Airworthiness Directives; British Aerospace (Jetstream) Model 4101 Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-302-AD]

RIN 2120-AA64

Airworthiness Directives; British Aerospace (Jetstream) Model

4101 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness

directive (AD) that is applicable to all British Aerospace (Jetstream)

Model 4101 airplanes. This proposal would require repetitive

inspections to detect loose or migrated levers of the elevator cable

tension regulators, and replacement of the regulator assembly with a

new assembly, if necessary. 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 loose or migrated regulator levers of

the elevator cable tension regulators, which could result in reduced

controllability of the airplane.

DATES: Comments must be received by November 18, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

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

Attention: Rules Docket No. 99-NM-302-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-302-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-302-AD, 1601 Lind Avenue, SW., Renton, Washington

98055-4056.

Discussion

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 all British Aerospace (Jetstream) Model

4101 airplanes. The CAA advises that an incident has been reported in

which an elevator cable tension regulator lever became detached from

the elevator cable tension regulator assembly on a Model Jetstream 4101

airplane. The exact cause of the detachment is unknown at this time.

This condition, if not corrected, could result in reduced

controllability of the associated elevator.

Explanation of Relevant Service Information

British Aerospace has issued Jetstream Alert Service Bulletin J41-

A-27-053, dated September 14, 1999, which describes procedures for

repetitive detailed visual inspections to detect loose or migrated

levers of the elevator cable tension regulators. For any discrepant

lever assembly, the alert service bulletin describes procedures for

replacement of the regulator assembly with a new assembly. The initial

inspection also involves a one-time inspection of the nut and bolt to

detect signs of the bolt being threadbound, and repair, if necessary.

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

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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 require accomplishment of

the actions specified in the alert service bulletin described

previously.

Interim Action

This is considered to be interim action until final action is

identified, at which time the FAA may consider further rulemaking.

Cost Impact

The FAA estimates that 57 airplanes of U.S. registry would be

affected by this proposed AD, that it would take approximately 2 work

hours per airplane to accomplish the proposed inspection, and that the

average labor rate is $60 per work hour. Based on these figures, the

cost impact of the proposed AD on U.S. operators is estimated to be

$6,840, or $120 per airplane, per inspection cycle.

The cost impact figure discussed above is based on assumptions that

no operator has yet accomplished any of the 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]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

British Aerospace Regional Aircraft [Formerly Jetstream Aircraft

Limited; British Aerospace (Commercial Aircraft) Limited]: Docket

99-NM-302-AD.

Applicability: All Model Jetstream 4101 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 (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 loose or migrated regulator levers of the

elevator cable tension regulators, which could result in reduced

controllability of the associated elevator, accomplish the

following:

(a) Within 7 weeks after the effective date of this AD, perform

a detailed visual inspection of the elevator cable tension regulator

lever assembly to detect discrepancies (including looseness and

migration along the splines of the elevator cable tension regulator

assembly), in accordance with Jetstream Alert Service Bulletin J41-

A-27-053, dated September 14, 1999. Repeat the inspection thereafter

at intervals not to exceed 1,500 flight hours.

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.''

(b) If no discrepancy is detected during the initial inspection

required by paragraph (a) of this AD, perform a detailed visual

inspection of the bolt and castellated nut for signs of the bolt

being threadbound, in accordance with Jetstream Alert Service

Bulletin J41-A-27-053, dated September 14, 1999.

(1) If the nut and bolt are serviceable, as specified by the

alert service bulletin, prior to further flight, reinstall and

retorque the nut, in accordance with the alert service bulletin.

(2) If the nut and bolt are not serviceable, as specified by the

alert service bulletin, prior to further flight, replace with a new

nut and bolt and torque the nut, in accordance with the alert

service bulletin.

(c) If any discrepancy is detected during any inspection

required by paragraph (a) of this AD: Prior to further flight,

replace the elevator cable tension regulator assembly with a new

assembly, in accordance with Jetstream Alert Service Bulletin J41-A-

27-053, dated September 14, 1999.

(d) For each inspection performed as required by paragraph (a)

of this AD: Submit a report of the inspection findings (both

positive and negative findings) to Information Services, British

Aerospace Regional Aircraft, Prestwick International Airport,

Ayrshire, KA9 2RW, Scotland; at the applicable time specified in

paragraph (d)(1) or (d)(2) of this AD. The report must include the

inspection results, a description of any discrepancies found, the

airplane serial number, and the number of landings and flight hours

on the airplane. Information collection requirements contained in

this regulation have been approved by the Office of Management and

Budget (OMB) under the provisions of the Paperwork Reduction Act of

1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control

Number 2120-0056.

(1) For airplanes on which the inspection is accomplished after

the effective date of this AD: Submit the report within 10 days

after performing the inspection required by paragraph (a) of this

AD.

(2) For airplanes on which the inspection has been accomplished

prior to the effective date of this AD: Submit the report within 10

days after the effective date of this AD.

(e) As of the effective date of this AD, no person shall install

any elevator cable tension regulator lever unless that lever has

been inspected and applicable corrective actions

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have been performed in accordance with the requirements of this AD.

Alternative Methods of Compliance

(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, 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 3: Information concerning the existence of approved

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

obtained from the International Branch, ANM-116.

Special Flight Permits

(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 October 13, 1999.

D.L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 99-27275 Filed 10-18-99; 8:45 am]

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