Airworthiness Directives; British Aerospace Model BAe 146-100A, - 200A, and -300A Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-237-AD]

RIN 2120-AA64

Airworthiness Directives; British Aerospace Model BAe 146-100A, -

200A, and -300A Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing

airworthiness directive (AD), applicable to certain British Aerospace

Model BAe 146-100A, -200A, and -300A series airplanes, that currently

requires either a one-time non-destructive test (NDT) inspection or a

detailed visual inspection for cracking of the fuselage skin in the

vicinity of frame 29 between stringers 12 and 13, and repair, if

necessary. This action would require that the current thresholds for

these inspections be reduced and that repetitive inspections be

performed. This proposal is prompted by issuance of mandatory

continuing airworthiness information by a foreign civil airworthiness

authority. The actions specified by the proposed AD are intended to

detect and correct fatigue cracking of the fuselage skin in the

specified area, which could result in reduced structural integrity of

the airplane.

DATES: Comments must be received by November 15, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Transport Airplane Directorate, ANM-114,

Attention: Rules Docket No. 99-NM-237-AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055-4056. Comments may be inspected at this

location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except

Federal holidays.

The service information referenced in the proposed rule may be

obtained from British Aerospace Regional Aircraft American Support,

13850 Mclearen Road, Herndon, Virginia 20171. This information may be

examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue,

SW., Renton, Washington.

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:

Comments Invited

Interested persons are invited to participate in the making of the

proposed rule by submitting such written data, views, or arguments as

they may desire. Communications shall identify the Rules Docket number

and be submitted in triplicate to the address specified above. All

communications received on or before the closing date for comments,

specified above, will be considered before taking action on the

proposed rule. The proposals contained in this notice may be changed in

light of the comments received.

Comments are specifically invited on the overall regulatory,

economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with

the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments

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

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

to Docket Number 99-NM-237-AD.'' The postcard will be date stamped and

returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request

to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules

Docket No. 99-NM-237-AD, 1601 Lind Avenue, SW., Renton, Washington

98055-4056.

Discussion

On September 28, 1998, the FAA issued AD 98-21-06, amendment 39-

10814 (63 FR 53550, October 6, 1998), applicable to certain British

Aerospace Model BAe 146-100A, -200A, and -300A series airplanes, to

require either a one-time non-destructive test (NDT) inspection or a

visual inspection for cracking of the fuselage skin in the vicinity of

frame 29 between stringers 12 and 13, and repair, if necessary. That

action was prompted by issuance of mandatory continuing airworthiness

information issued by a foreign civil airworthiness authority, which

reported that, during routine inspections, fatigue cracking was found

in the specified area. The requirements of that AD are intended to

detect and correct fatigue cracking of the fuselage skin in the

specified area, which could result in reduced structural integrity of

the airplane.

Information Received Since Issuance of Previous AD

Since issuance of that AD, the FAA has been advised of new

metallurgical analysis which necessitates changes to the current

inspection thresholds and the addition of repetitive inspections.

Explanation of Relevant Service Information

Since the issuance of AD 98-21-06, British Aerospace has issued

Service Bulletin SB.53-144, Revision 1, dated May 21, 1999. The

inspection procedures described in this revision are identical to those

described in the original service bulletin (which was referenced in AD

98-21-06). However, Revision 1 reduces the initial inspection

thresholds.

The new revision also adds a closing action which advises operators

to refer to a new Significant Structural Item (SSI) entry 53-20-160.

The service bulletin and the SSI task recommend the same inspection and

initial inspection threshold, but the SSI task also includes intervals

for repetitive inspections. This SSI task is identified in the Model

BAe 146 Maintenance Review Board (MRB) report.

The Civil Aviation Authority (CAA), which is the airworthiness

authority for the United Kingdom, classified Revision 1 of the service

bulletin as mandatory in

[[Page 55637]]

order to assure the continued airworthiness of these airplanes in the

United Kingdom.

FAA's Conclusions

This airplane model is manufactured in the United Kingdom and is

type certificated for operation in the United States under the

provisions of section 21.29 of the Federal Aviation Regulations (14 CFR

21.29) and the applicable bilateral airworthiness agreement. Pursuant

to this bilateral airworthiness agreement, the CAA has kept the FAA

informed of the situation described above. The FAA has examined the

findings of the CAA, reviewed all available information, and determined

that AD action is necessary for products of this type design that are

certificated for operation in the United States.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to

exist or develop on other airplanes of the same type design registered

in the United States, the proposed AD would supersede AD 98-21-06 to

require accomplishment of the actions specified in the service bulletin

described previously, except as discussed below.

Differences Between Proposed Rule and Service Bulletin

Operators should note that, although the service bulletin specifies

that the manufacturer may be contacted for disposition of cracking

conditions, this proposal would require the repair of those conditions

to be accomplished in accordance with a method approved by either the

FAA or the CAA (or its delegated agent). In light of the type of repair

that would be required to address the identified unsafe condition, and

in consonance with existing bilateral airworthiness agreements, the FAA

has determined that, for this proposed AD, a repair approved by either

the FAA or the CAA would be acceptable for compliance with this

proposed AD.

Revision 1 of Service Bulletin SB.53-144 refers to the repetitive

inspections identified in MRB new entry SSI 53-20-160, but does not

explicitly require that these inspections be performed. The proposed AD

would mandate these repetitive inspections directly.

Cost Impact

The FAA estimates that 23 airplanes of U.S. registry would be

affected by this proposed AD.

For operators that elect to accomplish the visual inspection rather

than the NDT inspection, it would take approximately 6 work hours per

airplane to accomplish it, at an average labor rate of $60 per work

hour. Based on these figures, the cost impact of the visual inspection

on U.S. operators is estimated to be $360 per airplane, per inspection

cycle.

For operators that elect to accomplish the NDT inspection rather

than the visual inspection, it would take approximately 8 work hours

per airplane to accomplish it, at an average labor rate of $60 per work

hour. Based on these figures, the cost impact of the NDT inspection on

U.S. operators is estimated to be $480 per airplane, per inspection

cycle.

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 proposed herein would 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

proposal would not have sufficient federalism implications to warrant

the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this proposed

regulation (1) is not a ``significant regulatory action'' under

Executive Order 12866; (2) is not a ``significant rule'' under the DOT

Regulatory Policies and Procedures (44 FR 11034, February 26, 1979);

and (3) if promulgated, 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 draft

regulatory 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, Safety.

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the

Administrator, the Federal Aviation Administration proposes to amend

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 removing amendment 39-10814 (63 FR

53550, November 10, 1998), and by adding the following new

airworthiness directive:

British Aerospace Regional Aircraft (Formerly British Aerospace

Regional Aircraft Limited, Avro International Aerospace Division;

British Aerospace, PLC; British Aerospace Commercial Aircraft

Limited): Docket 99-NM-237-AD. Supersedes AD 98-21-06, Amendment 39-

10814.

Applicability: Model BAe 146-100, -200, and -300 series

airplanes; as listed in British Aerospace Service Bulletin SB.53-

144, dated April 27, 1998, or Revision 1, dated May 21, 1999;

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 fuselage skin in

the vicinity of frame 29 between stringers 12 and 13, which could

result in reduced structural integrity of the airplane, accomplish

the following:

Inspections

(a) Perform either a non-destructive test (NDT) inspection or a

detailed visual inspection for cracking of the fuselage skin in the

vicinity of frame 29 between stringers 12 and 13, in accordance with

British Aerospace Service Bulletin SB.53-144, dated April 27, 1998,

or Revision 1, dated May 21, 1999, at the earlier of the applicable

times specified in paragraphs (a)(1) and (a)(2).

Note 2: The actions defined in the original issue and Revision 1

of the service bulletin are identical. However, the compliance times

and effectivity groupings are different. Accomplishment of either

revision level, at the earlier of the applicable compliance times of

paragraphs (a)(1) and (a)(2) of this AD, is acceptable for

compliance with the requirements of paragraph (a) of this AD.

Note 3: For the purposes of this AD, a detailed inspection is

defined as: ``An

[[Page 55638]]

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.''

(1) For airplanes identified in the specified paragraph of

Service Bulletin SB.53-144, dated April 27, 1998:

(i) Paragraph 1.D.(1)(a): Inspect prior to the accumulation of

12,000 total flight cycles, or within 1,000 flight cycles after

November 10, 1998 (the effective date of AD 98-21-06, amendment 39-

10814), whichever occurs later.

(ii) Paragraph 1.D.(1)(b): Inspect prior to the accumulation of

16,000 total flight cycles, or within 1,200 flight cycles after

November 10, 1998, whichever occurs later.

(iii) Paragraph 1.D.(1)(c): Inspect prior to the accumulation of

13,500 total flight cycles, or within 1,000 flight cycles after

November 10, 1998, whichever occurs later.

(iv) Paragraph 1.D.(1)(d): Inspect prior to the accumulation of

22,000 total flight cycles, or within 1,400 flight cycles after

November 10, 1998, whichever occurs later.

(2) For airplanes in the applicable configuration specified in

Table 1 of Service Bulletin SB.53-144, Revision 1, dated May 21,

1999:

(i) For Model BAe 146-100 airplanes on which Modification

HCM00020P has not been accomplished: Inspect prior to the

accumulation of 11,600 total flight cycles, or within 1,000 flight

cycles after the effective date of this AD, whichever occurs later.

(ii) For Model BAe 146-100 airplanes on which Modification

HCM00020P has been accomplished: Inspect prior to the accumulation

of 14,500 total flight cycles, or within 1,200 flight cycles after

the effective date of this AD, whichever occurs later.

(iii) For Model BAe 146-200 airplanes on which Modification

HCM00021J has not been accomplished: Inspect prior to the

accumulation of 12,600 total flight cycles, or within 1,000 flight

cycles after the effective date of this AD, whichever occurs later.

(iv) For Model BAe 146-200 airplanes on which Modification

HCM00021J has been accomplished: Inspect prior to the accumulation

of 11,600 total flight cycles, or within 1,000 flight cycles after

the effective date of this AD, whichever occurs later.

(v) For Model BAe 146-300 airplanes on which Modification

HCM01000B has not been accomplished: Inspect prior to the

accumulation of 17,200 total flight cycles, or within 1,400 flight

cycles after the effective date of this AD, whichever occurs later.

(b) Repeat the inspections required by paragraph (a) of this AD

at the intervals defined in Significant Structural Item (SSI) Task

No. 53-20-160 as detailed in Section 6 of the BAe 146 Maintenance

Review Board Report, Revision 5, dated November 1998.

Corrective Action

(c) If any cracking is detected during any inspection required

by paragraph (a) or (b) of this AD, prior to further flight, repair

in accordance with a method approved by either the Manager,

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

or the Civil Aviation Authority (or its delegated agent). For a

repair method to be approved by the Manager, International Branch,

ANM-116, 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, International Branch, ANM-116.

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 4: Information concerning the existence of approved

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

obtained from the International Branch, ANM-116.

(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.

Note 5: The subject of this AD is addressed in British

airworthiness directive 005-04-98.

Issued in Renton, Washington, on October 7, 1999.

D.L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 99-26868 Filed 10-13-99; 8:45 am]

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