[Federal Register Volume 59, Number 63 (Friday, April 1, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-7788]


[[Page Unknown]]

[Federal Register: April 1, 1994]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-CE-04-AD]

 

Airworthiness Directives: Aerostar Aircraft Corporation PA-60-600 
and PA-60-700 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of Proposed Rulemaking (NPRM).

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SUMMARY: This document proposes to supersede AD 92-13-01, which 
currently requires inspecting the nose landing gear (NLG) drag brace 
assembly for corrosion on certain Aerostar Aircraft Corporation 
(Aerostar) PA-60-600 (Aerostar 600) and PA-60-700 (Aerostar 700) series 
airplanes, and replacing any corroded components. It also requires 
replacing the existing spring and piston with new corrosion-resistant 
parts. The proposed action would require replacing the NLG drag link 
assembly with a new assembly of improved design. The Federal Aviation 
Administration (FAA) has received several reports of frozen moisture in 
the cylinder of the over-center release system, which has led to nose 
gear collapse on airplanes already in compliance with AD 92-13-01. The 
actions specified by the proposed AD are intended to prevent failure of 
the NLG caused by frozen moisture in the cylinder, which could lead to 
nose gear collapse and damage to the airplane.

DATES: Comments must be received on or before June 14, 1994.

ADDRESSES: Submit comments in triplicate to the FAA, Central Region, 
Office of the Assistant Chief Counsel, Attention: Rules Docket No. 94-
CE-04-AD, room 1558, 601 E. 12th Street, Kansas City, Missouri 64106. 
Comments may be inspected at this location between 8 a.m. and 4 p.m., 
Monday through Friday, holidays excepted.
    Service information that applies to this AD may be obtained from 
the Aerostar Aircraft Corporation, Customer Service Department, South 
3608 Davison Boulevard, Spokane, Washington 99204; telephone (509) 455-
8872. This information also may be examined at the Rules Docket at the 
address below. Send comments on the proposal in triplicate to the FAA, 
Central Region, Office of the Assistant Chief Counsel, Attention: Rules 
Docket No. 94-CE-04-AD, Room 1558, 601 E. 12th Street, Kansas City, 
Missouri 64106. Comments may be inspected at this location between 8 
a.m. and 4 p.m., Monday through Friday, holidays excepted.

FOR FURTHER INFORMATION CONTACT: Mr. William A. Swope, Aerospace 
Engineer, Seattle Aircraft Certification Office, 1601 Lind Avenue, 
S.W., Renton, Washington 98055-4056; telephone (206) 227-2589.

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 should 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 that summarizes 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 No. 94-CE-04-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, Central Region, Office of the Assistant Chief Counsel, 
Attention: Rules Docket No. 94-CE-04-AD, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106.

Discussion

    AD 92-13-01, Amendment 39-8270 (57 FR 23135, June 2, 1992), 
currently requires inspecting the nose landing gear (NLG) drag brace 
assembly for corrosion on certain Aerostar Aircraft Corporation 
(Aerostar) PA-60-600 (Aerostar 600) and PA-60-700 (Aerostar 700) series 
airplanes, and replacing any corroded components. It also requires 
replacing the existing spring and piston with new corrosion-resistant 
parts. These actions are accomplished in accordance with Aerostar 
Service Bulletin (SB) No. 600-121, dated September 12, 1991.
    Since issuing AD 92-13-01, the FAA has received several reports of 
frozen moisture in the cylinder of the over-center release system, 
which has led to nose gear collapse on airplanes in compliance with AD 
92-13-01. The actions required by this AD are intended to detect and 
correct any internal corrosion associated with water in the NLG 
cylinder and eliminate subsequent failure of the piston and return 
spring. However, moisture is still accumulating in the NLG cylinder, 
and subsequently, this moisture freezes on airplanes that are operated 
in below-freezing temperatures. Frozen moisture within the cylinder 
prevents the NLG from going to the over-center down and locked 
position.
    In order to prevent accumulation of water within the un-pressurized 
portion of the NLG cylinder, Aerostar has redesigned the cylinder as 
part of a new NLG drag link assembly. This cylinder utilizes a double 
acting piston where oil pressure is now used to return the piston as 
well as to extend it. A strengthened drag brace is also part of this 
assembly.
    Aerostar has issued SB No. 600-128, dated January 10, 1994, which 
references Kit No. 045-001 (Service Kit No. SB600-128), Drawing No. 
89414, Rev. N/C, dated December 28, 1993. This kit specifies procedures 
for installing this new improved NLG drag link assembly, part number 
(P/N) 450563-501.
    After examining the circumstances and reviewing all available 
information related to the incidents described above, the FAA has 
determined that (1) the existing drag link assembly should be replaced 
with this new assembly; and (2) AD action should be taken to prevent 
failure of the NLG caused by frozen moisture in the cylinder, which 
could lead to nose gear collapse and damage to the airplane.
    Since an unsafe condition has been identified that is likely to 
exist or develop in other Aerostar PA-60-600 (Aerostar 600) and PA-60-
700 (Aerostar 700) series airplanes of the same type design, the 
proposed AD would supersede AD 92-13-01 with a new AD that would 
require replacing the existing NLG drag link assembly, P/N 450563-1, 
with a new assembly of improved design, P/N 450563-501. The proposed 
actions would be accomplished in accordance with the instructions to 
Aerostar Kit No. 045-001 (Service Kit No. SB600-128), Drawing No. 
89414, Rev. N/C, dated December 28, 1993.
    The FAA estimates that 700 airplanes in the U.S. registry would be 
affected by the proposed AD, that it would take approximately 5 
workhours per airplane to accomplish the proposed action, and that the 
average labor rate is approximately $55 an hour. Parts cost 
approximately $1,500 per airplane. Based on these figures, the total 
cost impact of the proposed AD on U.S. operators is estimated to be 
$1,242,500. This figure is based on the assumption that no affected 
airplane operator has accomplished the proposed action. The FAA 
believes that numerous operators have already incorporated the 
modification referenced in this proposed AD.
    In addition, AD 92-13-01 requires installing a new spring and 
piston. The new NLG drag link assembly includes the improved design 
piston and spring. Aerostar will give a $96 credit for the piston and 
spring installed as required by AD 92-13-01. Aerostar has shipped 362 
of these piston and spring kits. Based on these figures, the cost 
referenced above would be reduced by $34,752 (362 airplanes x $96) from 
$1,242,500 to $1,207,748.
    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 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) 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 has been placed 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 14 
CFR part 39 of the Federal Aviation Regulations 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 AD 92-13-01, Amendment 39-
8270 (57 FR 23135, June 2, 1992), and by adding a new airworthiness 
directive to read as follows:

    Aerostar Aircraft Corporation: Docket No. 94-CE-04-AD. 
Supersedes AD 92-13-01, Amendment 39-8270.

    Applicability: The following model and serial numbered airplanes, 
certificated in any category: 

                                                                                                                
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                   Model                                                  Serial Nos.                           
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*PA-60-600 (Aerostar 600)...................  60-0001-003 through 60-0608-7961195.                              
PA-60-600 (Aerostar 600)....................  60-0614-7961196 through 60-0933-8164262.                          
*PA-60-601 (Aerostar 601)...................  61-0001-004 through 60-0605-7962136.                              
PA-60-601 (Aerostar 601)....................  61-0611-7962137 through 61-0880-8162157.                          
*PA-60-601P (Aerostar 601P).................  61P-0157-001 through 61P-0610-7963274.                            
PA-60-601P (Aerostar 601P)..................  61P-0612-7963275 through 61P-0859-8163455.                        
PA-60-602P (Aerostar 602P)..................  62P-0750-8165001 through 60-8365021.                              
PA-60-700P (Aerostar 700P)..................  60-8423001 through 60-8423025.                                    
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*=that have been converted to Wiebel nose gear system (Option No. 199)                                          

    Note 1: The manufacturing and ownership rights of the affected 
model airplanes were previously owned by the Piper Aircraft 
Corporation, but these rights were recently transferred to the 
Aerostar Aircraft Corporation.

    Compliance: Required within the next 100 hours time-in-service 
after the effective date of this AD, unless already accomplished.
    To prevent failure of the nose landing gear (NLG) caused by 
frozen moisture in the cylinder, which could lead to nose gear 
collapse and damage to the airplane, accomplish the following: (a) 
Replace the existing NLG drag link assembly, P/N 450563-1, with a 
new assembly of improved design, P/N 450563-501, in accordance with 
the instructions to Aerostar Kit No. 045-001 (Service Kit No. SB600-
128), Drawing No. 89414, Rev. N/C, dated December 28, 1993.
    (b) Special flight permits may be issued in accordance with 14 
CFR 21.197 and 21.199 to operate the airplane to a location where 
the requirements of this AD can be accomplished.
    (c) An alternative method of compliance or adjustment of the 
compliance time that provides an equivalent level of safety may be 
approved by the Manager, Seattle Aircraft Certification Office 
(ACO), 1601 Lind Avenue, SW., Renton, Washington 98055-4056. The 
request shall be forwarded through an appropriate FAA Maintenance 
Inspector, who may add comments and then send it to the Manager, 
Seattle ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

    (d) All persons affected by this directive may obtain copies of 
the documents referred to herein upon request to the Aerostar 
Aircraft Corporation, Customer Service Department, South 3608 
Davison Boulevard, Spokane, Washington 99204; or may examine these 
documents at the FAA, Central Region, Office of the Assistant Chief 
Counsel, room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.
    (e) This amendment supersedes AD 92-13-01, Amendment 39-8270.

    Issued in Kansas City, Missouri, on March 28, 1994.
Barry D. Clements,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 94-7788 Filed 3-31-94; 8:45 am]
BILLING CODE 4910-13-U