[Federal Register Volume 59, Number 81 (Thursday, April 28, 1994)]
[Unknown Section]
[Page ]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-10168]
[Federal Register: April 28, 1994]
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Part VII
Department of Transportation
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Federal Aviation Administration
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14 CFR Part 25
Design Standards for Airplane Jacking and Tie-Down Provision; Final
Rule
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. 26129; Amdt. No. 25-81]
RIN 2120-AD38
Design Standards for Airplane Jacking and Tie-Down Provisions
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment to the airworthiness standards for transport
category airplanes adds a new design standard for airplane jacking and
tie-down provisions. This amendment is needed to provide manufacturers
with design standards for jacking conditions and is intended to protect
primary airplane structure during jacking operations and from gusty
wind conditions while tied down.
EFFECTIVE DATE: May 31, 1994.
FOR FURTHER INFORMATION CONTACT:
Iven Connally, FAA, Airframe and Propulsion Branch (ANM-112), Transport
Airplane Directorate, Aircraft Certification Service, 1601 Lind Avenue
SW, Renton, WA 98055-4056; telephone (206) 227-2120.
SUPPLEMENTARY INFORMATION:
Background
This amendment is based on Notice of Proposed Rulemaking (NPRM) 90-
3, which was published in the Federal Register on February 9, 1990 (55
FR 4790). The notice was predicated on a need to protect primary
airplane structure from damage during jacking operations and during
gusty wind conditions.
Airplane jacking is achieved by either lifting on the airframe or
on the landing gear. In some instances, the airplane has either slipped
off the jacks or been blown off during gusty wind conditions. Also,
some transport category airplanes have tie-down provisions to restrain
the airplane during high wind conditions. Damage to primary structure
could result if the tie-down provisions were not designed to withstand
likely wind gusts.
Most manufacturers of transport category airplanes provide
information and instructions concerning jacking operations in addition
to providing appropriate jacking points on the airplane. However,
currently there is no requirement in the airworthiness standards for
transport category airplane designs to account for jacking or tie-down
loads. In the absence of specific standards, some manufacturers have
used jacking and tie-down criteria contained in military specifications
to design the airframe and landing gear of commercial transport
category airplanes. Others, primarily the manufacturers of smaller
transport category airplanes, have requested design criteria for
jacking and tie-down loads.
While the FAA is not aware of any existing airplanes that are
inadequately designed with respect to jacking and tie-down provisions,
it is conceivable that an airplane with inadequately designed jacking
and tie-down provisions may be certificated in the absence of specific
regulatory requirements. Structural damage at the jacking or tie-down
points could pose an immediate hazard while the airplane is on the
ground. Even if an airplane does not fall off the jacks, there is the
possibility that damage to primary structure could occur from the
static loads applied at inadequately designed jacking points. In
addition, there is a danger that the damage could remain undetected and
lead to a catastrophic structural failure during a subsequent flight.
Undetected damage from inadequately designed tie-down provisions poses
a similar hazard.
These concerns resulted in Notice 90-3 in which the FAA proposed to
require transport category airplanes to have suitable provisions for
jacking. In essence, standards consistent with current industry
practice were proposed to provide protection of primary airplane
structure from loads imposed during probable jacking conditions. As
there is no requirement for tie-down provisions, the FAA also proposed
to adopt standards to provide protection of primary airplane structure
in the event such provisions are provided. This standard is also
consistent with current industry practice.
Interested persons have been given an opportunity to participate in
this rulemaking and due consideration has been given to all matters
presented. Comments received in response to Notice 90-3 are discussed
below.
Discussion of Comments
The proposed standards are based on established military and
commercial airplane standards and on current industry practice and
therefore received general support from all commenters.
The European Joint Aviation Authorities (JAA) suggest the
requirements of JAR 25.519 (Joint Airworthiness Requirements) be
adopted as Sec. 25.519 of the Federal Aviation Regulations (FAR),
offering as justification the favorable service history associated with
the JAR.
The JAR standards differ from the proposals in Notice 90-3 in that
the load factors used in establishing the vertical and horizontal
jacking forces are slightly less. The wind force used to establish the
tie-down loads is also slightly less. Although the JAR standard is less
conservative than the proposed FAR standard, there is sufficient
satisfactory service experience based on the requirements of JAR 25.519
to justify its adoption as the basis for the FAR standard.
Additionally, some clarifying changes from the current JAR standard are
made in order to define clearly the structures to which the jacking
load factors apply. The word ``surrounding'' is changed to ``local'' to
differentiate between local structure and the entire airplane
structure. Also, since the maximum design weight, in this case, is the
maximum ramp weight, the rule is revised to avoid any confusion over
the weight to use in analyzing the support structure. These minor
changes in the final rule will more fully harmonize the FAR and JAR
requirements. The JAA also suggests that the introduction of jacking
requirements in Sec. 25.513 of the FAR, which corresponds with
requirements in JAR 25.519, could cause confusion. The FAA agrees, and
for consistency with the JAR, the jacking requirement has been moved
from proposed Sec. 25.513 of the FAR to Sec. 25.519.
One commenter recommends that consideration be given to
incorporating a design requirement to improve the airplane's ability to
maintain contact with the jack head. The FAA has determined that the
high side load requirements for the jack fittings achieves this
objective and should provide ample protection against an airplane
slipping off the jacks.
One commenter recommends the development of standards requiring the
use of jacks when working on aircraft with known landing gear problems.
The commenter cites an instance in which an airplane that had made a
gear up landing was parked with the gear down in an unrepaired
condition. Two pilots, while inspecting the airplane for damage, were
crushed when the gear collapsed. The FAA considers the concern
expressed by the commenter to relate to maintenance or salvage
procedures. Since such procedures are not the subject of certification
requirements, they are beyond the scope of the notice.
One operator suggests that the regulation include a requirement for
the manufacturer to provide specific jacking requirements in the
Structural Repair Manual and the Maintenance Manual, and that these
requirements include specific loads at each jack pad for various empty
weights and center of gravity locations. The manufacturers generally do
provide jacking instructions, including jack pad load limits, in the
maintenance and structural repair manuals which are approved as part of
the overall maintenance program. While the FAA does not consider it
necessary to mandate where the manufacturer places this information,
the final rule has been revised to require that load limit information
must be provided.
Regulatory Evaluation
This section summarizes the full regulatory evaluation prepared by
the FAA that provides more detailed estimates of the economic
consequences of this regulatory action. This summary and the full
evaluation quantify, to the extent practicable, estimated costs to the
private sector, consumers, Federal, State and local governments, as
well as anticipated benefits.
Proposed changes to Federal regulations must undergo several
economic analyses. First, Executive Order 12866 directs that each
Federal agency shall propose or adopt a regulation only upon a reasoned
determination that the benefits of the intended regulation justify its
costs. Second, the Regulatory Flexibility Act of 1980 requires agencies
to analyze the economic effect of regulatory changes on small entities.
Third, the Office of Management and Budget directs agencies to assess
the effects of regulatory changes on international trade. In conducting
these analyses, the FAA has determined that this rule: (1) Will
generate benefits that justify its costs and is not a ``significant
regulatory action'' as defined in the Executive Order, (2) is not
significant as defined in Department of Transportation Regulatory
Policies and Procedures; (3) will not have a significant impact on a
substantial number of small entities; and (4) will not constitute a
barrier to international trade. These analyses, available in the
docket, are summarized below.
Benefits
The FAA is unaware of any existing airplanes that are inadequately
designed with respect to jacking or tie-down provisions. In the absence
of specific regulatory standards, it is possible that an airplane with
inadequate design standards for jacking and tie-down could be
certificated. Structural damage at the jacking or tie-down points of an
inadequately designed airplane could pose a hazard while the airplane
is on the ground. More importantly, structural damage at jacking or
tie-down points could remain undetected and lead to catastrophic
structural failure during a subsequent flight. Transport category
airplanes particularly larger airplanes, seldom need to be tied down
for protection from high winds. Nevertheless, reliance on inadequately
designed tie-down provisions could also damage primary structure.
The FAA is unable to document specific instances where the
standards of this rule would have prevented damage to the primary
structure of transport category airplanes, primarily because it is
assumed that existing airplanes are properly designed with respect to
jacking and tie-down provisions. However, the FAA considers that the
potential risk of jacking and tie-down accidents will be reduced for
future airplane designs that might otherwise be built in the absence of
the consistent standards of this amendment. Significant but
unquantified benefits could result from reducing the risk of such
incidents.
Costs
Essentially all manufacturers of transport category airplanes
currently provide appropriate jacking points and jacking instructions
for their airplanes. In the absence of regulatory standards for jacking
and tie-down provisions on transport category airplanes, some
manufacturers have used the jacking and tie-down criteria of military
specifications for designing the airframes and landing gears of
commercial transport category airplanes. Others, primarily the
manufacturers of smaller transport category airplanes, have requested
design criteria for jacking and tie-down loads.
The FAA is not aware of any manufacturers who have not used either
military specifications or other comparable criteria for designing the
airframe and landing gear. Since all large airplanes must be jacked
periodically, reasonable and prudent manufacturers have had little
choice but to follow this course. Because this rule adopts standards
that are consistent with both current and expected industry practice,
it is not expected to result in any significant compliance costs.
Comparison of Costs and Benefits
The FAA is unaware of any existing airplanes that are inadequately
designed with respect to jacking or tie-down provisions. Since this
rule adopts the standards that industry has largely followed, and would
most likely continue to follow, in the absence of this rule, no
significant costs or benefits are expected.
In the absence of specific regulatory standards, it is possible
that an inadequately designed airplane could be certificated. In such a
case, the benefits of reducing the potential risk of jacking and tie-
down accidents would significantly exceed any incremental costs of
compliance. As such, the FAA considers this rule to be cost-beneficial.
Regulatory Flexibility Determination
The Regulatory Flexibility Act of 1980 (RFA) was enacted by
Congress to ensure that small entities are not unnecessarily and
disproportionately burdened by government regulations. The RFA requires
government agencies to review rules which may have ``a significant
economic impact on a substantial number of small entities.''
FAA Order 2100.14A, Regulatory Flexibility Criteria and Guidance,
establishes threshold cost values and small entity size standards for
complying with RFA review requirements in FAA rulemaking actions. This
rule will directly affect transport category airplane manufacturers
that certify their airplanes under part 25. The size standard for
manufacturers of airplanes is 75 employees of fewer. Since no transport
category airplane manufacturer meets the standard, this rule will not
have a significant economic impact on a substantial number of small
entities.
International Trade Impact Assessment
This rule is not expected to have an adverse impact either on the
trade opportunities of U.S. manufacturers of transport category
airplanes doing business abroad or on foreign airplane manufacturers
doing business in the United States. Since the certification rules are
applicable to both foreign and domestic manufacturers selling airplanes
in the United States, there will be no competitive trade advantage to
either.
Federalism Implications
The regulation adopted herein will not have substantial direct
effects on the States, on the relationship between the national
government and the States, or on the distribution of power and
responsibilities among the various levels of government. Therefore, in
accordance with Executive Order 12612, it is determined that this
regulation will not have sufficient federalism implications to warrant
the preparation of a Federalism Assessment.
Conclusion
Because the regulation adopted herein is not expected to result in
significant costs, the FAA has determined that this final rule is not a
significant regulatory action as defined in Executive Order 12866. For
the same reason and because this is an issue that has not prompted a
great deal of public concern, this final rule is not considered to be
significant as defined in Department of Transportation Regulatory
Policies and Procedures (44 FR 11034, February 26, 1979). In addition,
since there are no small entities affected by this rulemaking, it is
certified, under the criteria of the Regulatory Flexibility Act, that
this final rule will not have a significant economic impact, positive
or negative, on a substantial number of small entities. A copy of the
regulatory evaluation prepared for this final rule may be examined in
the public docket or obtained from the person identified under the
caption, for further information contact.
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Federal Aviation Administration,
Reporting and recordkeeping requirements.
Adoption of the Amendment
Accordingly, 14 CFR part 25 of the Federal Aviation Regulations
(FAR) is amended as follows:
PART 25--AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES
1. The authority citation for part 25 continues to read as follows:
Authority: 49 U.S.C. app. 1344, 1354(a), 1355, 1421, 1423, 1424,
1425, 1428, 1429, 1430; 49 U.S.C. 106(g); and 49 CFR 1.47(a).
2. A new Sec. 25.519 is added under the undesignated center heading
``Ground Loads'' to read as follows:
Sec. 25.519 Jacking and tie-down provisions.
(a) General. The airplane must be designed to withstand the limit
load conditions resulting from the static ground load conditions of
paragraph (b) of this section and, if applicable, paragraph (c) of this
section at the most critical combinations of airplane weight and center
of gravity. The maximum allowable load at each jack pad must be
specified.
(b) Jacking. The airplane must have provisions for jacking and must
withstand the following limit loads when the airplane is supported on
jacks--
(1) For jacking by the landing gear at the maximum ramp weight of
the airplane, the airplane structure must be designed for a vertical
load of 1.33 times the vertical static reaction at each jacking point
acting singly and in combination with a horizontal load of 0.33 times
the vertical static reaction applied in any direction.
(2) For jacking by other airplane structure at maximum approved
jacking weight:
(i) The airplane structure must be designed for a vertical load of
1.33 times the vertical reaction at each jacking point acting singly
and in combination with a horizontal load of 0.33 times the vertical
static reaction applied in any direction.
(ii) The jacking pads and local structure must be designed for a
vertical load of 2.0 times the vertical static reaction at each jacking
point, acting singly and in combination with a horizontal load of 0.33
times the vertical static reaction applied in any direction.
(c) Tie-down. If tie-down points are provided, the main tie-down
points and local structure must withstand the limit loads resulting
from a 65-knot horizontal wind from any direction.
Issued in Washington, DC, on April 13, 1994.
David R. Hinson,
Administrator.
[FR Doc. 94-10168 Filed 4-26-94; 8:45 am]
BILLING CODE 4910-13-M
