AD 96-10-13

[Federal Register Volume 61, Number 96 (Thursday, May 16, 1996)]
[Rules and Regulations]
[Pages 24691-24693]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-12141]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 90-CE-61-AD; Amendment 39-9620; AD 96-10-13]
RIN 2120-AA64


Airworthiness Directives; the New Piper Aircraft, Inc. (Formerly 
Piper Aircraft Corporation) Models PA31T, PA31T1, PA31T2, and PA31T3 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes Airworthiness Directive (AD) 84-08-
06, which currently requires the following on certain The New Piper 
Aircraft, Inc. (Piper) Models PA31T, PA31T1, PA31T2, and PA31T3 
airplanes: repetitively inspecting the fuselage station (FS) 332 
bulkhead for cracks, and reinforcing or replacing the FS 332 bulkhead 
if cracks are found. The Federal Aviation Administration's policy on 
aging commuter-class aircraft is to eliminate or, in certain instances, 
reduce the number of certain repetitive short-interval inspections when 
improved parts or modifications are available. This action retains the 
current repetitive inspections contained in AD 84-08-06, and requires 
incorporating a stabilizer forward spar attachment bulkhead 
reinforcement kit or installing a reinforced bulkhead assembly as 
terminating action for the repetitive inspection requirement. The 
actions specified in this AD are intended to prevent structural failure 
of the horizontal stabilizer and the aft fuselage attachment caused by 
cracks in the FS 332 bulkhead, which, if not detected and corrected, 
could result in loss of control of the airplane.

DATES: Effective June 27, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of June 27, 1996.

ADDRESSES: Service information that applies to this AD may be obtained 
from The New Piper Aircraft, Inc., Customer Services, 2926 Piper Drive, 
Vero Beach, Florida 32960. This information may also be examined at the 
Federal Aviation Administration (FAA), Central Region, Office of the 
Assistant Chief Counsel, Attention: Rules Docket 90-CE-61-AD, Room 
1558, 601 E. 12th Street, Kansas City, Missouri 64106; or at the Office 
of the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.

FOR FURTHER INFORMATION CONTACT: Christina Marsh, Aerospace Engineer,

[[Page 24692]]

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:

Events Leading to the AD

    A proposal to amend part 39 of the Federal Aviation Regulations (14 
CFR part 39) to include an AD that would apply to Piper Models PA31T, 
PA31T1, PA31T2, and PA31T3 airplanes was published in the Federal 
Register on January 19, 1996 (61 FR 1303). The action proposed to 
supersede AD 84-08-06 with a new AD that would (1) retain the 
requirement of repetitively inspecting the FS 332 bulkhead for cracks, 
reinforcing the FS 332 bulkhead (Piper Kit 764-983) if any crack is 
found that does not exceed certain limits, and replacing the bulkhead 
assembly with a reinforced bulkhead assembly (part number 45583-16 or 
45583-17) if any crack is found that exceeds certain limits; and (2) 
require incorporating a stabilizer forward spar attachment bulkhead 
reinforcement (Piper Kit 764-983) or a reinforced bulkhead assembly 
(part number 45583-16 or 45583-17) as terminating action for the 
repetitive inspection requirement. Accomplishment of the proposed 
inspections would be in accordance with Piper Service Bulletin No. 
773A, dated May 3, 1984. The incorporation of Piper Kit 764-983 would 
be accomplished in accordance with the instructions to this kit 
(Revised June 18, 1990), and the reinforced bulkhead installations 
would be accomplished in accordance with the applicable maintenance 
manual.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were received on the 
proposed rule or the FAA's determination of the cost to the public.
    After careful review of all available information related to the 
subject presented above, the FAA has determined that air safety and the 
public interest require the adoption of the rule as proposed except for 
minor editorial corrections. The FAA has determined that these minor 
corrections will not change the meaning of the AD and will not add any 
additional burden upon the public than was already proposed.

Cost Impact

    The FAA estimates that 736 airplanes in the U.S. registry will be 
affected by this AD, that it will take approximately 60 workhours per 
airplane to accomplish the required replacement, and that the average 
labor rate is approximately $60 an hour. Parts cost approximately $782 
per airplane. Based on these figures, the total cost impact of this AD 
on U.S. operators is estimated to be $3,225,152 or $4,382 per airplane. 
This figure is based on the assumption that no affected airplane owner/
operator has accomplished the required replacement.
    Piper has informed the FAA that parts have been distributed to 
enough owners/operators to equip 348 of the affected airplanes. 
Assuming that each set of parts has been installed on an affected 
airplane, the cost impact of this AD upon U.S. owners operators of the 
affected airplanes is reduced by $1,524,936 from $3,225,152 to 
$1,700,216.

The FAA's Aging Commuter Class Aircraft Policy

    This AD is part of the FAA's aging commuter class airplane policy, 
which briefly states that, when a modification exists that could 
eliminate or reduce the number of required critical inspections, the 
modification should be incorporated.
    The intent of the FAA's aging commuter airplane program is to 
ensure safe operation of commuter-class airplanes that are in 
commercial service without adversely impacting private operators. The 
FAA believes that a large number of the remaining 388 affected 
airplanes (736 affected airplanes--348 sets of parts distributed) that 
will be affected by the required modification AD are operated in 
various types of air transportation. This includes scheduled passenger 
service, air cargo, and air taxi.
    This AD allows 600 hours time-in-service (TIS) after the effective 
date of this AD before mandatory accomplishment of the design 
modification. The average utilization of the fleet for those airplanes 
in air transportation is between 25 to 40 hours TIS per week. Based on 
these figures, operators of commuter-class airplanes involved in 
commercial operation will have to accomplish the required modification 
within four to six months after this AD becomes effective. For private 
owners, who typically operate between 100 to 200 hours TIS per year, 
this will allow three to six years before the required modification 
will be mandatory.
    The FAA established the 600 hours TIS replacement compliance time 
based on its engineering evaluation of the problem. Among the issues 
examined in this engineering evaluation were analysis of service 
difficulty reports, the difficulty level of the inspection, and how 
critical the situation would be if cracks occurred in the subject area 
despite accomplishment of the repetitive inspections.
    Usually, the FAA establishes the mandatory design modification 
compliance time on AD's affecting aging commuter-class airplanes upon 
the accumulation of a certain number of hours TIS on the airplane. For 
this action, the FAA is mandating the modification for all operators 
``within the next 600 hours TIS after the effective date of this AD.'' 
The total TIS levels of the airplane fleet vary from under 1,000 hours 
TIS to over 5,000 hours TIS, and annual accumulation rates vary from 50 
hours TIS to over 1,000 hours TIS. Establishing a long-term set 
compliance time of hours TIS accumulated on Piper Models PA31T, PA31T1, 
PA31T2, and PA31T3 airplanes (such as 5,000 hours TIS) imposes an undue 
burden on the manufacturer of having to maintain a supply of 
replacement parts for the entire fleet when many airplanes in the fleet 
may never reach this compliance time.
    Instead, the FAA believes that Piper should maintain parts for 
several years; in this case about six years to allow low-usage 
airplanes time to accumulate the 600 hours after the effective date of 
the AD. The FAA has determined that the compliance time of this rule 
provides the level of safety required for commuter air service while 
still minimizing the impact on the private airplane owners of Piper 
Models PA31T, PA31T1, PA31T2, and PA31T3 airplanes.

Regulatory Impact

    The regulations adopted herein will 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 final 
rule does 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) 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 final evaluation prepared for this 
action is

[[Page 24693]]

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, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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 USC 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing Airworthiness Directive 
(AD) 84-08-06, Amendment 39-4851, and by adding a new AD to read as 
follows:

96-10-13  The New Piper Aircraft, Inc. (formerly Piper Aircraft 
Corporation): Amendment 39-9620; Docket No. 90-CE-61-AD. Supersedes 
AD 84-08-06, Amendment 39-4851.

    Applicability: The following model and serial number airplanes, 
certificated in any category, that do not have either Piper Kit 764-
983 (stabilizer forward spar attachment bulkhead reinforcement) 
incorporated at Fuselage Station (FS) 332 or have a part number (P/
N) 45583-16 or P/N 45583-17 bulkhead assembly installed:

------------------------------------------------------------------------
               Models                             Serial No.            
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PA31T..............................  31T-7400002 through 31T-8120104.   
PA31T1.............................  31T-7804001 through 31T-8104101,   
                                      31T-8304003, and 31T-1104004      
                                      through 31T-1104007.              
PA31T2.............................  31T-8166001 through 31T-8166032,   
                                      31T-8166034 through 31T-8166065,  
                                      31T-8166067 through 31T-8166071,  
                                      and 31T-8166073 through 31T-      
                                      8166075.                          
PA31T3.............................  31T-8275001, 31T-8275003 through   
                                      31T-8275012, 31T-8275014 through  
                                      31T-8275017, 31T-8275025, and 31T-
                                      8375001 through 31T-8375005.      
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    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 request approval for an 
alternative method of compliance in accordance with paragraph (h) 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 in the body of this AD, unless 
already accomplished.
    To prevent structural failure of the horizontal stabilizer and 
the aft fuselage attachment caused by cracks in the FS 332 bulkhead, 
which, if not detected and corrected, could result in loss of 
control of the airplane, accomplish the following:
    (a) Within the next 200 hours time-in-service (TIS) after the 
effective date of this AD, unless already accomplished (compliance 
with AD 84-08-06), and thereafter at intervals not to exceed 200 
hours TIS until the modification required by paragraph (c), (d), or 
(e) of this AD is incorporated, inspect (using dye penetrant 
methods) the FS 332 bulkhead for cracks. Accomplish the inspections 
in accordance with the INSTRUCTIONS section of Piper Service 
Bulletin (SB) No. 773A, dated May 3, 1984.
    (b) The initial dye penetrant inspection type must be utilized 
for all future repetitive inspections. Dye penetrant inspection 
types consist of Type I: fluorescent; Type II: non-fluorescent or 
visible dye; and Type III: dual sensitivity.
    (c) If cracks are found during any of the inspections required 
in paragraph (a) of this AD and no crack exceeds the limitations 
specified in Piper SB No. 773A, dated May 3, 1984, prior to further 
flight, repair the cracks in accordance with Piper SB No. 773A, 
dated May 3, 1984, and reinforce the FS 332 bulkhead by 
incorporating Piper Kit 764-983 in accordance with the instructions 
to Piper Kit 764-983, Revised June 18, 1990.
    (d) If cracks are found during any of the inspections required 
in paragraph (a) of this AD and any crack exceeds the limitations 
specified in Piper SB No. 773A, dated May 3, 1984, prior to further 
flight, replace the bulkhead assembly with a reinforced bulkhead 
assembly, P/N 45583-16 or P/N 45583-17. Accomplish this replacement 
in accordance with the applicable maintenance manual.
    (e) Upon the accomplishment of the third repetitive inspection 
required by this AD (600 hours TIS after the effective date of this 
AD), unless already accomplished as required by paragraph (c) or (d) 
of this AD, accomplish one of the following, as applicable:
    (1) If cracks are found and no crack exceeds the limitations 
specified in Piper SB No. 773A, dated May 3, 1984, repair the cracks 
in accordance with Piper SB No. 773A, dated May 3, 1984, and 
reinforce the FS 332 bulkhead by incorporating Piper Kit 764-983 in 
accordance with the instructions to Piper Kit 764-983, Revised June 
18, 1990;
    (2) If cracks are found and any crack exceeds the limitations 
specified in Piper SB No. 773A, dated May 3, 1984, replace the 
bulkhead assembly with a reinforced bulkhead assembly, P/N 45583-16 
or P/N 45583-17, in accordance with the applicable maintenance 
manual; or
    (3) If no cracks are found, either reinforce the FS 332 bulkhead 
by incorporating Piper Kit 764-983 in accordance with the 
instructions to Piper Kit 764-983, Revised June 18, 1990; or replace 
the bulkhead assembly with a reinforced bulkhead assembly, P/N 
45583-16 or P/N 45583-17, in accordance with the applicable 
maintenance manual.
    (f) Incorporating Piper Kit 764-983 or installing reinforced 
bulkhead assembly, P/N 45583-16 or P/N 45583-17, as required by 
paragraphs (c) and (d) or (e) of this AD is considered terminating 
action for the repetitive inspection requirement of this AD.
    (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.
    (h) An alternative method of compliance or adjustment of the 
compliance time 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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Atlanta ACO.
    Note 3: Alternative methods of compliance approved in accordance 
with AD 84-08-06 (superseded by this action) are not considered 
approved as alternative methods of compliance with this AD.

    (i) The inspections and possible repair required by this AD 
shall be done in accordance with Piper Service Bulletin No. 773A, 
dated May 3, 1984. The reinforcement required by this AD shall be 
done in accordance with the instructions to Piper Kit 764-983, 
Revised June 18, 1990. This incorporation by reference was approved 
by the Director of the Federal Register in accordance with 5 U.S.C. 
552(a) and 1 CFR part 51. Copies may be obtained from The New Piper 
Aircraft, Inc., 2926 Piper Drive, Vero Beach, Florida 32960. Copies 
may be inspected at the FAA, Central Region, Office of the Assistant 
Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, 
or at the Office of the Federal Register, 800 North Capitol Street 
NW., suite 700, Washington, DC.
    (j) This amendment (39-9620) supersedes AD 84-08-06, Amendment 
39-4851.
    (k) This amendment (39-9620) becomes effective on June 27, 1996.

    Issued in Kansas City, Missouri, on May 8, 1996.
Henry A. Armstrong,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-12141 Filed 5-15-96; 8:45 am]
BILLING CODE 4910-13-P