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[Federal Register Volume 89, Number 230 (Friday, November 29, 2024)]
[Proposed Rules]
[Pages 94620-94623]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-27786]

[[Page 94620]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2024-0190; Notice No. 25-24-02-SC]

Special Conditions: The Boeing Company, Boeing Model 747-8 Series 
Airplane; Short-Term Occupancy of Lower Lobe During Flight and 
Installation of Stairway Between Main Deck and Lower-Lobe

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed special conditions.

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SUMMARY: This action proposes special conditions for The Boeing Company 
(Boeing) Model 747-8 series airplane. This airplane, as modified by 
Boeing, 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 the installation 
of stairs for flightcrew to access the forward and aft lower lobe 
compartments during flight. These compartments will have two main 
functions: storage of service items and that of a Class C cargo 
compartment. 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 comments on or before January 13, 2025.

ADDRESSES: Send comments identified by Docket No. FAA-2024-1090 using 
any of the following methods:
    Federal eRegulations Portal: Go to 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.
    Docket: Background documents or comments received may be read at 
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: Alan Sinclair, Technical Policy 
Branch, Policy and Standards Division, Aircraft Certification Service, 
Federal Aviation Administration, FAA Seattle Headquarters, 2200 South 
216th Street, Des Moines, Washington 98198; telephone and fax 206-231-
3215; email [email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites 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 proposed special conditions, 
explain the reason for any recommended change, and include supporting 
data.
    The FAA will consider all comments received by the closing date for 
comments and will consider comments filed late if it is possible to do 
so without incurring delay. The FAA may change these special conditions 
based on the comments received.

Privacy

    Except for Confidential Business Information (CBI) as described in 
the following paragraph, and other information as described in title 
14, Code of Federal Regulations (14 CFR) 11.35, the FAA will post all 
comments received without change to www.regulations.gov, including any 
personal information you provide. The FAA will also post a report 
summarizing each substantive verbal contact received about these 
special conditions.

Confidential Business Information

    Confidential Business Information (CBI) is commercial or financial 
information that is both customarily and actually treated as private by 
its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), 
CBI is exempt from public disclosure. If your comments responsive to 
these special conditions contain commercial or financial information 
that is customarily treated as private, that you actually treat as 
private, and that is relevant or responsive to these special 
conditions, it is important that you clearly designate the submitted 
comments as CBI. Please mark each page of your submission containing 
CBI as ``PROPIN.'' The FAA will treat such marked submissions as 
confidential under the FOIA, and the indicated comments will not be 
placed in the public docket of these proposed special conditions. Send 
submissions containing CBI to the individual listed in the For Further 
Information Contact section above. Comments the FAA receives, which are 
not specifically designated as CBI, will be placed in the public docket 
for these proposed special conditions.

Background

    On July 2, 2018, Boeing applied for a supplemental type certificate 
(STC) for the installation of stairs for inflight flightcrew to access 
the forward and aft lower lobe compartments that will have two main 
functions: access of service items that have been stored and that of a 
Class C cargo compartment in the Model 747-8 series airplane. The 
modified Boeing Model 747-8 series airplane, which is a derivative of 
the Model 747-8F series airplane currently approved under Type 
Certificate No. A20WE, is a four-engine, transport category airplane 
with a VIP interior configuration, not for common carriage, seating for 
93 passengers and 15 flightcrew, and a maximum takeoff weight of 
987,000 pounds.

Type Certification Basis

    Under the provisions of title 14, Code of Federal Regulations (14 
CFR) 21.101, Boeing must show that changes to the Boeing Model 747-8 
series airplane, as changed, continues to meet the applicable 
provisions of the regulations listed in Type Certificate No. A20WE 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 (e.g., 14 CFR part 25) do not contain adequate or 
appropriate safety standards for the Boeing Model 747-8 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 applicant apply for a STC 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 747-8

[[Page 94621]]

series airplanes must comply with the 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

    Certain Boeing Model 747-8 series airplanes will incorporate the 
following novel or unusual design features:
    The installation of stairs for flightcrew to access the forward and 
aft lower lobe compartments during flight. The compartments will have 
two main functions: storage of service items and that of a Class C 
cargo compartment.

Discussion

    Existing regulations address service areas and Class C cargo 
compartments independently, but do not address compartments that have 
both uses. A service compartment can be occupied, and the Class C cargo 
compartment cannot. Further, firefighting is dealt with differently in 
each compartment. The crew fights a fire in a service compartment and a 
flooding suppression system is used to fight a fire in a Class C cargo 
compartment.
    The 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 proposed special conditions are 
applicable to the Boeing Model 747-8 airplanes as modified by Boeing. 
Should the applicant apply for a STC to modify any other model included 
on the same type certificate to incorporate the same novel or unusual 
design feature, these special conditions would apply to the other model 
as well.

Conclusion

    This action affects only a certain novel or unusual design feature 
on certain modified Boeing Model 747-8 series airplanes. 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 airplanes.

List of Subjects in 14 CFR Part 25

    Aircraft, Aviation safety, reporting, and recordkeeping 
requirements.

Authority Citation

    The authority citation for these special conditions is as follows:

    Authority: 49 U.S.C. 106(f), 106(g), 40113, 44701, 44702, and 
44704.

The Proposed Special Conditions

    Accordingly, the Federal Aviation Administration (FAA) proposes the 
following special conditions as part of the type certification basis 
for Boeing Model 747-8 series airplanes, as modified by The Boeing 
Company.

Requirements Specific to Lower Lobe Access

    (a) Alerts and indications are required in the lower lobe 
compartments to indicate decompression, smoke/fire detection, and the 
need to return to one's seat. (Definition for alert categorization must 
be consistent with 14 CFR 25.1322).
    (1) There must be a flight deck indication to advise the flightcrew 
when the lower lobe service/cargo compartment(s) are occupied. The 
indication must be accompanied by a placard or message in the flight 
deck indicating someone is in the lower lobe compartment(s). The flight 
deck indication must be initiated automatically when the compartments 
become occupied, without input from the occupying flightcrew other than 
required to gain access. The flight deck indication must be canceled 
automatically when the compartment(s) are no longer occupied, and the 
means of access is returned to the unoccupied configuration.
    (i) There must be flight deck indication to advise the flightcrew 
that the in-flight accessible doors to the lower lobe compartments are 
closed prior to initiation of the fire suppression system.
    (2) There must be an ``on/off'' visual alert light located outside 
and on or near the access doors to each lower lobe service/cargo 
compartment with a placard stating, ``When light is illuminated 
entrance is prohibited'' (or similar words). The alert is to be 
automatic in the event of decompression, smoke/fire detection or 
anytime the compartment visual alerting system is activated.
    (3) A flightcrew operated visual alerting system, which is 
recognized in accessible areas within the lower lobe compartment(s), 
must be installed to indicate, during turbulence, that persons must 
return to their seats. Appropriate procedures and limitations (if 
required) must be established to ensure that the flightcrew alerting 
systems notify the occupants to return to their seats at the onset of 
turbulence and prior to taxi, takeoff and landing.
    (4) An automatically activated aural and visual decompression 
alerting system must be present and immediately recognizable in 
accessible areas of the lower lobe compartments to notify occupants 
when to don oxygen masks.
    (5) An automatically activated aural and visual alerting system, 
which is recognized in the lower lobe compartment(s), must be 
installed. This aural and visual alerting system is to indicate that, 
in the event of smoke detection in the lower lobe compartment(s), 
persons must don their oxygen masks and initiate oxygen flow, exit the 
compartment, ensure that the door is closed (smoke barrier) and that 
communication with the flight deck is established. Entry must not be 
allowed during flight after release of fire suppressant.
    (6) These alerting requirements must be distinctive and effective, 
and:
    (i) Visual alerts must be visible from all occupant locations 
during all expected operational conditions including a rapid 
decompression where moisture in the air may condense.
    (ii) Aural alerts must be loud enough to be heard during all 
expected operational conditions including a rapid decompression where 
the ambient noise level will increase.
    (iii) If there are two or more alerts that an occupant may hear or 
is expected to respond to, there must be an automatic visual alert in 
addition to the automatic aural alert. There must be training in the 
sound of the alerting system, the meaning of the alerting system, and 
the response to the signal (i.e., procedures for donning the masks and 
activating the flow of oxygen).
    (b) Placards
    (1) There must be appropriate placards installed inside and outside 
each access door to the lower lobe compartment(s) to indicate:
    (i) The maximum number of occupants allowed, or number of occupants 
required, as applicable to the compartment.
    (ii) Occupancy is restricted to crewmembers trained in the 
procedures of the lower lobe compartment(s).
    (iii) Occupancy is prohibited during taxi, takeoff, and landing, 
and whilst the fire suppression system is activated.
    (iv) The access door must remain closed except when someone is 
entering or exiting the compartment.
    (v) Occupancy of the compartment should be of minimum duration.
    (vi) Anyone entering the lower lobe compartment(s) during flight 
must carry portable oxygen equipment for the entire time that they are 
in the compartment.
    (2) There must be appropriate placards located conspicuously on or

[[Page 94622]]

near each lower lobe compartment exit defining the location and 
operating instructions for each evacuation route. Placards must be 
readable from a distance of 30 inches under emergency lighting 
conditions.
    (3) There must be a placard located adjacent to the visual alert 
light required by condition (a) (2) that states, ``When light is 
illuminated, entrance is prohibited'' (or similar words).
    (4) In addition to the above requirements, the following additional 
placards must be included for an Electronic/Equipment (E/E) Bay:
    (i) No stowage allowed within an E/E Bay.
    (ii) In-flight access for panels/cabinets not designed to be used 
in-flight is prohibited.
    (iii) Provided the in-flight maintenance requirements in ICA 
section (g) are met, placarding must declare that ``Entrance is 
prohibited except by permission of the pilot in command'' (or similar 
words).
    (iv) ``Access is not permitted during flight'' if the in-flight 
maintenance requirements in ICA Section (g) are not met.
    (v) A placard must be installed on all access panels and doors 
within lower lobe compartments prohibiting use of those that are not 
intended for use in flight.
    (c) Equipment: In lieu of that required by Sec. Sec.  25.819, 
25.851(a), 25.1439(a) and 25.1447(c) the following equipment is 
required:
    (1) There must be a portable oxygen bottle with mask attached to it 
meeting the requirements Sec.  25.1439(b)(1), (2)(i), (4) for each 
crewmember occupying the lower lobe compartment(s). The equipment must 
be mounted outside each access door to the lower lobe service/cargo 
compartment(s). The equipment and system must be designed to prevent 
any inward leakage to the inside of the device and prevent any outward 
leakage causing significant increase in the oxygen content of the local 
atmosphere (i.e., full face mask type). A portable oxygen bottle must 
be carried by each crewmember who is occupying the lower lobe service/
cargo compartment. The portable oxygen bottle must also meet the 
minimum performance requirements of Sec.  25.1443(a) or (b), or the 
equipment must be shown to protect the occupant from hypoxia at an 
activity level required to return to a seat on the main deck where 
oxygen is available following a rapid decompression.
    (2) In addition to the emergency illumination required by Sec.  
25.819(a), at least two flashlights, each equipped with a locator 
light, must be provided. One flashlight must be located adjacent to 
each emergency exit and entrance in the lower lobe compartment(s).
    (3) In addition to the evacuation route requirements of Sec.  
25.819(a), all entrances and exits from the lower lobe service/cargo 
compartment must be capable of being closed after entering and exiting 
and, after closing, must prevent hazardous quantities of smoke, flames, 
or fire suppressant agent from entering any compartments occupied by 
passengers or crew and must prevent loss of fire suppressant agent when 
activated.
    (4) In lieu of the emergency equipment required by Sec. Sec.  
25.851(a) and 25.1439(a), when the procedures allow for a single 
occupant in a potential ``dead end'' volume further than 5 feet from an 
exit in the lower lobe compartment(s) there must be a readily 
accessible fire extinguisher, appropriate to the types and kinds of 
fires that may occur.
    (5) A means must be in place to preclude anyone from being trapped 
inside the lower lobe compartment(s). If a locking mechanism is 
installed in the door, it must be capable of being unlocked from the 
either side of the door without the aid of any tools.
    (6) A means must be in place to restrict access and prevent 
inadvertent damage to critical aircraft systems and equipment located 
within the compartment during flight.
    (7) There must be a means to communicate with the flight deck from 
within the E/E Bay.
    (d) Training: Training manuals and training must include:
    (1) Use and actions associated with aural and visual alerts and 
placards specified herein.
    (2) Entering and exiting the lower lobe compartment(s), including 
emergency exiting.
    (3) Checking the oxygen bottle pressure for adequacy prior to 
entering the lower lobe service/cargo compartment.
    (4) Carrying the oxygen bottle when entering the lower lobe 
compartment(s) and using the bottle in emergency situations.
    (5) Maintaining exit path aisle and access for the evacuation 
routes.
    (6) Identification of equipment related hazards such as the 
potential for electric shock and burns.
    (7) Limiting the occupancy for duration of the required tasks.
    (e) Procedures
    (1) A procedure must be established to ensure that the appropriate 
actions are taken in the event of smoke/fire detection. These actions 
are to include evacuation of the lower lobe compartments if occupied, 
communication with flight deck, determination of the event severity and 
the closure of the compartment doors for compartment sealing. These 
actions ensure the fire barriers (i.e., doors) are closed prior to 
release of fire suppressant agent in the cargo compartments. Reentry 
into the lower lobe service/cargo compartments after a smoke/fire 
detection event would only be allowed by the pilot in command, via 
controlled procedures.
    (2) A procedure must be established to ensure that required 
equipment, such as portable oxygen, fire extinguishers, protective 
breathing equipment, and warning light are functional prior to takeoff.
    (f) Limitations of Special Condition
    (1) An FAA approved Cabin Crew Manual requiring the cabin crew 
verify the lower lobe compartment(s) are not occupied during taxi, 
takeoff, landing, or after fire suppression activation must be created. 
The Cabin Crew Manual must include instructions for allowing access; 
procedures for fire/smoke detection/firefighting; procedures for 
decompression. The Cabin Crew Manual must be specified by the master 
drawing list and called out on the description of type design change 
section of the STC.
    (2) The Airplane Flight Manual (AFM) supplement must include 
instructions for: allowing access; procedures for fire/smoke detection/
firefighting; procedures for decompression.
    (3) The weight and balance manual must include cargo loading 
restrictions to maintain escape paths.
    (g) Instructions for Continued Airworthiness (ICAs)
    (1) The ICAs must contain appropriate procedures to ensure 
maintenance can be safely accomplished in-flight.
    (i) The ICA supplement must contain instructions that highlight the 
special considerations associated with in-flight maintenance. This 
content includes any assumptions or requirements for compliance with 
Sec. Sec.  25.1309, 25.1360, 25.1529 and 25.1721.
    (ii) The ICAs must establish an appropriate foreign object damage 
(FOD) control process for performing maintenance in-flight. The hazards 
associated with FOD may be mitigated by design and existing FOD control 
processes.
    (iii) The ICAs must establish an appropriate lock-out/tag-out 
procedure for performing maintenance in-flight. A new single lock-out/
tag-out procedure may be created for both ground and flight.

[[Page 94623]]

Requirements Specific to the Stairway

    (h) The stairway must have essentially straight route segments with 
a landing at each significant change in segment direction.
    (i) The stairway must have essentially rectangular treads.
    (j) The stairway must accommodate the carriage of an incapacitated 
occupant from the lower deck to the main deck. The crewmember 
procedures for such carriage must be established and included in the 
AFM.
    (k) In normal operation, the general illumination level must not be 
less than 0.05 foot-candles when measured along the center lines of 
each tread and landing.
    (l) The stairway must have a handrail on at least one side to allow 
occupants to steady themselves during moderate turbulence in flight. 
The handrail(s) must be constructed so there is no obstruction on them 
that will cause the user to release his/her grip or hinder the 
continuous movement of the hands along the handrail. The design must 
accommodate the stature of a 5th percentile female and a 95th 
percentile male.
    (m) The public address system must be intelligible in the stairway 
during all flight phases.
    (n) ``Return to seat'' signs must be installed and visible in the 
stairway both going up and down and at the stairway entrances.
    (o) Appropriate placards must be located outside each main deck 
entrance to the lower lobe access stairs to indicate:
    (1) The maximum number of occupants allowed in flight.
    (2) Occupancy during flight is restricted to crewmembers that are 
trained in the procedures for the lower lobe compartments.
    (3) Occupancy is prohibited during taxi, take-off, and landing.
    (4) The stowage of cargo or passenger baggage is not allowed in the 
stair enclosure. This placard is also required at each stair landing.
    (p) Passengers must be prevented from entering the stairway in the 
event of an emergency or when no flight attendant is present.
    (q) The means required by condition (p) must be capable of being 
quickly opened from inside the stairway, even when crowding occurs at 
the passenger cabin side of the stair entrance.
    (r) A means must be in place to preclude anyone from being trapped 
inside the stairway. If a locking mechanism is installed, it must be 
capable of being unlocked from either side without the aid of tools.
    (s) There must be appropriate placards conspicuously located as 
follows:
    (1) Inside the stairs on or near each exit to the main deck 
defining the operating instructions for the door.
    (2) On the cabin side, when the door is closed, no higher than 4 
feet from the floor, indicating that the door is not an emergency exit. 
For the placards required by condition (s) the following applies:
    (3) Placards must be readable from a distance of 30 inches under 
emergency lighting conditions.
    (4) Placards must be illuminated to at least 160 micro-lamberts 
under emergency lighting conditions.
    (t) There shall be a means (visible and audible) to notify an 
occupant of the stairway of the need to don supplemental oxygen 
equipment in the event of a decompression. The aural and visual alerts 
must activate before the cabin pressure altitude exceeds 15,000 feet.
    (u) A means must be available, in the event of failure of the 
airplane's main power system, or of the normal stairway lighting 
system, for emergency illumination to be automatically provided in the 
stairway.
    (1) This emergency illumination must be independent of the main 
lighting system.
    (2) The sources of general illumination may be common to both the 
emergency and the main lighting systems if the power supply to the 
emergency lighting system is independent of the power supply to the 
main lighting system.
    (3) Emergency illumination must be provided so that, when measured 
along the centerlines of each tread and landing, the illumination is 
not less than 0.05 foot-candles.

    Issued in Kansas City, Missouri, on signature November 18, 2024.
Patrick R. Mullen,
Manager, Technical Policy Branch, Policy and Standards Division, 
Aircraft Certification Service.
[FR Doc. 2024-27786 Filed 11-27-24; 8:45 am]
BILLING CODE 4910-13-P
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