This section of the FEDERAL REGISTER

contains notices to the public of the proposed

issuance of rules and regulations. The

purpose of these notices is to give interested

persons an opportunity to participate in the

rule making prior to the adoption of the final

rules.

Proposed Rules Federal Register

43128

Vol. 62, No. 155

Tuesday, August 12, 1997

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97–NM–56–AD]

RIN 2120–AA64

Airworthiness Directives; McDonnell

Douglas Model DC–9–10, –20, –30, –40,

and –50

Series Airplanes, and C–9 (Military)

Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes the

adoption of a new airworthiness

directive (AD) that is applicable to

certain McDonnell Douglas Model DC–

9–10, –20, –30, –40, and –50 series

airplanes, and C–9 (military) airplanes.

This proposal would require a one-time

visual inspection to determine if all

corners of the doorjamb of the forward

service door have been previously

modified. The proposal would also

require various repetitive inspections to

detect cracks of the fuselage skin and

doubler at all corners of the doorjamb of

the forward service door, and to detect

cracks on the skin adjacent to the

modification; and various follow-on

actions. This proposal is prompted by

reports of fatigue cracks found in the

fuselage skin and doubler at the corners

of the doorjamb of the forward service

door. The actions specified by the

proposed AD are intended to detect and

correct such fatigue cracking, which

could result in rapid decompression of

the fuselage and consequent reduced

structural integrity of the airplane.

DATES: Comments must be received by

September 29, 1997.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–103,

Attention: Rules Docket No. 97–NM–

56–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

McDonnell Douglas Corporation, 3855

Lakewood Boulevard, Long Beach,

California 90846, Attention: Technical

Publications Business Administration,

Department C1–L51 (2–60). This

information may be examined at the

FAA, Transport Airplane Directorate,

1601 Lind Avenue, SW., Renton,

Washington.

FOR FURTHER INFORMATION CONTACT:

Wahib Mina, Aerospace Engineer,

Airframe Branch, ANM–120L, FAA, Los

Angeles Aircraft Certification Office,

3960 Paramount Boulevard, Lakewood,

California 90712; telephone (562) 627–

5324; fax (562) 627–5210.

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 97–NM–56–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.

97–NM–56–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

The FAA has received reports of

fatigue cracks in the fuselage skin and

doubler at the corners of the doorjamb

of the forward service door on Model

DC–9 series airplanes. These cracks

were discovered during inspections

conducted as part of the Supplemental

Structural Inspection Document (SSID)

program, required by AD 96–13–03,

amendment 39–9671 (61 FR 31009, June

19, 1996). Investigation revealed that

such cracking was caused by fatiguerelated stress. Fatigue cracking in the

fuselage skin or doubler at the corners

of the doorjamb of the forward service

door, if not detected and corrected in a

timely manner, could result in rapid

decompression of the fuselage and

consequent reduced structural integrity

of the airplane.

Explanation of Relevant Service

Information

The FAA has reviewed and approved

McDonnell Douglas Service Bulletin

DC9–53–279, dated December 10, 1996,

and Revision 1, dated May 6, 1997. The

service bulletins describes the following

procedures:

1. Performing a one-time visual

inspection to determine if all corners of

the upper cargo doorjamb have been

previously modified;

2. For certain airplanes: Performing a

low frequency eddy current (LFEC) or xray inspections to detect cracks of the

fuselage skin and doubler at all corners

of the doorjamb of the forward service

door;

3. For certain other airplanes:

Performing high frequency eddy current

inspection (HFEC) or LFEC, as

applicable, to detect cracks on the skin

adjacent to the modification;

4. Conducting repetitive inspections,

or modifying the corner skin of the

doorjamb of the forward service door

and performing follow-on action eddy

current inspections, if no cracking is

detected;

5. Performing repetitive eddy current

inspections to detect cracks on the skin
Federal Register / Vol. 62, No. 155 / Tuesday, August 12, 1997 / Proposed Rules 43129

adjacent to any corner that has been

modified; and

6. Modifying any crack that is found

to be 2 inches or less in length at all

corners that have not been modified and

performing follow-on repetitive eddy

current inspections.

Accomplishment of the modification

will minimize the possibility of fatigue

cracks in the fuselage skin and doubler.

Explanation of Requirements of

Proposed Rule

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 a one-time visual inspection to

determine if all corners of the doorjamb

of the forward service door have been

previously modified. The proposed AD

would also require various repetitive

inspections to detect cracks of the

fuselage skin and doubler at all corners

of the doorjamb of the forward service

door, and to detect cracks on the skin

adjacent to the modification; and

various follow-on actions. The actions

would be required to be accomplished

in accordance with the service bulletins

described previously.

Operators should note that, although

the service bulletins specify that the

manufacturer must be contacted for

disposition of certain conditions, this

proposal would require the repair of

those conditions to be accomplished in

accordance with a method approved by

the Manager, Los Angeles Aircraft

Certification Office (ACO),

FAA,Transport Airplane Directorate.

Cost Impact

There are approximately 823

McDonnell Douglas Model DC–9–10,

–20, –30, –40, and –50 series airplanes,

and C–9 (military) airplanes of the

affected design in the worldwide fleet.

The FAA estimates that 575 airplanes of

U.S. registry would be affected by this

proposed AD.

It would take approximately 1 work

hour per airplane to accomplish the

proposed visual inspection, at an

average labor rate of $60 per work hour.

Based on these figures, the cost impact

of the visual inspection proposed by

this AD on U.S. operators is estimated

to be $34,500, or $60 per airplane.

Should an operator be required to

accomplish the proposed HFEC, LFEC,

or x-ray inspection, it would take

approximately 1 work hour per airplane

to accomplish, at an average labor rate

of $60 per work hour. Based on these

figures, the cost impact of this

inspection proposed by this AD on U.S.

operators is estimated to be $60 per

airplane, per inspection cycle.

Should an operator be required to

accomplish the proposed modification,

it would take approximately 30 work

hours per airplane to accomplish, at an

average labor rate of $60 per work hour.

Required parts would cost

approximately $1,256, $1,420, $5,804,

or $6,113 per airplane, depending on

the service kit purchased. Based on

these figures, the cost impact of the

modification proposed by this AD on

U.S. operators is estimated to be $3,056,

$3,220, $7,604, or $7,913 per airplane,

respectively.

The cost impact figures discussed

above are 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.

§ 39.13 [Amended]

2. Section 39.13 is amended by

adding the following new airworthiness

directive:

McDonnell Douglas: Docket 97–NM–56–AD.

Applicability: Model DC–9–10, –20, –30,

–40, and –50 series airplanes, and C–9

(military) airplanes, as listed in McDonnell

Douglas Service Bulletin DC9–53–279,

Revision 1, dated May 6, 1997; 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.

Compliance: Required as indicated, unless

accomplished previously.

To detect and correct fatigue cracking in

the fuselage skin or doubler at the corners of

the doorjamb of the forward service door,

which could result in rapid decompression of

the fuselage and consequent reduced

structural integrity of the airplane,

accomplish the following:

Note 2: Where there are differences

between the service bulletin and the AD, the

AD prevails.

Note 3: The words ‘‘repair’’ and ‘‘modify/

modification’’ in this AD and the referenced

service bulletin are used interchangeably.

Note 4: This AD is related to AD 96–13–

03, amendment 39–9671, (61 FR 31009, June

19, 1996), and will affect Principal Structural

Element (PSE) 53.09.033 of the DC–9

Supplemental Inspection Document (SID).

(a) Prior to the accumulation of 50,000 total

landings, or within 3,225 landings after the

effective date of this AD, whichever occurs

later, perform a one-time visual inspection to

determine if the corners of the doorjamb of

the forward service door have been modified

prior to the effective date of this AD.

(b) Group 1. If the visual inspection

required by paragraph (a) of this AD reveals

that the corners of the upper cargo doorjamb

have not been modified, prior to further

flight, perform a low frequency eddy current

(LFEC) or x-ray inspection to detect cracks of

the fuselage skin and doubler at all corners

of the doorjamb of the forward service door,

in accordance with McDonnell Douglas

Service Bulletin DC9–53–279, dated

December 10, 1996, or Revision 1, dated May

6, 1996.
43130 Federal Register / Vol. 62, No. 155 / Tuesday, August 12, 1997 / Proposed Rules

(1) Condition 1. If no crack is detected

during any inspection required by paragraph

(b) of this AD, accomplish either paragraph

(b)(1)(i) or (b)(1)(ii) of the AD.

(i) Option 1. Repeat the inspections as

follows until paragraph (b)(1)(ii) of this AD

is accomplished:

(A) If the immediately preceding

inspection was conducted using LFEC

techniques, conduct the next inspection

within 3,225 landings.

(B) If the immediately preceding inspection

was conducted using x-ray techniques,

conduct the next inspection within 3,075

landings.

(ii) Option 2. Prior to further flight, modify

the corners of the doorjamb of the forward

service door in accordance with the service

bulletin; this modification constitutes

terminating action for the repetitive

inspection requirements of paragraph (b)(1)(i)

of this AD. Prior to the accumulation of

28,000 landings after accomplishment of the

modification, perform a high frequency eddy

current (HFEC) inspection to detect cracks on

the skin adjacent to the modification, in

accordance with the service bulletin. Within

20,000 landings after accomplishment of the

HFEC inspection, perform an eddy current

inspection to detect cracks in the subject

area, in accordance with the service bulletin.

(A) If no crack is detected on the skin

adjacent to the modification during any eddy

current inspection required by paragraph

(b)(1)(ii) of this AD, repeat the eddy current

inspection thereafter at intervals not to

exceed 20,000 landings.

(B) If any crack is detected on the skin

adjacent to the modification during any eddy

current inspection required by paragraph

(b)(1)(ii) of this AD, repair it in accordance

with a method approved by the Manager, Los

Angeles ACO.

(2) Condition 2. If any crack is found

during any inspection required by paragraph

(b) of this AD and the crack is 2 inches or

less in length: Prior to further flight, modify

it in accordance with the service bulletin.

Prior to the accumulation of 28,000 landings

after accomplishment of the modification,

perform a HFEC inspection to detect cracks

on the skin adjacent to the modification, in

accordance with the service bulletin. Within

20,000 landings after accomplishment of the

HFEC inspection, perform an eddy current

inspection to detect cracks in the subject

area, in accordance with the service bulletin.

(i) If no crack is detected on the skin

adjacent to the modification during any eddy

current inspection required by paragraph

(b)(2) of this AD, repeat the eddy current

inspection thereafter at intervals not to

exceed 20,000 landings.

(ii) If any crack is detected on the skin

adjacent to the modification during any eddy

current inspection required by paragraph

(b)(2) of this AD, repair it in accordance with

a method approved by the Manager, Los

Angeles ACO.

(3) Condition 3. If any crack is found

during any inspection required by this

paragraph and the crack is greater than 2

inches in length: Prior to further flight, repair

it in accordance with a method approved by

the Manager, Los Angeles ACO.

(c) Group 2, Condition 1. If the visual

inspection required by paragraph (a) of this

AD reveals that the corners of the doorjamb

of the forward service door have been

modified in accordance with the DC–9

Structural Repair Manual (SRM) (using a

steel doubler), accomplish either paragraph

(c)(1) or (c)(2) of this AD in accordance with

McDonnell Douglas Service Bulletin DC9–

53–279, dated December 10, 1996, or

Revision 1, dated May 6, 1997.

(1) Option 1. Prior to the accumulation of

6,000 landings after the effective date of this

AD, perform a HFEC inspection to detect

cracks on the skin adjacent to the

modification in accordance with the service

bulletin. Within 3,000 landings after

accomplishment of the HFEC inspection,

perform an eddy current inspection to detect

cracks in the subject area, in accordance with

the service bulletin.

(i) If no crack is detected on the skin

adjacent to the modification during any eddy

current inspection required by paragraph

(c)(1) of this AD, repeat the eddy current

inspection thereafter at intervals not to

exceed 3,000 landings.

(ii) If any crack is detected on the skin

adjacent to the modification during any eddy

current inspection required by paragraph

(c)(1) of this AD, repair it in accordance with

a method approved by the Manager, Los

Angeles ACO.

(2) Option 2. Prior to further flight, modify

the corners of the doorjamb of the forward

service door in accordance with the service

bulletin. Prior to the accumulation of 28,000

landings after accomplishment of the

modification, perform a HFEC inspection to

detect cracks on the skin adjacent to the

modification, in accordance with the service

bulletin. Within 20,000 landings after

accomplishment of the HFEC inspection,

perform an eddy current inspection to detect

cracks in the subject area, in accordance with

the service bulletin.

(i) If no crack is detected on the skin

adjacent to the modification during any eddy

current inspection required by paragraph

(c)(2) of this AD, repeat the eddy current

inspection thereafter at intervals not to

exceed 20,000 landings.

(ii) If any crack is detected on the skin

adjacent to the modification during any eddy

current inspection required by paragraph

(c)(2) of this AD, repair it in accordance with

a method approved by the Manager, Los

Angeles ACO.

(d) Group 2, Condition 2. If the visual

inspection required by paragraph (a) of this

AD reveals that the corners of the doorjamb

of the forward service door have been

modified in accordance with DC–9 SRM or

Service Rework Drawing (using an aluminum

doubler), prior to the accumulation of 28,000

landings since accomplishment of the

modification, or within 3,225 after the

effective date of this AD, whichever occurs

later, perform an HFEC inspection to detect

cracks on the skin adjacent to the

modification, in accordance with McDonnell

Douglas Service Bulletin DC9–53–279, dated

December 10, 1996, or Revision 1, dated May

6, 1997. Within 20,000 landings after

accomplishment of the HFEC inspection,

perform an eddy current inspection to detect

cracks in the subject area, in accordance with

the service bulletin.

(1) If no crack is detected on the skin

adjacent to the modification during any eddy

current inspection required by paragraph (d)

of this AD, repeat the eddy current

inspection thereafter at intervals not to

exceed 20,000 landings.

(2) If any crack is detected on the skin

adjacent to the modification during any eddy

current inspection required by paragraph (d)

of this AD, repair it in accordance with a

method approved by the Manager, Los

Angeles ACO.

(e) Group 2, Condition 3. If the visual

inspection required by paragraph (a) of this

AD reveals that the corners of the doorjamb

of the forward service door have been

modified, but not in accordance with DC–9

SRM or Service Rework Drawing, prior to

further flight, repair it in accordance with a

method approved by the Manager, Los

Angeles ACO.

(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, Los

Angeles 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, Los Angeles ACO.

Note 5: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Los Angeles ACO.

(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 July 29,

1997.

Darrell M. Pederson,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 97–20438 Filed 8–11–97; 8:45 am]

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