Airworthiness Directives; Bombardier Model DHC-8-101, -102, -103, -106, -201, -202, -301, -311, and -315 Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-335-AD; Amendment 39-11401; AD 99-23-05]

RIN 2120-AA64

Airworthiness Directives; Bombardier Model DHC-8-101, -102, -103,

-106, -201, -202, -301, -311, and -315 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 all Bombardier Model DHC-8-101, -102, -103, -106, -201, -

202, -301, -311, and -315 series airplanes, that requires repetitive

detailed visual inspections and high frequency eddy current inspections

to detect cracking of the wing upper skin and ladder plates at over

wing access panels between certain stations; and repair, if necessary.

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 detect and correct

fatigue cracking of the wing ladder plates, which, if not corrected,

could reduce the structural integrity of the wing.

DATES: Effective December 17, 1999.

The incorporation by reference of certain publications listed in

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

of December 17, 1999.

ADDRESSES: The service information referenced in this AD may be

obtained from Bombardier, Inc., Bombardier Regional Aircraft Division,

Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. 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 FAA, Engine and Propeller Directorate, New York

Aircraft Certification Office, 10 Fifth Street,

[[Page 61479]]

Third Floor, Valley Stream, New York; or at the Office of the Federal

Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Franco Pieri, Aerospace Engineer,

Airframe and Propulsion Branch, ANE-171, FAA, Engine and Propeller

Directorate, New York Aircraft Certification Office, 10 Fifth Street,

Third Floor, Valley Stream, New York 11581; telephone (516) 256-7526;

fax (516) 568-2716.

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 all Bombardier Model DHC-8-101, -

102, -103, -106, -201, -202, -301, -311, and -315 series airplanes was

published in the Federal Register on September 3, 1999 (64 FR 48333).

That action proposed to require repetitive detailed visual inspections

and high frequency eddy current inspections to detect cracking of the

wing upper skin and ladder plates at over wing access panels between

certain stations; and repair, if necessary.

Comments

Interested persons have been afforded an opportunity to participate

in the making of this amendment. No comments were submitted in response

to the proposal or the FAA's determination of the cost to the public.

Conclusion

The FAA has determined that air safety and the public interest

require the adoption of the rule as proposed.

Cost Impact

The FAA estimates that 166 airplanes of U.S. registry will be

affected by this AD, that it will take approximately 40 work hours per

airplane to accomplish the inspections, and that the average labor rate

is $60 per work hour. Based on these figures, the cost impact of this

AD on U.S. operators is estimated to be $398,400, or $2,400 per

airplane, per inspection cycle.

The cost impact figure discussed above is 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 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:

99-23-05 Bombardier, Inc. (Formerly de Havilland, Inc.): Amendment

39-11401. Docket 98-NM-335-AD.

Applicability: All Model DHC-8-101, -102, -103, -106, -201, -

202, -301, -311, and -315 series airplanes, 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 (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 as indicated, unless accomplished

previously.

To detect and correct fatigue cracking of the wing ladder

plates, which if not corrected, could reduce the structural

integrity of the wing, accomplish the following:

Inspection for DHC-8-100 and -300 Series Airplanes

(a) At the applicable compliance time listed in paragraph

(a)(1), (a)(2), or (a)(3) of this AD, perform a detailed visual

inspection to detect cracking of the skin and a high frequency eddy

current (HFEC) inspection of the ladder plates at over wing access

panels between station YW42.00 and YW171.20, in accordance with de

Havilland Temporary Revision MTC-15, dated September 18, 1998, of

the de Havilland Maintenance Program Manual PSM 1-8-7 TC (for Model

DHC-8-100 series airplanes); or de Havilland Temporary Revision MTC

3-14, dated September 18, 1998, of the de Havilland Maintenance

Program Manual PSM 1-83-7TC (for Model DHC-8-300 series airplanes);

as applicable. Repeat the inspections thereafter at intervals not to

exceed 10,000 flight cycles.

(1) For airplanes that have accumulated 5,000 or fewer total

flight cycles as of the effective date of this AD, accomplish the

inspection prior to the accumulation of 10,000 total flight cycles.

(2) For airplanes that have accumulated more than 5,000 total

flight cycles, but fewer than 38,501 total flight cycles as of the

effective date of this AD, accomplish the inspection prior to the

accumulation of [5,522+(0.8955 x N Accumulated)] total cycles. ``N

Accumulated'' is defined as the total number of flight cycles as of

the effective date of this AD.

(3) For airplanes that have accumulated 38,501 or more total

flight cycles as of the effective date of this AD, accomplish the

inspection within 1,500 flight cycles after the effective date of

this AD.

Note 2: For the purposes of this AD, a detailed visual

inspection is defined as: ``An intensive visual examination of a

specific structural area, system, installation, or assembly to

detect damage, failure, or irregularity. Available lighting is

normally supplemented with a direct source of good lighting at

intensity deemed appropriate by the inspector. Inspection aids such

as mirror, magnifying lenses, etc., may be used. Surface cleaning

and elaborate access procedures may be required.''

Inspection for DHC-8-200 Series Airplanes

(b) At the applicable compliance time listed in paragraph (b)(1)

or (b)(2) of this AD, perform a detailed visual inspection of the

skin and an HFEC inspection to detect cracking of the ladder plates

at over wing access panels between station YW42.00 and YW171.20, in

accordance with de Havilland Temporary Revision MTC 2-14, dated

September 18, 1998, of the de Havilland Maintenance Program Manual

PSM 1-82-7TC. Repeat the inspections thereafter at intervals not to

exceed 10,000 flight cycles.

[[Page 61480]]

(1) For airplanes that have accumulated 5,000 or fewer total

flight cycles as of the effective date of this AD, accomplish the

inspection prior to the accumulation of 10,000 total flight cycles.

(2) For airplanes that have accumulated more than 5,000 total

flight cycles, but fewer than 38,501 total flight cycles as of the

effective date of this AD, accomplish the inspection prior to the

accumulation of [5,522+(0.8955 x N Accumulated)] total cycles,

where ``N Accumulated'' is defined as the total number of flight

cycles as of the effective date of this AD.

Repair

(c) If any crack is detected during any inspection required by

this AD, prior to further flight, repair in accordance with a method

approved by the Manager, New York Aircraft Certification Office

(ACO), FAA, Engine and Propeller Directorate; or the Transport

Canada Civil Aviation (TCCA) (or its delegated agent). For a repair

method to be approved by the Manager, New York ACO, as required by

this paragraph, the Manager's approval letter must specifically

reference this AD.

Alternative Methods of Compliance

(d) 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, New York Aircraft Certification

Office (ACO), FAA, Engine and Propeller Directorate. Operators shall

submit their requests through an appropriate FAA Principal

Maintenance Inspector, who may add comments and then send it to the

Manager, New York ACO.

Note 3: Information concerning the existence of approved

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

obtained from the New York ACO.

Special Flight Permits

(e) 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.

Incorporation by Reference

(f) Except as provided by paragraph (c) of this AD, the actions

shall be done in accordance with de Havilland Temporary Revision

MTC-15, dated September 18, 1998, of the de Havilland Maintenance

Program Manual PSM 1-8-7 TC; de Havilland Temporary Revision MTC 3-

14, dated September 18, 1998, of the de Havilland Maintenance

Program Manual PSM 1-83-7 TC; or de Havilland Temporary Revision MTC

2-14, dated September 18, 1998, of the de Havilland Maintenance

Program Manual PSM 1-82-7 TC; 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 Bombardier, Inc., Bombardier Regional Aircraft

Division, Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada.

Copies may be inspected at the FAA, Transport Airplane Directorate,

1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Engine and

Propeller Directorate, New York Aircraft Certification Office, 10

Fifth Street, Third Floor, Valley Stream, New York; or at the Office

of the Federal Register, 800 North Capitol Street, NW., suite 700,

Washington, DC.

Note 4: The subject of this AD is addressed in Canadian

airworthiness directive CF-98-30, dated August 31, 1998.

(g) This amendment becomes effective on December 17, 1999.

Issued in Renton, Washington, on October 28, 1999.

D.L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 99-28746 Filed 11-10-99; 8:45 am]

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