00-14016. Airworthiness Directives; Ayres Corporation S2R Series and Model 600 S2D Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule.

SUMMARY:

This amendment supersedes Airworthiness Directive (AD) 97-17-03, which currently requires you to accomplish the following on Ayres Corporation (Ayres) S2R Series and Model 600 S2D airplanes: inspect the 1/4-inch and 5/16-inch bolt hole areas on the lower spar caps for fatigue cracking; replace any lower spar cap where fatigue cracking is found; and report any fatigue cracking. This AD retains the inspection and replacement (if necessary) requirements of the lower spar caps that are currently required in AD 97-17-03. This AD also makes these inspections repetitive, adds additional airplanes to the Applicability of the AD, changes the initial compliance time for all airplanes, and arranges the affected airplanes into groups (six) based on usage and configurations. The existing AD was the result of an accident of an Ayres S2R series airplane where the wing separated from the airplane in flight. The actions specified by this AD are intended to detect and correct 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:

This AD becomes effective on July 25, 2000.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in the regulations as of July 25, 2000.

ADDRESSES:

You may get the service information referenced in this AD from the Ayres Corporation, P.O. Box 3090, One Rockwell Avenue, Albany, Georgia 31706-3090. You may examine this information at the Federal Aviation Administration (FAA), Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 98-CE-56-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:

Satish Lall, Aerospace Engineer, FAA, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia 30349; telephone: [phone]; facsimile: [phone].

SUPPLEMENTARY INFORMATION:

Events Leading to the Issuance of This AD

Has FAA taken any action to this point? An accident on an Ayres S2R series airplane where the wing separated from the airplane in flight caused FAA to issue AD 9717-03, Amendment 39-10195 (62 FR 43296, August 18, 1997). AD 97-17-03 currently requires you to accomplish the following:

• Inspect the 1/4-inch and 5/16-inch bolt hole areas on the lower spar caps for fatigue cracking;
• Replace any lower spar cap where fatigue cracking is found; and
• Report any fatigue cracking to FAA.

Investigation of all resources available to 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 1/2-inch and 5/16-inch bolt holes in the lower spar caps. 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 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, FAA categorized these airplanes into three groups for the Applicability of AD 97-17-03.

Since issuing AD 97-17-03, we 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
• Ayres has manufactured additional airplanes that have a similar type design to that of the airplanes affected by AD 97-17-03. The existing AD should also cover these airplanes.

To address the above areas, FAA issued a notice of proposed rulemaking (NPRM) to supersede AD 97-17-03. This NPRM was published in the Federal Register on January 13, 1999 (64 FR 2157). The NPRM proposed to supersede AD 97-17-03 with a new AD that would:

• Retain the inspection and replacement (if necessary) requirements of the lower spar caps that are currently required in AD 97-17-03;
• Make these inspections repetitive;
• Add additional airplanes to the Applicability of the AD;
• Change the initial compliance time for all airplanes; and
• Arrange the affected airplanes into four groups instead of three based on usage and configurations.

Was the public invited to comment on the NPRM? The FAA invited interested persons to participate in the making of the amendment. Based on the comments to this NPRM, we changed the NPRM and reopened the comment period through a supplemental NPRM. The supplemental NPRM specifically proposed to organize the affected airplanes into six groups based on usage and configurations, adjust the repetitive inspection intervals, provide alternatives for inspection methods, and include modification alternatives to replacing the spar cap.

The FAA again invited interested persons to participate in the making of this amendment. No comments were received.

The FAA's Determination

What is FAA's final determination on this issue? After careful review of all available information related to the subject presented above, we have determined that air safety and the public interest require the adoption of the rule as proposed except minor editorial corrections.

How do the minor editorial corrections affect the AD? We have determined that the 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

How many airplanes does this AD impact? We estimate that this AD will affect 1,000 airplanes in the U.S. registry.

What is the cost impact of the initial inspection on owners/operators of the affected airplanes? We estimate 3 workhours per airplane to accomplish the initial inspection, at an average labor rate of $60 an hour. Parts to accomplish the initial inspection cost approximately $417 per airplane. Based on these figures, we estimate the cost impact of the initial inspection of this AD on U.S. operators at $597,000, or $597 per airplane.

What about the cost of repetitive inspections and possible repairs and replacements? The figures above only take into account the cost of the initial inspection and do not take into account the cost of repetitive inspections. We have no way of determining how many repetitive inspections each owner/operator of the affected airplanes would incur. These figures are based upon the presumption that no affected airplane operator has accomplished the inspection, and do not take into account the cost for replacement if a crack is found. We have no way of determining the number of wing spar caps that may need to be replaced based upon the results of the inspections.

Regulatory Impact

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, FAA determines that this final rule does not have federalism implications under Executive Order 13132.

The FAA has determined 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. The FAA has prepared a final evaluation and placed it in the Rules Docket. You can get a copy of this evaluation at the location listed 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

[Amended]

2. FAA amends 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:

2000-11-16 Ayres Corporation: Docket No. 98-CE-56-AD, Amendment 39-11764; Supersedes AD 97-17-03, Amendment 39-10105.

(a) What airplanes are affected by this AD? Airplanes with the following model and serial number (S/N) 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, 3038R, 5047R, and 5085R.
S2R-R1820	R1820-001 through R1820-035.
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-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-xxx and T27-xxx. 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-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. And T34-234.*
S2R-T45	T45-001 through T45-014.
S2R-G6	G6-101 through G6-147.
S2R-G10	G10-101 through G10-136, 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.

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 R1340-035.
S2R-R3S	R3S-001 through R3S-011.
S2R-T11	T11-001 through T11-005.
*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 this AD.

Group 4 Airplanes

Model	Serial numbers
S2R-T34	T34-225, T34-236, T34-237, and T34-238.*
S2R-G1	G1-107, G1-108, and G1-109.
S2R-G10	G10-137, G10-139, and G10-142.
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.

Group 5 Airplanes

Model	Serial numbers
S2R-T34	T34-239 through T34-266.*
S2RHG-T34	T34HG-102.
S2R-T15	T15-034 through T15-040.**
S2R-T45	T45-015.
S2R-G1	G1-110 Through G1-114.
S2R-G6	G6-148 through G6-151.
S2R-G10	G10-143 through G10-160.
*The serial numbers of the Model S2R-T34 airplanes could incorporate T34-xxx, T36-xxx, T41-xxx, or T42-xxx. This AD applies to both of these serial designations as they are both Model S2R-T34 airplanes.
**The serial numbers of the Model S2R-T15 airplanes could incorporate T15-xxx and T27-xxx. This AD applies to both of these serial designations as they are both Model S2R-T15 airplanes.

Group 6 Airplanes

Model	Serial numbers
S2R	501R, 5031R, 5038R, 5047R, and 5085R.

(b) Who must comply with this AD? Anyone who wishes to operate any of the above airplanes on the U.S. Register.

(c) What problem does this AD address? The actions specified by this AD are intended to detect and correct fatigue cracking of the lower spar caps. This could result in the wing separating from the airplane with consequent loss of control of the airplane.

(d) What actions must I accomplish to address this problem? To address this problem, you must accomplish the following:

(1) Repetitively 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. Reference paragraph (e)(3) and (e)(4) of this AD (including all subparagraphs) to obtain the initial and repetitive inspection compliance times.

(i) 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.

(ii) You must inspect both of these areas.

(2) If any cracking is found during any inspection required by this AD, you must accomplish the following:

(i) Use the cold work process to ream out small cracks as defined in Ayres Service Bulletin No. SB-AG-39, dated September 17, 1996; or replace the affected spar cap in accordance with the maintenance manual; or ream the 1/4-inch bolt holes to 5/16 inches diameter as defined in Part I of Ayres Custom Kit No. CK-AG-29, dated December 23, 1997; and

(ii) Submit a report of inspection findings to the Manager, Atlanta ACO, One Crown Center, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia 30349; facsimile: [phone]. You must include the airplane serial number and engine model number; the total number of flight hours on the lower spar cap that is cracked; time on the spar cap since last inspection, if applicable; and the type of inspection used for the last inspection. Indicate if cold working has been accomplished or modifications incorporated such as installation of big butterfly plates. Include the time on the spar cap when the cold working or modifications were accomplished. Indicate which bolt hole is cracked and the length of the crack. 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.

(e) What is the compliance time of this AD? The compliance times for each of the actions of this AD are as follows:

(1) Any required repair or replacement: Prior to further flight after the inspection where the crack(s) was/were found.

(2) Reporting requirement:

(i) Submit the report within 10 days after finding any crack(s) during any inspection required by this AD.

(ii) For airplanes where cracking was found during any inspection 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.

(3) Initial Inspection: The following is for the initial inspections required by this AD. The affected airplanes are categorized into six different groups.

(i) 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 97-1703 or AD 97-13-11).

(ii) 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).

(iii) 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).

(iv) Group 4 Airplanes: Required upon the accumulation of 2,500 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).

(v) Group 5 Airplanes: Required upon the accumulation of 6,200 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).

(vi) Group 6 Airplanes: As presented below.

(A) 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.

(B) 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.

(C) 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.

(D) 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.

(4) Repetitive Inspections: The following chart gives the required repetitive inspection intervals based on the work performed and the method of inspection utilized. Each time is hours TIS intervals after the last inspection:

Work previously performed	Magnetic particle	Ultrasonic	Eddy current
(i) No cracks found previously on wing spar and no optional cold work or bolt hole reaming accomplished	500 hours TIS	550 hours	700 hours TIS.
(ii) One of the following where the airplane does not have butterfly plates, part number (P/N) 20211-09 and P/N 20211-11, installed per CK-AG-29, Part II ***	500 hours TIS	550 hours TIS	700 hours TIS
(A) Small cracks repaired through cold work (or done as an option if never cracked) accomplished per SB-AG-39; or
(B) Small cracks repaired through 1/4-inch bolt hole reamed to 5/16 inches diameter (or done as an option if never cracked) per CK-AG-29, Part I; or
(C) Small cracks repaired through previous Alternative Methods of Compliance **
(iii) One of the following where the airplane has butterfly plates, part number (P/N) 20211-09 and P/N 20211-11, installed per CK-AG-29, Part II ***	900 hours TIS	950 hours TIS	1,250 hours TIS.
(A) Small cracks repaired through cold work (or done as an option if no cracks found) accomplished per SB-AG-39; or
(B) Small cracks repaired through 1/4-inch bolt hole reamed to 5/16 inches diameter (or done as an option if no cracks found) per CK-AG-29, Part I; or
(C) Small cracks repaired through previous Alternative Methods of Compliance. **
(iv) Cracked wing spar found during previous inspection wing spar replacement	Time for initial and repetitive inspection intervals start over when wing spar is replaced	Time for initial and repetitive inspection intervals start over when wing spar is replaced	Time for initial and repetitive inspection intervals start over when wing spar is replaced.
* Aircraft S/N's T45-007DC and T45-10DC had modified splice block assemblies installed at Ayres (Ayres/Kaplan Assembly No. 88-251) and must still follow the repetitive inspection intervals listed here.
** If a crack is found, the reaming associated with the cold work process may remove a crack if it is small enough. Some aircraft owners/operators were issued alternative methods of compliance with AD 97-17-03 to ream the 1/4-inch bolt hole to5/16 inches diameter to remove small cracks. Ayres CK-AG-29, Part I, also provides procedures to ream the 1/4-inch bolt hole to5/16 inches diameter. If you use either of these two methods to remove cracks and the airplane is reinspected immediately with no cracks found, you may continue to follow the repetitive inspection intervals listed above.
*** Group 4 and Group 5 airplanes had the butterfly plates installed at the factory and may follow this repetitive inspection interval.

(f) What procedures must I use to accomplish the actions required in this AD? (1) Inspections:

(i) For the magnetic particle inspection, utilize the procedures contained in Ayres Service Bulletin No. SB-AG-39, dated September 17, 1996. Use only sections titled “Inspection Accomplishment Instructions” and “Lower Splice Fitting Removal and Installation Instructions.” You 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: You must firmly support the wings during the inspection to prevent movement of the spar caps when the splice blocks are removed. This will allow easier realignment of the splice block holes and the holes in the spar cap for bolt insertion.

(ii) The FAA must approve ultrasonic or eddy current inspection procedures. To obtain FAA approval, you must send your proposed procedure to the Manager, Atlanta Aircraft Certification (ACO), One Crown Center, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia 30349. You are not required to remove the splice block for either the ultrasonic or eddy current inspections, unless corrosion is visible.

(iii) All inspections required by this AD must 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.

(2) Repair: Utilize the procedures contained in Ayres Service Bulletin No. SB-AG-39, dated September 17, 1996; or in Part I of Ayres Custom Kit No. CK-AG-29, dated December 23, 1997 if necessary to remove small cracks. You must then immediately re-inspect and continue to accomplish the repetitive inspections.

(3) Replacement: Utilize the procedures contained in the maintenance manual.

(g) 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, approves your alternative. Submit your request through an FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager.

(2) 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 (g)(1) 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.

(3) 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 in this AD.

(h) Where can I get information about any already-approved alternative methods of compliance? Contact the Atlanta ACO, One Crown Center, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia 303496; telephone: [phone]; facsimile: [phone].

(i) 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, provided that:

(1) The hopper is empty.

(2) Vne is reduced to 126 miles per hour (109 knots) indicated airspeed (IAS).

(3) Flight into known turbulence is prohibited.

(j) Are any service bulletins incorporated into this AD by reference? You must accomplish the actions required by this AD in accordance with Ayres Service Bulletin No. SB-AG-39, dated September 17, 1996, and Ayres Custom Kit No. CK-AG-29, dated December 23, 1997. 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 Ayres Corporation, P.O. Box 3090, One Rockwell Avenue, Albany, Georgia 31706-3090. 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.

(k) Does this AD affect any other AD actions? This amendment supersedes AD 97-17-03, Amendment 39-10105.

(l) When does this amendment become effective? This amendment becomes effective on July 25, 2000.

Issued in Kansas City, Missouri, on May 26, 2000.

Larry E. Werth,

Acting Manager, Small Airplane Directorate, Aircraft Certification Service.