[Federal Register Volume 59, Number 167 (Tuesday, August 30, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-21293]
[[Page Unknown]]
[Federal Register: August 30, 1994]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 94-NM-91-AD]
Airworthiness Directives; Boeing Model 767 Series Airplanes
Equipped With Off-Wing Escape Slides
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to certain Boeing Model 767 series
airplanes. This proposal would require replacement of the currently
installed door opening actuators of the emergency off-wing escape
system with new, improved actuators. This proposal is prompted by
reports indicating that the requirements of a previously issued AD do
not adequately preclude leakage from these actuators. The actions
specified by the proposed AD are intended to prevent failure of the
escape slide to deploy, which could delay and possibly jeopardize
successful emergency evacuation of an airplane.
DATES: Comments must be received by October 24, 1994.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 94-NM-91-AD, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056. Comments may be inspected at this location
between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal
holidays.
The service information referenced in the proposed rule may be
obtained from OEA, Inc., P.O. Box 100488, Denver, Colorado 80250; and
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: Jayson Claar, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (206) 227-2784; 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 94-NM-91-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. 94-NM-91-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), applicable to certain Boeing Model 747 and
Model 767 series airplanes. That AD requires repetitive inspections
(weighing program) of the door opening/snubbing actuators of the escape
system (for Model 747 series airplanes) and the door opening/snubbing
actuators of the off-wing escape slide (for Model 767 series
airplanes), and modification of the door latching mechanism of the
escape slide compartment.
Since the issuance of that AD, the FAA has received a report from
an operator of Model 767 series airplanes that several actuators leaked
following accomplishment of the modification procedures required by AD
92-16-17. Therefore, the FAA has determined that the modification
requirements of AD 92-16-17 do not adequately preclude leakage from
these actuators.
Additionally, this operator also reported that, during subsequent
inspections (weighing program) of these actuators, the weight in
several actuators increased from the original weight measured during
the initial inspection (weighing program) required by AD 92-16-17.
Therefore, the FAA finds that the inspection requirements of AD 92-16-
17 cannot reliably determine the fluid level of these actuators by the
weighing program.
Further, since the issuance of AD 92-16-17, the manufacturer has
developed a new, improved actuator for Model 767 series airplanes.
These new actuators are not fluid-filled. The old actuators were fluid-
filled and had a tendency to leak, which caused the actuator to fail.
Failure of the door opening/snubbing actuator, if not corrected,
could result in the escape slide failing to deploy, which could delay
and possibly jeopardize the successful emergency evacuation of an
airplane.
The FAA has reviewed and approved Boeing Service Bulletin 767-25-
0216, dated February 3, 1994, which describes procedures for
replacement of currently installed door opening actuators of the off-
wing emergency escape system with new, improved actuators.
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 require replacement of the currently installed door
opening actuators of the emergency off-wing escape system on Model 767
series airplanes with new, improved actuators. The actions would be
required to be accomplished in accordance with the service bulletin
described previously.
The requirements of AD 92-16-17 to inspect the door opening/
snubbing actuators of the off-wing escape slide, and modify and inspect
the door latching mechanism of the escape slide compartment of Model
767 series airplanes have been retained in this proposal. However,
accomplishment of the proposed actuator replacement would constitute
terminating action for those requirements. Accordingly, the FAA will,
in a separate rulemaking action, revise AD 92-16-17 to remove these
requirements for Model 767 series airplanes from that AD.
There are approximately 460 Boeing Model 767 series airplanes of
the affected design in the worldwide fleet. The FAA estimates that 173
airplanes of U.S. registry would be affected by this proposed AD.
The inspections and modification currently required by AD 92-16-17,
and retained in this proposal, take approximately 12 work hours per
airplane to accomplish, at an average labor rate of $55 per work hour.
Required parts cost approximately $510 per airplane. Based on these
figures, the total cost impact of these inspections and modification on
U.S. operators is estimated to be $146,250, or $1,170 per airplane.
The proposed replacement would take approximately 2 work hours per
airplane at an average labor rate of $55 per work hour. Required parts
would cost approximately $6,400 per airplane. Based on these figures,
the total cost impact of the proposed replacement on U.S. operators is
estimated to be $1,126,230, or $6,510 per airplane.
The total cost impact figure discussed above is based on
assumptions that no operator has yet accomplished any of the proposed
requirements of this AD action, and that no operator would accomplish
those actions in the future if this AD were not adopted.
The FAA recognizes that the obligation to maintain aircraft in an
airworthy condition is vital, but sometimes expensive. Because AD's
require specific actions to address specific unsafe conditions, they
appear to impose costs that would not otherwise be borne by operators.
However, because of the general obligation of operators to maintain
aircraft in an airworthy condition, this appearance is deceptive.
Attributing those costs solely to the issuance of this AD is
unrealistic because, in the interest of maintaining safe aircraft, most
prudent operators would accomplish the required actions even if they
were not required to do so by the AD.
A full cost-benefit analysis has not been accomplished for this
proposed AD. As a matter of law, in order to be airworthy, an aircraft
must conform to its type design and be in a condition for safe
operation. The type design is approved only after the FAA makes a
determination that it complies with all applicable airworthiness
requirements. In adopting and maintaining those requirements, the FAA
has already made the determination that they establish a level of
safety that is cost-beneficial. When the FAA, as in this proposed AD,
makes a finding of an unsafe condition, this means that this cost-
beneficial level of safety is no longer being achieved and that the
proposed actions are necessary to restore that level of safety. Because
this level of safety has already been determined to be cost-beneficial,
a full cost-benefit analysis for this proposed AD would be redundant
and unnecessary.
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. App. 1354(a), 1421 and 1423; 49 U.S.C.
106(g); and 14 CFR 11.89.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
Boeing: Docket 94-NM-91-AD.
Applicability: Model 767 series airplanes equipped with off-wing
escape slides, certificated in any category.
Compliance: Required as indicated, unless accomplished
previously.
To prevent failure of the escape slide to deploy, which could
delay and possibly jeopardize 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), inspect the off-wing escape
slide door opening/snubbing actuators in accordance with OEA Service
Bulletin 3092100-25-002, dated July 26, 1991. Repeat this inspection
thereafter at intervals not to exceed 20 months until the
replacement required by paragraph (c) is accomplished. For operators
that have previously accomplished this inspection in accordance with
AD 92-16-17: This paragraph requires that the next scheduled
inspection be performed within 20 months after the last inspection
performed in accordance with paragraph (b)(1) of AD 92-16-17.
(b) Within 18 months after November 25, 1992 (the effective date
of AD 92-16-17, amendment 39-8327), inspect and modify the escape
slide compartment door latching mechanism in accordance with Boeing
Alert Service Bulletin 767-25A0174, dated August 15, 1991.
Accomplishment of the actions required by this paragraph prior to
the effective date of this AD terminates the actions required by
paragraph (b)(2) of AD 92-16-17.
(c) Within 2 years after the effective date of this AD, replace
the currently installed door opening actuator of the emergency off-
wing escape system with a new, improved actuator, in accordance with
Boeing Service Bulletin 767-25-0216, dated February 3, 1994.
Accomplishment of this replacement terminates the repetitive
inspection requirements of paragraph (a) of this AD.
(d) As of 2 years after the effective date of this AD, only door
opening actuators of the emergency off-wing escape system having OEA
part number 5262100 (Boeing part number 5416T208-12) shall be
installed 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: 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 August 23, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 94-21293 Filed 8-29-94; 8:45 am]
BILLING CODE 4910-13-P
