[Federal Register Volume 63, Number 207 (Tuesday, October 27, 1998)]
[Proposed Rules]
[Pages 57266-57268]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-28665]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-195-AD]
RIN 2120-AA64


Airworthiness Directives; British Aerospace (Jetstream) Model 
4101 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 British Aerospace 
(Jetstream) Model 4101 airplanes, that currently requires repetitive 
detailed visual inspections to detect cracks in the shear cleats of the 
roller guide structural support of the passenger door, and replacement 
of any cracked shear cleat with a new shear cleat. That AD also 
provides for an optional terminating modification that constitutes 
terminating action for the repetitive inspections. This action would 
mandate accomplishment of the previously optional terminating 
modification. This proposal is prompted by reports indicating that 
fatigue cracking was detected in the roller guide shear cleats of the 
passenger door. The actions specified by the proposed AD are intended 
to prevent such fatigue-related cracking, which could result in 
structural failure or loss of the passenger door, and consequent rapid 
depressurization of the airplane during flight.

DATES: Comments must be received by November 27, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 97-N-195-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 AI(R) American Support, Inc., 13850 Mclearen Road, 
Herndon, Virginia 20171. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2110; fax (425) 227-1149.

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 97-NM-195-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-114, Attention: Rules 
Docket No. 97-NM-195-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On July 21, 1997, the FAA issued AD 97-16-01, amendment 39-10090 
(62 FR 40267, July 28, 1997), applicable to certain British Aerospace 
(Jetstream) Model 4101 airplanes, to require repetitive detailed visual 
inspections to detect cracks in the shear cleats of the roller guide 
structural support of the passenger door, and replacement of any 
cracked shear cleat with a new shear cleat. That AD also provides for 
an optional modification that constitutes terminating action for the 
repetitive inspections. That action was prompted by a report indicating 
that fatigue cracking was found in the roller guide shear cleats of the 
passenger door. The requirements of that AD are intended to detect and 
correct such fatigue-related cracking, which could result in structural 
failure of the passenger door, and consequent rapid depressurization of 
the airplane or loss of the passenger door while the airplane is in 
flight.

Actions Since Issuance of Previous Rule

    When AD 97-16-01 was issued, it contained a provision for an 
optional modification of the passenger door which, if accomplished, 
would constitute terminating action for the required repetitive 
inspections. Also, in AD 97-16-01, the FAA indicated that the 
inspections required by that AD were considered ``interim action'' and 
that it was considering further rulemaking action to mandate 
accomplishment of the terminating modification. This action proposes 
such a requirement, to be accomplished in accordance with Jetstream 
Service Bulletin J41-52-050, dated May 6, 1997. (This service bulletin 
was described previously in AD 97-16-01.)

FAA's Conclusions

    This airplane model is manufactured in the United Kingdom and is 
type certificated for operation in the United States under the 
provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 
21.29) and the applicable bilateral airworthiness agreement. Pursuant 
to this bilateral airworthiness agreement, the Civil Aviation Authority 
(CAA), which is the airworthiness authority for the United Kingdom, has 
kept the FAA informed of the situation described above. The FAA has 
examined the findings of the CAA, reviewed all available information, 
and determined that AD action is indeed necessary for products of this 
type design that are certificated for operation in the United States.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design registered 
in the United States, the proposed AD would supersede AD 97-16-01 to 
continue to require repetitive detailed visual inspections to detect 
cracks in the shear cleats of the roller guide structural support of 
the passenger door, and replacement of any cracked shear cleat with a 
new shear cleat. In addition, the proposed AD would mandate 
accomplishment of the previously optional terminating modification.

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Differences Between Proposed Rule and Service Bulletin

    Operators should note that this AD proposes to mandate the 
modification of the passenger door described in Jetstream Service 
Bulletin J41-52-050 as terminating action for the repetitive 
inspections. Incorporation of this terminating action was classified as 
optional in this service bulletin.
    The FAA has determined that long-term continued operational safety 
will be better assured by design changes to remove the source of the 
problem, rather than by repetitive inspections. Long-term inspections 
may not be providing the degree of safety assurance necessary for the 
transport airplane fleet. This, coupled with a better understanding of 
the human factors associated with numerous continual inspections, has 
led the FAA to consider placing less emphasis on inspections and more 
emphasis on design improvements. The proposed modification requirement 
is in consonance with these conditions.

Cost Impact

    There are approximately 57 airplanes of U.S. registry that would be 
affected by this proposed AD.
    The inspections that are currently required by AD 97-16-01, and 
retained in this proposed AD, take approximately 3 work hours per 
airplane to accomplish, at an average labor rate of $60 per work hour. 
Based on these figures, the cost impact of the currently required 
inspections on U.S. operators is estimated to be $10,260, or $180 per 
airplane, per inspection cycle.
    The new modification that is proposed by this AD action would take 
approximately 55 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Required parts would cost 
approximately $2,460 per airplane. Based on these figures, the cost 
impact of the modification proposed by this AD on U.S. operators is 
estimated to be $328,320, or $5,760 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 39-10090 (62 FR 
40267, July 28, 1997), and by adding a new airworthiness directive 
(AD), to read as follows:

British Aerospace Regional Aircraft [Formerly Jetstream Aircraft 
Limited; British Aerospace (Commercial Aircraft) Limited]: Docket 
97-NM-195-AD. Supersedes AD 97-16-01, Amendment 39-10090.

    Applicability: Jetstream Model 4101 airplanes, constructor's 
numbers 41004 through 41099 inclusive; certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
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 (d) 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 fatigue-related cracking in the shear cleats of the 
roller guide structural support of the passenger door, which could 
result in structural failure or loss of the passenger door, and 
consequent rapid depressurization of the airplane during flight, 
accomplish the following:

Restatement of Reqirements of AD 97-16-01

    (a) Except as provided by paragraph (b) of this AD: Prior to the 
accumulation of 6,000 landings, or within 60 days after August 12, 
1997 (the effective date of AD 97-16-01, amendment 39-10090), 
whichever occurs later, perform a detailed visual inspection to 
detect cracks of the shear cleats of the roller guide structural 
support of the passenger door, in accordance with Part 1 of the 
Accomplishment Instructions of Jetstream Alert Service Bulletin J41-
A52-043, Revision 2, dated May 6, 1997. Repeat the detailed visual 
inspection, as specified in Part 2 of the Accomplishment 
Instructions of the alert service bulletin, thereafter at intervals 
not to exceed 1,500 landings.

    Note 2: Accomplishment of the initial detailed visual inspection 
prior to August 12, 1997, in accordance with Jetstream Alert Service 
Bulletin J41-52-043, dated March 14, 1997, or Revision 1, dated 
April 11, 1997, is considered acceptable for compliance with the 
initial inspection required by paragraph (a) of this AD.

    (1) If one cracked shear cleat is detected, and the crack is 
greater than 0.50 inches, prior to further flight, replace the 
cracked shear cleat with a new shear cleat in accordance with the 
alert service bulletin.
    (2) If one cracked shear cleat is detected, and the crack is 
less than or equal to 0.50 inches, within 170 landings following 
accomplishment of the inspection required by this paragraph, replace 
the cracked shear cleat with a new shear cleat in accordance with 
the alert service bulletin.
    (3) If more than one cracked shear cleat is detected, but no 
single crack is greater than 0.50 inches in length, prior to further 
flight, replace all cracked shear cleats with new shear cleats in 
accordance with the alert service bulletin.
    (b) For airplanes on which all shear cleats have been replaced: 
Inspect as required by paragraph (a) of this AD, prior to the 
accumulation of 6,000 total landings on the highest time new shear 
cleat, or within 60 days after August 12, 1997, whichever occurs 
later. Repeat the detailed visual inspection thereafter at intervals 
not to exceed 1,500 landings.

New Requirements of this AD

    (c) Modify the passenger door (Modification No. JM41576) at all 
four roller guide locations in accordance with Jetstream Service 
Bulletin J41-52-050, dated May 6, 1997, at the time specified in 
paragraph (c)(1) or (c)(2) of this AD, whichever occurs later. 
Accomplishment of this modification

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constitutes terminating action for the requirements of this AD.
    (1) Within 4,000 landings or 2 years after accomplishment of the 
initial inspection required by paragraph (a) of this AD. Or
    (2) Within 6 months after the effective date of this AD.
    (d) 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, International Branch, ANM-116, 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, International 
Branch, ANM-116.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.

    (e) 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 October 21, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-28665 Filed 10-26-98; 8:45 am]
BILLING CODE 4910-13-P