Airworthiness Directives; Avro Model BAe 146 Series Airplanes

[[Page 57541]]

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 95-NM-210-AD; Amendment 39-9428; AD 95-23-08]

Airworthiness Directives; Avro Model BAe 146 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),

applicable to certain Avro Model BAe 146 series airplanes. This action

requires inspections to detect cracking and damage of the fastener

holes in the butt strap at rib 2 at the lower surface of the right-hand

wing; repair of discrepancies; and replacement of the fastener bolts.

This amendment is prompted by a report that certain wings were

manufactured with a reduction in the amount of edge margin between the

fastener hole centers and the edge of the butt strap; this condition

can result in a decrease in the long-term damage tolerance residual

strength of the wing. The actions specified in this AD are intended to

prevent cracking and other problems associated with a such decrease in

the long-term damage tolerance residual strength of the wing.

DATES: Effective December 1, 1995.

The incorporation by reference of certain publications listed in

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

of December 1, 1995.

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

before January 16, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Transport Airplane Directorate, ANM-103,

Attention: Rules Docket No. 95-NM-210-AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055-4056.

The service information referenced in this AD may be obtained from

British Aerospace Holdings, Inc., Avro International Aerospace

Division, P.O. Box 16039, Dulles International Airport, Washington, DC

20041-6039. This information may be examined 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.

FOR FURTHER INFORMATION CONTACT: Tim Backman, Aerospace Engineer,

Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,

1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206)

227-2797; fax (206) 227-1149.

SUPPLEMENTARY INFORMATION: The Civil Aviation Authority (CAA), which is

the airworthiness authority for the United Kingdom, recently notified

the FAA that an unsafe condition may exist on certain Avro Model BAe

146 series airplanes. The CAA advises that four wing-sets, delivered

from the vendor and installed on four airplanes, were manufactured with

a marked reduction in the amount of edge margin between the fastener

hole centers and edge of the rib 2 butt strap on the lower surface of

the right-hand wing. (Edge margin is defined as the distance from the

center of the fastener hole to the nearest edge of the part.) A

reduction in edge margin could lead to a decrease in the long-term

damage tolerance residual strength of the wing. This condition, if not

corrected, could result in fatigue cracking and other damage occurring

in the subject area at a time that is earlier than anticipated.

Avro International Aerospace has issued Service Bulletin 57-40,

dated March 18, 1994. This service bulletin describes procedures for

removing four specific fasteners from the rib 2 butt strap on the lower

surface of the right-hand wing, and conducting an eddy current

inspection to detect cracking of the vacant fastener holes. The service

bulletin also describes procedures for conducting a visual inspection

of the fastener holes to detect other damage, such as scoring that has

resulted from removal of the bolts; and to check the diameter of each

hole to determine if it is within the allowable tolerance. The service

bulletin also contains procedures for repairing cracked, damaged, or

incorrectly sized holes by oversizing them, and for installing new

fastener bolts. The CAA classified this service bulletin as mandatory

in order to assure the continued airworthiness of these airplanes in

the United Kingdom.

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

21.19) 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.

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, this AD is being issued to prevent cracking and

other problems associated with a decrease in the long-term damage

tolerance residual strength of the wing. This AD requires repetitive

eddy current inspections to detect cracking of the 4 fastener holes at

the rib 2 butt strap on the lower surface of the right-hand wing. It

also requires repetitive visual inspections of the fastener holes to

detect other damage, such as scoring that has resulted from removal of

the bolts; and to check the diameter of each fastener hole to determine

if it is within the allowable tolerance. If no cracking or damage is

detected in a fastener hole, and if the hole's diameter is within

tolerance limits, a new bolt must be installed. If any cracking or

damage is detected, or if the hole's diameter is outside of tolerance

limits, the hole must be oversized and cleaned, and a new bolt must be

installed. The actions are required to be accomplished in accordance

with the service bulletin described previously.

None of the Model BAe 146 series airplanes affected by this action

are on the U.S. Register. All airplanes included in the applicability

of this rule currently are operated by non-U.S. operators under foreign

registry; therefore, they are not directly affected by this AD action.

However, the FAA considers that this rule is necessary to ensure that

the unsafe condition is addressed in the event that any of these

subject airplanes are imported and placed on the U.S. Register in the

future.

Should an affected airplane be imported and placed on the U.S.

Register in the future, it would require approximately 8 work hours to

accomplish the required actions, at an average labor charge of $60 per

work hour. Based on these figures, the total cost impact of this AD

would be $480 per airplane.

Since this AD action does not affect any airplane that is currently

on the U.S. register, it has no adverse economic impact and imposes no

additional burden on any person. Therefore, notice and public

procedures hereon are unnecessary and the amendment may be made

effective in less than 30 days after publication in the Federal

Register.

Comments Invited

Although this action is in the form of a final rule and was not

preceded by notice and opportunity for public 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 shall identify the Rules Docket number

[[Page 57542]]

and be submitted in triplicate to the address specified under the

caption ADDRESSES. 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 rule must submit a self-addressed,

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

to Docket Number 95-NM-210-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.

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 USC 106(g), 40101, 40113, 44701.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

95-23-08 Avro International Aerospace (Formerly British Aerospace):

Amendment 39-9428. Docket 95-NM-210-AD.

Applicability: Model BAe 146 series airplanes; having

constructors' numbers E2188, E2192, E3190, and E3194; 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 use the authority

provided in paragraph (d) of this AD to request approval from the

FAA. This approval may address either no action, if the current

configuration eliminates the unsafe condition; or different actions

necessary to address the unsafe condition described in this AD. Such

a request should include an assessment of the effect of the changed

configuration on the unsafe condition addressed by this AD. In no

case does the presence of any modification, alteration, or repair

remove any airplane from the applicability of this AD.

Compliance: Required as indicated, unless accomplished

previously.

To prevent cracking and other problems associated with a

decrease in the long-term damage tolerance residual strength of the

wing, accomplish the following:

(a) Prior to the accumulation of 36,000 total landings or within

3 months after the effective date of this AD, whichever occurs

later, remove the 4 fasteners from the rib 2 butt strap on the lower

wing surface of the right-hand wing and accomplish the requirements

of paragraphs (a)(1) and (a)(2) of this AD, in accordance with Avro

Service Bulletin 57-40, dated March 19, 1994: -

(1) Perform an eddy current inspection of each of the fastener

holes to detect cracking.

(2) Perform a visual inspection of each of the fastener holes to

detect evidence of damage, such as scoring that has resulted from

removal of the bolts; and to check the diameter of each hole to

determine if it is within the allowable tolerance specified in the

service bulletin.

(b) If the fastener hole is free of cracks and damage, and if

the hole's diameter is within the allowable tolerance, prior to

further flight, install a new bolt in accordance with the service

bulletin. Thereafter, repeat the inspections specified in paragraph

(a) of this AD at intervals not to exceed 9,000 landings.

(c) If the hole is cracked or shows evidence of damage, or if

the hole's diameter is outside the allowable tolerance, prior to

further flight, oversize the hole, clean out the damage, and install

a new bolt, in accordance with the service bulletin. Thereafter,

repeat the inspections specified in paragraph (a) of this AD at

intervals not to exceed 9,000 landings.

(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, Standardization Branch, ANM-113,

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,

Standardization Branch, ANM-113.

Note 2: Information concerning the existence of approved

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

obtained from the Standardization Branch, ANM-113.

(e) Special flight permits may be issued in accordance with

Secs. 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.

(f) The actions shall be done in accordance with Avro Service

Bulletin 57-40, dated March 18, 1994. 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 British Aerospace Holdings, Inc., Avro International

Aerospace Division, P.O. Box 16039, Dulles International Airport,

Washington, DC 20041-6039. 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.

(g) This amendment becomes effective on December 1, 1995.

Issued in Renton, Washington, on November 6, 1995.

Darrell M. Pederson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 95-27912 Filed 11-15-95; 8:45 am]

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