[Federal Register Volume 60, Number 112 (Monday, June 12, 1995)]
[Proposed Rules]
[Pages 30798-30801]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-14316]



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



DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-NM-173-AD]


Airworthiness Directives; Jetstream Model ATP Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to certain Jetstream Model ATP 
airplanes, that currently requires daily and/or pre- 
[[Page 30799]] flight cleaning and inspections to detect damaged main 
landing gear (MLG) wheel bearings and replacement of discrepant parts. 
That AD was prompted by reports of failure of the MLG wheel bearings. 
The actions specified by that AD are intended to prevent failure of the 
MLG wheel bearing, which could result in detachment of a MLG wheel from 
the airplane. This action would require an additional inspection, in 
lieu of the pre-flight inspection, for certain airplanes. This action 
would also require the accomplishment of a terminating modification 
that would eliminate the need for daily and pre-flight inspections.

DATES: Comments must be received by July 24, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-173-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 94-NM-173-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-173-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On February 18, 1994, the FAA issued AD 94-05-03, amendment 39-8841 
(59 FR 9400, February 28, 1994), applicable to certain Jetstream Model 
ATP airplanes, to require daily and/or pre-flight cleaning and detailed 
visual inspections to detect damage or discoloration of the main wheel 
hub caps and of the outer side of each inflation valve side hubs on the 
main landing gear (MLG) wheels. That amendment also requires 
replacement of the damaged or discolored MLG wheel assembly and 
bearings with a serviceable wheel assembly and bearings. That action 
was prompted by reports of failure of the MLG wheel bearings. The 
requirements of that AD are intended to prevent detachment of a MLG 
wheel from the airplane.
    Since the issuance of that AD, Jetstream has issued Revision 3 of 
Service Bulletin ATP-32-48, dated July 15, 1994. The daily cleaning and 
detailed visual inspection, and pre-flight detailed visual inspection 
procedures described in this revision are essentially identical to 
those described in Revision 1 of the service bulletin (which was 
referenced in AD 94-05-03 as the appropriate source of service 
information). For certain airplanes Revision 3 of the service bulletin 
describes procedures for performing an additional intermediate detailed 
visual inspection, in lieu of the pre-flight inspection. This 
intermediate inspection would detect damage (including blistering or 
flaking of the paint) or heat discoloration of the wheel hub cap and 
the outer side of each inflation valve side hub on the MLG wheels.
    Jetstream has also issued Service Bulletin ATP-32-51-35296A, dated 
May 12, 1994, which describes procedures for modification of the MLG. 
This modification involves drilling two additional locking holes in 
each axle. This modification will reduce the axial movement between the 
locking positions to provide a closer control of the wheel bearing 
preload.
    Additionally, Jetstream issued Service Bulletin ATP-32-53-35294A 
(including Erratum No. 1), dated July 18, 1994, and Revision 2, dated 
January 13, 1995, which describe procedures for modification of certain 
wheels on the MLG. This modification involves removing the existing 
valve side half hub assembly of the wheel and installing a new valve 
side half hub assembly, which is capable of accepting a new outer 
bearing with higher load capability.
    Accomplishment of these modifications described in Service 
Bulletins ATP-32-51-35296A and ATP-32-53-35294A would eliminate the 
need for the daily, pre-flight, and daily intermediate inspections, and 
would positively address the unsafe condition identified as detachment 
of a MLG wheel from the airplane.
    The Civil Aviation Authority (CAA), which is the airworthiness 
authority for the United Kingdom, has classified these service 
bulletins 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 supersede AD 94-05-03 to 
continue to require daily cleaning and daily/pre-flight detailed visual 
inspections to detect damage (including blistering or flaking of the 
paint) or discoloration of the wheel hub caps and of the outer side of 
the inflation valve side hubs on the MLG wheels. The proposed AD would 
[[Page 30800]] also require an additional daily intermediate detailed 
visual inspection, in lieu of the pre-flight inspection, for certain 
airplanes. This intermediate inspection would detect damage or heat 
discoloration of the wheel hub cap and the outer side of each inflation 
valve side hub on the MLG wheel. Additionally, the proposed AD would 
require modification of the MLG, which would constitute terminating 
action for the daily, pre-flight, daily intermediate inspection 
requirements. The actions would be required to be accomplished in 
accordance with the service bulletins described previously. If any 
damage or discoloration is found, the replacement of the existing MLG 
wheel assembly and bearings with a serviceable wheel assembly and 
bearings would be required to be accomplished in accordance with a 
method approved by the FAA.
    The FAA estimates that 10 airplanes of U.S. registry would be 
affected by this proposed AD.
    The inspections that were previously required by AD 94-05-03, and 
would be retained in this proposed AD, take approximately 2 work hours 
per airplane to accomplish, at an average labor rate of $60 per work 
hour. Based on these figures, the total cost impact of the inspection 
requirement of this AD on U.S. operators is estimated to be $1,200, or 
$120 per airplane, per inspection cycle.
    The inspections that would be added by this proposed AD would take 
approximately 2 work hours per airplane to accomplish , at an average 
labor rate of $60 per work hour. Based on these figures, the total cost 
impact of the inspections proposed by this AD on U.S. operators is 
estimated to be $1,200, or $120 per airplane, per inspection cycle.
    It would take approximately 11 work hours per airplane to 
accomplish the proposed modifications at an average labor rate of $60 
per work hour. Required parts would be supplied by the manufacturer at 
no cost to the operators. Based on these figures, the total cost impact 
of the modification proposed by this AD on U.S. operators is estimated 
to be $6,600, or $660 per airplane.
    The total cost impact figures discussed above are 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 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 removing amendment 39-8841 (59 FR 
9400, February 28, 1994), and by adding a new airworthiness directive 
(AD), to read as follows:

Jetstream Aircraft Limited (Formerly British Aerospace Commercial 
Aircraft Limited): Docket 94-NM-173-AD. Supersedes AD 94-05-03, 
Amendment 39-8841.
    Applicability: Model ATP airplanes, constructor numbers 2001 
through 2063 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 (d) 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, alteration, or repair 
remove any airplane from the applicability of this AD.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent detachment of a main landing gear (MLG) wheel from 
the airplane, accomplish the following:
    (a) For airplanes on which Jetstream Modification 35296A 
(reference Jetstream Service Bulletin ATP-32-51-35296A) has not been 
installed: Accomplish paragraphs (a)(1) and (a)(2) of this AD.
    (1) Within 24 hours after March 15, 1994 (the effective date of 
AD 94-05-03, amendment 39-8841), perform a cleaning and a detailed 
visual inspection to detect damage (including blistering or flaking 
of the paint) or discoloration of the wheel hub caps and of the 
outer side of the inflation valve side hubs on the MLG wheels, in 
accordance with paragraph 2.(2) of the Accomplishment Instructions 
of Jetstream Service Bulletin ATP-32-48, Revision 1, dated January 
28, 1994; or in accordance with paragraph 2.A.(2) of the 
Accomplishment Instructions of Jetstream Service Bulletin ATP-32-48, 
Revision 3, dated July 15, 1994. Thereafter, prior to the first 
flight of each day, repeat this cleaning and inspection. The 
cleaning and inspection must be performed by appropriately 
certificated maintenance personnel as specified in section 43.3 of 
the Federal Aviation Regulations (14 CFR 43.3). If any damage or 
discoloration is found during any inspection required by this 
paragraph, prior to further flight, replace the existing MLG wheel 
assembly and bearings with a serviceable wheel assembly and 
bearings, in accordance with the airplane maintenance manual.
    (2) Following accomplishment of the initial inspection required 
by paragraph (a)(1) of this AD, prior to each flight, with the 
exception of the first flight of each day, perform a pre-flight 
detailed visual inspection to detect damage (including blistering or 
flaking of the paint) or heat discoloration of the wheel hub cap and 
the outer side of each inflation valve side hub on the MLG wheels, 
in accordance with paragraph 2.A.(3) of the Accomplishment 
Instructions of Jetstream Service Bulletin ATP-32-48, Revision 1, 
dated January 28, 1994; or in accordance with paragraph 2.A.(3) of 
the Accomplishment Instruction of Jetstream Service Bulletin ATP-32-
48, Revision 3, dated July 15, 1994. The pre-flight inspections must 
be performed by appropriately certificated maintenance personnel, as 
specified in section 43.3. If any damage or discoloration is found 
during any inspection required by this paragraph, prior to further 
flight, replace the existing MLG wheel assembly and bearings with a 
[[Page 30801]] serviceable wheel assembly and bearings, in 
accordance with the airplane maintenance manual.
    (b) For airplanes on which Jetstream Modification 35296A 
(reference Jetstream Service Bulletin ATP-32-51-35296A) has been 
installed: Accomplish paragraphs (b)(1) and (b)(2) of this AD.
    (1) Within 24 hours after the last inspection performed in 
accordance with paragraph (a)(1) of this AD, perform a cleaning and 
a detailed visual inspection to detect damage (including blistering 
or flaking of the paint) or discoloration of the wheel hub caps and 
of the outer side of the inflation valve side hubs on the MLG 
wheels, in accordance with paragraph 2.Part B.(2) of the 
Accomplishment Instructions of Jetstream Service Bulletin ATP-32-48, 
Revision 3, dated July 15, 1994. Thereafter, prior to the first 
flight of each day, repeat this cleaning and inspection. The 
cleaning and inspection must be performed by appropriately 
certificated maintenance personnel as specified in section 43.3 of 
the Federal Aviation Regulations (14 CFR 43.3). If any damage or 
discoloration is found during any inspection required by this 
paragraph, prior to further flight, replace the existing MLG wheel 
assembly and bearings with a serviceable wheel assembly and 
bearings, in accordance with the airplane maintenance manual.
    (2) Following accomplishment of the initial inspection required 
by paragraph (b)(1) of this AD, once a day, perform an additional 
intermediate detailed visual inspection to detect damage (including 
blistering or flaking of the paint) or heat discoloration of the 
wheel hub cap and the outer side of each inflation valve side hub on 
the MLG wheels, in accordance with paragraph 2.Part B.(3) of the 
Accomplishment Instructions of Jetstream Service Bulletin ATP-32-48, 
Revision 3, dated July 15, 1994. The once-a-day inspections must be 
performed by appropriately certificated maintenance personnel, as 
specified in 14 CFR 43.3. If any damage or discoloration is found 
during any inspection required by this paragraph, prior to further 
flight, replace the existing MLG wheel assembly and bearings with a 
serviceable wheel assembly and bearings, in accordance with the 
airplane maintenance manual.
    (c) Within 10 months after the effective date of this AD, modify 
the MLG, in accordance with Jetstream Service Bulletin ATP-32-51-
35296A (including Erratum No. 1), dated May 12, 1994; and Jetstream 
Service Bulletin ATP-32-53-35294A, dated July 18, 1994, or Revision 
2, dated January 13, 1995. Accomplishment of these modifications 
constitutes terminating action for the daily and pre-flight 
inspection requirements 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, 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.

    (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 June 6, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-14316 Filed 6-9-95; 8:45 am]
BILLING CODE 4910-13-U