[Federal Register Volume 60, Number 35 (Wednesday, February 22, 1995)]
[Proposed Rules]
[Pages 9799-9800]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-4251]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 93-CE-61-AD]


Airworthiness Directives; Piper Aircraft Corporation PA24, PA28R, 
PA30, PA32R, PA32RT, PA34-200, PA34-200T, PA39, and PA44 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to adopt a new airworthiness directive 
(AD) that would apply to certain Piper Aircraft Corporation (Piper) 
PA24, PA28R, PA30, PA32R, PA32RT, PA34-200, PA34-200T, PA39, and PA44 
series airplanes. The proposed action would require repetitively 
inspecting the main gear side brace studs for cracks and replacing any 
cracked main gear side brace stud. Several reports of main gear side 
brace stud cracks on the affected airplanes, including seven incidents 
where the main landing gear (MLG) collapsed, prompted the proposed AD. 
The actions specified by the proposed AD are intended to prevent a MLG 
collapse caused by main gear side brace stud cracks, which, if not 
detected and corrected, could result in loss of control of the airplane 
during landing operations.

DATES: Comments must be received on or before May 5, 1995.

ADDRESSES: Submit comments in triplicate to the FAA, Central Region, 
Office of the Assistant Chief Counsel, Attention: Rules Docket No. 93-
CE-61-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.
    Information that relates to the proposed AD may be inspected at the 
Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Christina Marsh, Aerospace Engineer, 
FAA, Atlanta Aircraft Certification Office, Campus Building, 1701 
Columbia Avenue, Suite 2-160, College Park, Georgia 30337-2748; 
telephone (404) 305-7362; facsimile (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 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. 93-CE-61-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. 93-CE-61-AD, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106.

Discussion

    The FAA has received several reports of main gear side brace stud 
cracks on Piper PA24, PA32R, PA34-200, and PA34-200T series airplanes. 
These reports include an accident in the United Kingdom where the main 
landing gear (MLG) collapsed on a Piper PA34-200 series airplane 
because of high cycle fatigue cracking of the main gear side brace 
stud. Metallurgical examination of the stud revealed that separate 
fatigue cracks had originated from both the inboard and the outboard 
edges near the bending radius of the shank. Reverse bending loads then 
allowed these cracks to extend across approximately 30-percent of the 
shank cross-section. The remaining 70-percent of the shank cross-
section failed because of overstress. Review of service difficulty 
records in the United Kingdom and Canada, as well as the United States, 
indicated that this accident was almost identical to other accidents on 
Piper airplane models of similar type design.
    On February 11, 1994, the FAA issued an advance notice of proposed 
rulemaking (ANPRM) to solicit comments from owners/operators of the 
affected airplanes in order to adequately make a determination as to 
what type of action to take (if any). From responses to this ANPRM, the 
FAA found that most of the owners/operators that responded are 
currently inspecting the main gear side brace studs on a routine basis 
(every annual or 100 hours); however, these operators are not removing 
the studs or using non-destructive inspection methods. Based on its 
review of the above-referenced incidents, the FAA has determined that, 
in order to adequately detect any cracks on the main gear side brace 
studs, these studs must be removed and inspected using dye penetrant or 
magnetic particle methods.
    After examining the circumstances and reviewing all available 
information related to the incidents and accidents described above, 
including the comments received in response to the ANPRM, the FAA has 
determined that AD action should be taken to prevent MLG collapse 
caused by main gear side brace stud cracks, which, if not detected and 
corrected, could result in loss of control of the airplane during 
landing operations.
    Since an unsafe condition has been identified that is likely to 
exist or develop in other Piper PA24, PA28R, PA30, PA32R, PA32RT, PA34-
200, PA34-200T, PA39, and PA44 series airplanes of the same type 
design, the proposed AD would require repetitively inspecting (using 
dye penetrant or magnetic particle methods) the main gear side brace 
studs for cracks, and replacing any cracked main gear side brace stud.
    The FAA estimates that 9,200 airplanes in the U.S. registry would 
be affected by the proposed AD, that it would take approximately 5 
workhours to initially inspect both the right and left main landing 
gear side brace studs, and that the average labor rate is approximately 
$60 an hour. Based on these figures, the total cost impact of the 
proposed AD on U.S. operators is estimated to be $2,760,000. This 
figure represents the cost of the initial inspection, and does not 
reflect costs for [[Page 9800]] repetitive inspections or possible 
replacements. The FAA has no way of determining how many main gear side 
brace studs may need replacement or how many repetitive inspections 
each owner/operator may incur.
    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.

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 adding a new AD to read as follows:

Piper Aircraft Corporation: Docket No. 93-CE-61-AD. Applicability: 
PA24, PA28R, PA30, PA32R, PA32RT, PA34-200, PA34-200T, PA39, and 
PA44 series airplanes (all models and serial numbers), certificated 
in any category. Compliance: Required within the next 100 hours 
time-in-service (TIS) after the effective date of this AD, unless 
already accomplished, and thereafter as indicated.
    To prevent main landing gear (MLG) collapse caused by main gear 
side brace stud cracks, which, if not detected and corrected, could 
result in loss of control of the airplane during landing operations, 
accomplish the following:
    (a) Remove both the left and right main gear side brace studs 
from the airplane in accordance with the instructions contained in 
the Landing Gear section of the maintenance manual, and inspect each 
main gear side brace stud for cracks, using FAA-approved dye 
penetrant or magnetic particle methods.
    (1) For any main gear side brace stud found cracked, prior to 
further flight, replace the cracked stud with an FAA-approved 
serviceable part (part numbers referenced in the table in paragraph 
(b) of this AD) in accordance with the instructions contained in the 
Landing Gear section of the applicable maintenance manual, and 
reinspect as specified in paragraph (b) of this AD.
    (2) For any main gear side brace stud not found cracked, prior 
to further flight, reinstall the uncracked stud in accordance with 
the instructions contained in the Landing Gear section of the 
applicable maintenance manual, and reinspect as specified in 
paragraph (b) of this AD.
    (b) Reinspect both the left and right main gear side brace 
studs, using FAA-approved dye penetrant or magnetic particle 
procedures, at the applicable intervals presented below, and replace 
any cracked stud or reinstall any uncracked stud as specified in 
paragraphs (a)(1) and (a)(2) of this AD, respectively:

------------------------------------------------------------------------
                                                     Series Airplanes   
 Part number installed   TIS inspection interval       Installed on     
------------------------------------------------------------------------
20829-00...............  1,000 hours............  PA24.                 
22512-00...............  1,000 hours............  PA24, PA30, and PA39  
                95299-0  500 hours..............  PA28R, PA32R, PA32RT, 
                 0 or                              PA34-200, PA34-200T, 
                 95299-                            and PA44.            
                 02.                                                    
78717-02 (contained in   1,000 hours............  PA28R, PA32R, PA32T,  
 the part number 95643-                            PA34-200, PA34-200T, 
 06 or 95643-07 bracket                            and PA44.            
 assembly).                                                             
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    Note 1: Main gear side brace studs, part numbers, 95299-00 and 
95299-02, are no longer manufactured, and any main gear side brace 
stud found cracked incorporating one of these part numbers may be 
replaced with a part number 78717-02 main gear side brace stud 
contained in the part number 95643-06 and 95643-07 bracket assembly.

    Note 2: Accomplishing the actions of this AD does not affect the 
requirements of AD 77-13-21, Amendment 39-3093. The tolerance 
inspection requirements of that AD still apply for Piper PA24, PA30, 
and PA39 series airplanes.

    (c) 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.
    (d) An alternative method of compliance or adjustment of the 
initial or repetitive compliance times that provides an equivalent 
level of safety may be approved by the Manager, Atlanta Aircraft 
Certification Office (ACO), Campus Building, 1701 Columbia Avenue, 
Suite 2-160, College Park, Georgia 30337-2748. The request shall be 
forwarded through an appropriate FAA Maintenance Inspector, who may 
add comments and then send it to the Manager, Atlanta ACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Atlanta ACO.

    (e) Information related to this AD may be inspected at the FAA, 
Central Region, Office of the Assistant Chief Counsel, Room 1558, 
601 E. 12th Street, Kansas City, Missouri.

    Issued in Kansas City, Missouri, on February 14, 1995.
Barry D. Clements,
Manager, Small Airpane Directorate, Aircraft Certification Service.
[FR Doc. 95-4251 Filed 2-21-95; 8:45 am]
BILLING CODE 4910-13-U