[Federal Register Volume 60, Number 198 (Friday, October 13, 1995)]
[Proposed Rules]
[Pages 53312-53314]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-25449]



-----------------------------------------------------------------------


DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-NM-238-AD]


Airworthiness Directives; Jetstream ATP Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Jetstream ATP airplanes. 
This proposal would require inspections to detect fatigue cracking and 
corrosion in the gussets of the rear passenger door and rear baggage 
door apertures, and replacement of the gussets, if necessary. This 
proposal is prompted by fatigue tests which indicated that fatigue 
cracking and corrosion can occur in these gussets. The actions 
specified by the proposed AD are intended to prevent degradation of the 
structural integrity of the fuselage pressure vessel due to the 
problems associated with cracking and corrosion in the gussets of the 
rear passenger door and rear baggage door apertures.

DATES: Comments must be received by November 14, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-238-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 Jetstream Aircraft, Inc., P.O. Box 16029, Dulles 
International Airport, Washington, DC 20041-6029. This information may 
be examined at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Tim Backman, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-2747; fax (206) 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 

[[Page 53313]]
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-238-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-238-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Civil Aviation Authority (CAA), which is the airworthiness 
authority for the United Kingdom, recently notified the FAA that an 
unsafe condition may exist on certain Jetstream Model ATP airplanes. 
The CAA advises that results of fatigue testing of Model ATP airplanes, 
which was conducted by the manufacturer, indicate that fatigue cracking 
and corrosion is likely to occur in the gussets of the rear passenger 
door and rear baggage door apertures. Such fatigue cracking and 
corrosion, if not detected and corrected in a timely manner, could 
degrade the structural integrity of the fuselage pressure vessel.
    Jetstream Aircraft, Ltd., has issued Service Bulletin ATP-53-29, 
dated October 31, 1994, which describes procedures for performing 
detailed visual inspections to detect fatigue cracking and corrosion in 
the gussets of the rear baggage door and rear passenger door apertures. 
It also describes procedures for replacing cracked and corroded 
gussets. The CAA classified this service bulletin as mandatory in order 
to assure the continued airworthiness of these airplanes in the United 
Kingdom.
    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 CAA 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 necessary for products of this type design that are 
certificated for operation in the United States.
    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 require a one-time detailed 
visual inspection for fatigue cracking and corrosion in the gussets of 
the rear passenger door and the rear baggage door apertures. It also 
would require replacement of cracked gussets, and either replacement or 
repair of corroded gussets. The inspection and replacement actions 
would be required to be accomplished in accordance with the service 
bulletin described previously. The repair of corroded gussets would be 
required to be accomplished in accordance with the Structural Repair 
Manual (SRM).
    The Limitations section of the Instructions for Continued 
Airworthiness in the Aircraft Maintenance Manual for these airplanes 
has recently been revised to include a repetitive inspection (at 
regular intervals) for the subject gussets. The FAA has determined that 
the one-time inspection of the gussets that would be required by this 
AD, coupled with the mandatory repetitive inspections that are now a 
part of the maintenance program, is adequate to provide a level of 
safety equivalent to that required by the Federal Aviation Regulations 
(FAR). This combination of inspections will ensure that any cracked or 
corroded gusset is detected and replaced/repaired before it could fail 
and consequently affect the operational safety of the airplane.
    The FAA estimates that 10 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 8 work 
hours per airplane to accomplish the proposed inspection actions, and 
that the average labor rate is $60 per work hour. Based on these 
figures, the total cost impact of the proposed AD on U.S. operators is 
estimated to be $4,800, or $480 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 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 USC 106(g), 40101, 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Jetstream Aircraft Limited (Formerly British Aerospace Commercial 
Aircraft, Ltd.): Docket 94-NM-238-AD.

    Applicability: Model ATP airplanes; having serial numbers 2002 
through 2012 inclusive, and 2019 through 2022 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 use the authority 
provided in paragraph (c) to request approval from the FAA. This 
approval may address either no action, if the current configuration 
eliminates the unsafe condition; or different actions necessary to 
address the unsafe condition described in this AD. Such a request 
should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, 

[[Page 53314]]
alteration, or repair remove any airplane from the applicability of 
this AD.

    Compliance: Required as indicated, unless accomplished 
previously. To prevent degradation of the structural integrity of 
the fuselage pressure vessel due to the problems associated with 
cracking and corrosion in the gussets of the rear passenger door and 
rear baggage door apertures, accomplish the following:
    (a) Prior to the accumulation of 12,000 total landings or within 
1,500 landings after the effective date of this AD, whichever occurs 
later, perform a detailed visual inspection to detect cracks and 
corrosion of the gussets of the rear passenger door aperture, in 
accordance with Jetstream Service Bulletin ATP-53-29, dated October 
31, 1994.
    (1) If any crack is found, prior to further flight, replace the 
gusset in accordance with the service bulletin.
    (2) If any corrosion is found, prior to further flight, either 
replace the gusset in accordance with the service bulletin, or 
repair the gusset in accordance with the Structural Repair Manual, 
chapter 53-10-12.
    (b) Prior to the accumulation of 15,000 total landings or within 
1,500 landings after the effective date of this AD, whichever occurs 
later, perform a detailed visual inspection to detect cracks and 
corrosion of the gussets of the rear baggage door aperture, in 
accordance with Jetstream Service Bulletin ATP-53-29, dated October 
31, 1994.
    (1) If any crack is found, prior to further flight, replace the 
gusset in accordance with the service bulletin.
    (2) If any corrosion is found, prior to further flight, either 
replace the gusset in accordance with the service bulletin, or 
repair the gusset in accordance with the Structural Repair Manual, 
chapter 53-10-12.
    (c) 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, Standardization Branch, ANM-113, 
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, 
Standardization Branch, ANM-113.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (d) 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 6, 1995.
Gary L. Killion,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-25449 Filed 10-12-95; 8:45 am]
BILLING CODE 4910-13-U