Airworthiness Directives; Saab Model SAAB 340B Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-176-AD; Amendment 39-10782; AD 98-20-15]

RIN 2120-AA64

Airworthiness Directives; Saab Model SAAB 340B Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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

applicable to certain Saab Model SAAB 340B series airplanes, that

requires a one-time inspection for moisture or other contamination of a

certain wiring harness, electrical relay, and relay socket; a one-time

inspection for electrical damage of the same electrical relay and

socket; corrective actions, if necessary; and replacement of certain

nut plates with new, improved parts. This amendment is prompted by

issuance of mandatory continuing airworthiness information by a foreign

civil airworthiness authority. The actions specified by this AD are

intended to prevent a short circuit caused by fluid leakage, which

could result in inability to retract the landing gear or require the

use of emergency extension.

DATES: Effective October 27, 1998.

The incorporation by reference of certain publications listed in

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

of October 27, 1998.

ADDRESSES: The service information referenced in this AD may be

obtained from Saab Aircraft AB, SAAB Aircraft Product Support, S-

581.88, Linkoping, Sweden. This information may be examined at the

Federal Aviation Administration (FAA), Transport Airplane Directorate,

Rules Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the

Office of the Federal Register, 800 North Capitol Street, NW., suite

700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager,

International Branch, ANM-116, FAA, Transport Airplane Directorate,

1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)

227-2110; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39) to include an airworthiness

directive (AD) that is applicable to certain Saab Model SAAB 340B

series airplanes was published in the Federal Register on July 16, 1998

(63 FR 38353). That action proposed to require a one-time inspection

for moisture or other contamination of a certain wiring harness,

electrical relay, and relay socket; a one-time inspection for

electrical damage of the same electrical relay and socket; corrective

actions, if necessary; and replacement of certain nut plates with new,

improved parts.

Interested persons have been afforded an opportunity to participate

in the making of this amendment. Due consideration has been given to

the comments received.

Request To Revise Descriptive Language

One commenter notes that the description of the incident that

appeared in the Discussion section of the preamble to the notice of

proposed rulemaking (NPRM) refers to ``* * * the flightcrew being

unable to extend and lock down the landing gear.'' The commenter notes

that it was the normal extension operation that failed, and that the

crew used emergency extension and made a normal landing. The commenter

suggests that a more accurate description would be ``the flightcrew

having to use emergency extension of the landing gear.'' The FAA

acknowledges that the commenter's wording is more accurate. Since the

Discussion section is not restated in this final rule, no change to the

final rule is necessary.

The same commenter also suggests that the description of the unsafe

condition that appeared in the NPRM be revised to read ``* * * which

could result in inability to retract the landing gear or require the

use of emergency extension. * * *'' The FAA concurs with this

suggestion and has revised the pertinent wording throughout the final

rule.

Request To Reference Latest Saab Service Bulletin

In addition, the commenter requests that paragraph (a) of the

proposed AD be revised to reference Revision 01 of Saab Service

Bulletin 340-32-115, dated August 12, 1998. The commenter notes that

the reason for this revision was to clarify identification of wire

numbers. The FAA concurs. Since issuance of the NPRM, Saab has issued

Revision 01 of the subject service bulletin. The inspections,

replacement, and corrective actions described in Revision 01 of the

service bulletin are essentially identical to those described in the

original version of the service bulletin (which was referenced in the

NPRM as the appropriate source of service information). As noted by the

commenter, the only relevant change is to clarify wire numbers.

Therefore, the FAA has revised paragraph (a) of the final rule to

reference Revision 01 of the subject service bulletin as an additional

source of service information.

Conclusion

After careful review of the available data, including the comments

noted above, the FAA has determined that air safety and the public

interest require the adoption of the rule with the changes described

previously. The FAA has determined that these changes will neither

increase the economic burden on any operator nor increase the scope of

the AD.

Cost Impact

The FAA estimates that 120 Model SAAB 340B series airplanes of U.S.

registry will be affected by this AD.

It will take approximately 1 work hour per airplane to accomplish

the required inspections, at an average labor rate of $60 per work

hour. Based on these figures, the cost impact of the inspections

required by this AD on U.S. operators is estimated to be $7,200, or $60

per airplane.

It would take approximately 3 work hours per airplane to accomplish

the required replacement, at an average labor rate of $60 per work

hour. Required parts will be provided by the manufacturer at no cost to

operators. Based on these figures, the cost impact of the replacement

required by this AD on U.S. operators is estimated to be $21,600, or

$180 per airplane.

The cost impact figures discussed above are based on assumptions

that no operator has yet accomplished any of the requirements of this

AD action, and that no operator would accomplish those actions in the

future if this AD were not adopted.

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

[[Page 50501]]

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 final

evaluation has been prepared for this action and it is contained in the

Rules Docket. A copy of it may be obtained from 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 U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

98-20-15 Saab Aircraft AB: Amendment 39-10782. Docket 98-NM-176-AD.

Applicability: Model SAAB 340B series airplanes, manufacturer

serial numbers 380 through 499 inclusive; certificated in any

category.

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 (b) 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 as indicated, unless accomplished

previously.

To prevent a short circuit caused by fluid leakage, which could

result in inability to retract the landing gear or require the use

of emergency extension, accomplish the following:

(a) Within 400 flight hours after the effective date of this AD,

accomplish the actions required by paragraphs (a)(1), (a)(2),

(a)(3), and (a)(4) of this AD, in accordance with Saab Service

Bulletin 340-32-115, dated April 7, 1998, or Revision 01, dated

August 12, 1998. As of the effective date of this AD, Revision 01 of

the service bulletin shall be used.

(1) Perform a detailed visual inspection to detect moisture or

other contamination of the electrical wiring harness above relay

consoles 305VU and 306VU. If any moisture or other contamination is

found, prior to further flight, clean the wiring harness.

(2) Perform a detailed visual inspection to detect moisture or

other contamination of electrical relay 15GA and its socket. If any

moisture or other contamination is found, prior to further flight,

accomplish corrective actions.

(3) Perform a detailed visual inspection for electrical damage

of electrical relay 15GA and its socket. If any sign of electrical

damage (arcing, discoloration, or charring) is detected, prior to

further flight, replace the existing relay and socket with new

parts.

(4) Replace the existing nut plates on the floor of the cockpit

with new, improved nut plates, on the left and right sides of the

airplane.

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

compliance time that provides an acceptable level of safety may be

used if approved by the Manager, International Branch, ANM-116, FAA,

Transport Airplane Directorate. Operators shall submit their

requests through an appropriate FAA Principal Maintenance Inspector,

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

Branch, ANM-116.

Note 2: Information concerning the existence of approved

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

obtained from the International Branch, ANM-116.

(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) The actions shall be done in accordance with Saab Service

Bulletin 340-32-115, dated April 7, 1998, or Saab Service Bulletin

340-32-115, Revision 01, dated August 12, 1998. 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 Saab Aircraft AB, SAAB Aircraft Product Support, S-

581.88, Linkoping, Sweden. Copies may be inspected at the FAA,

Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,

Washington; or at the Office of the Federal Register, 800 North

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

Note 3: The subject of this AD is addressed in Swedish

airworthiness directive SAD 1-125, dated April 7, 1998.

(e) This amendment becomes effective on October 27, 1998.

Issued in Renton, Washington, on September 14, 1998.

Dorenda D. Baker,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 98-25121 Filed 9-21-98; 8:45 am]

BILLING CODE 4910-13-U