Airworthiness directives: Ayres Corp.,
[Federal Register: January 13, 1999 (Volume 64, Number 8)]
[Proposed Rules]
[Page 2157-2161]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr13ja99-16]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-CE-56-AD]
RIN 2120-AA64
Airworthiness Directives; Ayres Corporation S2R Series and Model 600 S2D Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: This document proposes to supersede Airworthiness Directive (AD) 97-17-03, which currently requires inspecting the \1/4\-inch and \5/16\-inch bolt hole areas on the lower spar caps for fatigue cracking on Ayres S2R series and Model 600 S2D airplanes, and replacing any lower spar cap where fatigue cracking is found. That AD resulted from an accident on an Ayres S2R series airplane where the wing separated from the airplane in flight. The proposed AD would retain the initial inspection and possible replacement requirements of AD 97-17-03, would require the inspections to be repetitive, would add certain Ayres airplanes to the Applicability of the AD, would change the initial compliance time for all airplanes, and would arrange the affected airplanes into four groups instead of three based on usage and configurations. The actions specified by the proposed AD are intended to detect fatigue cracking of the lower spar caps, which could result in the wing separating from the airplane with consequent loss of control of the airplane.
DATES: Comments must be received on or before March 15, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 98-CE-56-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 the proposed AD may be obtained from the Ayres Corporation, P.O. Box 3090, One Rockwell Avenue, Albany, Georgia 31706-3090. This information also may be examined at the Rules Docket at the address above.
FOR FURTHER INFORMATION CONTACT: Satish Lall, Aerospace Engineer, FAA, Atlanta Aircraft Certification Office,
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One Crown Center, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia 30349; telephone: (770) 703-6082; facsimile: (770) 703-6097.
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 filedin 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. 98-CE-56-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 Regional Counsel, Attention: Rules Docket No. 98-CE-56-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.
Discussion
AD 97-17-03, Amendment 39-10105 (62 FR 43926, August 18, 1997), currently requires the following on Ayres S2R series and Model 600 S2D airplanes:
--Inspecting the \1/4\-inch and \5/16\-inch bolt hole areas on the lower spar caps for fatigue cracking; and --Replacing any lower spar cap where fatigue cracking is found.
AD 97-17-03 superseded AD 97-13-11 (62 FR 36978, July 10, 1997), which required the same actions but contained an incorrect designation of the Model S2R-R1340 airplanes.
Accomplishment of the inspection is required in accordance with Ayres Service Bulletin No. SB-AG-39, dated September 17, 1996. This inspection utilizes magnetic particle procedures and must follow American Society for Testing Materials (ASTM) E1444-94A, using wet particles meeting the requirements of the Society for Automotive Engineers (SAE) AMS 3046. This inspection is to be accomplished by a Level 2 or Level 3 inspector certified using the guidelines established by the American Society for Nondestructive Testing or MIL-STD-410.
Accomplishment of the replacement, if necessary, is required in accordance with the applicable maintenance manual.
That AD resulted from an accident on an Ayres S2R series airplane where the wing separated from the airplane in flight. Investigation of all resources available to the FAA at the time of the accident showed nine occurrences of fatigue cracking in the lower spar caps of Ayres S2R airplanes, specifically emanating from the \1/4\-inch and \5/16\- inch bolt holes. Investigation of the above-referenced accident revealed that the cause can be attributed to fatigue cracks emanating from the \1/4\-inch and \5/16\-inch bolt holes in the left lower spar cap. Because the Ayres Model 600 S2D airplanes have a similar type design to that of the S2R series airplanes, they were included in the Applicability of AD 97-17-03.
Data accumulated by the FAA indicates that the fatigue cracks on these Ayres S2R series airplanes become detectable at different times based upon the type of engines and design of the airplane. With this in mind, the FAA categorized these airplanes into three groups for the Applicability of AD 97-17-03:
--Group 1 airplanes have steel spar caps with aluminum webs. These airplanes are capable of carrying heavier loads and data indicated that the inspections in the affected areas of the lower spar caps required by AD 97-17-03 should begin upon the accumulation of 2,700 hours time- in-service (TIS); --Group 2 airplanes have steel spar caps with steel webs. Because of the steel webs as opposed to aluminum, data indicated that the inspections in the affected areas of the lower spar caps required by AD 97-17-03 should begin upon the accumulation of 4,300 hours TIS; and --Group 3 airplanes, which are the ones manufactured first, have steel spars with aluminum webs and low horsepower radial engines, and thus do not have the ability to carry as much weight as airplanes in the other two groups. Data indicated that the inspections in the affected areas of the lower spar caps required by AD 97-17-03 should begin upon the accumulation of 9,000 hours TIS.
Manufacture of the affected airplanes began in 1965 with the airplanes incorporating the lower horsepower radial engines. Many of the airplane models referenced in AD 97-17-03 are still currently in production. These airplanes are used in agricultural operations and average 500 hours TIS annually. With this in mind, some of the earlier manufactured airplanes could have as many as 16,000 hours total TIS.
Actions Since Issuance of Previous Rule
Since the issuance of both AD 97-13-11 and AD 97-17-03, the FAA has received data specifying 29 additional occurrences of fatigue cracks found in the lower spar caps of Ayres S2R and Model 600 S2D airplanes. The data from these occurrences indicate the following:
--Several of these occurrences involved airplanes that had not accumulated enough hours to require the initial inspection of AD 97-17- 03; --Detectable cracks could still develop after the initial inspection on the affected airplanes; and --The following airplanes were recently manufactured and have a similar type design to that of the airplanes affected by AD 97-17-03:
Model
Serial numbers
S2R-T34............................ T34-227 through T34-232, T34-234, and T34-236. S2R-G6............................. G6-147. S2R-G10............................ G10-139, G10-140, and G10-141
Relevant Service Information
The Ayres Corporation has issued Service Bulletin No. SB-AG-39, Rev. 1, dated December 12, 1997, which adds the above-referenced airplanes, specifies that the inspection be repetitive, and references different compliance times for the repetitive inspections depending on whether the method used is magnetic particle, ultrasonic, or eddy current. Procedures for the inspection are contained in Ayres Service Bulletin No. SB-AG-39, dated September 17, 1996. Ayres Custom Kit No. CK-AG-29, dated December 23, 1997, includes procedures for reworking the spar cap if a small crack is found in the \1/4\-inch spar cap hole; and includes procedures for replacing the butterfly center splice
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plate, part number 20211-3, from the aft surface of the wing spar join area.
The FAA's Determination
After examining the circumstances and reviewing all available information related to the incidents described above, the FAA has determined that:
--The above-referenced airplanes should be added to the Applicability of AD 97-17-03; --The inspections should be repetitive; --The initial compliance time should be changed for all airplanes; --The affected airplanes should be arranged into four groups instead of three based on usage and configurations; and --AD action should be taken to continue to detect fatigue cracking of the lower spar caps, which could result in the wing separating from the airplane with consequent loss of control of the airplane.
Explanation of the Provisions of the Proposed AD
Since an unsafe condition has been identified that is likely to exist or develop in other Ayres 600 S2D and S2R airplanes of the same type design, the FAA is proposing AD action to supersede AD 97-17-03. The proposed AD would retain the inspection and replacement (if necessary) of the lower spar caps that are currently required in AD 97- 17-03; and would make these inspections repetitive, would add additional airplanes to the Applicability of the AD, would change the initial compliance time for all airplanes, and would arrange the affected airplanes into four groups instead of three based on usage and configurations.
Accomplishment of the actions specified in this NPRM would be required in accordance with the service information previously referenced, as applicable.
Cost Impact
The FAA estimates that 1,000 airplanes in the U.S. registry would be affected by the proposed AD, that it would take approximately 3 workhours per airplane to accomplish the proposed initial inspection, and that the average labor rate is approximately $60 an hour. Parts to accomplish the proposed initial inspection cost approximately $417 per airplane. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $597,000, or $597 per airplane. This figure only takes into account the cost of the proposed initial inspection and does not take into account the cost of proposed repetitive inspections. The FAA has no way of determining how many repetitive inspections each owner/operator of the affected airplanes would incur.
In addition, these figures are based upon the presumption that no affected airplane operator has accomplished the proposed inspection, and does not take into account the cost for replacement if a crack is found. The FAA has no way of determining the number of wing spar caps that may need to be replaced based upon the results of the proposed inspections.
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 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
-
The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
-
Section 39.13 is amended by removing Airworthiness Directive (AD) 97-17-03, Amendment 39-10105 (62 FR 43926, August 18, 1997), and by adding a new AD to read as follows:
Ayres Corporation: Docket No. 98-CE-56-AD; Supersedes AD 97-17-03, Amendment 39-10105.
Applicability: Airplanes with the following model and serial number designations with or without a -DC or -X suffix, certificated in any category:
Group 1 Airplanes
Model
Serial numbers
S-2R............................... 5000R through 5099R, except 5010R, 5031R, 5038R, 5047R, and 5085R. S2R-R1340.......................... R1340-011, R1340-012, R1340-019, R1340-020, R1340-024, R1340-025, and R1340-027. S2R-R1820.......................... R1820-001 through 1820-035. S2R-T34............................ 6000R through 6049R, T34-001 through T34-143, T34-145, T34-147 through T34-167, T34-171, T34-180, and T34-181*. S2R-T15............................ T15-001 through T15-033**. S2R-T11............................ T11-001 through T11-005. S2R-G1............................. G1-101 through G1-106.
*The serial numbers of the Model S2R-T34 airplanes could incorporate T34- xxx, T36-xxx, T41-xxx, or T42-xxx. This AD applies to all of these serial number designations as they are all Model S2R-T34 airplanes. **The serial numbers of the Model S2R-T15 airplanes could incorporate T15-xx and T27-xx. This AD applies to both of these serial number designations as they are both Model S2R-T15 airplanes.
Group 2 Airplanes
Model
Serial numbers
S2R-R1340.......................... R1340-028 through R1340-035. S2R-R1820.......................... R1820-036. S2R-T65............................ T65-001 through T65-017. S2RHG-T65.......................... T65-002 through T65-017. S2R-T34............................ T34-144, T34-146, T34-168, T34-169, T34-172 through T34-179, and T34- 189 through T34-232, T34-234*. S2R-T45............................ T45-001 through T45-014. S2R-G6............................. G6-101 through G6-147. S2R-G10............................ G10-101 through G10-138, G10-140, and G10-141**. S2R-G5............................. G5-101 through G5-105.
* The serial numbers of the Model S2R-T34 airplanes could incorporate T34-xxx, T36-xxx, T41-xxx, or T42-xxx. This AD applies to all of these serial number designations as they are all Model S2R-T34 airplanes. ** The bolt holes in the Model S2R-G10 airplanes, S/N's G10-137, G10- 140, and G10-141 only, have been cold worked at the Ayres factory. The repetitive inspection intervals for the airplanes incorporating these three serial numbers should follow those given for cold worked holes presented in the Repetitive Inspections chart in the Compliance section of this AD.
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Group 3 Airplanes*
Model
Serial numbers
600 S2D............................ All serial numbers beginning with 600-1311D. S-2R............................... 1380R and 1416R through 4999R. S2R-R1340.......................... R1340-001 through R1340-010, R1340- 013 through R1340-018, R1340-021 through R1340-023, and R1340-026. S2R-R3S............................ R3S-001 through R3S-011.
* Any Group 3 airplane that has been modified with a hopper of a capacity over 410 gallons, a piston engine greater than 600 horsepower, or any gas turbine engine makes the airplane a Group 1 airplane for the purposes of this AD. The owner/operator must inspect the airplane at the Group 1 compliance time specified in the Compliance section of this AD.
Group 4 Airplanes
Model
Serial numbers
S-2R............................... 5010R, 5031R, 5038R, 5047R, and 5085R. S2R-T34............................ T34-236. S2R-G1............................. G1-107, G1-108. S2R-G10............................ G10-139.
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 (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 the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
Compliance: Initial and repetitive inspections required as indicated below, and any necessary replacement required prior to further flight as indicated in the body of this AD. The initial inspection may already have been accomplished in accordance with AD 97-17-03, which is superseded by this AD; or in accordance with AD 97-13-11, which was superseded by AD 97-17-03.
Initial Inspections
--Group 1 Airplanes: Required upon the accumulation of 2,000 hours time-in-service (TIS) on each lower spar cap or within 50 flight hours after the effective date of this AD, whichever occurs later, unless already accomplished (compliance with AD 97-17-03 or AD 97- 13-11), and thereafter at intervals specified in the Repetitive Inspections chart in this section of the AD. --Group 2 Airplanes: Required upon the accumulation of 2,200 hours TIS on each lower spar cap or within 50 flight hours after the effective date of this AD, whichever occur later, unless already accomplished (compliance with AD 97-17-03 or AD 97-13-11), and thereafter at intervals specified in the Repetitive Inspections chart in this section of the AD. --Group 3 Airplanes: Required upon the accumulation of 6,400 hours TIS on each lower spar cap or within 50 flight hours after the effective date of this AD, whichever occurs later, unless already accomplished (compliance with AD 97-17-03 or AD 97-13-11), and thereafter at intervals specified in the Repetitive Inspections chart in this section of the AD. --Group 4 Airplanes: As presented below.
For S/N's T34-236, G1-107, G1-108, and G10-139: Required upon the accumulation of 2,600 hours TIS on each lower spar cap or within the next 50 hours TIS after the effective date of this AD, whichever occurs later; and thereafter at intervals specified in the Repetitive Inspections chart in this section of the AD.
For S/N 5010R: Required upon the accumulation of 5,530 hours TIS on each lower spar cap or within the next 50 hours TIS after the effective date of this AD, whichever occurs later; and thereafter at intervals specified in the Repetitive Inspections chart in this section of the AD.
For S/N 5038R: Required upon the accumulation of 5,900 hours TIS on each lower spar cap or within the next 50 hours TIS after the effective date of this AD, whichever occurs later; and thereafter at intervals specified in the Repetitive Inspections chart in this section of the AD.
For S/N's 5031R and 5047R: Required upon the accumulation of 6,400 hours TIS on each lower spar cap or within the next 50 hours TIS after the effective date of this AD, whichever occurs later; and thereafter at intervals specified in the Repetitive Inspections chart in this section of the AD.
For S/N 5085R: Required upon the accumulation of 6,290 hours TIS on each lower spar cap or within the next 50 hours TIS after the effective date of this AD, whichever occurs later; and thereafter at intervals specified in the Repetitive Inspections chart in this section of the AD.
Repetitive Inspections
The following gives the required repetitive inspection intervals based on the situation found during the last inspection and the method of inspection utilized:
Magnetic
Eddy Situation
particle Ultrasonic current (hours TIS) (hours TIS) (hours TIS)
No cracks........................
500
400
450 No cracks; and cold work accomplished per SB-AG-39*......
1,500
1,200
1,300 No cracks; cold work accomplished per SB-AG-39; and butterfly plates, part number (P/N) 20211- 09 and 20211-11 installed per CK- AG-29, Part II**................
2,500
1,950
2,150 Small crack found; cold work to remove crack accomplished per SB- AG-39***, or CK-AG-29, Part I, accomplished to remove crack, and then cold work accomplished per SB-AG-39****................
950
750
825 Small crack found; cold work to remove crack accomplished per SB- AG-39***, or CK-AG-29, Part I, accomplished to remove crack, and then cold work accomplished per SB-AG-39; and butterfly plates, part number (P/N) 20211- 09 and 20211-11, installed per CK-AG-29, Part II...............
1,550
1,200 1,350
* Aircraft S/N's G10-137, G10-140 and G10-141 were cold worked at the factory and may follow this repetitive inspection interval. ** Aircraft S/N's T34-236, G1-107, G1-108, and G10-139 were cold worked and had the butterfly plates installed at the factory and may follow this repetitive inspection interval. *** If a crack is small enough, it may be removed through the reaming associated with the cold work process. **** Some aircraft owners/operators were issued alternative methods of compliance with AD 97-17-03 to ream the \1/4\-inch bolt hole to a \5/ 16\-inch diameter.
To detect fatigue cracking of the lower spar caps, which could result in the wing separating from the airplane with consequent loss of control of the airplane, accomplish the following:
(a) Inspect, using magnetic particle, ultrasonic or eddy current procedures, the \1/4\ inch and \5/16\ inch bolt hole areas on each lower spar cap for fatigue cracking. Accomplish the inspection in accordance with Ayres Service Bulletin No. (SB) SB-AG-39, dated September 17, 1996, and SB SB-AG-39 Rev. 1, dated December 12, 1997. The cracks may emanate from the bolt hole on the face of the spar cap or they may occur in the shaft of the hole; both areas must be inspected.
(1) The magnetic particle inspection must follow American Society for Testing Materials (ASTM) E1444-94A, using wet particles meeting the requirements of the Society for Automotive Engineers (SAE) AMS 3046.
Caution: The wings must be firmly supported during the inspection to prevent movement of the spar caps when the splice
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blocks are removed. This will allow easier realignment of the splice block holes and the holes in the spar cap for bolt insertion.
(2) Ultrasonic or eddy current inspection procedures must be approved by the FAA. To obtain FAA approval, send your proposed procedure to the Manager, Atlanta Aircraft Certification (ACO), One Crown Center, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia 30349. Removal of the splice block is not required for either the ultrasonic or eddy current inspections, unless corrosion is visible.
(3) All inspections required by this AD shall be accomplished by a Level 2 or Level 3 inspector certified for that inspection method using the guidelines established by the American Society for Nondestructive Testing or MIL-STD-410.
(b) If any cracking is found during any inspection required by this AD and if the crack is too large to be removed by the reaming used in the cold work process of Ayres SB No. SB-AG-39, dated September 17, 1996, or by using the method specified in Part I of Ayres Custom Kit No. CK-AG-29, dated December 23, 1997, prior to further flight, replace the affected lower spar cap in accordance with the applicable maintenance manual. Upon replacement of a spar cap, total hours TIS starts over for that particular lower spar cap. Use the compliance time specified in the Repetitive Inspection chart in the Compliance section of this AD to determine when the inspection is required.
(c) If any cracking is found during the inspections required by this AD, submit a report of inspection findings to the Manager, Atlanta ACO, One Crown Center, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia 30349; facsimile: (770) 703-6097; at the applicable time specified in paragraph (c)(1) or (c)(2) of this AD. The report must include a description of any cracking found; the airplane serial number and engine model number; the total number of flight hours on the lower spar cap that is found cracked; time since last inspection, if applicable; and the time on the spar cap when the bolt holes were cold worked or when the butterfly plate was installed, if applicable. Information collection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056.
(1) For airplanes on which the inspection is accomplished after the effective date of this AD, submit the report within 10 days after performing the inspection required by paragraph (a) of this AD.
(2) For airplanes on which the inspection has been accomplished in accordance with AD 97-17-03, which is superseded by this AD; or by AD 97-13-11, which was superseded by AD 97-17-03, submit the report within 10 days after the effective date of this AD, unless already accomplished.
(d) 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 to accomplish the modification requirements of this AD provided the following is followed:
(1) The hopper is empty.
(2) Vne is reduced to 126 miles per hour (109 knots).
(3) Flight into known turbulence is prohibited.
(e) 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 ACO, One Crown Center, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia 30349.
(1) The request shall be forwarded through an appropriate FAA 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 97-17-03, which is superseded by this AD; or in accordance with AD 97-13-11, which was superseded by AD 97-17-03, are approved as alternative methods of compliance with this AD unless otherwise noted by this AD.
Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Atlanta ACO.
(f) All persons affected by this directive may obtain copies of the documents referred to herein upon request to Ayres Corporation, P.O. Box 3090, One Rockwell Avenue, Albany, Georgia 31706-3090; or may examine these documents at the FAA, Central Region, Office of the Regional Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.
(g) This amendment supersedes AD 97-17-03, Amendment 39-10105.
Issued in Kansas City, Missouri, on January 6, 1999. Michael K. Dahl, Acting Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 99-684Filed1-12-99; 8:45 am]
BILLING CODE 4910-13-U
