Airworthiness Directives; Beech Model 400A and 400T (Military T- 1A) Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-NM-18-AD]

Airworthiness Directives; Beech Model 400A and 400T (Military T-

1A) 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 certain Beech Model 400A and 400T

(military T-1A) airplanes. This proposal would require an inspection of

certain flap roller retention components to detect discrepant or

missing parts, and replacement of discrepant or missing parts; and

installation of new washers on the roller attach bolts. This proposal

is prompted by reports of undersized tabs on some lock washers, and

tabs or inner tangs missing from the washers installed on the flap

roller bolts. Such discrepancies defeat the locking function of the tab

washer, and could result in loss of the nut and flap roller. The

actions specified by the proposed AD are intended to prevent loss of

the main or aft flap surface and subsequent reduced controllability of

the airplane.

DATES: Comments must be received by May 9, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

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

Attention: Rules Docket No. 94-NM-18-AD, 1601 Lind Avenue, SW., Renton,

Washington 98055-4056. Comments may be inspected at this location

between 9 a.m. and 3 p.m., Monday through Friday, except Federal

holidays.

The service information referenced in the proposed rule may be

obtained from Beech Aircraft Corporation, P.O. Box 85, Wichita, Kansas

67201-0085. This information may be examined at the FAA, Transport

Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at

the FAA, Small Airplane Directorate, Wichita Aircraft Certification

Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita,

Kansas.

FOR FURTHER INFORMATION CONTACT: Larry Engler, Aerospace Engineer,

Airframe Branch, ACE-120W, FAA, Small Airplane Directorate, Wichita

Aircraft Certification Office, 1801 Airport Road, room 100, Mid-

Continent Airport, Wichita, Kansas 67209; telephone (316) 946-4122; fax

(316) 946-4407.

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 94-NM-18-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-103, Attention: Rules

Docket No. 94-NM-18-AD, 1601 Lind Avenue, SW., Renton, Washington

98055-4056.

Discussion

The FAA has received a report that, during investigation of flap

roll problems on Beech Model 400T (military T-1A) airplanes, lock

washer inner tabs were missing from the washers installed on the flap

roller bolts. Subsequent investigation of production aircraft revealed

that, in addition to missing tabs, undersized inner tabs were found on

some lock washers. In addition, the FAA has received a report that the

locking tab washers may be missing an inner tang, which is designed to

engage the keyway in the bolt. Absence of this tang defeats the locking

function of the tab washer, and could result in loss of the nut and

flap roller. This condition, if not corrected, could result in loss of

the main or aft flap surface and subsequent reduced controllability of

the airplane.

Model 400A airplanes are similar in design to Model 400T (military

T-1A) airplanes and, therefore, also are subject to the addressed

unsafe condition.

The FAA has reviewed and approved Beech Service Bulletin No. 2522,

dated January 1994, that describes procedures for an inspection of

certain flap roller retention components to detect discrepant or

missing parts, and replacement of discrepant or missing parts with new

or serviceable parts; and installation of new washers, tab washers, and

flat washers on the roller attach bolts. Installation of these new

components will ensure the locking function of the tab washer and the

structural integrity of the flap roller.

Since an unsafe condition has been identified that is likely to

exist or develop on other products of this same type design, the

proposed AD would require an inspection of certain flap roller

retention components to detect discrepant or missing parts, and

replacement of discrepant or missing parts with new or serviceable

parts; and installation of new washers, tab washers, and flat washers

on the roller attach bolts. The actions would be required to be

accomplished in accordance with the service bulletin described

previously.

There are approximately 122 Model Beech 400A and 400T (military T-

1A) airplanes of the affected design in the worldwide fleet. The FAA

estimates that 102 airplanes of U.S. registry would be affected by this

proposed AD, that it would take approximately 8 work hours per airplane

to accomplish the proposed actions, and that the average labor rate is

$55 per work hour. Required parts would cost approximately $100 per

airplane. Based on these figures, the total cost impact of the proposed

AD on U.S. operators is estimated to be $55,080, or $540 per airplane.

The total 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.

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 14

CFR part 39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C.

106(g); and 14 CFR 11.89.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

Beech Aircraft Corporation: Docket 94-NM-18-AD.

Applicability: Model 400A airplanes, serial numbers RK-1 through

RK-79 inclusive; and Model 400T (military T-1A) airplanes, serial

numbers TT-1 through TT-42 inclusive, and TT-44; certificated in any

category.

Compliance: Required as indicated, unless accomplished

previously.

To prevent loss of the main or aft flap surface and subsequent

reduced controllability of the airplane, accomplish the following:

(a) Within 200 hours time-in-service after the effective date of

this AD, accomplish the requirements of paragraphs (a)(1) and (a)(2)

of this AD in accordance with Beech Service Bulletin No. 2522, dated

January 1994.

(1) Perform an inspection of the flap roller retention

components to detect discrepant or missing parts; and, prior to

further flight, replace any discrepant or missing part with a new or

serviceable part.

(2) Install new washers, new tab washers, and new flat washers

on the roller attach bolts.

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

a bolt, part number 45A97115-1 or 45A97115-51; or a tab washer, part

number 168AS-06-2; on any airplane unless the requirements of

paragraph (a)(1) of this AD have been accomplished on that bolt or

tab washer.

(c) 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, Wichita Aircraft Certification

Office (ACO), FAA, Small 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, Wichita ACO.

Note: Information concerning the existence of approved

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

obtained from the Wichita ACO.

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

Federal Aviation Regulations (FAR) 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 March 9, 1994.

Darrell M. Pederson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-5936 Filed 3-14-94; 8:45 am]

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