24686 Federal Register / Vol. 61, No. 96 / Thursday, May 16, 1996 / Rules and Regulations

equipped with a flight control stick with a

wall thickness of .035 inch.

Note 1: All Model S–2A airplanes and

some Model S–2S airplanes were equipped

with a .035-inch wall thickness flight control

stick at manufacture. Models S–1S, S–1T, S–

2, S–2B and certain Model S–2S airplanes

were manufactured with control sticks with

a wall thickness greater than .035 inch, but

could have .035-inch flight control sticks

installed through FAA-approved field

modification.

Note 2: 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 (d) 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 initially upon

accumulating 1,000 hours time-in-service

(TIS) or within the next 25 hours TIS after

the effective date of this AD, whichever

occurs later, unless already accomplished,

and thereafter as indicated in the body of this

AD.

To prevent the inability to maneuver the

airplane because of a cracked control stick,

which, if not detected and corrected, could

result in loss of control of the airplane,

accomplish the following:

(a) Inspect, using dye penetrant methods,

the .035-inch wall thickness flight control

stick for cracking in accordance with the

ACCOMPLISHMENT INSTRUCTIONS

section of Aviat Service Bulletin (SB) No. 23,

dated March 29, 1996.

Note 3: Aviat SB No. 23, dated March 29,

1996, only references the Model S–2A

airplanes. The procedures included in this

service bulletin should be utilized for all of

the airplanes affected by this AD.

(1) If cracking is found, prior to further

flight, replace the .035-inch wall thickness

flight control stick with one with a .058 inch

wall thickness in accordance with the

ACCOMPLISHMENT INSTRUCTIONS

section of Aviat SB No. 23, dated March 29,

1996.

(2) If no cracks are found, reinspect at

intervals not to exceed 50 hours TIS. If

cracking is found during any repetitive

inspection, prior to further flight, accomplish

the replacement specified in paragraph (a)(1)

of this AD.

(b) Replacing the .035-inch wall thickness

flight control stick with one with a .058-inch

wall thickness in accordance with the

ACCOMPLISHMENT INSTRUCTIONS

section of Aviat SB No. 23, dated March 29,

1996, is considered terminating action for the

repetitive inspection requirement of this AD.

This replacement may be accomplished at

any time, and must be accomplished prior to

further flight if cracking is found as required

by paragraph (a)(1) of this AD.

(c) 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.

(d) An alternative method of compliance or

adjustment of the initial or repetitive

compliance times that provides an equivalent

level of safety may be approved by the

Manager, Denver Aircraft Certification Office,

5440 Roslyn Street, suite 133, Denver,

Colorado 80216. The request shall be

forwarded through an appropriate FAA

Maintenance Inspector, who may add

comments and then send it to the Manager,

Denver ACO.

Note 4: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Denver ACO.

(e) The inspection and replacement (if

necessary) required by this AD shall be done

in accordance with Aviat Service Bulletin

No. 23, dated March 29, 1996. 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 Aviat

Aircraft, Inc., The Airport-Box 1240, South

Washington Street, Afton, Wyoming 83110.

Copies may be inspected at the FAA, Central

Region, Office of the Assistant Chief Counsel,

Room 1558, 601 E. 12th Street, Kansas City,

Missouri, or at the Office of the Federal

Register, 800 North Capitol Street, NW., suite

700, Washington, DC.

(f) This amendment (39–9619) becomes

effective on June 7, 1996.

Issued in Kansas City, Missouri, on May 8,

1996.

Henry A. Armstrong,

Acting Manager, Small Airplane Directorate,

Aircraft Certification Service.

[FR Doc. 96–12137 Filed 5–15–96; 8:45 am]

BILLING CODE 4910–13–U

14 CFR Part 39

[Docket No. 95–NM–191–AD; Amendment

39–9623; AD 96–10–16]

RIN 2120–AA64

Airworthiness Directives; McDonnell

Douglas MD–11 Series Airplane

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment adopts a

new airworthiness directive (AD),

applicable to certain McDonnell

Douglas Model MD–11 series airplanes,

that requires inspections to detect

damage of the sidewall vent box

diaphragms, and repair, if necessary.

This amendment also requires the

eventual installation of stops on the

vent box diaphragm, which terminates

the inspection requirements of the AD.

This amendment is prompted by reports

of damage to sidewall vent box

diaphragms, which can result in nonfunctional diaphragms during a rapid

decompression. The actions specified by

this AD are intended to prevent

buckling of the floor beams due to

insufficient air flow of the cabin

sidewall vent box diaphragms during

rapid decompression, and consequent

reduction in the controllability of the

airplane.

DATES: Effective June 20, 1996.

The incorporation by reference of

certain publications listed in the

regulations is approved by the Director

of the Federal Register as of June 20,

1996.

ADDRESSES: The service information

referenced in this AD 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

Federal Aviation Administration (FAA),

Transport Airplane Directorate, Rules

Docket, 1601 Lind Avenue SW., Renton,

Washington; or at the FAA, Los Angeles

Aircraft Certification Office, Transport

Airplane Directorate, 3960 Paramount

Boulevard, Lakewood, California; or at

the Office of the Federal Register, 800

North Capitol Street NW., suite 700,

Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Andrew Gfrerer, Aerospace Engineer,

Systems and Equipment Branch, ANM–

130L, FAA, Los Angeles Aircraft

Certification Office, 3960 Paramount

Boulevard, Lakewood, California 90712;

telephone (310) 627–5338; fax (310)

627–5210.

SUPPLEMENTARY INFORMATION:

A proposal to amend part 39 of the

Federal Aviation Regulations (14 CFR

part 39) to include an airworthiness

directive (AD) that is applicable to

certain McDonnell Douglas Model MD–

11 series airplanes was published in the

Federal Register on February 21, 1996

(61 FR 6581). That action proposed to

require repetitive inspections to detect

damage of the sidewall vent box

assemblies. Initially, that action

proposed to permit continued flight if

only a certain number of assembleis are

found to be damaged. However, once

that number is exceeded, the damaged

assemblies would be required to be

modified, prior to further flight, until

the remaining number of damaged

assemblies does not exceed a certain

number. That amendment also proposed

to require the eventual installation of

stop pads for all vent box diaphragms

and reidentification of the assemblies,
Federal Register / Vol. 61, No. 96 / Thursday, May 16, 1996 / Rules and Regulations 24687

which, when accomplished, terminates

the requirement for the repetitive

inspections.

Interested persons have been afforded

an opportunity to participate in the

making of this amendment. Due

consideration has been given to the two

comments received.

Both commenters support the

proposed rule.

Conclusion

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 as proposed.

Cost Impact

There are approximately 123 Model

MD–11 series airplanes of the affected

design in the worldwide fleet. The FAA

estimates that 39 airplanes of U.S.

registry will be affected by this AD.

To accomplish the required

inspections will take approximately 2

work hours per airplane, per inspection,

at an average labor rate of $60 per work

hour. Based on these figures, the cost

impact of the required inspections on

U.S. operators is estimated to be $4,680,

or $120 per airplane, per inspection

cycle.

To accomplish the requried

installation and reidentification will

take a total of approximately 270 work

hours per airplane. This figure

represents 3 work hours per vent box,

and up to a maximum of 90 vent boxes

on an airplane. The average labor rate is

$60 per work hour. The cost of requried

parts will be negligible; the parts may be

fabricated locally. Based on these

figures, the cost impact of the required

installation on U.S. operators is

estimated to be $631,800, or $16,200 per

airplane.

The cost impact figures discussed

above is based on assumptions that no

operator has yet accomplished any of

the 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 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), 40113, 44701.

§ 39.13 [Amended]

2. Section 39.13 is amended by

adding the following new airworthiness

directive:

96–10–16 McDonnell Douglas: Amendment

39–9623. Docket 95–NM–191–AD.

Applicability: Model MD–11 series

airplane, as listed in McDonnell Douglas

Alert Service Bulletin MD11–25A181, dated

September 28, 1995; 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 (c) 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 prevent buckling of the floor beams due

to insufficient air flow of the cabin sidewalk

vent box diaphragms during rapid

decompression, and subsequent loss of

airplane control capabilities, accomplish the

following:

(a) Within 90 days after the effective date

of this AD, perform an inspection to detect

damage of the sidewalk vent box diaphragms,

in accordance with McDonnell Douglas Alert

Service Bulletin MD11–25A181, dated

September 28, 1995. Based on the findings of

the initial inspection, or any repetitive

inspection, accomplish the requirements of

paragraph (a)(1), (a)(2), or (a)(3) of this AD,

as applicable:

(1) Condition 1. If no damage is detected:

Repeat the inspection at intervals not to

exceed 90 days.

(2) Condition 2. If damage is detected, but

the number of damaged sidewall vent box

assemblies does not exceed the applicable

allowable number specified in Table 1 of the

alert service bulletin: Repeat the inspection

at intervals not to exceed 90 days.

(3) Condition 3. If damage is detected, and

the number of damaged vent box assemblies

exceeds the applicable number specified in

Table 1 of the alert service bulletin: Prior to

further flight, install stops on and re-identify

as many damaged sidewall vent box

assemblies as necessary so that the total

number of damaged vent box assemblies does

not exceed the applicable allowable number

specified in Table 1 of the alert service

bulletin. Accomplish the installation of the

stops and reidentification of the assemblies

in accordance with the alert service bulletin.

The installation of stops on and

reidentification of an assembly constitutes

terminating action for the repetitive

inspections of that assembly only. All other

assemblies must continue to be inspected

thereafter at intervals not to exceed 90 days.

(b) Within 30 months after the effective

date of this AD, install stops on and

reidentify all sidewalk vent box assemblies

that do not already have stops installed and

have not been reidentified in accordance

with McDonnell Douglas Alert Service

Bulletin MD11–25A181, dated September 28,

1995. Accomplishment of this action

constitutes terminating action for the

inspection requirements of this AD.

(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, Los

Angeles Aircraft Certification Office (ACO),

FAA, Transport Airplane Directorate.

Operators shall submit their requests through

an appropriate FAA Principal Maintenance

Inspectors, who may add comments and then

send it to the Manager, Los Angeles ACO.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Los Angeles ACO.

(d) 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.

(e) The inspections and installations shall

be done in accordance with McDonnell

Douglas Alert Service Bulletin MD11–

25A181, dated September 28, 1995. This

incorporation by reference was approved by
24688 Federal Register / Vol. 61, No. 96 / Thursday, May 16, 1996 / Rules and Regulations

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

McDonnell Douglas Corporation, 3855

Lakewood Boulevard, Long Beach, California

90846, Attention: Technical Publications

Business Administration, Department C1–

L51 (2–60). Copies may be inspected at the

FAA, Transport Airplane Directorate, 1601

Lind Avenue SW., Renton, Washington; or at

the FAA, Los Angeles Aircraft Certification

Office, Transport Airplane Directorate, 3960

Paramount Boulevard, Lakewood, California;

or at the Office of the Federal Register, 800

North Capitol Street NW., suite 700,

Washington, DC.

(f) This amendment becomes effective

on June 20, 1996.

Issued in Renton, Washington, on May 9,

1996.

S.R. Miller,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 96–12148 Filed 5–15–96; 8:45 am]

BILLING CODE 4910–13–M

14 CFR Part 39

[Docket No. 95–NM–108–AD; Amendment

39–9624; AD 96–10–17]

RIN 2120–AA64

Airworthiness Directives; McDonnell

Douglas Model DC–10–10, –15, and,

–30 Series Airplanes and KC–10

(Military) Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment adopts a

new airworthiness directive (AD),

applicable to certain McDonnell

Douglas Model DC–10–10, –15, and –30

series airplanes and KC–10A (military)

airplanes, that requires inspections to

detect cracks of the upper aft mating

bolt hole of the wing pylon truss

fittings, and various follow-on actions.

This amendment is prompted by reports

of cracks found in the upper aft mating

bolt hole of the wing pylon truss fitting

located near the engine forward mount

on Model DC–10–30 series airplanes,

which were caused by fatigue-related

stress. The actions specified by this AD

are intended to prevent fatigue-related

cracking, which could lead to failure of

the fitting, separation of a portion of the

engine forward mount truss from the

pylon, and consequent separation of the

engine from the airplane.

DATES: Effective June 20, 1996.

The incorporation by reference of

certain publications listed in the

regulations is approved by the Director

of the Federal Register as of June 20,

1996.

ADDRESSES: The service information

referenced in this AD 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

Federal Aviation Administration (FAA),

Transport Airplane Directorate, Rules

Docket, 1601 Lind Avenue SW., Renton,

Washington; or at the FAA, Los Angeles

Aircraft Certification Office, Transport

Airplane Directorate, 3960 Paramount

Boulevard, Lakewood, California; or at

the Office of the Federal Register, 800

North Capitol Street NW., suite 700,

Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Maureen Moreland, Aerospace

Engineer, Airframe Branch, ANM–120L,

FAA, Los Angeles Aircraft Certification

Office, 3960 Paramount Boulevard,

Lakewood, California 90712; telephone

(310) 627–5238; fax (310) 627–5210.

SUPPLEMENTARY INFORMATION: A

proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39) to

include an airworthiness directive (AD)

that is applicable to certain McDonnell

Douglas Model DC–10–10, –15, and –30

series airplanes and KC–10A (military)

airplanes was published in the Federal

Register on September 27, 1995 (60 FR

49809). That action proposed to require

repetitive ultrasonic or eddy current

inspections to detect cracks of the upper

aft mating bolt hole of the wing pylon

truss fittings, and various follow-on

actions.

Interested persons have been afforded

an opportunity to participate in the

making of this amendment. Due

consideration has been given to the

comments received.

Support for the Proposal

Two commenters support the

proposed rule.

Request for Extension of Compliance

Time for Initial Inspection

One commenter requests that the

compliance time for the initial

inspection be extended from the

proposed 1,000 landings to 1,200

landings for Model DC–10–30 series

airplanes. The commenter states such a

compliance time would follow the

recommendations of McDonnell

Douglas DC–10 Service Bulletin 54–108,

dated February 9, 1995. The commenter

also questions what data or analysis the

FAA used to justify shortening the

threshold to 1,000 landings.

The FAA does not agree with the

commenter’s request to extend the

compliance time. The FAA points out

that 1,000 landings is not the inspection

‘‘threshold,’’ but a ‘‘grace period’’ that

was established to preclude

unnecessarily grounding airplanes that

have exceeded the 10,000-landing

threshold or will exceed it within 1,000

landings. In determining the appropriate

‘‘grace period’’ for this action, the FAA

not only considered the degree of

urgency associated with addressing the

unsafe condition, but the amount of

time necessary for operators to

accomplish the required inspection and

other factors affecting the ability of the

operators to comply. In light of all these

factors, the FAA finds the 1,000 landing

‘‘grace period’’ for initiating the

required inspections to be warranted, in

that it represents an appropriate interval

of time allowable for affected airplanes

to continue to operate without

compromising safety.

Clarification of Requirements for Type

of Inspection

One commenter points out that

proposed paragraphs (a) and (b) indicate

that operators are to perform either

ultrasonic or eddy current inspections

to detect the subject cracking. However,

the commenter states that the initial and

repetitive eddy current inspections are

not an option if the upper aft and/or

middle mating bolt hole(s) have

bushings installed from previous

rework, in accordance with McDonnell

Douglas DC–10 Service Bulletin 54–108,

dated February 9, 1995.

The FAA finds that clarification of

this point is necessary. As paragraphs

(a) and (b) of the proposed rule were

worded, operators could incorrectly

interpret the requirements as meaning

that they have a choice between

performing an ultrasonic inspection or

an eddy current inspection for all

configurations of the bolt holes.

However, the intent of those

requirements was to require operators to

perform either an ultrasonic inspection

or an eddy current inspection, as

appropriate, depending upon the

configuration of the subject area and as

specified in the service bulletin.

Therefore, the commenter is correct in

noting that, for airplanes on which the

upper aft and middle mating bolt holes

have bushings installed from previous

rework (Condition 2), operators must

accomplish the inspection by using only

the ultrasonic method. In light of this,

the FAA has revised the wording of

paragraphs (a) and (b) of the final rule

to clarify this.

Clarification of Requirements for

Repetitive Inspections

The same commenter asks if the

repetitive ultrasonic inspection intervals