Airworthiness Directives; Boeing Model 727 Series Airplanes

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 93-NM-97-AD; Amendment 39-8821; AD 94-04-03]

Airworthiness Directives; Boeing Model 727 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive

(AD), applicable to all Boeing Model 727 series airplanes, that

currently requires repetitive inspections to detect cracks in the slat

track roller bearing bolts, and replacement, if necessary. This

amendment adds an inspection of the positional plates installed on

certain airplanes, and replacement, if necessary; reduces the

compliance time for the initial inspection; and cites the latest

revision to the service bulletin as the appropriate service information

source. This amendment is prompted by a report that certain positional

plates may not stop rotation of the roller bearing bolts. The actions

specified by this AD are intended to prevent jamming of the affected

slat or separation of the slat from the airplane.

DATES: Effective March 21, 1994.

The incorporation by reference of certain publications listed in

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

of March 21, 1994.

ADDRESSES: The service information referenced in this AD may be

obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle,

Washington 98124-2207. This information may be examined at the Federal

Aviation Administration (FAA), Transport Airplane Directorate, Rules

Docket, 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: Walter Sippel, Aerospace Engineer,

Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle

Aircraft Certification Office, 1601 Lind Avenue SW., Renton, Washington

98055-4056; telephone (206) 227-2774; fax (206) 227-1181.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal

Aviation Regulations by superseding AD 90-18-02, Amendment 39-6708 (55

FR 34699, August 24, 1990), which is applicable to all Boeing Model 727

series airplanes, was published in the Federal Register on August 23,

1993 (58 FR 44466). The action proposed to require repetitive

inspections to detect cracks in the slat track roller bearing bolts,

and replacement, if necessary; and an inspection of the positional

plates installed on certain airplanes, and replacement, if necessary.

Interested persons have been afforded an opportunity to participate

in the making of this amendment. Due consideration has been given to

the comments received.

One commenter supports the proposed rule.

One commenter requests that the compliance time of 2,500 flight

cycles, as specified in paragraphs (b) and (d) of the proposal, be

reduced to 2,000 flight cycles to coincide with the interval expressed

in Boeing Service Bulletin 727-57-0172, which is cited in the proposed

rule.

The FAA does not concur with the commenter's request to shorten the

proposed compliance time. In developing an appropriate compliance time,

the FAA considered the safety implications, parts availability, and

normal maintenance schedules for timely accomplishment of the

modifications. Further, this AD supersedes an existing AD that

specified a compliance time of 2,500 flight cycles. The FAA has

received no reports to date of any problem encountered as a result of

that compliance time. To reduce the compliance time of the proposal

would necessitate (under the provisions of the Administrative Procedure

Act) reissuing the notice, reopening the period for public comment,

considering additional comments received, and eventually issuing a

final rule; the time required for that procedure may be as long as four

additional months. In light of these considerations, and in

consideration of the amount of time that has already elapsed since

issuance of the original notice, the FAA has determined that further

delay of this final rule action is not warranted.

The Air Transport Association (ATA) of America, on behalf of its

members, requests that the FAA review existing approvals of alternative

methods of compliance for AD 90-18-02 and determine if these approvals

remain valid for this AD and, if so, either place a ``NOTE'' in the

final rule or convey that information to affected operators through

individual notices. ATA contends that including such a ``NOTE'' in this

AD would expedite AD handling and reduce processing costs for both

operators and the FAA.

The FAA has reviewed existing approvals of alternative methods of

compliance for AD 90-18-02 and finds that these approvals would not

necessarily be acceptable for this AD, since the actions required by

the existing AD do not adequately address the unsafe condition.

However, if an operator believes its existing approval also should be

considered acceptable for this AD, that operator should resubmit its

request for approval from the FAA in accordance with the provisions of

paragraph (f) of this AD.

One ATA member suggests that, in lieu of being superseded, AD 90-

18-02 should be revised or amended so that operators with approvals of

alternative methods of compliance for that AD would not be required to

resubmit requests for such approvals for this AD. The FAA does not

concur. The FAA has determined that the actions required by AD 90-18-02

do not adequately address the specified unsafe condition. Consequently,

issuance of this AD is necessary to require additional actions in order

to fully address the unsafe condition. The FAA's normal policy in this

regard is that when an AD requires additional actions, the existing AD

is superseded by being removed from the system and a new AD added.

One commenter requests that the FAA include an initial

implementation period of 2,500 flight cycles in the final rule to allow

operators that are currently performing inspections in accordance with

the requirements of AD 90-18-02 additional time to ``transition over''

to the use of Revision 3 of Boeing Service Bulletin 727-57-0172. The

commenter states that, as written, the proposed rule would require that

those operators begin accomplishing the inspections in accordance with

Revision 3 immediately after the effective date of this AD.

The FAA does not concur with the commenter's request. The FAA

infers that the commenter's request for an implementation period to

``transition over'' refers to a need for additional time to update

records and plan/schedule subsequent inspections. The FAA finds that

additional time to begin accomplishing the inspections in accordance

with Revision 3 of the service bulletin is not warranted.

Paragraphs (a) and (b) of the final rule are purposefully redundant

with the exception of the inspection thresholds specified. The intent

of paragraph (b) is to reduce the inspection threshold from that

specified in paragraph (a) and to require that operators accomplish the

inspection in accordance with Revision 3 of the service bulletin.

Revision 3 of the service bulletin does not contain significant changes

from other issues of the service bulletin. Further, operators have been

provided ample notice through the proposed AD of the FAA's intent to

require that Revision 3 of the service bulletin be used for any

inspection accomplished after the effective date of this final rule.

Operators will also receive 30 additional days after publication of

this final rule in the Federal Register before this AD will become

effective.

The FAA has revised paragraph (a) of this AD to clarify its intent

that operators currently accomplishing the repetitive inspections

required by AD 90-18-02 continue to perform those inspections in

accordance with Revision 3 of the service bulletin until the first

inspection required by paragraph (b) of this AD has been accomplished.

In addition, paragraph (b) of this AD has been revised to specify that

accomplishment of the repetitive inspections in accordance with

Revision 3 of the service bulletin terminates the repetitive

inspections required by paragraph (a) of this AD.

One commenter requests that paragraph (d) of the proposal be

revised to indicate that no further action is required if a ``checking

tool'' is used to ensure that a functionally acceptable positional

plate was installed per Boeing Drawing 65C31395. The commenter

indicates that it has developed a tool for checking the dimensions of

the positional plate in accordance with the Boeing drawing. The

commenter states that, since it has used a functionally acceptable

solution to the problem and since this solution is recognized by Boeing

as being equivalent to the procedures described in Revision 3 of the

service bulletin cited in the proposal, the FAA should also recognize

this procedure as an acceptable method of complying with the proposed

requirements of this AD.

The FAA does not concur with the commenter's request to revise

paragraph (d) of this AD to indicate that no further action is required

if a ``checking tool'' is used. Paragraph (d) of this AD requires that

the gap between the roller bolt head and the positional plate be

measured in accordance with Revision 3 of Boeing Service Bulletin 727-

57-0172. However, that service bulletin does not specify the use of any

particular tool when performing the measurement. The FAA has no data

available to evaluate the validity of the tool referenced by the

commenter. In addition, the FAA does not find it necessary to limit the

methods available to operators to accomplish the requirements of

paragraph (d) of this AD. Since the service bulletin does not specify

the use of any particular tool, the FAA considers that any measuring

tool that allows operators to determine if the gap between the roller

bolt head and the positional plate is within specified limits meets the

intent of paragraph (d) of this AD.

After careful review of the available data, including the comments

noted above, the FAA has determined that air safety and the public

interest require the adoption of the rule with the changes previously

described. The FAA has determined that these changes will neither

increase the economic burden on any operator nor increase the scope of

the AD.

There are approximately 1,635 Model 727 series airplanes of the

affected design in the worldwide fleet. The FAA estimates that 1,047

airplanes of U.S. registry will be affected by this AD, that it will

take approximately 18 work hours per airplane to accomplish the

required actions, and that the average labor rate is $55 per work hour.

Based on these figures, the total cost impact of the AD on U.S.

operators is estimated to be $1,036,530, or $990 per airplane. This

total cost figure assumes that no operator has yet accomplished the

requirements of this AD.

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 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 removing amendment 39-6708 (55 FR

34699, August 24, 1990), and by adding a new airworthiness directive

(AD), amendment 39-8821, to read as follows:

94-04-03 Boeing: Amendment 39-8821. Docket 93-NM-97-AD. Supersedes

AD 90-18-02, Amendment 39-6708.

Applicability: All Model 727 series airplanes, certificated in

any category.

Compliance: Required as indicated, unless accomplished

previously.

To prevent cracking of the roller bearing bolts and subsequent

jamming of the affected slat or separation of the slat from the

airplane, accomplish the following:

(a) Prior to the accumulation of 12,000 total flight cycles, or

within 2,500 flight cycles after September 30, 1990 (the effective

date of AD 90-18-02, Amendment 39-6708), whichever occurs later:

Accomplish paragraph (a)(1) or (a)(2) of this AD, as applicable, in

accordance with Boeing Service Bulletin 727-57-0172, Revision 1,

dated October 12, 1989; Revision 2, dated June 27, 1991; or Revision

3, dated March 19, 1992. After the effective date of this AD, the

inspection shall be accomplished only in accordance with Revision 3

of the service bulletin. Repeat the inspection thereafter at

intervals not to exceed 5,000 flight cycles until the inspection

required by paragraph (b) of this AD is accomplished.

(1) For airplanes equipped with roller bearing bolts made from

CRES material: Perform a fluorescent particle inspection of the slat

track roller bearing bolts to detect cracks.

(2) For airplanes equipped with roller bearing bolts not made

from CRES material: Perform a magnetic particle inspection of the

slat track roller bearing bolts to detect cracks.

(b) Prior to the accumulation of 8,000 total flight cycles, or

within 2,500 flight cycles after the effective date of this AD,

whichever occurs later, unless accomplished previously within the

last 2,500 flight cycles prior to the effective date of this AD:

Accomplish paragraph (b)(1) or (b)(2) of this AD, as applicable, in

accordance with Boeing Service Bulletin 727-57-0172, Revision 3,

dated March 19, 1992. Repeat this inspection thereafter at intervals

not to exceed 5,000 flight cycles. Accomplishment of this inspection

terminates the repetitive inspection requirement of paragraph (a) of

this AD.

(1) For airplanes equipped with roller bearing bolts made from

CRES material: Perform a fluorescent particle inspection of the slat

track roller bearing bolts to detect cracks.

(2) For airplanes equipped with roller bearing bolts not made

from CRES material: Perform a magnetic particle inspection of the

slat track roller bearing bolts to detect cracks.

(c) If any cracked bolt is found during any inspection required

by this AD, prior to further flight, replace the cracked bolt with a

serviceable bolt and inspect the associated roller to detect

seizure, in accordance with Boeing Service Bulletin 727-57-0172,

Revision 1, dated October 12, 1989, Revision 2, dated June 27, 1991,

or Revision 3, dated March 19, 1992. If the roller is seized or does

not turn smoothly, prior to further flight, replace the defective

roller with a serviceable roller in accordance with the service

bulletin.

(d) For airplanes having positional plates installed in

accordance with Boeing Service Bulletin 727-57-0172, dated September

6, 1985, Revision 1, dated October 12, 1989, or Revision 2, dated

June 27, 1991: Prior to the accumulation of 5,000 flight cycles

since modification, or within 2,500 flight cycles after the

effective date of this AD, whichever occurs later, measure the gap

between the roller bolt head and the positional plate in accordance

with Boeing Service Bulletin 727-57-0172, Revision 3, dated March

19, 1992.

(1) If the gap measures 0.020 inch or less, no further action is

required by this AD.

(2) If the gap measures more than 0.020 inch, prior to further

flight, replace the positional plate with a new positional plate in

accordance with Figure 3 of the service bulletin.

(e) Modification of the bolts and slat tracks in accordance with

Boeing Service Bulletin 727-57-0172, Revision 3, dated March 19,

1992, constitutes terminating action for the actions required by

paragraphs (a), (b), and (d) of this AD.

(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, Seattle Aircraft Certification

Office (ACO), 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, Seattle ACO.

Note: Information concerning the existence of approved

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

obtained from the Seattle ACO.

(g) Special flight permits may be issued in accordance with FAR

21.197 and 21.199 to operate the airplane to a location where the

requirements of this AD can be accomplished.

(h) The inspections, replacements, gap measurement, and

modification shall be done in accordance with Boeing Service

Bulletin 727-57-0172, Revision 1, dated October 12, 1989; Boeing

Service Bulletin 727-57-0172, Revision 2, dated June 27, 1991; and

Boeing Service Bulletin 727-57-0172, Revision 3, dated March 19,

1992. 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 Boeing Commercial Airplane

Group, P.O. Box 3707, Seattle, Washington 98124-2207. 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.

(i) This amendment becomes effective on March 21, 1994.

Issued in Renton, Washington, on February 4, 1994.

N. B. Martenson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-3103 Filed 2-16-94; 8:45 am]

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