Federal Register / Vol. 67, No. 71 / Friday, April 12, 2002 / Rules and Regulations 17917

Subpart C—Bank/Association Lending 

Relationship

§ 614.4130 [Amended]

4. Amend § 614.4130 by removing the 

reference ‘‘§ 611.1205(c)’’ and adding in 

its place the reference ‘‘§ 611.1205’’ in 

paragraph (a).

Dated: April 5, 2002. 

Kelly Mikel Williams, 

Secretary, Farm Credit Administration Board.

[FR Doc. 02–8711 Filed 4–11–02; 8:45 am] 

BILLING CODE 6705–01–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. 98–NM–196–AD; Amendment 

39–12702; AD 2002–07–08] 

RIN 2120–AA64 

Airworthiness Directives; Boeing 

Model 737–200, –200C, –300, –400, and 

–500 Series Airplanes

AGENCY: Federal Aviation 

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment supersedes 

an existing airworthiness directive (AD), 

applicable to certain Boeing Model 737 

series airplanes, that currently requires 

repetitive inspections to find cracking of 

the lower skin at the lower row of 

fasteners in the lap joints of the 

fuselage, and repair of any cracking 

found. That amendment also requires 

modification of the fuselage lap joints at 

certain locations, which constitutes 

terminating action for repetitive 

inspections of the modified areas. This 

amendment adds repetitive inspections 

and requires replacement of the current 

preventive modification with an 

improved modification. This 

amendment is prompted by the FAA’s 

determination that, in light of additional 

crack findings, certain modifications of 

the fuselage lap joints do not provide an 

adequate level of safety. The actions 

specified by this AD are intended to 

find and fix cracking of the fuselage lap 

joints, which could result in sudden 

decompression of the airplane.

DATES: Effective May 17, 2002. 

The incorporation by reference certain 

publications, as listed in the regulations, 

is approved by the Director of the 

Federal Register as of May 17, 2002.

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:

Scott Fung, Aerospace Engineer, 

Airframe Branch, ANM–120S, FAA, 

Seattle Aircraft Certification Office 

(ACO), 1601 Lind Avenue, SW., Renton, 

Washington; telephone (425) 227–1221; 

fax (425) 227–1181.

SUPPLEMENTARY INFORMATION: A 

proposal to amend part 39 of the Federal 

Aviation Regulations (14 CFR part 39) 

by superseding AD 97–22–07, 

amendment 39–10179 (62 FR 55732, 

October 28, 1997), which is applicable 

to certain Boeing Model 737 series 

airplanes, was published in the Federal 

Register on July 12, 2001 (66 FR 36509). 

The action proposed to continue to 

require repetitive inspections to find 

cracking of the lower skin at the lower 

row of fasteners in the lap joints of the 

fuselage, and repair of any cracking 

found. That action also adds a 

requirement for modification of the 

fuselage lap joints at certain locations, 

which constitutes terminating action for 

repetitive inspections of the modified 

areas. That action also adds new 

repetitive inspections and requires 

replacement of the current preventive 

modification with an improved 

modification. 

Comments 

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 intent of the proposed rule. 

Another commenter states that the 

proposed rule does not affect its fleet. 

Typographical Error 

One commenter states that in the 

section titled, ‘‘Other Relevant Proposed 

Rulemaking,’’ specified in the proposed 

rule, the line numbers listed for 

replacement of certain Structural Repair 

Manual (SRM) repairs are line numbers 

292 through 2595 inclusive. The 

commenter notes that the correct 

reference is line numbers 292 through 

2565 inclusive. The FAA agrees that a 

typographical error was made in that 

section, however, that section is not 

carried over to the final rule so no 

change is necessary. 

Clarify Paragraphs (a) and (g) 

One commenter states that the 

repetitive low frequency eddy current 

inspections (LFEC) of the crown areas as 

specified in paragraph (a) of the 

proposed rule need clarification. The 

commenter notes that the crown areas 

are not defined in the proposed rule and 

Part 1.E.1. (‘‘Compliance’’) of Boeing 

Service Bulletin 737–53A1177, Revision 

6, dated May 31, 2001 (specified in the 

proposed rule as the source of service 

information for doing the specified 

actions), defines the areas to be 

inspected. The commenter adds that the 

lap joint modification (repair) in the 

crown areas, as specified in paragraph 

(g) of the proposed rule, needs 

clarification. The commenter notes that 

the crown areas are not defined in the 

proposed rule and Part 1.E.1. 

(‘‘Compliance’’) of the service bulletin 

defines the areas to be inspected. 

The FAA agrees that inclusion of 

references to Part 1.E.1. (‘‘Compliance’’) 

in paragraphs (a) and (g) of this final 

rule provides clarification of the crown 

lap joint areas to be inspected. We have 

changed paragraphs (a) and (g) of the 

final rule accordingly. 

Credit for Previously Accomplished 

Modifications 

Two commenters ask that paragraph 

(g) of the proposed rule be changed to 

include credit for lap joint 

modifications (repairs) accomplished 

per the instructions described in Boeing 

Service Bulletin 737–53A1177, Revision 

4, dated September 2, 1999, or Revision 

5, dated February 15, 2001. One 

commenter adds that this would 

terminate the post-NACA-modification 

inspections required by paragraph (i) of 

the proposed rule. 

We agree that accomplishment of the 

lap joint modification (repairs) per 

Revision 4 or 5 of the referenced service 

bulletin meets the requirements 

specified in paragraph (g) of the final 

rule and terminates the repetitive postNACA-modification inspections 

required by paragraph (i) of the final 

rule, as those revisions are technically 

equivalent to the modification specified 

in Revision 6 of the service bulletin. We 

have changed paragraph (g) of the final 

rule accordingly. 

Change Paragraph (g)(5) 

One commenter asks that paragraph 

(g)(5) of the proposed rule, for airplanes 

having a NACA modification per Boeing 

Alert Service Bulletin 737–53A1177, 

Revision 3, dated September 18, 1997, 

be changed to include airplanes that 

have been modified per Revision 1, 

dated September 19, 1996, or Revision 

2, dated July 24, 1997, of that service 

bulletin. 

We agree that airplanes having a 

NACA modification per Revision 1 or 2 

17918 Federal Register / Vol. 67, No. 71 / Friday, April 12, 2002 / Rules and Regulations 

of the service bulletin meet the 

requirements specified in paragraph 

(g)(5) of the final rule. The modification 

in those revisions is technically 

equivalent to the modification specified 

in Revision 3 of the service bulletin. We 

have changed paragraph (g)(5) of the 

final rule accordingly. 

Clarify Repair Instructions for 737 

Cargo Airplanes 

One commenter states that paragraph 

(g) of the proposed rule does not address 

a certain lap joint repair for Model 737–

200C series airplanes, Groups 3 and 5, 

as specified in Revisions 4, 5, and 6 of 

the service bulletin. The commenter 

notes that Part 1.E.1. (‘‘Compliance’’) of 

the service bulletin instructs operators 

to contact Boeing for repair instructions 

for stringers 4R and 10R. The 

commenter asks that a new paragraph be 

added with repair instructions for that 

area.

We agree and have changed paragraph 

(g) of the final rule to exclude repair per 

the service bulletin for certain 737–200C 

series airplanes. We also added a new 

paragraph (h) to this final rule (and 

renumbered subsequent paragraphs) to 

specify repair instructions for stringers 

4R and 10R on Groups 3 and 5 

airplanes. 

Clarify Paragraph (h) 

One commenter states that the 

repetitive LFEC inspections outside the 

crown areas as specified in paragraph 

(h) of the proposed rule need 

clarification. The commenter notes that 

the areas outside the crown lap joints 

are not defined in the proposed rule and 

Part 1.E.2. (‘‘Compliance’’) of Boeing 

Service Bulletin 737–53A1177, Revision 

6, defines the areas to be inspected. The 

commenter adds that the instructions 

specified in paragraph (h) of the 

proposed rule are for operators to 

inspect for cracking at lap joints 

identified in Figures 2 through 7 of the 

referenced service bulletin. The 

commenter notes that Figure 7 

addresses inspection of Group 6 

airplanes (737–200 and 737–200C series 

airplanes, line numbers 1 through 291 

inclusive), and those airplanes are not 

subject to the requirements of this AD. 

We agree that inclusion of a reference 

to Part 1.E.2. (‘‘Compliance’’) of the 

service bulletin provides clarification of 

the areas outside the crown lap joints to 

be inspected. We also agree that Group 

6 airplanes are not subject to the 

requirements of this AD and have been 

addressed in another rulemaking action. 

Therefore, paragraph (i) of the final rule 

(which was paragraph (h) in the 

proposed rule) includes a reference to 

Part 1.E.2. (‘‘Compliance’’) of the service 

bulletin, and includes no reference to 

Figure 7 of the service bulletin. 

Clarify Paragraph (i) 

One commenter asks that paragraph 

(i) of the proposed rule include 

clarification of the areas that require 

post-accomplishment inspections for 

the NACA modifications in the crown 

areas as specified in Part 1.E.4.a. 

(‘‘Compliance’’) of Revision 6 of the 

service bulletin. The commenter also 

asks that accomplishment of the NACA 

modification per PART III of the 

Accomplishment Instructions of Boeing 

Alert Service Bulletin 737–53A1177, 

Revision 1, dated September 19, 1996; 

Revision 2, dated July 24, 1997; or 

Revision 3, dated September 18, 1997; 

be accepted. 

We agree that inclusion of a reference 

to Part 1.E.4.a. (‘‘Compliance’’) of the 

service bulletin provides clarification of 

the areas in the crown lap joints to be 

inspected. We also agree that inclusion 

of Revisions 1, 2, and 3 of the service 

bulletin into paragraph (j) of the final 

rule clarifies the service bulletins that 

can be used to do the NACA 

modification. Paragraph (j) of the final 

rule (which was paragraph (i) in the 

proposed rule) includes a reference to 

Part 1.E.4.a. (‘‘Compliance’’) of the 

service bulletin. 

Clarify Paragraph (j) 

One commenter asks that paragraph 

(j) of the proposed rule include 

clarification of the areas that require 

post-accomplishment inspections for 

the NACA modifications outside the 

crown areas as specified in Part 1.E.4.b. 

(‘‘Compliance’’) of Revisions 1, 2, and 3 

of the service bulletin. The commenter 

also asks that accomplishment of the 

NACA modification per PART III of the 

Accomplishment Instructions of Boeing 

Alert Service Bulletin 737–53A1177, 

Revision 1, dated September 19, 1996; 

Revision 2, dated July 24, 1997; or 

Revision 3, dated September 18, 1997, 

be accepted. 

We agree that inclusion of a reference 

to Part 1.E.4.b. (‘‘Compliance’’) provides 

clarification of the areas outside the 

crown lap joints to be inspected. We 

also agree that inclusion of reference to 

Revisions 1, 2, and 3 of the service 

bulletin in paragraph (j) of the final rule 

clarifies the service bulletins that can be 

used to do the NACA modification. 

Paragraph (k) of this final rule (which 

was paragraph (j) in the proposed rule) 

includes a reference to Part 1.E.4.b. 

(‘‘Compliance’’) of the service bulletin. 

Clarify Paragraph (l) 

One commenter states that paragraph 

(l) of the proposed rule (‘‘Follow-on 

LFEC Inspections’’) should reference 

Part 1.E.7. (‘‘Compliance’’) of the 

referenced service bulletin and should 

instruct operators to do the external 

inspection per the 737 Nondestructive 

Test (NDT) Manual, Part 6, Chapter 53–

30–00, Figure 5. 

We agree that inclusion of a reference 

to Part 1.E.7. (‘‘Compliance’’) provides 

clarification of the area for the external 

inspection as specified in the 737 NDT 

Manual. However, we do not agree to 

instruct operators to do the external 

inspection per the 737 NDT Manual. 

Part 1.E.7. (‘‘Compliance’’) of the service 

bulletin references the 737 NDT 

Manual, which addresses the 

commenter’s concerns. Paragraph (m) of 

the final rule (which was paragraph (l) 

in the proposed rule) includes a 

reference to Part 1.E.7. (‘‘Compliance’’) 

of the service bulletin. 

Clarify Paragraph (m) 

One commenter asks that paragraph 

(m) of the proposed rule, (‘‘Repetitive 

High Frequency Eddy Current (HFEC) 

Inspections—Window Corners’’), be 

changed to reference Part 1.E.10. 

(‘‘Compliance’’) of the referenced 

service bulletin to define the procedures 

necessary for inspecting the fuselage 

skin adjacent to the window corners 

that have not been modified. 

We agree that inclusion of a reference 

to Part 1.E.10 (‘‘Compliance’’) provides 

clarification of the inspection 

procedures necessary for doing the 

HFEC inspections of the window 

corners. Paragraph (n) of the final rule 

(which was paragraph (m) in the 

proposed rule) includes a reference to 

Part 1.E.10 (‘‘Compliance’’) of the 

service bulletin. 

Another commenter states that the 

repair and modification instructions 

specified in paragraph (m) of the 

proposed rule are not clear for those 

operators who have already installed the 

lap joint doublers in the corresponding 

area of the window belt. The commenter 

adds that, as written, it is unable to 

determine that the terminating 

modification for uncracked window 

corners consists of oversizing the 

fastener holes and installing Hi-lok 

fasteners. The commenter asks for 

further review of the proposed rule 

given additional circumstances and 

questions from operators who have 

already met the intent of the 

modification specified in Boeing Service 

Bulletin 737–53A1177, Revision 5, 

dated February 15, 2001. 

We agree that clarification of the 

repair and modification instructions 

specified in paragraph (m) of the 

proposed rule is necessary. Therefore, 

we have added that the modification 

Federal Register / Vol. 67, No. 71 / Friday, April 12, 2002 / Rules and Regulations 17919

includes removing and discarding 

fasteners, oversizing fastener holes, and 

installing rivets or Hi-Lok fasteners, as 

applicable. We also agree that 

accomplishment of the modification per 

Revision 5 of the referenced service 

bulletin meets the requirements for the 

modification specified in paragraph (n) 

of the final rule. This terminates the 

repetitive inspections for operators who 

have accomplished the required actions 

per either of those service bulletins. 

Paragraph (n) of the final rule (which 

was paragraph (m) in the proposed rule) 

has been changed accordingly. 

Extend Compliance Time in Paragraph 

(m) 

One commenter, the airplane 

manufacturer, asks that the compliance 

time for the initial and repetitive 

inspections specified in paragraph (m) 

of the proposed rule be extended. The 

commenter states that the 1,200-flightcycle threshold specified is the same 

inspection threshold specified for lap 

joint lower row cracking in paragraph 

(a) of the proposed rule. The commenter 

notes that the cracking of the holes of 

the window corner is much less critical 

than the cracking of the lap joint lower 

row, so it finds a less-restrictive 

inspection threshold is acceptable for 

the window corner cracking. The 

commenter adds that fleet data on 

cracking of the holes of the window 

corner show that such cracking is not 

extensive on airplanes with less than 

60,000 total flight cycles, and that 

information supports an inspection 

threshold of 2,250 flight cycles after the 

effective date of the AD for airplanes 

with less than 60,000 total flight cycles.

We agree with the commenter that the 

cracking of the window corner is less 

critical than cracking of the lap joint 

lower row; however, the fleet data to 

date indicate that cracking can occur on 

airplanes with fewer than 50,000 total 

flight cycles. Therefore, we have 

changed the initial inspection threshold 

required by paragraph (n) of the final 

rule (which was paragraph (m) in the 

proposed rule) to read, ‘‘Before the 

accumulation of 50,000 total flight 

cycles or within 2,250 flight cycles after 

the effective date of this AD, whichever 

comes later. * * *’’

A second commenter suggests an 

extension of the threshold for the 

inspections to ‘‘Before the accumulation 

of 60,000 total flight cycles or within 

5,500 flight cycles after the effective 

date of the AD, whichever occurs later.’’

The commenter states that this will 

allow operators that have done the postmodification a reasonable opportunity 

to meet the intent of the new 

requirement specified in Part V 

(window corner inspection) of Revision 

5 or 6 of the referenced service bulletin. 

The commenter adds that its data 

indicates that the window corner 

cracking is largely due to pressurization 

cycles. The commenter’s operations are 

such that its airframe cycles are of 

relatively low-pressure differential, and 

very short duration. 

A third commenter asks that the 

1,200-flight-cycle threshold be elevated 

to 5,000 flight cycles so that the initial 

inspection and the preventative 

modification of the window corner on 

its airplanes can be accomplished at the 

same time as the lap joint modification. 

The commenter states that it has 

approximately 25 airplanes that are over 

50,000 flight cycles that have not 

accomplished the window corner 

inspection or lap joint repairs. The 

commenter adds that a compliance 

interval of 1,200 flight cycles will 

require the airlines to bring in those 

airplanes for inspection within a 3-

month timeframe, without the ability to 

accomplish the preventative 

modifications. 

The same commenter asks that the 

compliance time for the initial 

inspection of the window belts be 

required within 10,000 flight cycles 

after the effective date of the AD, or 

20,000 flight cycles after 

accomplishment of the lap joint repairs, 

whichever occurs first. The commenter 

states that the structural integrity for 

airplanes on which the lap joint repairs 

have been done has already been 

improved, which justifies changing the 

compliance time. 

A fourth commenter suggests that the 

inspection be accomplished before the 

accumulation of 50,000 total flight 

cycles or within 4,500 flight cycles after 

the effective date of the AD, whichever 

occurs later. The commenter states that 

this will allow operators to schedule the 

inspection into a ‘‘C’’ check visit. The 

commenter adds that, for airplanes with 

50,000-plus total flight cycles, the 1,200-

flight-cycle threshold for the initial 

inspection will place a significant 

burden on operators that have already 

accomplished the skin lap modifications 

because the inspection will have to be 

accomplished outside a scheduled 

maintenance visit. 

We do not agree to extend the 

compliance threshold for the initial 

inspection further, per the above 

requests from the second, third, and 

fourth commenters. We have already 

considered factors such as operators’

maintenance schedules in setting a 

compliance time for the required 

modification, and have determined that 

an inspection threshold of 2,250 flight 

cycles is an appropriate compliance 

time in which the inspection may be 

accomplished during scheduled 

airplane maintenance for the majority of 

affected operators. Since maintenance 

schedules vary from operator to 

operator, it would not be possible to 

guarantee that all affected airplanes 

could be modified during scheduled 

maintenance, even with a compliance 

threshold of 2,250 flight cycles. In any 

event, we find that this threshold 

represents the maximum time wherein 

the affected airplanes may continue to 

operate prior to inspection without 

compromising safety. No further change 

to the final rule is necessary in this 

regard.

Extend Compliance Time in Paragraph 

(i) 

One commenter asks that the 

compliance threshold in paragraph (i) of 

the proposed rule be changed. The 

commenter states that it has one 

airplane on which the preventative 

change of the crown lap joint stringers 

has been done, and that airplane will 

have flown more than 12,000 flight 

cycles when this final rule is effective. 

The commenter asks for an alternate 

initial inspection threshold in paragraph 

(i) of the proposed rule to avoid 

immediate grounding of that airplane 

when the final rule is issued. The 

commenter asks that a provision be 

added which states, ‘‘* * * if an 

airplane has reached the 12,000 flight 

cycle limit, the initial inspection must 

be done within 6 months or 1,500 flight 

cycles, whichever occurs later, after the 

effective date of the AD.’’

We acknowledge the need for 

operators with airplanes that have 

exceeded the 12,000 flight cycle limit to 

have ample time to accomplish the 

initial inspection required by paragraph 

(j) of the final rule (which was 

paragraph (i) in the proposed rule). 

Paragraph (k) of this final rule (which 

was paragraph (j) in the proposed rule) 

has a similar compliance threshold. 

Therefore, we have changed paragraphs 

(j) and (k) of this final rule to add a grace 

period, ‘‘* * * or within 750 flight 

cycles after the effective date of this AD, 

whichever is later.’’

Add Previous Alternative Methods of 

Compliance (AMOC) 

One commenter asks that paragraph 

(n) of the proposed rule be changed to 

add a paragraph for previously 

approved AMOCs for AD 97–22–07, 

amendment 39–10179. 

We agree to change paragraph (o) of 

the final rule (which was paragraph (n) 

in the proposed rule) to add a new 

paragraph (o)(2) for AMOCs previously 

approved for AD 97–22–07 that are 

17920 Federal Register / Vol. 67, No. 71 / Friday, April 12, 2002 / Rules and Regulations 

approved for certain paragraphs in this 

AD. 

Eliminate References to Bear Strap 

Areas 

One commenter, the airplane 

manufacturer, states that, since the 

release of Revision 6 of the referenced 

service bulletin, its review suggests that 

the cracking of the skin and doublers 

common to the bear strap around the 

entry and service doors may be caused 

by hinge cutouts, and may not be related 

to the typical cracking of the lower row 

of the lap splice. The commenter 

submits this comment for FAA review 

and consideration. 

We infer that the commenter wants to 

eliminate all references to the areas that 

are common to the bear strap around the 

entry and service doors, as specified in 

the proposed rule. We do not agree. The 

commenter has not provided 

substantiating data for its request. We 

may eliminate these areas from the 

requirements of the final rule in future 

rulemaking if data are submitted 

showing that cracking in these areas is 

definitely caused by hinge cutouts. No 

change to the final rule is necessary in 

this regard. 

Delete Paragraph (f) 

Two commenters ask that the 

compliance plan requirement specified 

in paragraph (f) of the proposed rule be 

deleted. 

One commenter states that the 

inclusion of paragraph (f) does nothing 

to address the safety issue for which the 

proposed rule is being written, and asks 

that it be deleted from the final rule. 

Another commenter does not consider 

the requirements of paragraph (f) an 

airworthiness issue and states that it 

should not be included as such in the 

final rule. The commenter adds that the 

letter check does not determine if an 

airplane is airworthy, and the airplanes 

on which the actions required by 

paragraph (g) of the proposed rule have 

been done, as well as the airplanes on 

which the actions are not required in 

the near future, are not excluded from 

paragraph (f). The commenter also states 

that a simple forecast report with 

estimated due dates based on average 

airplane utilization cycles can be 

provided to the Principle Maintenance 

Inspector upon request. 

We partially agree with the 

commenters, as follows: 

We do not agree to delete paragraph 

(f) of the final rule. As specified in the 

preamble of the proposed rule, we 

recognize that doing the lap joint 

modification will require a lengthy 

maintenance visit, within a relatively 

short compliance time. This makes it 

necessary for operators to do 

compliance planning to ensure that 

when the compliance deadline is 

reached all the required actions have 

been done on all affected airplanes. 

Although plans and schedules can 

change over time, a compliance plan 

ensures that the operator is aware of the 

complexity of the actions required by 

this final rule at the start rather than at 

of the end of the compliance period. 

We agree that the requirements 

specified in paragraph (f) of the final 

rule can be changed to exclude 

operators that have previously done the 

modification required by either 

paragraph (g) or (h) of the final rule; and 

by revising the requirement to provide 

dates and maintenance events (e.g., 

letter checks) to just estimated dates, for 

operators that have not yet done the 

required actions. Paragraph (f) of the 

final rule has been changed accordingly. 

Change Cost Impact Information 

Two commenters ask that the cost 

impact section of the proposed rule be 

changed. 

One commenter states that the cost 

impact to the industry is 

underestimated in the proposed rule. 

The commenter notes that, after 

accomplishing the lap joint 

modifications on some of its fleet, it 

found that the cost estimates and man 

hours were 30–40% higher than the 

estimate in the proposed rule. The 

commenter adds that the amount of time 

required for access and close-up equates 

to approximately 4 additional days of 

downtime in which no revenue can be 

generated. The commenter also states 

that the estimate of 14 hours to 

accomplish the window corner 

inspections is on the condition that it is 

done in conjunction with the lap joint 

modifications, and does not account for 

fastener removal. If the inspection is 

done separately, the access and close-up 

time would take at least one week. 

Another commenter also asks that the 

time required for access and close-up be 

added to the proposed rule. The 

commenter notes that the cost impact is 

particularly useful to operators and the 

public when a proposed compliance 

period would not allow 

accomplishment of the actions during a 

scheduled intermediate or heavy 

maintenance visit. The commenter adds 

that in such cases, access and close-up 

are direct requirements of, and are 

solely attributable to, the proposed rule, 

and in some cases the out-of-service 

time and other impacts of unscheduled 

access and close-up may account for 

nearly all of the actual economic 

impact. The commenter recommends a 

re-evaluation of the cost impact 

estimated in the proposed rule. 

We do not agree that the cost impact 

section of the final rule should be 

changed to add in the work hours and 

cost for access, close-up, and fastener 

removal. The cost estimates for the 

actions required by this final rule are 

estimated over the life of the AD, which 

is approximately 20–25 years. The cost 

impact section of the final rule 

references paragraph 1.G. of the service 

bulletin for more detailed information, 

and that section includes, among other 

things, time necessary for access, closeup, and fastener removal. Therefore, no 

change to the final rule is necessary in 

this regard. 

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 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. 

Cost Impact 

There are approximately 2,203 Model 

737 series airplanes of the affected 

design in the worldwide fleet. The FAA 

estimates that 905 airplanes of U.S. 

registry will be affected by this AD.

Cost estimates for the actions required 

by this AD for U.S. operators over the 

life of the AD are included in the 

following table:

Paragraph/AD action Number 

affected 

Work 

hours Parts ($) Cost/Airplane ($) Total Cost ($) 

(a) Lap joint inspection .......................................................................................... 905 100 0 6,000 5,430,000 

(f) Compliance planning ......................................................................................... 905 24 0 1,440 1,303,200 

(g) Lap joint modification ....................................................................................... 905 4,200 12,000 264,000 238,920,000 

Federal Register / Vol. 67, No. 71 / Friday, April 12, 2002 / Rules and Regulations 17921

Paragraph/AD action Number 

affected 

Work 

hours Parts ($) Cost/Airplane ($) Total Cost ($) 

(h) Lap joint inspection .......................................................................................... 905 100 0 6,000 5,430,000 

(i) Post-NACA inspection ....................................................................................... 25 100 0 6,000 150,000 

(j) Post-NACA inspection ....................................................................................... 10 100 0 6,000 60,000 

(m) Window corner inspection ............................................................................... 807 14 0 840 677,880

The cost estimates are based on the 

following criteria: 

• Lap joint inspection cost estimates 

reflect costs for a single inspection 

cycle, and the work hours vary between 

groups of airplanes. Refer to paragraph 

1.G. of Boeing Service Bulletin 737–

53A1177 for more detailed information. 

An average of 100 work hours was used 

in determining the cost estimates. 

• An average of 24 work hours was 

used in estimating the costs for 

compliance planning. 

• Lap joint modification work hours 

vary between groups of airplanes. Refer 

to paragraph 1.G of Boeing Service 

Bulletin 737–53A1177 for more detailed 

information. An average of 4,200 work 

hours and $12,000 for parts were used 

in estimating these costs. Modification 

costs are spread over the estimated life 

of the AD, which is approximately 20 to 

25 years. 

• Window corner inspection work 

hours vary between groups of airplanes. 

Refer to paragraph 1.G of Boeing Service 

Bulletin 737–53A1177 for more detailed 

information. An average of 14 work 

hours was used in estimating the costs 

of the inspections only. 

The FAA estimates that during the 10-

year period after issuance of this AD, 

worldwide operators will be required to 

modify 805 Model 737 series airplanes. 

The new modification required by this 

AD will take an average of 

approximately 4,200 work hours to 

accomplish, at an average labor rate of 

$60 per work hour. The worldwide cost 

impact of the required modification is 

estimated to be $212,701,000 over 10 

years, or an average of $21,270,000 per 

year. The highest impact year is the 

third year after issuance of the AD: an 

estimated 155 Model 737 series 

airplanes will require modification in 

that year. Therefore, the worldwide cost 

impact of the modification is estimated 

to be $40,955,000 in that year. The 

affected Model 737 airplanes operated 

by U.S. operators comprise 

approximately 41 percent of the total 

worldwide costs. Therefore, the highest 

cost impact in any given year for the 

modifications is estimated to be 

$16,791,000 for U.S. operators. 

The cost impact figures discussed 

above are 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. The cost impact 

figures discussed in AD rulemaking 

actions represent only the time 

necessary to perform the specific actions 

actually required by the AD. These 

figures typically do not include 

incidental costs, such as the time 

required to gain access and close up, 

planning time, or time necessitated by 

other administrative actions. 

Regulatory Impact 

The regulations adopted herein will 

not have a substantial direct effect 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, it is 

determined that this final rule does not 

have federalism implications under 

Executive Order 13132. 

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 U.S.C. 106(g), 40113, 44701.

§ 39.13 [Amended] 

2. Section 39.13 is amended by 

removing amendment 39–10179 (62 FR 

55732, October 28, 1997), and by adding 

a new airworthiness directive (AD), 

amendment 39–12702, to read as 

follows:

2002–07–08 Boeing: Amendment 39–12702. 

Docket 98–NM–196–AD. Supersedes AD 

97–22–07, Amendment 39–10179.

Applicability: Model 737–200, –200C, 

–300, –400, and –500 series airplanes having 

line numbers 292 through 2565 inclusive, 

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 (o)(1) 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 find and fix cracking of certain fuselage 

lap joints, which could result in sudden 

decompression of the airplane, accomplish 

the following: 

Repetitive Low Frequency Eddy Current 

(LFEC) Inspections—Crown Areas 

(a) Do an LFEC inspection to find cracking 

of the lower skin at the lower row of fasteners 

in the lap joints of the fuselage as specified 

in Part 1.E.1. (‘‘Compliance’’) of Boeing 

Service Bulletin 737–53A1177, Revision 6, 

dated May 31, 2001; per PART I 

(‘‘Inspection’’) of the Accomplishment 

Instructions of the service bulletin; at the 

time specified in paragraph (b) or (c) of this 

AD, as applicable. 

(b) For airplanes that have accumulated 

more than 65,000 total flight cycles but not 

17922 Federal Register / Vol. 67, No. 71 / Friday, April 12, 2002 / Rules and Regulations 

more than 70,000 total flight cycles as of the 

effective date of this AD: Do the inspection 

at the earlier of the times specified in 

paragraphs (b)(1) and (b)(2) of this AD. 

Repeat the inspection after that at intervals 

not to exceed 1,200 flight cycles until 

accomplishment of the lap joint repair 

required by paragraph (g) of this AD. 

(1) Within 1,200 flight cycles after the 

effective date of this AD. 

(2) Within 1,200 flight cycles after the last 

inspection, if any, accomplished in 

accordance with AD 97–22–07, amendment 

39–10179. 

(c) For airplanes that have accumulated at 

least 45,000 total flight cycles but not more 

than 65,000 total flight cycles as of the 

effective date of this AD: Do the inspection 

at the earlier of the times specified in 

paragraphs (c)(1) and (c)(2) of this AD. Repeat 

the inspection after that at intervals not to 

exceed 1,200 flight cycles until 

accomplishment of the lap joint repair 

required by paragraph (g) of this AD. 

(1) At the later of the times specified in 

paragraphs (c)(1)(i) and (c)(1)(ii) of this AD. 

(i) Before the accumulation of 50,000 total 

flight cycles. 

(ii) Within 1,200 flight cycles after the 

effective date of this AD. 

(2) Within 1,200 flight cycles after the last 

inspection, if any, accomplished in 

accordance with AD 97–22–07, amendment 

39–10179. 

Crack Repair 

(d) Except as provided by paragraph (e) of 

this AD: If any cracking is found during any 

inspection required by this AD, before further 

flight, repair per PART II (‘‘Crack Repair’’) of 

the Accomplishment Instructions of Boeing 

Service Bulletin 737–53A1177, Revision 6, 

dated May 31, 2001. 

(e) If any cracking is found during any 

inspection required by this AD, and Boeing 

Service Bulletin 737–53A1177, Revision 6, 

dated May 31, 2001, specifies to contact 

Boeing for repair instructions: Repair any 

cracking, before further flight, per a method 

approved by the Manager, Seattle Aircraft 

Certification Office (ACO), FAA; or per data 

meeting the type certification basis of the 

airplane approved by a Boeing Company 

Designated Engineering Representative (DER) 

who has been authorized by the Manager, 

Seattle ACO, to make such findings. For a 

repair method to be approved by the 

Manager, Seattle ACO, as required by this 

paragraph, the approval letter must 

specifically reference this AD. 

Compliance Plan 

(f) For airplanes on which the applicable 

lap joint modification as required by 

paragraph (g) or (h) of this AD, as applicable, 

has not been done as of the effective date of 

this AD: Within 3 months after the effective 

date of this AD, submit a plan to the FAA 

identifying a schedule for compliance with 

paragraph (g) and (h) of this AD, as 

applicable. This schedule must include, for 

each of the operator’s affected airplanes, the 

estimated dates when the required actions 

will be accomplished. For the purposes of 

this paragraph, ‘‘FAA’’ means the Principal 

Maintenance Inspector (PMI) for operators 

that are assigned a PMI, or the cognizant 

Flight Standards District Office for other 

operators. 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.

Note 2: Operators are not required to 

submit revisions to the compliance plan 

required by paragraph (f) of this AD to the 

FAA.

Lap Joint Modification (Repair)—Crown 

Areas 

(g) Except as provided by paragraph (h) of 

this AD: Install the lap joint repair as 

specified in Part 1.E.1. (‘‘Compliance’’) of 

Boeing Service Bulletin 737–53A1177, 

Revision 4, dated September 2, 1999; 

Revision 5, dated February 15, 2001; or 

Revision 6, dated May 31, 2001; per PART III 

or IV (‘‘Lap Joint Repair’’), as applicable, of 

the Accomplishment Instructions of the 

applicable service bulletin; at the time 

specified in paragraph (g)(1), (g)(2), (g)(3), 

(g)(4), or (g)(5) of this AD, as applicable. 

Accomplishment of this repair terminates the 

repetitive inspections required by paragraphs 

(b), (c), and (j) of this AD.

(1) For airplanes that have accumulated 

70,000 total flight cycles or more as of the 

effective date of this AD: Within 600 flight 

cycles after the effective date of this AD, do 

the lap joint repair. 

(2) For airplanes that have accumulated 

65,000 total flight cycles or more, but less 

than 70,000 total flight cycles as of the 

effective date of this AD: Do the repair at the 

later of the times specified in paragraphs 

(g)(2)(i) and (g)(2)(ii) of this AD. 

(i) Before the accumulation of 70,000 total 

flight cycles. 

(ii) Within 600 flight cycles after the 

effective date of this AD. 

(3) For airplanes that have accumulated 

45,000 total flight cycles or more, but less 

than 65,000 total flight cycles as of the 

effective date of this AD: Within 5,000 flight 

cycles after the effective date of this AD. 

(4) For airplanes that have accumulated 

less than 45,000 total flight cycles as of the 

effective date of this AD: Before the 

accumulation of 50,000 total flight cycles. 

(5) Notwithstanding the times specified in 

paragraphs (g)(1), (g)(2), (g)(3), and (g)(4) of 

this AD, for airplanes on which the 

‘‘Preventive Change’’ (NACA modification) 

has been accomplished per PART III of the 

Accomplishment Instructions of Boeing Alert 

Service Bulletin 737–53A1177, Revision 1, 

dated September 19, 1996; Revision 2, dated 

July 24, 1997; or Revision 3, dated September 

18, 1997: Within 18,000 flight cycles after 

accomplishment of the NACA modification. 

(h) For Groups 3 and 5 airplanes as listed 

in Boeing Service Bulletin 737–53A1177, 

Revision 6, dated May 31, 2001: Install the 

lap joint repair at stringers 4R and 10R, as 

specified in Part 1.E.1. (‘‘Compliance’’) of 

Boeing Service Bulletin 737–53A1177, 

Revision 6, dated May 31, 2001; at the time 

specified in paragraph (g)(1), (g)(2), (g)(3), 

(g)(4), or (g)(5) of this AD, as applicable; per 

a method approved by the Manager, Seattle 

ACO; or per data meeting the type 

certification basis of the airplane approved 

by a Boeing Company DER who has been 

authorized by the Manager, Seattle ACO, to 

make such findings. For a repair method to 

be approved by the Manager, Seattle ACO, as 

required by this paragraph, the approval 

letter must specifically reference this AD. 

Repetitive LFEC Inspections—Outside 

Crown Areas 

(i) Before the accumulation of 70,000 total 

flight cycles, or within 2,500 flight cycles 

after the effective date of this AD, whichever 

comes later: Do an LFEC inspection to find 

cracking of the lap joints of the fuselage, as 

specified in Part 1.E.2. (‘‘Compliance’’) of 

Boeing Service Bulletin 737–53A1177, 

Revision 6, dated May 31, 2001, and as 

identified in Figures 2 through 6 of the 

Accomplishment Instructions of the service 

bulletin. Do the inspection per the service 

bulletin. Repeat the inspection after that at 

intervals not to exceed 5,000 flight cycles. 

Post-NACA Modification Inspections—

Crown Areas 

(j) For airplanes that have the ‘‘Preventive 

Change’’ (NACA modification) of the crown 

lap joint stringers (‘‘Crown Laps’’) done per 

PART III of the Accomplishment Instructions 

of Boeing Alert Service Bulletin 737–

53A1177, Revision 1, dated September 19, 

1996; Revision 2, dated July 24, 1997; or 

Revision 3, dated September 18, 1997: 

Within 12,000 flight cycles after 

accomplishment of the NACA modification, 

or within 750 flight cycles after the effective 

date of this AD, whichever is later, do either 

an external (Figure 8) or internal (Figure 9) 

LFEC inspection to find cracking and 

corrosion as specified in Part 1.E.4.a. 

(‘‘Compliance’’) of Boeing Service Bulletin 

737–53A1177, Revision 6, dated May 31, 

2001; per PART I (‘‘Inspection’’) of the 

Accomplishment Instructions of Revision 6 

of the service bulletin. 

(1) If the external inspection is done: 

Repeat the inspection after that at intervals 

not to exceed 1,500 flight cycles until 

accomplishment of the lap joint repair 

required by paragraph (g) of this AD. 

(2) If the internal inspection is done: 

Repeat the inspection after that at intervals 

not to exceed 4,500 flight cycles until 

accomplishment of the lap joint repair 

required by paragraph (g) of this AD. 

Post-NACA Modification Inspections—

Outside Crown Areas 

(k) For airplanes that have the ‘‘Preventive 

Change’’ (NACA modification) outside the 

crown areas done per PART III of the 

Accomplishment Instructions of Boeing Alert 

Service Bulletin 737–53A1177, Revision 1, 

dated September 19, 1996; Revision 2, dated 

July 24, 1997; or Revision 3, dated September 

18, 1997: Before the accumulation of 20,000 

flight cycles after accomplishment of the 

NACA modification or within 750 flight 

cycles after the effective date of this AD, 

whichever is later, do either an external 

(Figure 8) or internal (Figure 9) LFEC 

inspection to find cracking and corrosion as 

specified in Part 1.E.4.b. (‘‘Compliance’’) of 

Boeing Service Bulletin 737–53A1177, 

Revision 6, dated May 31, 2001, per PART I 

Federal Register / Vol. 67, No. 71 / Friday, April 12, 2002 / Rules and Regulations 17923

(‘‘Inspection’’) of the Accomplishment 

Instructions of Revision 6 of the service 

bulletin. 

(1) If the external inspection is done: 

Repeat the external inspection after that at 

intervals not to exceed 1,500 flight cycles. 

(2) If the internal inspection is done: 

Repeat the internal inspection after that at 

intervals not to exceed 4,500 flight cycles. 

Modification of Tear Strap Splice Straps 

(l) For airplanes that have the ‘‘lap joint 

repair,’’ as specified in Part IV of the 

Accomplishment Instructions of Boeing Alert 

Service Bulletin 737–53A1177, Revision 2, 

dated July 24, 1997, or Revision 3, dated 

September 18, 1997: Within 45,000 flight 

cycles after accomplishment of this lap joint 

repair, modify the splice straps per Figures 

10, 11, and 12 of the Accomplishment 

Instructions of Boeing Service Bulletin 737–

53A1177, Revision 6, dated May 31, 2001.

Follow-On LFEC Inspections 

(m) Within 45,000 flight cycles after 

accomplishment of the lap joint repair 

required by paragraph (g) or (h) of this AD, 

as applicable: Do either an external or 

internal (Figure 9) LFEC inspection as 

specified in Part 1.E.7. (‘‘Compliance’’) of 

Boeing Service Bulletin 737–53A1177, 

Revision 6, dated May 31, 2001, to find 

cracking of the lap joint repair, per PART I 

(‘‘Inspection’’) of the Accomplishment 

Instructions of the service bulletin. Repeat 

the inspection after that at intervals not to 

exceed 2,800 flight cycles. 

Repetitive High Frequency Eddy Current 

(HFEC) Inspections—Window Corners 

(n) For airplanes having line numbers 520 

through 2565 inclusive: Before the 

accumulation of 50,000 total flight cycles or 

within 2,250 flight cycles after the effective 

date of this AD, whichever comes later, do 

an HFEC inspection to find cracking as 

specified in Part 1.E.10 (‘‘Compliance’’) of 

Boeing Service Bulletin 737–53A1177, 

Revision 6, dated May 31, 2001, per PART V 

(‘‘Window Corner Fastener Hole Cracking, 

Inspection and Repair’’) of the 

Accomplishment Instructions of the service 

bulletin. Repeat the inspection after that at 

intervals not to exceed 4,500 flight cycles. 

Accomplishment of the modification (which 

includes removing and discarding fasteners, 

oversizing fastener holes, and installing 

rivets or Hi-Lok fasteners, as applicable), per 

PART V of the Accomplishment Instructions 

of Boeing Service Bulletin 737–53A1177, 

Revision 5, dated February 15, 2001, or 

Revision 6, dated May 31, 2001, constitutes 

terminating action for the inspections 

required by this paragraph. 

Alternative Methods of Compliance 

(o)(1) 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 

ACO. Operators shall submit their requests 

through an appropriate FAA PMI, who may 

add comments and then send it to the 

Manager, Seattle ACO. 

(2) Alternative methods of compliance, 

approved in accordance with AD 97–22–07, 

amendment 39–101–79 are approved as 

alternative methods of compliance with 

paragraphs (a), (b), (d), (e), (g), and (i) of this 

AD.

Note 3: Information concerning the 

existence of approved alternative methods of 

compliance with this AD, if any, may be 

obtained from the Seattle ACO.

Special Flight Permits 

(p) 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. 

Incorporation by Reference 

(q) Except as provided by paragraphs (e), 

(f), and (h) of this AD, the actions shall be 

done in accordance with Boeing Service 

Bulletin 737–53A1177, Revision 4, dated 

September 2, 1999; Boeing Service Bulletin 

737–53A1177, Revision 5, dated February 15, 

2001; or Boeing Service Bulletin 737–

53A1177, Revision 6, dated May 31, 2001, as 

applicable. This incorporation by reference is 

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. 

Effective Date 

(r) This amendment becomes effective on 

May 17, 2002.

Issued in Renton, Washington, on April 2, 

2002. 

Ali Bahrami, 

Acting Manager, Transport Airplane 

Directorate, Aircraft Certification Service.

[FR Doc. 02–8454 Filed 4–11–02; 8:45 am] 

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. 99–NM–105–AD; Amendment 

39–12703; AD 2002–07–09] 

RIN 2120–AA64 

Airworthiness Directives; Boeing 

Model 727, 727C, 727–100, 727–100C, 

727–200, and 727–200F Series 

Airplanes

AGENCY: Federal Aviation 

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment supersedes 

an existing airworthiness directive (AD), 

applicable to all Boeing Model 727, 

727C, 727–100, 727–100C, 727–200, and 

727–200F series airplanes, that 

currently requires repetitive inspections 

to find cracking of the lower skin panel 

at the lower row of fasteners in certain 

lap joints of the fuselage, and repair, if 

necessary. This amendment limits the 

applicability of the existing AD, adds 

certain repetitive inspections, revises 

certain compliance times, and adds 

certain modifications. This amendment 

is prompted by the FAA’s determination 

that, in light of additional crack 

findings, certain modifications of the 

fuselage lap joints are necessary. The 

actions specified by this AD are 

intended to find and fix fatigue cracking 

of the fuselage lap joints, which could 

result in sudden fracture and failure of 

the lower skin lap joints, and rapid 

decompression of the airplane.

DATES: Effective May 17, 2002. 

The incorporation by reference of 

certain publications listed in the 

regulations is approved by the Director 

of the Federal Register as of May 17, 

2002.

ADDRESSES: The service information 

referenced in this AD may be obtained 

from Boeing Commercial Airplane 

Group, PO 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: Walt 

Sippel, Aerospace Engineer, Airframe 

Branch, ANM–120S, FAA, Seattle 

Aircraft Certification Office, 1601 Lind 

Avenue, SW., Renton, Washington 

98055–4056; telephone (425) 227–2774; 

fax (425) 227–1181.

SUPPLEMENTARY INFORMATION: A 

proposal to amend part 39 of the Federal 

Aviation Regulations (14 CFR part 39) 

by superseding AD 99–04–22, 

amendment 39–11047 (64 FR 7774, 

February 17, 1999), which is applicable 

to all Boeing Model 727, 727–100, 727–

200, 727C, 727–100C, and 727–200F 

series airplanes, was published in the 

Federal Register on July 12, 2001 (66 FR 

36516). The action proposed to continue 

to require repetitive inspections to find 

cracking of the lower skin panel at the 

lower row of fasteners in certain lap 

joints of the fuselage, and repair, if 

necessary. The action also proposed to 

limit the applicability of the existing 

AD, add certain repetitive inspections, 

revise certain compliance times, and 

add certain modifications.