[Federal Register Volume 62, Number 91 (Monday, May 12, 1997)]
[Rules and Regulations]
[Pages 25836-25837]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-12044]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-168-AD; Amendment 39-10021; AD 97-10-09]
RIN 2120-AA64


Airworthiness Directives; Jetstream Model 4101 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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

SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Jetstream Model 4101 airplanes, that requires 
repetitive detailed visual inspections to detect cracks on frame 179 at 
the attachment bracket for the door restraint cable, and various 
follow-on actions. This amendment also requires installation of new 
doublers and stress pads on frame 179, which would terminate the 
repetitive inspections. This amendment is prompted by reports of cracks 
in frame 179 of the fuselage at the attachment bracket for the door 
restraint cable on in-service airplanes due to improper rigging of the 
door restraint system. The actions specified by this AD are intended to 
prevent such cracking, which could result in structural failure of the 
fuselage and consequent rapid decompression of the pressurized section 
of the fuselage.

DATES: Effective June 16, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of June 16, 1997.

ADDRESSES: The service information referenced in this AD 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 Federal Aviation Administration (FAA), Transport 
Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, 
Washington; or at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: William Schroeder, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2148; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Jetstream Model 4101 
airplanes was published in the Federal Register on February 14, 1997 
(62 FR 6888). That action proposed to require repetitive detailed 
visual inspections to detect cracks on frame 179 at the attachment 
bracket for the door restraint cable, and various follow-on actions. 
That action also proposed to require installation of new doublers and 
stress pads on frame 179, which would constitute terminating action for 
the repetitive inspection requirements.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were submitted in response 
to the proposal or the FAA's determination of the cost to the public.

Conclusion

    The FAA has determined that air safety and the public interest 
require the adoption of the rule as proposed.

Cost Impact

    The FAA estimates that 49 Jetstream Model 4101 airplanes of U.S. 
registry will be affected by this AD.
    The required inspection will take approximately 2 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 inspection required by 
this AD on U.S. operators is estimated to be $5,880, or $120 per 
airplane, per inspection cycle.
    The required installation will take approximately 8 work hours per 
airplane to accomplish, at an average labor rate of $60 per work hour. 
Required parts will be supplied by the manufacturer at no cost to the 
operators. Based on these figures, the cost impact of the installation 
required by this AD on U.S. operators is estimated to be $23,520, or 
$480 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the 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 adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) Is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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 adding the following new 
airworthiness directive:

97-10-09  Jetstream Aircraft Limited: Amendment 39-10021. Docket 96-
NM-168-AD.

    Applicability: Model 4101 airplanes, constructors numbers 41004 
through 41086 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

[[Page 25837]]

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 cracking in frame 179 of the fuselage, which could 
result in structural failure of the fuselage and consequent rapid 
decompression of the pressurized section of the fuselage, accomplish 
the following:
    (a) Prior to the accumulation of 3,000 total flight cycles, or 
within 300 flight cycles after the effective date of this AD, 
whichever occurs later, perform a detailed visual inspection to 
detect cracks on frame 179 at the attachment bracket for the door 
restraint cable, in accordance with Part 1 of the Accomplishment 
Instructions of Jetstream Alert Service Bulletin J41-A53-024, dated 
April 26, 1996.
    (1) If no crack is detected, repeat the visual inspection 
thereafter at intervals not to exceed 1,000 flight cycles. After 
each inspection, perform the actions specified in paragraph (c) of 
this AD.
    (2) If any crack is detected, prior to further flight, repair it 
in accordance with a method approved by the Manager, Standardization 
Branch, ANM-113, FAA, Transport Airplane Directorate. After repair, 
perform the actions specified in paragraph (c) of this AD.
    (b) Within 24 months after the effective date of this AD, 
perform the visual inspection specified in paragraph (a) of this AD 
in accordance with Part 2 of the Accomplishment Instructions of 
Jetstream Alert Service Bulletin J41-A53-024, dated April 26, 1996; 
and accomplish the applicable follow-on actions specified in 
paragraph (b)(1) or (b)(2) of this AD.
    (1) If no crack is detected, prior to further flight, install 
new doublers and stress pads on frame 179 in accordance with the 
alert service bulletin. Immediately after installation, perform the 
actions specified in paragraph (c) of this AD. Accomplishment of 
these actions constitutes terminating action for the repetitive 
inspection requirements of paragraph (a)(1) of this AD.
    (2) If any crack is detected, prior to further flight, repair it 
in accordance with a method approved by the Manager, Standardization 
Branch, ANM-113. Prior to further flight following accomplishment of 
the repair, install new doublers and stress pads on frame 179 in 
accordance with the alert service bulletin; and then perform the 
actions specified in paragraph (c) of this AD. Accomplishment of 
these actions constitutes terminating action for the repetitive 
inspection requirements of paragraph (a)(1) of this AD.
    (c) Prior to further flight following accomplishment of the 
actions as specified in paragraph (a)(1), (a)(2), (b)(1), or (b)(2) 
of this AD, perform a test to verify proper adjustment of the 
restraint cable, in accordance with Jetstream Alert Service Bulletin 
J41-A53-024, dated April 26, 1996. If the restraint cable has been 
improperly adjusted, prior to further flight, correct the 
discrepancy in accordance with the alert service bulletin.
    (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, Standardization Branch, ANM-113. 
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.

    (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.
    (f) Certain actions shall be done in accordance with Jetstream 
Alert Service Bulletin J41-A53-024, dated April 26, 1996. This 
incorporation by reference was approved by the Director of the 
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 
51. Copies may be obtained from Jetstream Aircraft, Inc., P.O. Box 
16029, Dulles International Airport, Washington, DC 20041-6029. 
Copies may be inspected at the FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington; or at the Office of the 
Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.
    (g) This amendment becomes effective on June 16, 1997.

    Issued in Renton, Washington, on May 2, 1997.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-12044 Filed 5-9-97; 8:45 am]
BILLING CODE 4910-13-U