[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]
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