[Federal Register Volume 60, Number 226 (Friday, November 24, 1995)]
[Proposed Rules]
[Pages 58023-58025]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-28524]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-95-AD]


Airworthiness Directives; Jetstream Model 4101 Airplanes

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 Jetstream Model 4101 
airplanes. This proposal would require inspections of the handrail 
assembly at the main entrance door to detect loose or missing rivets, 
abnormal movement between the handrail pivot-tube and the spigot that 
attaches to the bearing assembly, and cracks on the handrail pivot-
tube. It would also require repair or replacement of the assembly, if 
necessary. This proposal is prompted by a report indicating that 
fatigue cracks and loose rivets were found on the handrail assembly of 
the main passenger entrance door on an in-service airplane. The actions 
specified by the proposed AD are intended to prevent these conditions, 
which can lead to the failure of the door handrail assembly; such 
failure could allow the door to fall free and subsequently cause injury 
to people on the airplane or on the ground.

DATES: Comments must be received by January 2, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-95-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: William Schroeder, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone (206) 
227-2148; 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 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 95-NM-95-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. 95-NM-95-AD, 1601 Lind Avenue SW., Renton, Washington 98055-
4056.

Discussion

    The Civil Aviation Authority (CAA), which is the airworthiness 
authority for the United Kingdom, has notified the FAA that an unsafe 
condition may exist on certain Jetstream Model 4101 airplanes. The CAA 
advises that cracks and loose rivets have been found on the handrail 
assembly of the main passenger entrance door. These conditions are the 
result of fatigue stress. If such cracking were to lead to complete 
failure of the handrail assembly, the entrance door, which is hinged on 
the bottom, could fall free. This condition, if not corrected, could 
result in injury to passengers, flightcrew, or groundcrew.

Description of Relevant Service Information

    Jetstream has issued Alert Service Bulletin J41-A52-036, dated June 
13, 1994, which describes procedures for conducting repetitive 
inspections of the handrail assembly at the main entrance door to 
detect:
    1. loose or missing rivets,
    2. abnormal movement between the handrail pivot-tube and the spigot 
that attaches to the bearing assembly, and
    3. cracks on the handrail pivot-tube.
    If the inspection reveals evidence of loose or missing rivets or 
abnormal movement between the handrail pivot-tube and the spigot, the 
service bulletin calls for removing the rivets and conducting 
inspections for elongation of the rivet holes and for cracks in the 
pivot tube under the cross-tube fitting and pivot rod.
    If the inspection reveals evidence of elongation of the rivet 
holes, the service bulletin calls for drilling the holes to a certain 
maximum diameter and installation of new rivets.
    If any of the inspections reveal evidence of cracking in the 
assembly, the service bulletin calls for installing either:
    1. a standard handrail assembly;
    2. an interim reinforcement of the handrail assembly, or
    3. structural improvements to the door and door support, and a 
completely redesigned handrail assembly.
    If a standard handrail assembly is installed, the repetitive 
inspections must continue. If the interim reinforcement is installed, 
or if the 

[[Page 58024]]
structural improvements and redesigned handrail assembly are installed, 
the repetitive inspections are no longer needed.
    The CAA classified this service bulletin as mandatory in order to 
assure the continued airworthiness of these airplanes in the United 
Kingdom.
    Jetstream also has issued Service Bulletin J41-52-041-42619, dated 
June 13, 1994, which describes procedures for installing an interim 
reinforcement of the handrail assembly (Customer Option Kit No. 
JK2619). The reinforcement entails installing a new improved pivot 
trunnion and handrail pivot tube to strengthen the main handrail sub-
assembly. The CAA classified this service bulletin as optional.
    Additionally, Jetstream Service Bulletin J41-52-041-42619 refers to 
Flight Refuelling Service Bulletin 6020303-52-1, dated June 10, 1994, 
which contains detailed instructions for installing the interim 
reinforcement of the handrail assembly, identified as ``Flight 
Refuelling Modification No. 60291.'' When the reinforcement is 
installed, the part number of the handrail assembly is changed to 
``Flight Refuelling Part Number 6020203 Issue D.''
    Jetstream also has issued Service Bulletin J41-52-025, dated 
February 11, 1994, which describes procedures for installing structural 
improvements of the door and door support, and a completely redesigned 
handrail assembly (Modification No. JM41224A). Once all of these items 
are installed, the resulting assembly is stronger and has improved 
fatigue life. The CAA also classified this service bulletin as 
optional.
    Additionally, Jetstream Service Bulletin J41-52-025 refers to 
Flight Refuelling Service Bulletin 6020303-52-2, Revision 1, dated 
December 10, 1993, which contains detailed instructions for installing 
the completely redesigned handrail assembly, specified as Flight 
Refuelling Part No. 6020205. The redesigned handrail assembly includes 
a new latch mechanism and tensator spring to secure (safety) the 
overcenter lock. It also includes new gas struts that have better 
reliability.

Description of the Proposed Rule

    The Jetstream Model 4101 airplane 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 repetitive 
inspections of the handrail assembly at the main entrance door to 
detect loose or missing rivets; abnormal movement between the handrail 
pivot-tube and the spigot that attaches to the bearing assembly; and 
cracks on the handrail pivot-tube.
    If evidence of loose/missing rivets or abnormal movement is 
detected, operators would be required to accomplish various corrective 
procedures. If cracking is detected, operators would be required to 
correct the discrepancy by either:
    1. replacing the handrail assembly with a serviceable like part, 
and continuing with the repetitive inspections; or
    2. installing an interim reinforcement of the handrail assembly, 
which would constitute terminating action for the repetitive 
inspections; or
    3. installing structural improvements of the door and door support, 
and a completely redesigned handrail assembly, which would constitute 
terminating action for the repetitive inspections.
    The proposed actions would be required to be accomplished in 
accordance with the Jetstream service bulletins described previously.

Economic Impact

    The FAA estimates that 4 airplanes of U.S. registry would be 
affected by this proposed AD. To accomplish the proposed inspections, 
it would take approximately 1 work hour per airplane, at an average 
labor rate of $60 per work hour. Based on these figures, the cost 
impact of the proposed AD on U.S. operators is estimated to be $240, or 
$60 per airplane, per inspection.
    This cost impact figure 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.

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), 40101, 40113, 44701.


Sec. 39.13  [Amended]

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

Jetstream: Docket 95-NM-95-AD.

    Applicability: Model 4101 airplanes; equipped with handrail 
assembly, Part No. 6020203 Issue C, with Modification No. JM41179 
(reference Jetstream Alert Service Bulletin J41-A52-009); 
certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise 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 (f) of this AD to 

[[Page 58025]]
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, alteration, or repair remove any airplane from the 
applicability of this AD.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent failure of the entrance door handrail assembly, which 
subsequently could result in injury to passengers, flightcrew, or 
groundcrew, accomplish the following:
    (a) Within 50 landings after the effective date of this AD, 
conduct a detailed visual inspection of the handrail assembly at the 
main entrance door to detect loose or missing rivets, abnormal 
movement between the handrail pivot-tube and the spigot that 
attaches to the bearing assembly, and cracks on the handrail pivot-
tube, in accordance with Jetstream Alert Service Bulletin J41-A52-
036, dated June 13, 1994.
    (b) If no cracks or other discrepancies are detected during the 
inspection required by paragraph (a) of this AD, repeat the 
inspection thereafter at intervals not to exceed 300 hours time-in-
service.
    (c) If evidence of any loose or missing rivet is revealed, or if 
abnormal movement between the handrail pivot-tube and the spigot 
that attaches to the bearing assembly is detected, as a result of 
any of the inspections required by this AD, prior to further flight, 
accomplish the procedures specified in paragraph 2.B.(4) of 
Jetstream Alert Service Bulletin J41-A52-036, dated June 13, 1994. 
Thereafter, repeat the inspection required by paragraph (a) of this 
AD at intervals not to exceed 300 hours time-in-service.
    (d) If evidence of cracking is revealed as a result of any of 
the inspections required by this AD, prior to further flight, 
accomplish the requirements of either paragraph (d)(1), (d)(2), or 
(d)(3) of this AD:
    (1) Install a new handrail assembly, Part No. 6020203 Issue C 
standard, as specified in paragraph 2.B.(5)(d) of Jetstream Service 
Bulletin J41-A52-036, dated June 13, 1994. After installation, 
repeat the inspection required by paragraph (a) of this AD at 
intervals not to exceed 300 hours time-in-service. Or
    (2) Install the interim reinforcement of the handrail assembly 
(Customer Option Kit. No. Jk42619) in accordance with Jetstream 
Service Bulletin J41-52-041-42619, dated June 13, 1994. Such 
installation constitutes terminating action for the inspections 
required by this AD. Or

    Note 2: Jetstream Service Bulletin J41-52-041-42619 refers to 
Flight Refuelling Service Bulletin 6020303-52-1 for additional 
installation information.

    (3) Install the structural improvements of the door and door 
support, and the completely redesigned door handrail assembly, in 
accordance with Jetstream Service Bulletin J41-52-025, dated 
February 11, 1994. Such installation constitutes terminating action 
for the inspections required by this AD.

    Note 3: Jetstream Service Bulletin J41-52-025 refers to Flight 
Refuelling Service Bulletin 6020303-52-2 for additional installation 
information.

    (e) Terminating action for the inspections required by this AD 
consists of installation of the item(s) specified in either 
paragraph (e)(1) or (e)(2) of this AD:
    (1) Installation of the interim reinforcement of the handrail 
assembly (Customer Option Kit. No. Jk42619) in accordance with 
Jetstream Service Bulletin J41-52-041-42619, dated June 13, 1994. Or
    (2) Installation of the structural improvements of the door and 
door support, and the completely redesigned door handrail assembly, 
in accordance with Jetstream Service Bulletin J41-52-025, dated 
February 11, 1994.
    (f) 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 4: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (g) 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 November 15, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-28524 Filed 11-22-95; 8:45 am]
BILLING CODE 4910-13-U