Special Conditions: Boeing Model 747SP; NASA Stratospheric Observatory for Infrared Astronomy (SOFIA); Cryogenic Systems Using Liquid Nitrogen and Liquid Helium, 6598-6600 [05-2319]
Download as PDF
<![CDATA[
6598
Federal Register / Vol. 70, No. 25 / Tuesday, February 8, 2005 / Proposed Rules
State and local officials. (See 7 CFR part
3015, subpart V.)
Executive Order 12988
This proposed rule has been reviewed
under Executive Order 12988, Civil
Justice Reform. If this proposed rule is
adopted: (1) All State and local laws and
regulations that are inconsistent with
this rule will be preempted; (2) no
retroactive effect will be given to this
rule; and (3) administrative proceedings
will not be required before parties may
file suit in court challenging this rule.
Paperwork Reduction Act
This interim rule contains no
information collection or recordkeeping
requirements under the Paperwork
Reduction Act of 1995 (44 U.S.C. 3501
et seq.).
List of Subjects
7 CFR Part 300
Incorporation by reference, Plant
diseases and pests, Quarantine.
Agricultural commodities, Plant
diseases and pests, Quarantine,
Reporting and recordkeeping
requirements, Transportation.
Accordingly, we are proposing to
amend 7 CFR parts 300 and 301 as
follows:
Background
§ 301.92–10
Treatments.
Treatment schedules listed in the
Plant Protection and Quarantine
Treatment Manual to destroy
Phytophothora ramorum are authorized
for use on certain regulated articles. The
Plant Protection and Quarantine
Treatment Manual is incorporated by
reference at § 300.1 of this chapter. The
following treatments also may be used
for the regulated articles indicated:
(a) Soil—Heat to a temperature of at
least 180 °F for 30 minutes in the
presence of an inspector.
(b) Wreaths, garlands, and greenery of
host material—Dip for 1 hour in water
that is held at a temperature of at least
160 °F.
DEPARTMENT OF AGRICULTURE
Agricultural Marketing Service
7 CFR Part 923
1. The authority citation for part 300
would continue to read as follows:
Authority: 7 U.S.C. 7701–7772; 7 CFR 2.22,
2.80, and 371.3.
2. Section 300.1 would be amended as
follows:
a. In paragraph (a)(8), by removing the
word ‘‘and’’.
b. In paragraph (a)(9), by removing the
period and adding the word ‘‘; and’’ in
its place.
c. By adding a new paragraph (a)(10)
to read as set forth below:
§ 300.1 Plant Protection and Quarantine
Treatment Manual.
(a) * * *
(10) Treatment T101–m–2–1–2,
datedll.
*
*
*
*
*
PART 301—DOMESTIC QUARANTINE
NOTICES
3. The authority citation for part 301
would continue to read as follows:
Authority: 7 U.S.C. 7701–7772; 7 CFR 2.22,
2.80, and 371.3.
Section 301.75–15 also issued under Sec.
204, Title II, Pub. L. 106–113, 113 Stat.
Jkt 205001
4. Section 301.92–10 would be
revised to read as follows:
BILLING CODE 3410–34–U
PART 300—INCORPORATION BY
REFERENCE
15:26 Feb 07, 2005
Box 1035, Moab, UT 84532, telephone:
(435) 259–7988, fax: (435) 259–4945.
SUPPLEMENTARY INFORMATION:
Done in Washington, DC, this 2nd day of
February 2005.
Elizabeth E. Gaston,
Acting Administrator, Animal and Plant
Health Inspection Service.
[FR Doc. 05–2322 Filed 2–7–05; 8:45 am]
7 CFR Part 301
VerDate jul<14>2003
1501A–293; sections 301.75–15 and 301.75–
16 also issued under Sec. 203, Title II, Pub.
L. 106–224, 114 Stat. 400 (7 U.S.C. 1421
note).
[Docket Nos. AO–F&V–923–3; FV03–923–01]
Sweet Cherries Grown in Designated
Counties in Washington; Secretary’s
Decision and Referendum Order on
Proposed Amendments to Marketing
Agreement and Order No. 923;
Correction
Agricultural Marketing Service,
USDA.
ACTION: Proposed rule and referendum
order; correction.
AGENCY:
The Agricultural Marketing
Service published in the Federal
Register on January 14, 2005, a
Secretary’s Decision and Referendum
Order on proposed amendments to the
Washington sweet cherry marketing
order. This docket corrects the
representative period for voting in the
referendum from April 1, 2003, through
March 31, 2004, to April 1, 2004,
through February 28, 2005.
FOR FURTHER INFORMATION CONTACT:
Melissa Schmaedick, Marketing Order
Administration Branch, Fruit and
Vegetable Programs, Agricultural
Marketing Service, USDA, Post Office
SUMMARY:
PO 00000
Frm 00003
Fmt 4702
Sfmt 4702
The Secretary’s decision and
referendum order that are the subject of
this correction propose amendments to
the marketing agreement and order
(order) and provide growers with the
opportunity to vote in a referendum to
determine if they favor the proposed
amendments.
Need for Correction
As published, the representative
period for the purpose of the
referendum is being changed from April
1, 2003, through March 31, 2004, to
April 1, 2004, through February 28,
2005, to reflect the most recent crop
year.
Correction of Publication
Accordingly, the publication of the
proposed rule and referendum order
(Docket Nos. AO–F&V–923–3; FV03–
923–01), which was the subject of FR
Doc. 05–825 published on January 14,
2005 (70 FR 2573) is corrected as
follows:
1. On page 2574, column one, under
DATES; the dates ‘‘April 1, 2003, through
March 31, 2004,’’ are corrected to read
‘‘April 1, 2004, through February 28,
2005.’’
Authority: 7 U.S.C. 601–674.
Dated: February 3, 2005.
Kenneth C. Clayton,
Acting Administrator, Agricultural Marketing
Service.
[FR Doc. 05–2388 Filed 2–7–05; 8:45 am]
BILLING CODE 3410–02–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NN301; Notice No. 25–05–01–
SC]
Special Conditions: Boeing Model
747SP; NASA Stratospheric
Observatory for Infrared Astronomy
(SOFIA); Cryogenic Systems Using
Liquid Nitrogen and Liquid Helium
Federal Aviation
Administration (FAA), DOT.
ACTION: Notice of proposed special
conditions.
AGENCY:
SUMMARY: This notice proposes special
conditions for the Boeing Model 747SP
airplane. This airplane, as modified by
L–3 Communications/Integrated
E:\FR\FM\08FEP1.SGM
08FEP1
Federal Register / Vol. 70, No. 25 / Tuesday, February 8, 2005 / Proposed Rules
Systems of Waco, Texas, will have novel
and unusual design features associated
with cryogenic systems using liquid
nitrogen and liquid helium. 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: Comments must be received on
or before March 25, 2005.
ADDRESSES: Comments on this proposal
may be mailed in duplicate to: Federal
Aviation Administration, Transport
Airplane Directorate, Attn: Rules Docket
(ANM–113), Docket No. NN301, 1601
Lind Avenue SW., Renton, Washington,
98055–4056; or delivered in duplicate to
the Transport Airplane Directorate at
the above address. Comments must be
marked: Docket No. NM301. Comments
may be inspected in the Rules Docket
weekdays, except Federal holidays,
between 7:30 a.m. and 4 p.m.
FOR FURTHER INFORMATION CONTACT:
Kathi Ishimaru, FAA, Propulsion/
Mechanical Systems Branch, ANM–112,
Transport Airplane Directorate, Aircraft
Certification Service, 1601 Lind Avenue
SW., Renton, Washington, 98055–4056;
telephone (425) 227–2674; facsimile
(425) 227–1232.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites interested persons to
participate in this rulemaking by
submitting written comments, data, or
views. The most helpful comments
reference a specific portion of the
special conditions, explain the reason
for any recommended changes, and
include supporting data. We ask that
you send us two copies of written
comments.
We will file in the docket all
comments we receive, as well as a
report summarizing each substantive
public contact with FAA personnel
concerning these special conditions.
The docket is available for public
inspection before and after the comment
closing date. If you wish to review the
docket in person, go to the address in
the ADDRESSES section of this preamble
between 7:30 a.m., and 4 p.m., Monday
through Friday, except Federal holidays.
We will consider all comments we
receive on or before the closing date for
comments. We will consider comments
filed late if it is possible to do so
without incurring expense or delay. We
may change these special conditions in
light of the comments received.
VerDate jul<14>2003
14:57 Feb 07, 2005
Jkt 205001
If you want the FAA to acknowledge
receipt of your comments on this
proposal, include with your comments
a pre-addressed, stamped postcard on
which the docket number appears. We
will stamp the date on the postcard and
mail it back to you.
Background
On March 17, 1997, L–3
Communications/Integrated Systems,
7500 Maehr Road, Waco, Texas 76705,
applied for a Supplemental Type
Certificate (STC) to modify a Boeing
Model 747SP airplane for use as a flying
observatory. This airplane will fly in the
stratosphere to altitudes of 45,000 feet
and use infrared technology to observe
objects in space. The airplane is a
stratospheric observatory for infrared
astronomy or SOFIA. The modification
consists of the installation of a 2.5-meter
telescope, scientist workstations, and
containment vessels for liquid helium
and nitrogen (liquid converters, valves,
evaporating coils, liquid lines,
regulators, indicators, fittings, etc).
Various science instruments (each
having their own airworthiness
approval), each weighing approximately
800 pounds, located in the workstation
area, can be attached to the telescope for
a specific mission (one per mission
only).
The mission of the SOFIA airplane is
to collect infrared signals. The
observatory collects very weak infrared
signals that were emitted by distant
objects in space thousands of years ago.
These signals are focused through the
telescope onto sensors in the science
instrument which is located on the
cabin side of the telescope. To detect the
weak infrared signals, the detectors in
these sensors are cooled to temperatures
near absolute zero by the use of
cryogenic fluids. These fluids are
contained in vessels similar to vacuum
bottles. Their design and installation are
covered by these special conditions.
These extremely cold environments can
only be produced by cryogenic liquids.
The SOFIA observatory depends on
liquid helium and nitrogen to chill the
internal passageways of the detector
systems. The amount of cryogens used
here is small.
Cryogens, in a much greater quantity,
are used in the area where the telescope
mirror is installed. Liquid nitrogen is
converted to a gas and circulated around
the mirror to pre-cool it to prevent it
from fogging up as it goes from a warm
moist atmosphere on the ground to the
cold dry atmosphere at high altitudes.
L–3 Communications/Integrated
Systems has designed the installation to
fly to 45,000 feet and fly in a gradual arc
pattern for extended periods of time.
PO 00000
Frm 00004
Fmt 4702
Sfmt 4702
6599
Additionally, various science
instruments will be installed under this
STC or similar STCs, which will be
referenced back to this STC.
The cryogenic systems must be
designed and installed to ensure that no
failure of the systems, including a leak
in any part of the systems, would
prevent continued safe flight and
landing of the airplane.
There are no specific regulations that
address the design and installation of
liquid nitrogen systems and liquid
helium systems. Existing requirements
such as 14 CFR 25.1309 and 25.1438(b)
are applicable to this installation.
However, the FAA needs to specify
additional design standards for systems
utilizing cryogen liquids to ensure that
a minimum level of safety is
maintained.
Type Certification Basis
Under the provisions of 14 CFR
21.101, L–3 Communications/Integrated
Systems must show that the modified
Boeing Model 747SP airplane, as
changed, continues to meet the
applicable provisions of the regulations
incorporated by reference in Type
Certificate No. A20WE, or the applicable
regulations in effect on the date of
application for the change. The
regulations incorporated by reference in
the type certificate are commonly
referred to as the ‘‘original type
certification basis.’’
If the Administrator finds that the
applicable airworthiness regulations
(i.e., part 25, as amended) do not
contain adequate or appropriate safety
standards for the Boeing Model 747SP
airplane modified by L–3
Communications/Integrated Systems
because of a novel or unusual design
feature, special conditions are
prescribed under the provisions of
§ 21.16.
In addition to the applicable
airworthiness regulations and special
conditions, the Boeing Model 747SP
must comply with the fuel vent exhaust
emission requirements of 14 CFR part
34 and the noise certification
requirements of 14 CFR part 36.
Special conditions, as defined in 14
CFR 11.19, are issued in accordance
with § 11.38 and become part of the type
certification basis in accordance with
§ 21.101.
Special conditions are initially
applicable to the model for which they
are issued. Should L–3
Communications/Integrated Systems
apply at a later date 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
E:\FR\FM\08FEP1.SGM
08FEP1
6600
Federal Register / Vol. 70, No. 25 / Tuesday, February 8, 2005 / Proposed Rules
conditions would also apply to the other
model under the provisions of § 21.101.
Novel or Unusual Design Features
The modified Boeing Model 747SP
will incorporate the following novel or
unusual design features:
1. Cryogenic fluids (liquid nitrogen
and liquid helium) contained in the
science instrument in the cabin
compartment. The cryogenic gases
could cause an asphyxiation hazard to
the crew and passengers.
2. The cryogens (liquid nitrogen),
stored for chilling the mirror during
ascent, might come in contact with the
airplane’s structure, which could cause
damage to the surrounding structural
areas.
Discussion
There are no specific regulations that
address requirements for the use of
liquid cryogens on board airplanes. To
ensure that a minimum level of safety is
achieved equivalent to that intended by
the regulations incorporated by
reference, special conditions are needed
for the Boeing Model 747SP airplane.
These special conditions require
cryogenic systems to be designed and
installed to preclude or minimize the
existence of unsafe conditions that
could result from system leakage,
malfunction, or damage from external
sources. In the event of leakage in the
cabin area, ventilation must be provided
that is adequate to protect crew and
passengers from asphyxiation. The
airplane’s structure must also be
protected from contacting the liquids.
Rotor burst of high-energy equipment
must be considered and adequate
protection must be provided to protect
the liquid containers (either in the cabin
or in the aft telescope area).
Applicability
As discussed above, these special
conditions are applicable to Boeing
747SP airplane. Should L–3
Communications/Integrated Systems
apply at a later date for a supplemental
type certificate to modify any other
model included on Type Certificate No.
A20WE 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 the
Boeing Model 747SP airplane. It is not
a rule of general applicability and it
affects only the applicant who applied
to the FAA for approval of these features
on the airplane.
VerDate jul<14>2003
14:57 Feb 07, 2005
Jkt 205001
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Reporting
and record keeping 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, the Federal Aviation
Administration (FAA) proposes the
following special conditions as part of
the type certification basis for the
Boeing Model 747SP airplane as
modified by L–3 Communications/
Integrated Systems of Waco, Texas:
1. Occupied compartments that
contain cryogenic fluids must be
provided with a means of ventilation to
prevent the accumulation of cryogenic
gases to a level that may cause an
asphyxiation hazard to the crew or
passengers.
2. Cryogen dewars will be limited to
a maximum capacity of 70 liters of
liquid nitrogen and 80 liters of liquid
helium. These limits placed on the
instrument are adequate to allow the
instrument to perform the mission.
3. Pressure relief valves will provide
release of gases to prevent overpressure
of dewars and plumbing lines. The
pressure relief valves shall be vented
overboard through a drain in the bottom
of the airplane unless it is substantiated
that the valves can be safely vented
inside the airplane. The cryogenic
system must be designed to prohibit the
pressure relief valves from freezing due
to air condensing and freezing.
4. Cryogenic equipment and plumbing
installations will be designed such that
a spill, rupture, or any other failure to
contain the liquid cryogen will not
result in direct contact of the liquid
cryogen with load bearing structure or
critical airplane equipment that is
essential for the continued safe flight
and landing of the airplane.
5. An analysis will be accomplished
to substantiate that the airplane will not
be overpressurized in the event of a
catastrophic failure of all the dewars
containing cryogenic fluid.
6. The location of the cryogenic
equipment and plumbing installations
shall minimize the risk of damage due
to an uncontained rotor or fan blade
failure. All equipment containing highenergy rotors must be considered, such
as turbine engines, auxiliary power
units, ram air turbines, electric/
pneumatic engine starters, air cycle
machines, and certain cooling fans. In
addition to properly locating the
cryogenic system, operational
procedures and shields may be used to
minimize the risk of damage. New
PO 00000
Frm 00005
Fmt 4702
Sfmt 4702
equipment containing high-energy
rotors whose uncontained failure could
damage the cryogenic system must
comply with § 25.1461, Amendment 25–
41.
7. The cryogenic system must be
designed to minimize condensation of
the atmospheric air, which could result
in a liquid enriched with oxygen due to
nitrogen having a lower boiling point
than oxygen. Any condensation from
system components or lines will be
collected by drip pans, shields, or other
suitable collection means and drained
overboard through a drain fitting
separate from the pressure relief vent
fittings, if equipped for compliance with
Special Condition No. 3. The
condensation will be isolated from
combustible materials including grease,
oil, and ignition sources.
8. Instructions for continued
airworthiness (ICA) will require
periodic inspection of cryogenic
components. The ICA will also include
periodic inspection of plumbing
insulation to ensure integrity.
9. Shutoff valves will be installed
where multiple cryogenic pressurized
storage vessels are connected together
by manifolds so that a leak in one
pressurized storage vessel will not allow
leakage of the cryogenic fluids from any
other pressurized storage vessel.
10. Cryogenic components must be
burst pressure tested to 3.0 times, and
proof pressure tested to 1.5 times the
maximum normal operating pressure.
Tests shall account for the worst-case
temperature and material strength
properties the components are exposed
to in service.
11. The plumbing installation must be
designed to consider thermal expansion
and thermally induced stresses.
12. The cryogenic system must be
protected from unsafe temperatures and
located where the probability of hazards
of rupture in a crash landing are
minimized.
13. The proof of strength of airframe
load bearing structure in the vicinity of
cryogenic equipment and plumbing
must account for temperature extremes,
and the effect on the strength of
materials, resulting from carriage of
cryogenic fluids.
Issued in Renton, Washington, on January
28, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate,
Aircraft Certification Service.
[FR Doc. 05–2319 Filed 2–7–05; 8:45 am]
BILLING CODE 4910–13–U
E:\FR\FM\08FEP1.SGM
08FEP1
]]>Agencies
[Federal Register Volume 70, Number 25 (Tuesday, February 8, 2005)]
[Proposed Rules]
[Pages 6598-6600]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-2319]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NN301; Notice No. 25-05-01-SC]
Special Conditions: Boeing Model 747SP; NASA Stratospheric
Observatory for Infrared Astronomy (SOFIA); Cryogenic Systems Using
Liquid Nitrogen and Liquid Helium
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed special conditions.
-----------------------------------------------------------------------
SUMMARY: This notice proposes special conditions for the Boeing Model
747SP airplane. This airplane, as modified by L-3 Communications/
Integrated
[[Page 6599]]
Systems of Waco, Texas, will have novel and unusual design features
associated with cryogenic systems using liquid nitrogen and liquid
helium. 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: Comments must be received on or before March 25, 2005.
ADDRESSES: Comments on this proposal may be mailed in duplicate to:
Federal Aviation Administration, Transport Airplane Directorate, Attn:
Rules Docket (ANM-113), Docket No. NN301, 1601 Lind Avenue SW., Renton,
Washington, 98055-4056; or delivered in duplicate to the Transport
Airplane Directorate at the above address. Comments must be marked:
Docket No. NM301. Comments may be inspected in the Rules Docket
weekdays, except Federal holidays, between 7:30 a.m. and 4 p.m.
FOR FURTHER INFORMATION CONTACT: Kathi Ishimaru, FAA, Propulsion/
Mechanical Systems Branch, ANM-112, Transport Airplane Directorate,
Aircraft Certification Service, 1601 Lind Avenue SW., Renton,
Washington, 98055-4056; telephone (425) 227-2674; facsimile (425) 227-
1232.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites interested persons to participate in this
rulemaking by submitting written comments, data, or views. The most
helpful comments reference a specific portion of the special
conditions, explain the reason for any recommended changes, and include
supporting data. We ask that you send us two copies of written
comments.
We will file in the docket all comments we receive, as well as a
report summarizing each substantive public contact with FAA personnel
concerning these special conditions. The docket is available for public
inspection before and after the comment closing date. If you wish to
review the docket in person, go to the address in the ADDRESSES section
of this preamble between 7:30 a.m., and 4 p.m., Monday through Friday,
except Federal holidays.
We will consider all comments we receive on or before the closing
date for comments. We will consider comments filed late if it is
possible to do so without incurring expense or delay. We may change
these special conditions in light of the comments received.
If you want the FAA to acknowledge receipt of your comments on this
proposal, include with your comments a pre-addressed, stamped postcard
on which the docket number appears. We will stamp the date on the
postcard and mail it back to you.
Background
On March 17, 1997, L-3 Communications/Integrated Systems, 7500
Maehr Road, Waco, Texas 76705, applied for a Supplemental Type
Certificate (STC) to modify a Boeing Model 747SP airplane for use as a
flying observatory. This airplane will fly in the stratosphere to
altitudes of 45,000 feet and use infrared technology to observe objects
in space. The airplane is a stratospheric observatory for infrared
astronomy or SOFIA. The modification consists of the installation of a
2.5-meter telescope, scientist workstations, and containment vessels
for liquid helium and nitrogen (liquid converters, valves, evaporating
coils, liquid lines, regulators, indicators, fittings, etc). Various
science instruments (each having their own airworthiness approval),
each weighing approximately 800 pounds, located in the workstation
area, can be attached to the telescope for a specific mission (one per
mission only).
The mission of the SOFIA airplane is to collect infrared signals.
The observatory collects very weak infrared signals that were emitted
by distant objects in space thousands of years ago. These signals are
focused through the telescope onto sensors in the science instrument
which is located on the cabin side of the telescope. To detect the weak
infrared signals, the detectors in these sensors are cooled to
temperatures near absolute zero by the use of cryogenic fluids. These
fluids are contained in vessels similar to vacuum bottles. Their design
and installation are covered by these special conditions. These
extremely cold environments can only be produced by cryogenic liquids.
The SOFIA observatory depends on liquid helium and nitrogen to chill
the internal passageways of the detector systems. The amount of
cryogens used here is small.
Cryogens, in a much greater quantity, are used in the area where
the telescope mirror is installed. Liquid nitrogen is converted to a
gas and circulated around the mirror to pre-cool it to prevent it from
fogging up as it goes from a warm moist atmosphere on the ground to the
cold dry atmosphere at high altitudes.
L-3 Communications/Integrated Systems has designed the installation
to fly to 45,000 feet and fly in a gradual arc pattern for extended
periods of time. Additionally, various science instruments will be
installed under this STC or similar STCs, which will be referenced back
to this STC.
The cryogenic systems must be designed and installed to ensure that
no failure of the systems, including a leak in any part of the systems,
would prevent continued safe flight and landing of the airplane.
There are no specific regulations that address the design and
installation of liquid nitrogen systems and liquid helium systems.
Existing requirements such as 14 CFR 25.1309 and 25.1438(b) are
applicable to this installation. However, the FAA needs to specify
additional design standards for systems utilizing cryogen liquids to
ensure that a minimum level of safety is maintained.
Type Certification Basis
Under the provisions of 14 CFR 21.101, L-3 Communications/
Integrated Systems must show that the modified Boeing Model 747SP
airplane, as changed, continues to meet the applicable provisions of
the regulations incorporated by reference in Type Certificate No.
A20WE, or the applicable regulations in effect on the date of
application for the change. The regulations incorporated by reference
in the type certificate are commonly referred to as the ``original type
certification basis.''
If the Administrator finds that the applicable airworthiness
regulations (i.e., part 25, as amended) do not contain adequate or
appropriate safety standards for the Boeing Model 747SP airplane
modified by L-3 Communications/Integrated Systems because of a novel or
unusual design feature, special conditions are prescribed under the
provisions of Sec. 21.16.
In addition to the applicable airworthiness regulations and special
conditions, the Boeing Model 747SP must comply with the fuel vent
exhaust emission requirements of 14 CFR part 34 and the noise
certification requirements of 14 CFR part 36.
Special conditions, as defined in 14 CFR 11.19, are issued in
accordance with Sec. 11.38 and become part of the type certification
basis in accordance with Sec. 21.101.
Special conditions are initially applicable to the model for which
they are issued. Should L-3 Communications/Integrated Systems apply at
a later date 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
[[Page 6600]]
conditions would also apply to the other model under the provisions of
Sec. 21.101.
Novel or Unusual Design Features
The modified Boeing Model 747SP will incorporate the following
novel or unusual design features:
1. Cryogenic fluids (liquid nitrogen and liquid helium) contained
in the science instrument in the cabin compartment. The cryogenic gases
could cause an asphyxiation hazard to the crew and passengers.
2. The cryogens (liquid nitrogen), stored for chilling the mirror
during ascent, might come in contact with the airplane's structure,
which could cause damage to the surrounding structural areas.
Discussion
There are no specific regulations that address requirements for the
use of liquid cryogens on board airplanes. To ensure that a minimum
level of safety is achieved equivalent to that intended by the
regulations incorporated by reference, special conditions are needed
for the Boeing Model 747SP airplane.
These special conditions require cryogenic systems to be designed
and installed to preclude or minimize the existence of unsafe
conditions that could result from system leakage, malfunction, or
damage from external sources. In the event of leakage in the cabin
area, ventilation must be provided that is adequate to protect crew and
passengers from asphyxiation. The airplane's structure must also be
protected from contacting the liquids. Rotor burst of high-energy
equipment must be considered and adequate protection must be provided
to protect the liquid containers (either in the cabin or in the aft
telescope area).
Applicability
As discussed above, these special conditions are applicable to
Boeing 747SP airplane. Should L-3 Communications/Integrated Systems
apply at a later date for a supplemental type certificate to modify any
other model included on Type Certificate No. A20WE 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 the Boeing Model 747SP airplane. It is not a rule of general
applicability and it 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 record keeping
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, the Federal Aviation Administration (FAA) proposes the
following special conditions as part of the type certification basis
for the Boeing Model 747SP airplane as modified by L-3 Communications/
Integrated Systems of Waco, Texas:
1. Occupied compartments that contain cryogenic fluids must be
provided with a means of ventilation to prevent the accumulation of
cryogenic gases to a level that may cause an asphyxiation hazard to the
crew or passengers.
2. Cryogen dewars will be limited to a maximum capacity of 70
liters of liquid nitrogen and 80 liters of liquid helium. These limits
placed on the instrument are adequate to allow the instrument to
perform the mission.
3. Pressure relief valves will provide release of gases to prevent
overpressure of dewars and plumbing lines. The pressure relief valves
shall be vented overboard through a drain in the bottom of the airplane
unless it is substantiated that the valves can be safely vented inside
the airplane. The cryogenic system must be designed to prohibit the
pressure relief valves from freezing due to air condensing and
freezing.
4. Cryogenic equipment and plumbing installations will be designed
such that a spill, rupture, or any other failure to contain the liquid
cryogen will not result in direct contact of the liquid cryogen with
load bearing structure or critical airplane equipment that is essential
for the continued safe flight and landing of the airplane.
5. An analysis will be accomplished to substantiate that the
airplane will not be overpressurized in the event of a catastrophic
failure of all the dewars containing cryogenic fluid.
6. The location of the cryogenic equipment and plumbing
installations shall minimize the risk of damage due to an uncontained
rotor or fan blade failure. All equipment containing high-energy rotors
must be considered, such as turbine engines, auxiliary power units, ram
air turbines, electric/pneumatic engine starters, air cycle machines,
and certain cooling fans. In addition to properly locating the
cryogenic system, operational procedures and shields may be used to
minimize the risk of damage. New equipment containing high-energy
rotors whose uncontained failure could damage the cryogenic system must
comply with Sec. 25.1461, Amendment 25-41.
7. The cryogenic system must be designed to minimize condensation
of the atmospheric air, which could result in a liquid enriched with
oxygen due to nitrogen having a lower boiling point than oxygen. Any
condensation from system components or lines will be collected by drip
pans, shields, or other suitable collection means and drained overboard
through a drain fitting separate from the pressure relief vent
fittings, if equipped for compliance with Special Condition No. 3. The
condensation will be isolated from combustible materials including
grease, oil, and ignition sources.
8. Instructions for continued airworthiness (ICA) will require
periodic inspection of cryogenic components. The ICA will also include
periodic inspection of plumbing insulation to ensure integrity.
9. Shutoff valves will be installed where multiple cryogenic
pressurized storage vessels are connected together by manifolds so that
a leak in one pressurized storage vessel will not allow leakage of the
cryogenic fluids from any other pressurized storage vessel.
10. Cryogenic components must be burst pressure tested to 3.0
times, and proof pressure tested to 1.5 times the maximum normal
operating pressure. Tests shall account for the worst-case temperature
and material strength properties the components are exposed to in
service.
11. The plumbing installation must be designed to consider thermal
expansion and thermally induced stresses.
12. The cryogenic system must be protected from unsafe temperatures
and located where the probability of hazards of rupture in a crash
landing are minimized.
13. The proof of strength of airframe load bearing structure in the
vicinity of cryogenic equipment and plumbing must account for
temperature extremes, and the effect on the strength of materials,
resulting from carriage of cryogenic fluids.
Issued in Renton, Washington, on January 28, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 05-2319 Filed 2-7-05; 8:45 am]
BILLING CODE 4910-13-U
