[Federal Register Volume 62, Number 44 (Thursday, March 6, 1997)]
[Proposed Rules]
[Pages 10224-10226]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-5463]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 62, No. 44 / Thursday, March 6, 1997 / 
Proposed Rules  

[[Page 10224]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-18-AD]
RIN 2120-AA64


Airworthiness Directives; Gulfstream Aerospace Corporation Model 
G-159 (G-I) 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 all Gulfstream Model G-159 
(G-I) airplanes, that currently requires repetitive inspections to 
detect corrosion in the wing planks under the bottom wing center 
fairings, and repair, if necessary. This action would require the 
installation of a protective paint system which, when accomplished, 
will allow the inspections to be conducted at longer intervals. This 
action was prompted by the development of a modification that will 
improve the corrosion resistance of the subject area. The actions 
specified by the proposed AD are intended to detect and prevent 
corrosion in the lower skins of the wing center section. If corrosion 
in this area remains unchecked, it could reduce the integrity of the 
wing-to-fuselage fitting, and consequently could lead to separation of 
the wing from the airplane.

DATES: Comments must be received by April 14, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 97-NM-18-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 Gulfstream Aerospace Corporation, Technical Operations 
Department, P.O. Box 2206, M/S D-10, Savannah, Georgia 31402-2206. This 
information may be examined at the FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Christina Marsh, Aerospace Engineer, 
Airframe and Propulsion Branch, ACE-117A, FAA, Small Airplane 
Directorate, Atlanta Aircraft Certification Office, Campus Building, 
1701 Columbia Avenue, Suite 2-160, College Park, Georgia 30337-2748; 
telephone (404) 305-7362; fax (404) 305-7348.

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-18-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. 97-NM-18-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    In 1967, the FAA issued AD 67-04-01, amendment 39-1234 (36 FR 
12688, July 3, 1971), applicable to all Gulfstream Model G-159 (G-I) 
airplanes. That AD requires a visual inspection to detect corrosion of 
the wing planks under the bottom wing center fairing assemblies (having 
part numbers 159W10400-121 and 159W10401-121), and repair if necessary. 
After the initial inspection is accomplished, and after any repair is 
made, the inspection is required to be repeated at intervals of 26 
weeks.
    That action was prompted by reports indicating that corrosion was 
found in the lower skins of the wing center section of several of these 
airplanes. The requirements of that AD are intended to detect and 
correct corrosion in this area. If such corrosion remains unchecked, it 
could reduce the integrity of the wing-to-fuselage fitting, and 
consequently could lead to separation of the wing from the airplane.

Actions Since Issuance of Previous Rule

    As part of its on-going program to address issues relevant to the 
continued operational safety of the aging transport fleet, the FAA, 
along with Gulfstream Aerospace Corporation and several U.S. and non-
U.S. operators of the affected airplanes, agreed to undertake the task 
of identifying and implementing procedures to ensure the continuing 
structural airworthiness of aging commuter-class airplanes. This group 
recently reviewed selected service bulletins, applicable to Gulfstream 
Model G-159 airplanes, to be recommended for mandatory rulemaking 
action to ensure the continued operational safety of these airplanes.

Explanation of Relevant Service Information

    The group reviewed and recommended Grumman Gulfstream I Aircraft 
Service Change No. 190, dated June 28, 1971, for mandatory regulatory 
action. That service change describes procedures for repetitive 
inspections to detect corrosion of the center section lower wing 
planks, and repair, if necessary. It also describes the

[[Page 10225]]

installation of a protective paint system to the fairing assemblies and 
bottom wing cover. This protective system is intended to improve the 
corrosion resistance of this area. Once it is installed, the repetitive 
inspections may be conducted at longer intervals.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would supersede AD 67-04-01. It would continue to require 
the repetitive visual inspections, specified in AD 67-04-01, to detect 
corrosion of the wing planks under the bottom wing center fairing 
assemblies, and repair, if necessary.
    For airplanes on which a protective paint system had not been 
installed previously, this new action would require that the inspection 
continue to be repeated at intervals of 6 months (26 weeks), until a 
protective paint system is installed within 12 months. Once the paint 
system is installed, the repetitive inspections would be required to 
continue, but the repetitive interval would be extended to 18 months.
    For airplanes on which a protective paint system was installed 
previously, this new action would extend the currently-required 
repetitive inspection interval of 12 months to 18 months.
    These actions would be required to be accomplished in accordance 
with the aircraft service change described previously.

Cost Impact

    There are approximately 146 Gulfstream Model G-159 airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 72 
airplanes of U.S. registry would be affected by this proposed AD.
    The inspections that are currently required by AD 67-04-01, and 
those that would be required by this proposed action, take 
approximately 40 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 proposed inspection actions on U.S. operators is 
estimated to be $172,800, or $2,400 per airplane, per inspection.
    The installation of the protective paint system that is proposed in 
this AD action would take approximately 30 work hours per airplane to 
accomplish, at an average labor rate of $60 per work hour. Required 
materials would cost approximately $100 per airplane. Based on these 
figures, the cost impact of the proposed requirements of this AD on 
U.S. operators is estimated to be $136,800, or $1,900 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 39-1234 (36 FR 
12688, July 3, 1971), and by adding a new airworthiness directive (AD), 
to read as follows:

Gulfstream Aerospace Corporation: Docket 97-NM-18-AD. Supersedes AD 
67-04-01, Amendment 39-1234.

    Applicability: All Model G-159 (G-I) airplanes, 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 request approval for an 
alternative method of compliance in accordance with paragraph (d)(1) 
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 detect and prevent corrosion in the lower skins of the wing 
center section, which could reduce the integrity of the wing-to-
fuselage fitting and consequently could lead to separation of the 
wing from the airplane, accomplish the following:
    (a) For all airplanes: Within 4 weeks after July 3, 1971 (the 
effective date of AD 67-04-01, amendment 39-1234), remove the bottom 
wing center fairings having part numbers (P/N) 159W10400-121 and 
159W10401-121, or use an FAA-approved equivalent method, to perform 
a visual inspection to detect corrosion of the wing planks under 
these fairings.

    Note 2: Paragraph (a) of this AD merely restates the actions 
previously required by AD 67-04-01, amendment 39-1234. As allowed by 
the phrase, ``unless accomplished previously,'' if those 
requirements of AD 67-04-01 have already been accomplished, this AD 
does not require that those actions be repeated.
    Note 3: Care must be exercised when removing the fairings, since 
the attaching rivets go into the pressure vessel. Use caution not to 
enlarge rivet holes when removing rivets. When reinstalling the 
fairings, an adequate type fastener and sealant must be used.
    Note 4: Grumman Service Newsletter, Volume 166, dated August-
September 1966, pertains to this subject.

    (b) For airplanes on which a protective paint system has not 
been installed in accordance with Grumman Gulfstream I Aircraft 
Service Change No. 190, dated June 28, 1971: Accomplish paragraphs 
(b)(1) and (b)(2) of this AD. As of the effective date of this AD, 
the inspections required by this paragraph shall be accomplished in 
accordance with Grumman Gulfstream I Aircraft Service Change No. 
190, dated June 28, 1971.

    Note 5: The repeated inspection referred to in this paragraph is 
the same inspection previously required by AD 67-04-01. Paragraph 
(b)(1) of this AD merely restates

[[Page 10226]]

the requirement of AD 67-04-01 to repeat the inspection at intervals 
of 6 months. Paragraph (b)(2) permits the reinspection interval to 
be extended to 18 months once the specified protective paint system 
is installed.

    (1) As a result of the inspection required by paragraph (a) of 
this AD:
    (i) If no corrosion is detected, repeat the inspection 
thereafter at intervals not to exceed 6 months (26 weeks) until the 
actions specified in paragraph (b)(2) of this AD are accomplished.
    (ii) If any corrosion is detected, prior to further flight, 
either repair the corroded part with an FAA-approved repair; or 
replace the corroded part with a new or serviceable part of the same 
part number; or replace the corroded part with a part approved by 
the FAA. Thereafter, continue to perform the inspection at intervals 
not to exceed 6 months (26 weeks) until paragraph (b)(2) of this AD 
is accomplished.
    (2) Within 12 months after the effective date of this AD, 
install the protective paint system in accordance with Grumman 
Gulfstream I Aircraft Service Change No. 190, dated June 28, 1971. 
After installation, continue to perform the inspection required by 
this paragraph at intervals not to exceed 18 months.
    (c) For airplanes on which a protective paint system has been 
installed previously in accordance with Grumman Gulfstream I 
Aircraft Service Change No. 190, dated June 28, 1971: Accomplish 
paragraphs (c)(1) and (c)(2) of this AD. As of the effective date of 
this AD, the inspections required by this paragraph shall be 
accomplished in accordance with Grumman Gulfstream I Aircraft 
Service Change No. 190, dated June 28, 1971.

    Note 6: The repeated inspection referred to in this paragraph is 
the same inspection previously required by AD 67-04-01. Paragraph 
(c)(1) of this AD merely restates the requirement of AD 67-04-01 to 
repeat the inspection at intervals of 12 months. Paragraph (c)(2) 
permits the reinspection interval to be extended to 18 months.
    (1) As a result of the inspection required by paragraph (a) of 
this AD:
    (i) If no corrosion is detected, repeat the inspection 
thereafter at intervals not to exceed 12 months until paragraph 
(c)(2) of this AD is accomplished.
    (ii) If any corrosion is detected, prior to further flight, 
either repair the corroded part with an FAA-approved repair; or 
replace the corroded part with a new or serviceable part of the same 
part number; or replace the corroded part with a part approved by 
the FAA. Thereafter, continue to perform the inspection at intervals 
not to exceed 12 months until paragraph (c)(2) of this AD is 
accomplished.
    (2) Within 18 months since the last inspection accomplished in 
accordance with paragraph (c)(1) of this AD (i.e., the last 
inspection accomplished in accordance with AD 67-04-01), repeat the 
inspection specified in paragraph (c)(1) of this AD.
    (i) If no corrosion is detected, repeat the inspection 
thereafter at intervals not to exceed 18 months.
    (ii) If any corrosion is detected, prior to further flight, 
repair in accordance with the service change. After repair, continue 
to perform the inspection at intervals not to exceed 18 months.
    (d)(1) 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, Atlanta Aircraft Certification 
Office (ACO), FAA, Small 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, Atlanta ACO.
    (2) Alternative methods of compliance, approved previously in 
accordance with AD 67-04-01, amendment 39-1234, are approved as 
alternative methods of compliance with this AD.

    Note 7: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Atlanta ACO.

    (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 February 27, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-5463 Filed 3-5-97; 8:45 am]
BILLING CODE 4910-13-U