Airworthiness Directives; British Aerospace Model BAC 1-11 200 and 400 Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-47-AD]

RIN 2120-AA64

Airworthiness Directives; British Aerospace Model BAC 1-11 200

and 400 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 BAC 1-11 200 and 400 series airplanes. That AD currently limits

the number of operations at increased cabin pressure differential, and

requires repetitive structural inspections for cracking of the

fuselage, and repair or replacement of parts, if necessary. This action

would require additional repetitive inspections for cracking of the

fuselage. This proposal is prompted by the determination that airplanes

operating at increased cabin pressure differential are more likely to

develop fatigue cracking earlier in their service lives than those

airplanes operating at normal cabin differential pressures. The actions

specified by the proposed AD are intended to detect and correct fatigue

cracking of the airplane fuselage, which could result in reduced

structural integrity of the airplane.

DATES: Comments must be received by February 4, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

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

Attention: Rules Docket No. 98-NM-47-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, Service Support, Airbus Limited, P.O.

Box 77, Bristol BS99 7AR, England. This information may be examined at

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

Washington.

pected 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, Service Support, Airbus Limited, P.O.

Box 77, Bristol BS99 7AR, England. 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 98-NM-47-AD.'' The postcard will be date stamped and

returned to the commenter.

Availability of NPRMs

ith

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 98-NM-47-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. 98-NM-47-AD, 1601 Lind Avenue, SW., Renton, Washington

98055-4056.

Discussion

On August 14, 1989, the FAA issued AD 89-18-10, amendment 39-6310

(54 FR 34768, August 22, 1989), applicable to certain British Aerospace

Model BAC 1-11 200 and 400 series airplanes. That AD currently limits

the number of operations at increased cabin pressure differential, and

requires repetitive structural inspections for cracking of the

fuselage, and repair or replacement of parts, if necessary. That action

was prompted by the determination that airplanes operating at increased

cabin pressure differential are more likely to develop fatigue cracking

earlier in their service lives than those airplanes operating at normal

cabin differential pressures. The requirements of that AD are intended

to prevent inability of the

airplane structure to carry required loads.

Actions Since Issuance of AD 89-18-10

Since the issuance of AD 89-18-10, the Civil Aviation Authority

(CAA), which is the airworthiness authority for the United Kingdom,

advises that it has reviewed existing mandated supplemental fatigue

inspections applied to older Model BAC 1-11 series airplanes. Following

this review, additional routine visual inspections of the fuselage were

recommended to improve the probability of the detection of fatigue

cracking. Such fatigue cracking, if not corrected, could result in

reduced structural integrity of the airplane.

Explanation of Relevant Service Information

dated supplemental fatigue

inspections applied to older Model BAC 1-11 series airplanes. Following

this review, additional routine visual inspections of the fuselage were

recommended to improve the probability of the detection of fatigue

cracking. Such fatigue cracking, if not corrected, could result in

reduced structural integrity of the airplane.

Explanation of Relevant Service Information

The manufacturer has issued British Aerospace Alert Service

Bulletin 53-A-PM5922, Issue 2, dated April 27, 1995, which describes

procedures for repetitive structural inspections for cracking of the

fuselage. The procedures described in Issue 2 of the service bulletin

are essentially identical to Issue 1, however, it adds additional areas

to be inspected and revises certain inspection thresholds and

intervals. The CAA classified this alert service bulletin as mandatory

in 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

ss 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 89-18-10 to

continue to limit the number of operations at increased cabin pressure

differential, and require repetitive structural inspections for

cracking of the fuselage, and repair or replacement of parts, if

necessary. The proposed AD would require additional repetitive

structural inspections for cracking of the fuselage, revise certain

inspection thresholds and intervals, and corrective actions, if

necessary. The actions would be required to be accomplished in

accordance with Issue 2 of the alert service bulletin described

previously, except as discussed below.

Differences Between Proposed Rule and Alert Service Bulletin

Operators should note that, although the alert service bulletin

does not specify an initial compliance time for performing the

additional visual inspections, the FAA has determined that a threshold

of 3 months to accomplish those inspections would address the

identified unsafe condition in a timely manner. In developing this

compliance time, the FAA considered the degree of urgency associated

with addressing the subject unsafe condition, the average utilization

of the affected fleet, and the time necessary to perform the

inspections. In light of all of these factors, the FAA finds that this

compliance time represents an appropriate interval of time allowable

for affected airplanes to continue to operate without compromising

safety.

Cost Impact

ed the degree of urgency associated

with addressing the subject unsafe condition, the average utilization

of the affected fleet, and the time necessary to perform the

inspections. In light of all of these factors, the FAA finds that this

compliance time represents an appropriate interval of time allowable

for affected airplanes to continue to operate without compromising

safety.

Cost Impact

There are approximately 42 airplanes of U.S. registry that would be

affected by this proposed AD.

The actions that are currently required by AD 89-18-10, and

retained in this proposed AD, take approximately 67 work hours per

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

Based on these figures, the cost impact of the currently required

actions on U.S. operators is estimated to be $168,840, or $4,020, per

airplane.

The new inspections that are proposed in this AD action would take

approximately 29 work hours per airplane to accomplish, at an average

labor rate of $60 per work hour. Based on these figures, the cost

impact of the new proposed requirements of this AD on U.S. operators is

estimated to be $73,080, or $1,740 per airplane, per inspection cycle.

The cost impact figures discussed above are based on assumptions

that no operator has yet accomplished any of the current or proposed

requirements of this AD action, and that no operator would accomplish

those actions in the future if this AD were not adopted.

Regulatory Impact

requirements of this AD on U.S. operators is

estimated to be $73,080, or $1,740 per airplane, per inspection cycle.

The cost impact figures discussed above are based on assumptions

that no operator has yet accomplished any of the current or proposed

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]

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 39-6310 (54 FR

34768, August 22, 1989), and by adding a new airworthiness directive

(AD), to read as follows:

British Aerospace Airbus Limited (Formerly British Aerospace

Commercial Aircraft Limited, British Aerospace Aircraft Group):

Docket 98-NM-47-AD. Supersedes AD 89-18-10, Amendment 39-6310.

Applicability: Model BAC 1-11 200 and 400 series airplanes on

which British Aerospace Modifications PM2840 and PM3187 have been

accomplished; or on which British Aerospace Modification PM4886 has

been accomplished; except for airplanes on which British Aerospace

Modification PM5282 (cabin freight door) has been accomplished; and

certificated in any category.

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

preceding applicability provision, regardless of whether it has been

otherwise 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 (f) 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.

d, the owner/operator must request approval for an

alternative method of compliance in accordance with paragraph (f) 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 airplane fuselage,

which could result in reduced structural integrity of the airplane,

accomplish the following:

(a) Except as provided by paragraph (c) of this AD: For

airplanes modified for operation to a maximum of 7.75 pounds per

square inch (psi) cabin pressure differential, as specified in

British Aerospace Alert Service Bulletin 53-A-PM5922, Issue 1, dated

January 27, 1987, accomplish the requirements of paragraphs (a)(1)

and (a)(2) of this AD.

(1) At or prior to the accumulation of 55,000 total landings, or

within 15 months after September 28, 1989 (the effective date of AD

89-18-10, amendment 39-6310), whichever occurs later, perform the

inspections specified in paragraph 2.1 of the alert service

bulletin. Thereafter, repeat the inspections in accordance with

paragraph 2.1.1 of the alert service bulletin at intervals shown in

Table AA of the alert service bulletin.

(2) At or prior to the accumulation of 60,000 total landings, or

within 30 days after September 28, 1989, whichever occurs later,

reduce the aircraft maximum cabin pressure differential to 7.5 psi

by system modification, in accordance with a method approved by the

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

Directorate.

ls shown in

Table AA of the alert service bulletin.

(2) At or prior to the accumulation of 60,000 total landings, or

within 30 days after September 28, 1989, whichever occurs later,

reduce the aircraft maximum cabin pressure differential to 7.5 psi

by system modification, in accordance with a method approved by the

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

Directorate.

(b) Except as provided by paragraph (d) of this AD: For

airplanes modified for operation at cabin pressure differentials

above 7.75 psi up to a maximum of 8.2 psi, as specified in British

Aerospace Alert Service Bulletin 53-A-PM5922, Issue 1, dated January

27, 1987, accomplish the requirements of paragraph (b)(1) or (b)(2)

of this AD, as applicable. Subsequently, accomplish the requirements

of paragraphs (b)(3) and (b)(4), or paragraphs (b)(5) and (b)(6) of

this AD, as applicable.

(1) For airplanes originally manufactured for operation at cabin

pressure differentials above 7.75 psi, at or prior to the

accumulation of the number of landings shown for initial inspection

in the ``NE period'' column of Table AA in the alert service

bulletin, or within 15 months after September 28, 1989, whichever

occurs later, perform inspections specified in paragraph 2.2.1 of

the alert service bulletin and repeat the inspections as specified

in paragraph 2.2.3 of the alert service bulletin at the intervals

shown in Table AA of the alert service bulletin.

initial inspection

in the ``NE period'' column of Table AA in the alert service

bulletin, or within 15 months after September 28, 1989, whichever

occurs later, perform inspections specified in paragraph 2.2.1 of

the alert service bulletin and repeat the inspections as specified

in paragraph 2.2.3 of the alert service bulletin at the intervals

shown in Table AA of the alert service bulletin.

(2) For airplanes modified for operation at cabin pressure

differential above 7.75 psi after the airplane entered service, at

or prior to the accumulation of the number of landings shown for

initial inspection in the ``NE period'' column [obtained using the

inspection adjustment graph (page 6) of the alert service bulletin],

in Table AA of the alert service bulletin, or within 15 months after

September 28, 1989, whichever occurs later, perform initial

inspections specified in paragraph 2.2.2 of the alert service

bulletin. Thereafter, repeat the inspections as specified in

paragraph 2.2.3 of the alert service bulletin, at intervals shown in

Table AA of the alert service bulletin.

(3) At or prior to the accumulation of 55,000 total landings, or

within 30 days after September 28, 1989, whichever occurs later,

reduce the aircraft cabin maximum operating pressure differential to

7.5 or 7.75 psi by modification as specified in paragraph 2.2.4 of

the alert service bulletin, in accordance with a method approved by

the Manager, International Branch, ANM-116.

(4) For airplanes which have had the cabin pressure differential

reduced from 8.2 psi to 7.75 psi as specified in paragraph 2.2.6 of

the alert service bulletin, perform repetitive inspections at the

intervals specified in the ``N.E. period'' column in Table AA of the

alert service bulletin.

service bulletin, in accordance with a method approved by

the Manager, International Branch, ANM-116.

(4) For airplanes which have had the cabin pressure differential

reduced from 8.2 psi to 7.75 psi as specified in paragraph 2.2.6 of

the alert service bulletin, perform repetitive inspections at the

intervals specified in the ``N.E. period'' column in Table AA of the

alert service bulletin.

(5) At or prior to the accumulation of 60,000 total landings, or

within 30 days after September 28, 1989, whichever occurs later, the

airplane cabin maximum operating pressure differential must be

reduced to 7.5 psi by modification as specified in paragraph 2.2.7

of the alert service bulletin, in accordance with a method approved

by the Manager, International Branch, ANM-116.

(6) For airplanes modified for 8.2 psi maximum cabin operating

pressure differential and operated for a period in excess of any

Table AA inspection threshold in the alert service bulletin, perform

one additional inspection at or prior to the Table AA ``N.E.

period'' column repeat interval after limiting operation to 7.5 psi,

as specified in paragraph 2.2.5 of the alert service bulletin.

(c) For airplanes modified for operation to a maximum of 7.75

pounds per square inch (psi) cabin pressure differential, as

specified in British Aerospace Alert Service Bulletin 53-A-PM5922,

Issue 2, dated April 27, 1995: Prior to the accumulation of the

number of landings specified in Table AA of the alert service

bulletin, or within 3 months after the effective date of this AD,

whichever occurs later, perform the inspections specified in

paragraph 2.1 of the alert service bulletin. Thereafter, repeat the

inspections in accordance with paragraph 2.1.1 of the alert service

bulletin at the intervals shown in Table AA of the alert service

bulletin. Accomplishment of the inspections required by this

paragraph terminates the repetitive inspections required by

paragraph (a)(1) of this AD.

later, perform the inspections specified in

paragraph 2.1 of the alert service bulletin. Thereafter, repeat the

inspections in accordance with paragraph 2.1.1 of the alert service

bulletin at the intervals shown in Table AA of the alert service

bulletin. Accomplishment of the inspections required by this

paragraph terminates the repetitive inspections required by

paragraph (a)(1) of this AD.

Note 2: Paragraph (a)(1) of this AD restates the requirement for

an initial and repetitive inspections contained in paragraph A.1. of

AD 89-18-10. Therefore, for operators who have previously

accomplished at least the initial inspection in accordance with AD

89-18-10, paragraph (c) of this AD requires that the next scheduled

inspection be performed within the repetitive inspection interval

specified in Table AA of Issue 2 of the alert service bulletin,

after the last inspection performed in accordance with paragraph

A.1. of AD 89-18-10.

(d) For airplanes modified for operation at cabin pressure

differentials above 7.75 psi up to a maximum of 8.2 psi, as

specified in British Aerospace Alert Service Bulletin 53-A-PM5922,

Issue 2, dated April 27, 1995: Prior to the accumulation of the

number of landings specified in Table AA of the alert service

bulletin, or within 3 months after the effective date of this AD,

whichever occurs later, perform the inspections specified in

paragraph 2.2.1 of the alert service bulletin. Thereafter, repeat

the inspections in accordance with paragraph 2.2.3 of the alert

service bulletin at the intervals shown in Table AA of the alert

service bulletin. Accomplishment of the inspections required by this

paragraph terminates the repetitive inspections required by

paragraph (b)(1), (b)(2) or (b)(4) of this AD, as applicable.

this AD, as applicable.

(1) Replace the defective part with a serviceable part of the

same part number in accordance with the Structural Repair Manual; or

(2) For damage within the limits specified in the BAC 1-11

Structural Repair Manual, repair in accordance with the Structural

Repair Manual; or

(3) Repair in accordance with a method approved by the Manager,

International Branch, ANM-116.

(f) 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.

(g) 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.

Issued in Renton, Washington, on December 28, 1998.

Darrell M. Pederson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 99-49 Filed 1-4-99; 8:45 am]

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