[Federal Register Volume 61, Number 124 (Wednesday, June 26, 1996)]
[Proposed Rules]
[Pages 33050-33052]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-16243]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-NM-226-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the supersedure of an existing
airworthiness directive (AD), applicable to certain Boeing Model 747
and 767 series
[[Page 33051]]
airplanes, that currently requires inspection of the door opening
thrusters and door opening/snubbing actuators for proper oil quantity,
and modification of the off-wing compartment latching assemblies. This
action would add a requirement for replacement of the currently
installed door opening thrusters with new, improved thrusters for Model
747 series airplanes. This action also would remove Model 767 series
airplanes from the applicability of the existing AD. This proposal is
prompted by reports indicating that the requirements of the existing AD
do not adequately preclude leakage of fluid from the actuators. The
actions specified by the proposed AD are intended to prevent such
leakage, which could result in failure of the escape slide to deploy;
such failure could delay and possibly jeopardize the successful
emergency evacuation of an airplane.
DATES: Comments must be received by August 5, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 95-NM-226-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056. Comments may be inspected at this
location between 9 a.m. and 3 p.m., Monday through Friday, except
Federal holidays.
The service information referenced in the proposed rule may be
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle,
Washington 98124-2207. This information may be examined at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington.
FOR FURTHER INFORMATION CONTACT: Gregory L. Schneider, Aerospace
Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft
Certification Office, 1601 Lind Avenue, SW., Renton, Washington;
telephone (206) 227-2028; fax (206) 227-1181.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed rule by submitting such written data, views, or arguments as
they may desire. Communications shall identify the Rules Docket number
and be submitted in triplicate to the address specified above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this notice may be changed in
light of the comments received.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed rule. All
comments submitted will be available, both before and after the closing
date for comments, in the Rules Docket for examination by interested
persons. A report summarizing each FAA-public contact concerned with
the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 95-NM-226-AD.'' The postcard will be date stamped and
returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules
Docket No. 95-NM-226-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
On July 15, 1992, the FAA issued AD 92-16-17, amendment 39-8327 (57
FR 47987, October 21, 1992), which is applicable to certain Model 747
and 767 series airplanes. That AD requires repetitive inspections
(weighing program) of the door opening thrusters and door opening/
snubbing actuators for proper oil quantity, and modification of the
off-wing compartment latching assemblies. That action was prompted by
reports of failure of the off-wing escape slide system to deploy when
commanded. The requirements of that AD are intended to prevent such
failure, which could delay and possibly jeopardize the successful
emergency evacuation of an airplane.
Actions Since Issuance of Previous Rule
Since the issuance of that AD, the FAA received a report from an
operator of Model 767 series airplanes indicating that several
actuators leaked following accomplishment of the modification required
by AD 92-16-17. Consequently, the FAA determined that the modification
requirements of that AD do not adequately preclude leakage from the
actuators. Additionally, the operator reported that, during inspections
(weighing program) of the actuators, the weight of several actuators
increased from the original weight measured during the initial
inspection required by AD 92-16-17. Therefore, the FAA determined that
the inspection requirements of AD 92-16-17 cannot reliably determine
the fluid level of these actuators.
Subsequently, the manufacturer developed a new, improved actuator
for Model 767 series airplanes. On April 10, 1995, the FAA issued AD
95-08-11, amendment 39-9200 (60 FR 20013, April 24, 1995), to require
replacement of the currently installed door opening actuators of the
off-wing emergency escape system on Model 767 series airplanes with
new, improved actuators. Accomplishment of that replacement constitutes
terminating action for the repetitive inspections (weighing program) of
the door opening/snubbing actuators for those airplanes. The FAA
indicated in AD 95-08-11 that it was considering a separate rulemaking
action to remove the requirements for Model 767 series airplanes from
AD 92-16-17.
The door opening thrusters installed on Model 747 series airplanes
are similar in design to the door opening/snubbing actuators installed
on Model 767 series airplanes in that both require a small quantity of
oil to operate, and both have a tendency to leak oil from the chamber.
Such leakage can result in failure of an actuator or thruster.
Explanation of Relevant Service Information
Boeing has issued Service Bulletin 747-25-3073, dated September 21,
1995, which describes procedures for replacement of existing door
opening thrusters on Model 747 series airplanes with new, improved
thrusters. Since the new, improved thruster is not fluid filled,
accomplishment of the replacement eliminates the need for inspections
of the door opening thrusters and door opening/snubbing actuators for
proper oil quantity.
Explanation of Requirements of Proposed Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other products of this same type design, the
proposed AD would supersede AD 92-16-17 to continue to require
repetitive inspections of the door opening thrusters and door opening/
snubbing actuators for proper oil quantity, and modification of the
off-wing compartment latching assemblies for Model 747 series
airplanes. For those airplanes, this proposed AD would add a
requirement for replacement of existing door opening thrusters with
new, improved thrusters. Accomplishment of the replacement constitutes
terminating action for the repetitive inspections. The actions would be
required to be accomplished
[[Page 33052]]
in accordance with the service bulletin described previously.
Additionally, the proposed AD would remove Model 767 series
airplanes from the applicability of the existing AD, since the subject
unsafe condition on those airplanes is addressed in AD 95-08-11.
Cost Impact
There are approximately 400 Model 747 series airplanes of the
affected design in the worldwide fleet. The FAA estimates that 125
airplanes of U.S. registry would be affected by this proposed AD.
The actions that are currently required by AD 92-16-17 take
approximately 12 work hours per airplane to accomplish, at an average
labor rate of $60 per work hour. Required parts cost approximately $510
per airplane. Based on these figures, the cost impact on U.S. operators
of the actions currently required is estimated to be $153,750, or
$1,230 per airplane.
The new actions that are proposed in this AD action would take
approximately 2 work hours per airplane to accomplish, at an average
labor rate of $60 per work hour. Required parts would cost
approximately $6,400 per airplane. Based on these figures, the cost
impact on U.S. operators of the proposed requirements of this AD is
estimated to be $815,000, or $6,520 per airplane.
The cost impact figures discussed above are based on assumptions
that no operator has yet accomplished any of the current or proposed
requirements of this AD action, and that no operator would accomplish
those actions in the future if this AD were not adopted.
Regulatory Impact
The regulations proposed herein would 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
proposal would not have sufficient federalism implications to warrant
the preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this proposed
regulation (1) is not a ``significant regulatory action'' under
Executive Order 12866; (2) is not a ``significant rule'' under the DOT
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979);
and (3) if promulgated, will not have a significant economic impact,
positive or negative, on a substantial number of small entities under
the criteria of the Regulatory Flexibility Act. A copy of the draft
regulatory evaluation prepared for this action is contained in the
Rules Docket. A copy of it may be obtained by contacting the Rules
Docket at the location provided under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
part 39 of the Federal Aviation Regulations (14 CFR part 39) as
follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing amendment 39-8327 (57 FR
47987, October 21, 1992), and by adding a new airworthiness directive
(AD), to read as follows:
Boeing: Docket 95-NM-226-AD. Supersedes AD 92-16-17, Amendment 39-
8327.
Applicability: Model 747-100, -200, and -300 series airplanes
equipped with an off-wing, two-piece escape slide on Door 3;
certificated in any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
otherwise modified, altered, or repaired in the area subject to the
requirements of this AD. For airplanes that have been modified,
altered, or repaired so that the performance of the requirements of
this AD is affected, the owner/operator must request approval for an
alternative method of compliance in accordance with paragraph (e) of
this AD. The request should include an assessment of the effect of
the modification, alteration, or repair on the unsafe condition
addressed by this AD; and, if the unsafe condition has not been
eliminated, the request should include specific proposed actions to
address it.
Compliance: Required as indicated, unless accomplished
previously.
To prevent failure of the escape slide to deploy, which could
delay and possibly jeopardize the successful emergency evacuation of
an airplane, accomplish the following:
(a) Within 18 months after November 25, 1992 (the effective date
of AD 92-16-17, amendment 39-8327), perform an inspection of the
door opening thrusters of the escape system in accordance with OEA
Service Bulletin 2174200-25-013, dated July 29, 1991. Repeat this
inspection thereafter at intervals not to exceed 20 months until the
replacement required by paragraph (c) of this AD is accomplished.
(b) Within 18 months after November 25, 1992, inspect and modify
the door latching mechanism of the escape slide compartment in
accordance with Boeing Service Bulletin 747-25-2951, dated August
15, 1991.
(c) Within 2 years after the effective date of this AD, replace
the door opening thrusters having part number (P/N) 60B50077-14 or -
17 with new thrusters having P/N 60B50077-19 in accordance with
Boeing Service Bulletin 747-25-3073, dated September 21, 1995.
Accomplishment of this replacement terminates the repetitive
inspections required by this AD.
(d) As of the effective date of this AD, no person shall install
a door opening thruster having P/N 60B50077-14 or -17 on any
airplane.
(e) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used if approved by the Manager, Seattle Aircraft Certification
Office (ACO), FAA, Transport Airplane Directorate. Operators shall
submit their requests through an appropriate FAA Principal
Maintenance Inspector, who may add comments and then send it to the
Manager, Seattle ACO.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
(f) Special flight permits may be issued in accordance with
sections 21.197 and 21.199 of the Federal Aviation Regulations (14
CFR 21.197 and 21.199) to operate the airplane to a location where
the requirements of this AD can be accomplished.
Issued in Renton, Washington, on June 19, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-16243 Filed 6-25-96; 8:45 am]
BILLING CODE 4910-13-U
