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 Department of Transportation Federal Aviation Administration 14 CFR Part 39
[Docket No. 96-CE-69-AD; Amendment 39-12035; AD 2000-25-01]
RIN 2120-AA64
 AGENCY: Federal Aviation Administration, DOT.
 ACTION: Final rule.
 SUMMARY: This amendment supersedes Airworthiness Directive (AD) 80-26-05, which currently requires you to repetitively inspect the main landing gear (MLG) inboard door hinges and attachment angles for cracks on certain The New Piper Aircraft, Inc. (Piper) PA-31 series airplanes. AD 80-26-05 also requires you to replace any cracked MLG inboard door hinge or attachment angle with parts of improved design. This AD results from the Federal Aviation Administration's policy on aging commuter-class aircraft and the determination that an improved design MLG inboard door hinge and attachment assembly, when incorporated, will eliminate the need for the currently required repetitive short-interval inspections; however, we have received reports of cracks in the improved design MLG inboard door hinge assemblies on the affected airplanes. This AD retains the current repetitive inspections contained in AD 80-26-05, and requires inspections on the improved design parts. The actions specified by this AD are intended to detect and correct cracked MLG inboard door hinge assemblies. These cracked door hinge assemblies could result in the MLG becoming jammed, with consequent loss of control of the airplane during landing operations.
 DATES: This AD becomes effective on January 19, 2001. The Director of the Federal Register approved the incorporation by reference of certain publications listed in the regulations as of January 19, 2001.
 ADDRESSES: You may get the service information referenced in this AD from The New Piper Aircraft, Inc., Customer Services, 2926 Piper Drive, Vero Beach, Florida 32960. You may examine this information at the Federal Aviation Administration (FAA), Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 96-CE-69-AD, 901 Locust, Room 506, 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: William O. Herderich, Aerospace Engineer, FAA, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, Georgia 30349; telephone: (770) 703-6082; facsimile: (770) 703-6097; e-mail: 
                        *william.o.herderich@faa.gov.*


SUPPLEMENTARY INFORMATION: Discussion *What prior AD action did FAA take on this subject?*
                    In 1980, FAA issued AD 80-26-05, Amendment 39-3994, in order to detect and correct cracked main landing gear (MLG) inboard door hinge assemblies on certain Piper PA-31 series airplanes. AD 80-26-05 currently requires you to repetitively inspect the MLG inboard door hinges and attachment angles for cracks; and requires you to replace any cracked MLG inboard door hinge or attachment angle. On December 1, 1995, we issued a proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to certain Piper PA-31 series airplanes. This proposal was published in the 
                    **Federal Register**
                     as a notice of proposed rulemaking (NPRM) on December 7, 1995 (60 FR 62774), and proposed to supersede AD 80-26-05, Amendment 39-3994. The NPRM proposed to: —Retain the requirement of repetitively inspecting the MLG inboard door hinge assemblies for cracks, and replacing any cracked MLG inboard door hinge assembly; and —Require incorporating a MLG inboard door hinge assembly of improved design (part number (P/N) 47529-32) or FAA-approved equivalent part number, as terminating action for the repetitive inspection requirement. Accomplishment of the proposed inspections would have been required in accordance with Piper Service Bulletin (SB) No. 682, dated July 24, 1980. This NPRM was consistent with FAA's aging commuter-class aircraft 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. This policy is based on FAA's determination that reliance on critical repetitive inspections on aging commuter-class airplanes carries an unnecessary safety risk when a design change exists that could eliminate or, in certain instances, reduce the number of those critical inspections. The alternative to installing the improved design hinge assemblies on the affected airplanes would be to rely on the repetitive inspections required by AD 80-26-05 to detect cracks in these areas. *Was the public invited to comment on the NPRM?*
                     The FAA invited interested persons to participate in the making of this amendment. Due consideration was given to the one comment received. *What issue did this comment address?*
                     The comment received on the NPRM contained information that the improved design MLG inboard door hinge assemblies, P/N 47529-32, are also susceptible to fatigue cracking, and that installing this assembly should not eliminate the need for the repetitive inspections currently required by AD 80-26-05. The commenter stated that its airplane fleet has experienced three failures and three incidents related to fatigue cracking of the P/N 47529-32 hinge assemblies. *What action did FAA take?*
                     We conducted a review of the manufacturer's service history and service difficulty reports in FAA's database associated with the P/N 47529-32 MLG inboard door hinge assembly. Based on a review of this information, including the information received from the commenter, we determined that more information and analysis were needed before mandating MLG inboard door hinge assembly replacements through an AD. We then issued an advance notice of proposed rulemaking (ANPRM) on February 11, 1997. The ANPRM was published in the 
                    **Federal Register**
                     on February 19, 1997 (62 FR 7375). The purpose of the ANPRM was to encourage interested persons to provide information that describes what they consider the best action (if any) for FAA to take regarding the P/N 47529-32 MLG inboard door hinge assembly issue. The FAA also withdrew the NPRM. We received no information or comments regarding the ANPRM. We then re-evaluated the information in our service difficulty database. The database, at that time, contained 10 reports of failure or cracks found in the MLG inboard door hinge assembly on the affected airplanes. The commenter to the original NPRM had submitted six 
                    ( print page 78903)
                    of these reports. Three of these six incident reports were specifically attributed to the original MLG inboard door hinge assemblies and three to the improved design MLG inboard door hinge assemblies. The four reports that others submitted do not specifically identify whether the original MLG inboard door hinge assemblies were installed or the improved design assemblies were installed. Since the incidents occurred on high service time airplanes and since there is no AD action mandating the installation of the improved-design MLG inboard door hinge assemblies, we presumed that the original hinge assemblies were installed. The FAA then reviewed the three incident reports on the improved design MLG inboard door hinge assemblies and, along with the National Transportation Safety Board (NTSB), performed extensive testing and analysis of the improved design MLG inboard door hinge assemblies. Based on this review, testing, and analysis, we determined that: —The incidents were isolated and that mandating repetitive inspections was not needed when the P/N 47529-32 MLG inboard door hinge assemblies are installed; and —AD action should be taken to eliminate the repetitive short-interval inspections that AD 80-26-05 requires and to prevent separation of a MLG door from the airplane caused by a cracked inboard door hinge assembly. On October 14, 1997, FAA issued an NPRM to address these issues. The NPRM was published in the 
                    **Federal Register**
                     on October 21, 1997 (62 FR 54595). *What has happened to justify this AD action?*
                     Since issuance of the NPRM, we have received additional reports of cracks in the MLG inboard door hinge assemblies. The reports reference incidents on both the original design assemblies and the improved design hinges. As of the issue date of this document, we have reports of the following: —27 reports of cracked improved design MLG inboard door hinge assemblies; and —41 reports of cracked original design MLG inboard door hinge assemblies. We issued a proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to certain Piper PA-31 series airplanes. This proposal was published in the 
                    **Federal Register**
                     as a supplemental NPRM on July 21, 2000 (65 FR 45323). The supplemental NPRM proposed to supersede AD 80-26-05, Amendment 39-3994, with a new AD that proposed to require: —Repetitively inspecting the MLG inboard door hinge assemblies (regardless of part number); and —Immediately replacing any cracked MLG inboard door hinge assembly with a new MLG inboard door hinge assembly, Piper part number (P/N) 47529-32 (or FAA-approved equivalent part number). *What is the potential impact if FAA took no action?*
                     These actions are necessary to detect and correct cracked MLG inboard door hinge assemblies. These cracked door hinge assemblies could result in the MLG becoming jammed with consequent loss of control of the airplane during landing operations. *Was the public invited to comment?*
                     The FAA encouraged interested persons to participate in the making of this amendment. The following presents the comments received on the proposal and FAA's response to each comment: Comment Issue No. 1: Piper Part Number (P/N) 47529-32 MLG Door Hinge Assemblies Are Not Made of Steel *What is the commenter's concern?*
                     The commenter states that the NPRM incorrectly identifies the Piper P/N 47529-32 MLG door hinge assemblies as parts made of steel. The commenter explains that these assemblies are made of aluminum. *What is FAA's response to the concern?*
                     We concur that the Piper P/N 47529-32 MLG door hinge assemblies are made of aluminum. We inadvertently referenced these parts as steel parts in the supplemental NPRM. We are changing the final rule AD accordingly. Comment Issue No. 2: All MLG Door Hinge Assemblies Should Be Inspected at 100-Hour TIS Intervals *What is the commenter's concern?*
                     The commenter expresses doubt that the Piper P/N 47529-32 MLG door hinge assemblies can go as long as 2,000-hour TIS intervals between inspections before cracking. The commenter recommends 100-hour TIS interval inspections for these assemblies. *What is FAA's response to the concern?*
                     We determined that the 2,000-hour TIS interval was an adequate compliance time for these parts based on our conservative estimate of all quantitative information available. The service reports indicate failures on airplanes ranging from a low of 3,615 total hours TIS to a high of 14,852 total hours TIS. We are not changing the final rule AD as a result of this comment. Comment Issue No. 3: FAA Underestimated the Cost Impact *What is the commenter's concern?*
                     The commenter states that the cost impact presented in the supplemental NPRM is incorrect because: —Removal of the hinges provides the most practical method of fluorescent dye-penetrant inspections and this would raise the inspections costs from $120 to $500; and —The cost of Piper P/N 47-528-32 MLG door hinge assemblies is approximately $465 instead of $270 as specified in the supplemental NPRM. *What is FAA's response to the concern?*
                     We do not concur with changing the cost to accomplish the inspection. While removing the hinges from the airplane to accomplish the inspection is an option, FAA has determined that you can adequately accomplish the inspections without removing the hinges. After checking with the manufacturer, we concur that the cost for the replacement MLG door hinge assemblies is approximately $465. We are changing the Cost Impact section of this document accordingly. Comment Issue No. 4: AD Should Not Apply to MLG Door Hinge Assemblies That Are Made of Steel *What is the commenter's concern?*
                     The commenter states that the AD should follow Piper Service Bulletin No. 682 and not require inspections on airplanes that have MLG door hinge assemblies that are made of steel. The commenter also requests that FAA include a list of the two outside sources that currently provide assemblies made of steel. *What is FAA's response to the concern?*
                     We concur that the AD should not apply to MLG door hinge assemblies that are made of steel and we are changing the final rule accordingly. However, FAA is not including the list of those outside sources that currently provide assemblies made of steel. If we did include this list, out of fairness, we would feel obligated to revise the AD anytime an outside source developed and received approval for installation of MLG door hinge assemblies made of steel on the affected airplanes. A list of outside vendors with FAA-approved assemblies made of steel is always available from the FAA address included in the AD. 
                    ( print page 78904) The FAA's Determination *What is FAA's final determination on this issue?*
                     We carefully reviewed all available information related to the subject presented above and determined that air safety and the public interest require the adoption of the rule as proposed except for the changes discussed above and editorial corrections. These changes and corrections provide the intent that was proposed in the supplemental NPRM for correcting the unsafe condition and do not impose any additional burden than what was intended in the supplemental NPRM. Cost Impact *How many airplanes does this AD impact?*
                     We estimate that this AD affects 2,344 airplanes in the U.S. registry. *What is the cost impact of this AD on owners/operators of the affected airplanes?*
                     We estimate the following costs to accomplish the initial inspection: Labor cost
Parts cost
Total cost per airplane
Total cost on U.S. 
                             airplane  
                             operators2 workhours × $60 per hour = $120
No parts required for the inspection
$120 per airplane
$281,280
 We estimate the following costs to accomplish the replacement, if necessary: Labor cost
Parts cost
Total cost per airplane2 workhours × $60 per hour = $120
$465 per airplane
$585 per airplane.
 Regulatory Impact *Does this AD impact various entities?*
                     The regulations adopted herein will not have a substantial direct effect 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, it is determined that this final rule does not have federalism implications under Executive Order 13132. *Does this AD involve a significant rule or regulatory action?*
                     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 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, under 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 U.S.C. 106(g), 40113, 44701. § 39.13
 2.FAA amends § 39.13 by removing Airworthiness Directive (AD) 80-26-05, Amendment 39-3994, and by adding a new AD to read as follows: **2000-25-01 The New Piper Aircraft, Inc. (formerly Piper Aircraft Corporation):**
                             Amendment 39-12035; Docket No. 96-CE-69-AD; Supersedes AD 80-26-05, Amendment 39-3994. (a) 
                            *What airplanes are affected by this AD?*
                             The following airplane models and serial numbers that are: (1) Certificated in any category; and (2) Equipped with Piper part number 46653-00 or 47529-32 main landing gear door hinge assemblies made of aluminum (or FAA-approved equivalent part numbers). Models
Serial Nos.PA-31
31-2 through 31-900 and 31-7300901 through 31-8312019.PA-31-300
31-2 through 31-900 and 31-7300901 through 31-8312019.PA-31-350
31-5001 through 31-5004 and 31-7305005 through 31-8553002.PA-31-325
31-7400990, 31-7512001 through 31-8312019.PA-31P
31P-1 through 31P-109 and 31P-7300110 through 31P-7730012.PA-31T
31T-7400002 through 31T-8120104.PA-31T1
31T-7804001 through 31T-8104073; 31T-8104101; 31T-8304001 through 31T-8304003; and 31T-1104004 through 31T-1104017.PA-31T2
31T-8166001 through 31T-8166076, and 31T-1166001 through 31T-1166008.PA-31T3
31T-8275001 through 31T-8475001, and 31T-5575001.PA-31P-350
31P-8414001 through 31P-8414050.
 Note 1: Aircraft referred to as Model PA-31-310 are actually Model PA-31 airplanes. Actions specified for PA-31 airplanes must also be performed. See also AD 80-26-05, Piper Service Bulletin No. 682, dated July 24, 1980, and type certificate data sheet A20SO. (b) 
                            *Who must comply with this AD?*
                             Anyone who wishes to operate any of the above airplanes must comply with this AD. (c) 
                            *What problem does this AD address?*
                             The actions specified by this AD are intended to detect and correct cracked main landing gear (MLG) inboard door hinge assemblies. This could result in the MLG becoming jammed with consequent loss of control of the airplane during landing operations. 
                            ( print page 78905) (d) 
                            *What actions must I accomplish to address this problem?*
                             To address this problem, you must accomplish the following: Action
Compliance time
Procedures(1) For airplanes with any MLG inboard door hinge assembly that is Piper part number 47529-32 (or FAA-approved equivalent part number), accomplish the following: 
                                     (i) Inspect all hinges and hinge attachment angles in the MLG inboard door hinge assembly; and
Inspect upon accumulating 2,000 hours time-in-service (TIS) on the MLG inboard door hinge assembly or within the next 100 hours TIS after January 19, 2001 (the effective date of this AD), whichever occurs later; and thereafter at intervals not to exceed 2,000 hours TIS. Accomplish the replacement, if necessary, prior to further flight after the inspection
Accomplish in accordance with the INSTRUCTIONS section of Piper Service Bulletin No. 682, dated July 24, 1980(ii) Replace any cracked MLG inboard door hinge assembly with a Piper part number 47529-32 assembly (or FAA-approved equivalent part number)(2) For airplanes with any aluminum MLG inboard door hinge assembly that is not Piper part number 47529-32 (or FAA-approved equivalent part number) or any assembly that is not made of steel, accomplish the following: 
                                     (i) Inspect all hinges and hinge attachment angles in the MLG inboard door hinge assembly; and
Inspect at the next inspection required by AD 80-26-05 or within the next 100 hours time-in-service (TIS) after January 19, 2001 (the effective date of this AD), whichever occurs first, and thereafter at intervals not to exceed 100 hours TIS. Accomplish the replacement, if necessary, prior to further flight after the inspection where the cracked assembly was found
Accomplish in accordance with the INSTRUCTIONS section of Piper Service Bulletin No. 682, dated July 24, 1980.(ii) Replace any cracked MLG inboard door hinge assembly with a Piper part number 47529-32 assembly (or FAA-approved equivalent part number)
 (e) 
                            *Can I comply with this AD in any other way?* (1) You may use an alternative method of compliance or adjust the compliance time if: (i) Your alternative method of compliance provides an equivalent level of safety; and (ii) The Manager, Atlanta Aircraft Certification Office (ACO), approves your alternative. Submit your request through an FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Atlanta ACO. (2) Alternative methods of compliance approved in accordance with AD 80-26-05 (superseded by this action) are not considered approved as alternative methods of compliance with this AD. Note 2: This AD applies to each airplane identified in paragraph (a) of this AD, 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 (e) 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 you have not eliminated the unsafe condition, specific actions you propose to address it. (f) 
                            *Where can I get information about any already-approved alternative methods of compliance?*
                             Contact William O. Herderich, Aerospace Engineer, FAA, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, Georgia 30349; telephone: (770) 703-6082; facsimile: (770) 703-6097; e-mail: 
                            *william.o.herderich@faa.gov.* (g) 
                            *What if I need to fly the airplane to another location to comply with this AD?*
                             The FAA can issue a special flight permit under sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate your airplane to a location where you can accomplish the requirements of this AD (h) 
                            *Are any service bulletins incorporated into this AD by reference?*
                             Actions required by this AD must be done in accordance with Piper Service Bulletin No. 682, dated July 24, 1980. The Director of the Federal Register approved this incorporation by reference under 5 U.S.C. 552(a) and 1 CFR part 51. You can get copies from The New Piper Aircraft, Inc., Customer Service, 2926 Piper Drive, Vero Beach, Florida 32960. You can look at copies at FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW, suite 700, Washington, DC. (i) 
                            *Does this AD action affect any existing AD actions?*
                             This amendment supersedes AD 80-26-05, Amendment 39-3994. (j) 
                            *When does this amendment become effective?*
                             This amendment becomes effective on January 19, 2001. Issued in Kansas City, Missouri, on November 30, 2000. William J. Timberlake, Acting Manager, Small Airplane Directorate, Aircraft Certification Service.


[FR Doc. 00-31451 Filed 12-15-00; 8:45 am] BILLING CODE 4910-13-P