrument and display transparencies. The regulations 
for certification of transport-category airplanes only address, and 
thus only recognize, the use of glass in windshield or window 
applications. These regulations do address the adverse properties of 
glass, but even so, pilots are occasionally injured from shattered 
glass windshields. FAA policy allows glass on instruments and display 
transparencies.
    Other installations of large, non-structural glass items have 
included the following:
     Glass panels integrated onto a stairway handrail closeout.
     Glass panels mounted in doors to allow visibility through 
the door when desired.
     Glass doors on some galley compartments containing small 
amounts of service items.
    These special conditions will reduce the hazards from breakage, or 
from these panels' potential separation from the cabin interior.
    The FAA recently received comments on proposed special conditions 
similar to the special conditions in this document. Notice of Proposed 
Special Conditions no. 25-16-03-SC, for Lufthansa modifications to the 
Boeing Model 747-8 airplane, was published in the Federal Register on 
February 25, 2016 (81 FR 9363). The Boeing Company provided comments to 
that notice by letter no. B-H020-REG-16-TLM-17, dated March 24, 2016. 
The first comment referred to the first two conditions in Notice no. 
25-16-03-SC, and recommended revising the text in special condition no. 
2 to more clearly define how it is different from special condition no. 
1. We agreed that those two conditions could be addressed with a single 
test, so we combined those two conditions into a single condition, 
special condition no. 1, for clarity. This document also reflects that 
change.

[[Page 63053]]

    Boeing commented that the load conditions in special condition no. 
4, in Notice no. 25-16-03-SC, which corresponds to special condition 
no. 3 in this document, should include all flight and landing loads, 
rather than only emergency landing. These special conditions are in 
addition to the load requirements in the certification basis for the 
glass installation, rather than in lieu of the load requirements. Thus, 
is it not necessary to repeat that all of these loads apply to this 
installation. The emergency-landing load condition is not normally 
applied to installations of this type, but for the use of large glass 
in the cabin, we determined that this additional safety standard is 
necessary. We made no changes to special condition number 3 in response 
to the Boeing comments.
    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 
Boeing Model 737-700 airplanes modified by Lufthansa. Should Lufthansa 
apply at a later date for a supplemental type certificate to modify any 
other model included on Type Certificate No. A16WE to incorporate 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 one model series of airplane. It is not a rule of general 
applicability and affects only the applicant who applied to the FAA for 
approval of these features on the airplane.

List of Subjects in 14 CFR Part 25

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.

0
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 Boeing Model 737-700 airplanes 
modified by Lufthansa.
    1. Material Fragmentation--The applicant must use tempered or 
otherwise treated glass to ensure that, when fractured, the glass 
breaks into small pieces with relatively dull edges. The glass 
component installation must retain all glass fragments to minimize the 
danger from flying glass shards or pieces. The applicant must 
demonstrate this characteristic by impact and puncture testing, and 
testing to failure. The applicant may conduct this test with or without 
any glass coating that may be utilized in the design.
    2. Strength--In addition to meeting the load requirements for all 
flight and landing loads, including any of the applicable emergency-
landing conditions in subparts C & D of 14 CFR part 25, the glass 
components that are located such that they are not protected from 
contact with cabin occupants must not fail due to abusive loading, such 
as impact from occupants stumbling into, leaning against, sitting on, 
or performing other intentional or unintentional forceful contact with 
the glass component. The applicant must assess the effect of design 
details such as geometric discontinuities or surface finish, including 
but not limited to embossing and etching.
    3. Retention--The glass component, as installed in the airplane, 
must not come free of its restraint or mounting system in the event of 
an emergency landing, considering both the directional loading and 
resulting rebound conditions. The applicant must assess the effect of 
design details such as geometric discontinuities or surface finish, 
including but not limited to embossing and etching.
    4. Instruction for Continued Airworthiness--The instructions for 
continued airworthiness must reflect the glass-panel fastening method 
used, and must ensure the reliability of the methods used (e.g., life 
limit of adhesives, or clamp connection). Inspection methods and 
intervals must be defined based upon adhesion data from the 
manufacturer of the adhesive, or actual adhesion test data, if 
necessary.

    Issued in Renton, Washington, on September 7, 2016.
Michael Kaszycki,
Assistant Manager, Transport Airplane Directorate, Aircraft 
Certification Service.
[FR Doc. 2016-22048 Filed 9-13-16; 8:45 am]
 BILLING CODE 4910-13-P