AD 98-01-10

This amendment supersedes Airworthiness Directive (AD) 87-03-10, which currently requires repetitively inspecting the fillet area of both the left and right main landing gear (MLG) wheel axle/piston tube support junction area for cracks on Empresa Brasileira de Aeronautica S.A. (EMBRAER) Models EMB-110P1 and EMB-110P2 airplanes, and requires replacing any MLG wheel axle/piston tube assembly where a crack is found. AD 87-03-10 also provided the option of reworking this area when no cracks were found as terminating action for the repetitive inspections. 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 AD requires the following on EMBRAER Models EMB 110-P1 and EMB 110-P2 airplanes that do not have an "R" stamped on both the left and right MLG wheel axle/piston tube assembly end-piece:inspecting (one-time) the fillet area of each MLG wheel axle/piston tube support junction area to assure that the area is free of cracks, replacing any MLG wheel axle/piston tube assembly if a crack is found, and reworking this area on both the left and right MLG's, as terminating action for the repetitive inspections that are currently required by AD 87-03-10. The actions specified in this AD are intended to prevent failure of the MLG wheel axle/piston tube assembly caused by fatigue cracking, which could result in loss of control of the airplane during landing operations.

Final rule

98-01-10 EMPRESA BRASILEIRA DE AERONAUTICA S.A.: Amendment 39-10273; Docket 96-CE-66-AD. Supersedes AD 87-03-10, Amendment 39-5524.
Applicability: Models EMB-110P1 and EMB-110P2 airplanes, all serial numbers, certificated in any category, that do not have an "R" stamped on both the left and right main landing gear (MLG) wheel axle/piston tube assembly end-piece.

NOTE 1: Airplanes that have an "R" stamped on both the left and right MLG wheel axle/piston tube assembly end-piece either (1) have a design configuration that is different from the unsafe condition specified in this AD; or (2) already have both the left and right MLG wheel axle/piston tube support junction area reworked. EMBRAER Service Bulletin (SB) No. 110-032-0071, Change No. 01, dated June 21, 1988, includes procedures for this rework, including stamping an "R" on both the left and right MLG wheel axle/piston tube assembly end-piece.

NOTE 2: This AD applies to each airplane identified in the precedingapplicability 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 (d) 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 within the next 100 landings after the effective date of this AD, unless already accomplished.

NOTE 3: If the number of landings is unknown, hours time-in-service (TIS) may be used by multiplying the number of hours TIS by 0.50. If hours TIS are utilized to calculate the number of landings, this would make the AD effective "within the next 200 hours TIS after the effective date of this AD."

To prevent failure of a MLG wheel axle/piston tube assembly caused by fatigue cracking, which could result in loss of control of the airplane during landing operations, accomplish the following:

(a) Inspect, using either eddy current, dye penetrant, or magnetic particle methods, the fillet area in both the left and right MLG wheel axle/piston support junction area for cracks in accordance with the instructions contained in EMBRAER SB No. 110-032-0068, dated December 20, 1985. Included in this SB is ERAM SB No. 32-22, which includes procedures for accomplishing this inspection. If any cracks are found, prior to further flight, replace the MLG wheel axle/piston tube assembly with an uncracked assembly.

(b) Visually inspect the fillet radius in both the left and right MLG wheel axle/piston tube support junction area to determine whether the profile requires rework. Accomplish theinspection in accordance with the instructions in ERAM SB No. 32-25, which is part of EMBRAER SB No. 110-032- 0071, Change No. 01, dated June 21, 1988.

(1) If the profile of the area of each MLG is like the one presented in image (A) Figure 1 of ERAM SB No. 32-25, which is part of EMBRAER SB No. 110-032-0071, Change No. 01, dated June 21, 1988, prior to further flight, polish the junction area using a fine grit abrasive cloth and stamp the letter "R" on the MLG wheel axle/piston tube assembly end-pipe.

(2) If the profile of the area of each MLG is like the one presented in image (B) Figure 1 of ERAM SB No. 32-25, which is part of EMBRAER SB No. 110-032-0071, Change No. 01, dated June 21, 1988, prior to further flight, accomplish the following in accordance with EMBRAER SB No. 110-032-0071, Change No. 01, dated June 21, 1988:

(i) Rework each MLG wheel axle/piston tube support junction area;

(ii) Polish each junction area using a fine grit abrasive cloth; and(iii) Stamp the letter "R" on each MLG wheel axle/piston tube assembly end-pipe.

(c) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

(d) An alternative method of compliance or adjustment of the 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.

(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 87-03-10 (superseded by this action) are not considered approved as alternative methods of compliance with this AD.

NOTE 4: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Atlanta ACO.

(e) The inspection required by this AD shall be done in accordance with EMBRAER Service Bulletin No. 110-032-0068, dated December 20, 1985. The modification (rework, polishing, and stamping) required by this AD shall be done in accordance with EMBRAER Service Bulletin No. 110-032- 0071, Change No. 01, dated June 21, 1988. 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 EMBRAER, Av. Brig Faira Lima 2170, 12227-901, Sao Jose dos Campos-SP, Brazil. Copies may be inspected at the FAA, Central Region, Office of the Regional 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.

(f) This amendment (39-10273) supersedes AD 87-03-10,Amendment 39-5524.

(g) This amendment becomes effective on February 9, 1998.

Events Leading to the Issuance of This AD
A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to EMBRAER Models EMB-110P1 and EMB-110P2 airplanes that do not have an "R" stamped on both the left and right MLG wheel axle/piston tube assembly end-piece was published in the Federal Register as a notice of proposed rulemaking (NPRM) on March 12, 1997 (62 FR 11384). The NPRM proposed to supersede AD 87-03-10 with a new AD that would require inspecting (one-time) the fillet area of both the left and right MLG wheel axle/piston tube support junction area to assure that the area is free of cracks, replacing any MLG wheel axle/piston tube assembly if a crack is found, and reworking this area on both the left and right MLG's, as terminating action for the repetitive inspections that are currently required by AD 87-03-10. Airplanes that have an "R" stamped on both the left and right MLG wheel axle/piston tube assembly end-piece either (1) have a design configuration that is different from the unsafe condition specified in this document; or (2) the airplanes already have both the left and right the MLG wheel axle/piston tube assembly reworked. Accomplishment of the proposed inspection as specified in the NPRM would be in accordance with EMBRAER Service Bulletin (SB) No. 110-032-0068, dated December 20, 1985. Accomplishment of the proposed rework as specified in the NPRM would be required in accordance with EMBRAER SB No. 110-032-0071, Change No. 01, dated June 21, 1988.

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.

The FAA's Determination
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 50 airplanes in the U.S. registry will be affected by this AD, that it will take approximately 22 workhours (inspection: 8 workhours; rework: 14 workhours) per airplane to accomplish this AD, and that the average labor rate is approximately $60 an hour. There is no cost for parts to accomplish this AD. Based on these figures, the total cost impact of this AD on U.S. operators is estimated to be $66,000.

The initial inspection cost of this AD is the same as that required by AD 87-03-10. The difference in the inspection costs of this AD and AD 87-03-10 is that this AD does not require the repetitive inspections and AD 87-03-10 currently requires repetitive inspections every 1,000 landings. The required rework eliminates the repetitive inspection requirement, and is optional in AD 87-03-10.

The FAA does not have any way of determining how many airplanes have an "R" stamped on both the left and right MLG wheel axle/piston tube support junction area end-piece and have these areas reworked, and, therefore already have the actions of this AD accomplished. The affected airplanes are no longer in production with few airplanes being operated in the United States. Since AD 87-03-10 provided the option of reworking the area on both the left and right MLG's as terminating action for the repetitive inspections, the FAA believes that most of the operators will have accomplished the rework and will not be affected by this AD.

The FAA's Aging Commuter Aircraft Policy
The actions required by this AD are consistent with the FAA's aging commuter 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 the FAA's determination that reliance on critical repetitive inspections on airplanes utilized in commuter service carries an unnecessary safety risk when a design change exists that could eliminate or, in certain instances, reduce the number of those critical inspections. In determining what inspections are critical, the FAA considers (1) the safety consequences of the airplane if the known problem is not detected by the inspection; (2) the reliability of the inspection such as the probability of not detecting the known problem; (3) whether the inspection area is difficult to access; and (4) the possibility of damage to an adjacent structure as a result of the problem.

The alternative to reworking the fillet area of the left and right MLG wheel axle/piston tube support junction area is to rely on the repetitive inspections currently required by AD 87-03-10 to detect cracks in this area.

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 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.

39.13 [Amended]
2. Section 39.13 is amended by removing Airworthiness Directive (AD) 87-03-10, Amendment 39-5524, and by adding a new AD to read as follows: