Airworthiness Directives; Fairchild Aircraft SA226 and SA227 Series Airplanes

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 95-CE-58-AD; Amendment 39-9369; AD 95-19-07]

Airworthiness Directives; Fairchild Aircraft SA226 and SA227

Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that

applies to Fairchild Aircraft SA226 and SA227 series airplanes equipped

with certain main landing gear (MLG) and nose landing gear (NLG). This

action requires repetitively inspecting, using ultrasonic methods, the

left-hand and right-hand MLG yokes and the NLG yokes for stress

corrosion cracking, and, if any cracked yokes are found that exceed

certain limits, either replacing the cracked yoke, the yoke/cylinder

combination, or the affected MLG or NLG assembly. Several reports of

landing gear failures on the affected airplanes that have the affected

MLG or NLG yokes installed prompted this action. The actions specified

by this AD are intended to prevent MLG or NLG failure caused by stress

corrosion cracks in the yokes, which, if not detected and corrected,

could result in loss of control of the airplane during landing

operations.

DATES: Effective September 28, 1995.

The incorporation by reference of certain publications listed in

the regulations is approved by the Director of the Federal Register as

of September 28, 1995.

Comments for inclusion in the Rules Docket must be received on or

before November 4, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Central Region, Office of the Assistant Chief

Counsel, Attention: Rules Docket No. 95-CE-58-AD, Room 1558, 601 E.

12th Street, Kansas City, Missouri 64106.

Service information that applies to this AD may be obtained from

Fairchild Aircraft, P.O. Box 790490, San Antonio, Texas 78279-0490;

telephone (210) 824-9421. This information may also be examined at the

FAA, Central Region, Office of the Assistant Chief Counsel, Attention:

Rules Docket 95-CE-58-AD, Room 1558, 601 E. 12th Street, Kansas City,

Missouri 64106; or at the Office of the Federal Register, 800 North

Capitol Street NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Mr. Werner Koch, Aerospace Engineer,

FAA, Airplane Certification Office, 2601 Meacham Boulevard, Fort Worth,

Texas 76193-0150; telephone (817) 222-5133; facsimile (817) 222-5960.

SUPPLEMENTARY INFORMATION: The FAA has received several reports of main

landing gear (MLG) and nose landing gear (NLG) failure on Fairchild

Aircraft SA226 and SA227 series airplanes. The airplanes in these

incidents are equipped with part number (P/N) OAS5453 MLG and P/N

OAS5451 NLG.

Metallurgical analysis of the yokes of the right-hand and left-hand

MLG and NLG gear on several of these airplanes revealed that the

failure was initiated by stress corrosion cracking of the yokes, which

started as corrosion fatigue. This condition, if not detected and

corrected, could result in loss of control of the airplane during

landing operations.

Fairchild Aircraft has issued Service Bulletin (SB) 226-32-065, SB

227-32-039, and SB CC7-32-007, all Issued: August 16, 1995, which

specify procedures for ultrasonically inspecting the left-hand and

right-hand MLG yoke, P/N 5453005-1, 5453005-3, or 5453005-5, and the

NLG yoke, P/N 5451005-1, on Fairchild Aircraft SA226 and SA227 series

airplanes.

After examining the circumstances and reviewing all available

information related to the incidents described above, the FAA has

determined that AD action should be taken to prevent MLG or NLG failure

caused by stress corrosion cracks of the yokes, which, if not detected

and corrected, could result in loss of control of the airplane during

landing operations.

Since an unsafe condition has been identified that is likely to

exist or develop in other Fairchild Aircraft SA226 and SA227 series

airplanes of the same type design, this AD requires repetitively

inspecting, using ultrasonic methods, the left-hand and right-hand MLG

yokes and the NLG yokes for stress corrosion cracking, and, if any

cracked yokes are found that exceed certain limits, either replacing

the cracked yoke, the yoke/cylinder combination, or the affected MLG or

NLG assembly. Accomplishment of the ultrasonic inspections shall be in

accordance with either Fairchild Aircraft SB 226-32-065, SB 227-32-039,

and SB CC7-32-007, all Issued: August 16, 1995, as applicable. The

replacement, if necessary, shall be accomplished in accordance with the

applicable maintenance manual.

Since a situation exists (possible loss of control of the airplane

during landing operations) that requires the immediate adoption of this

regulation, it is found that notice and opportunity for public prior

comment hereon are impracticable, and that good cause exists for making

this amendment effective in less than 30 days.

Comments Invited

Although this action is in the form of a final rule that involves

requirements affecting immediate flight safety and, thus, was not

preceded by notice and opportunity to comment, comments are invited on

this rule. Interested persons are invited to comment on this rule by

submitting such written data, views, or arguments as they may desire.

Communications should identify the

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Rules Docket number and be submitted in triplicate to the address

specified above. All communications received on or before the closing

date for comments will be considered, and this rule may be amended in

light of the comments received. Factual information that supports the

commenter's ideas and suggestions is extremely helpful in evaluating

the effectiveness of the AD action and determining whether additional

rulemaking action would be needed.

Comments are specifically invited on the overall regulatory,

economic, environmental, and energy aspects of the rule that might

suggest a need to modify the 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

AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments

submitted in response to this request must submit a self-addressed,

stamped postcard on which the following statement is made: ``Comments

to Docket No. 95-CE-58-AD.'' The postcard will be date stamped and

returned to the commenter.

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.

The FAA has determined that this regulation is an emergency

regulation and that must be issued immediately to correct an unsafe

condition in aircraft, and is not a significant regulatory action under

Executive Order 12866. It has been determined further that this action

involves an emergency regulation under DOT Regulatory Policies and

Procedures (44 FR 11034, February 26, 1979). If it is determined that

this emergency regulation otherwise would be significant under DOT

Regulatory Policies and Procedures, a final regulatory evaluation will

be prepared and placed in the Rules Docket (otherwise, an evaluation is

not required). A copy of it, if filed, may be obtained from the Rules

Docket.

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), 40101, 40113, 44701.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding a new airworthiness directive

(AD) to read as follows:

95-19-07 Fairchild Aircraft: Amendment 39-9369; Docket No. 95-CE-

58-AD.

Applicability: Models SA226-T, SA226-AT, SA226-TC, SA226-T(B),

SA227-AC, SA227-AT, SA227-BC, SA227-TT, SA227-CC, and SA227-DC

airplanes (all serial numbers), certificated in any category, that

are equipped with one or more of the following:

1. Main landing gear part number (P/N) OAS5453-*(dash numbers 1

through 19) with either a P/N 5453005-1, 5453005-3, or 5453005-5

yoke installed; or

2. Nose landing gear P/N OAS5451-*(dash numbers 1 through 17)

with a P/N 5451005-1 yoke installed.

Note 1: This AD applies to each airplane identified in the

preceding applicability revision, 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: Required initially as follows and thereafter as

indicated in the body of this AD:

1. Within the next 75 hours time-in-service (TIS) after the

effective date of this AD, unless already accomplished; and

2. Upon the installation of one of the affected main landing

gear or nose landing gear assemblies or yokes.

To prevent main landing gear or nose landing gear failure caused

by stress corrosion cracks of the yoke, which, if not detected and

corrected, could result in loss of control of the airplane during

landing operations, accomplish the following:

Note 2: The paragraph structure of this AD is as follows:

Level 1: (a), (b), (c), etc.

Level 2: (1), (2), (3), etc.

Level 3: (i), (ii), (iii), etc.

Level 2 and Level 3 structures are designations of the Level 1

paragraph they immediately follow.

(a) Inspect, using ultrasonic methods, the left-hand and right-

hand main landing gear and the nose landing gear yoke for stress

corrosion cracking in accordance with one of the following, as

applicable:

(1) The ACCOMPLISHMENT INSTRUCTIONS section of Fairchild Service

Bulletin (SB) 226-32-065, Issued: August 16, 1995.

(2) The ACCOMPLISHMENT INSTRUCTIONS section of Fairchild SB 227-

32-039, Issued: August 16, 1995.

(3) The ACCOMPLISHMENT INSTRUCTIONS section of Fairchild SB CC7-

32-007, Issued: August 16, 1995.

(b) Reinspect or replace the right-hand or left-hand main

landing gear or nose landing gear yoke as follows based on the

results of any required inspection:

(1) If no cracks are found or a crack is found that is less than

.25 inch, accomplish the following:

(i) Prior to further flight after the inspection required by

paragraph (a) of this AD, clean the main landing gears and nose

landing gear yoke and piston in accordance with Figure 2 of the

service bulletins referenced in paragraphs (a)(1), (a)(2), and

(a)(3) of this AD;

(ii) Prior to further flight after the inspection required by

paragraph (a) of this AD, apply a small bead of Products Research

and Chemical Corporation PR-1422 or PR-1435 sealant to the main

landing gears and nose landing gear yoke as shown in Figure 2 of the

service bulletins referenced in paragraphs (a)(1), (a)(2), and

(a)(3) of this AD, and as described in the SA226/227 Series Service

Repair Manual, Chapter 51-30-03, Standard Practices--Sealing; and

(iii) Reinspect at intervals not to exceed 2,000 hours TIS

provided no cracks are found that are .25 inch or more in length.

(2) If a crack is found with a length of .25 inch or more but

not more than .50 inch, reinspect at intervals not to exceed 1,000

hours TIS provided the crack is no longer than .50 inch.

(3) If a crack is found with a length more than .50 inch but not

more than .75 inch, reinspect at intervals not to exceed 500 hours

TIS provided the crack is no longer than .75 inch.

(4) If a crack is found with a length more than .75 inch but not

more than 1 inch, reinspect at intervals not to exceed 200 hours TIS

provided the crack is no longer than 1 inch.

(5) If a crack is found with a length more than 1 inch but not

more than 1.5 inches, accomplish the following:

(i) Within 100 hours TIS after the inspection required by

paragraph (a) of this AD, replace the cracked part with a new part

in accordance with the applicable maintenance manual. This may be

accomplished by replacing the cracked yoke, the total gear assembly,

or the yoke/cylinder combination;

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(ii) Prior to further flight after replacing the cracked part,

clean the main landing gears and nose landing gear yoke and piston

in accordance with figure 2 of the service bulletins referenced in

paragraphs (a)(1), (a)(2), and (a)(3) of this AD;

(iii) Prior to further flight after replacing the cracked part,

apply a small bead of Products Research and Chemical Corporation PR-

1422 or PR-1435 sealant to the main landing gears and nose landing

gear yoke as shown in Figure 2 of the service bulletins referenced

in paragraphs (a)(1), (a)(2), and (a)(3) of this AD, and as

described in the SA226/227 Series Service Repair Manual, Chapter 51-

30-03, Standard Practices--Sealing; and

(iv) Repeat the inspections specified in paragraphs (a) and (b)

of this AD and replace the part as required.

(6) If a crack is found with a length more than 1.5 inches,

accomplish the following:

(i) Prior to further flight after the inspection required by

paragraph (a) of this AD, replace the cracked part with a new part

in accordance with the applicable maintenance manual. This may be

accomplished by replacing the cracked yoke, the total gear assembly,

or the yoke/cylinder combination;

(ii) Prior to further flight after replacing the cracked part,

clean the main landing gears and nose landing gear yoke and piston

in accordance with figure 2 of the service bulletins referenced in

paragraphs (a)(1), (a)(2), and (a)(3) of this AD;

(iii) Prior to further flight after replacing the cracked part,

apply a small bead of Products Research and Chemical Corporation PR-

1422 or PR-1435 sealant to the main landing gears and nose landing

gear yoke as shown in Figure 2 of the service bulletins referenced

in paragraphs (a)(1), (a)(2), and (a)(3) of this AD, and as

described in the SA226/227 Series Service Repair Manual, Chapter 51-

30-03, Standard Practices--Sealing; and

(iv) Repeat the inspections specified in paragraphs (a) and (b)

of this AD and replace the part as required.

(7) If multiple cracks are found, add the total length of the

cracks and use the criteria presented in paragraphs (b)(1) through

(b)(6) of this AD, including all subparagraph designations, to

establish repetitive inspection intervals or replacement times.

(c) The MLG and NLG yokes affected by this AD are manufactured

by Ozone Industries, Inc. Replacing these yokes with approved parts

manufactured by Fairchild Aircraft eliminates the repetitive

inspection requirements of this AD.

(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 where

the requirements of this AD can be accomplished.

(e) An alternative method of compliance or adjustment of the

compliance time that provides an equivalent level of safety may be

approved by the Manager, Airplane Certification Office (ACO), FAA,

2601 Meacham Boulevard, Fort Worth, Texas 76193-0150. The request

shall be forwarded through an appropriate FAA Maintenance Inspector,

who may add comments and then send it to the Manager, Fort Worth

ACO.

Note 3: Information concerning the existence of approved

alternative methods of compliance with this AD, if any, may be

obtained from the Fort Worth ACO.

(f) The inspections required by this AD shall be done in

accordance with Fairchild Aircraft Service Bulletin 226-32-065,

Issued: August 16, 1995, Fairchild Aircraft Service Bulletin 227-32-

039, Issued: August 16, 1995, or Fairchild Aircraft Service Bulletin

CC7-32-007, Issued: August 16, 1995, as applicable. This

incorporation by reference was approved by the Director of the

Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part

51. Copies may be obtained from Fairchild Aircraft, P.O. Box 790490,

San Antonio, Texas 78279-0490. Copies may be inspected at the FAA,

Central Region, Office of the Assistant Chief Counsel, Room 1558,

601 E. 12th Street, Kansas City, Missouri, or at the Office of the

Federal Register, 800 North Capitol Street NW., 7th Floor, suite

700, Washington, DC.

(g) This amendment (39-9369) becomes effective on September 28,

1995.

Issued in Kansas City, Missouri, on September 6, 1995.

Gerald W. Pierce,

Acting Manager, Small Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 95-22646 Filed 9-13-95; 8:45 am]

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