22426 Federal Register / Vol. 74, No. 91 / Wednesday, May 13, 2009 / Rules and Regulations 

Management, P.O. Box 3707, MC 2H–65, 

Seattle, Washington 98124–2207; telephone 

206–544–5000, extension 1; fax 206–766– 

5680; e-mail me.boecom@boeing.com; 

Internet https://www.myboeingfleet.com. 

(3) You may review copies of the service 

information at the FAA, Transport Airplane 

Directorate, 1601 Lind Avenue, SW., Renton, 

Washington. For information on the 

availability of this material at the FAA, call 

425–227–1221 or 425–227–1152. 

(4) You may also review copies of the 

service information that is incorporated by 

reference at the National Archives and 

Records Administration (NARA). For 

information on the availability of this 

material at NARA, call 202–741–6030, or go 

to: http://www.archives.gov/federal_register/ 

code_of_federal_regulations/ 

ibr_locations.html. 

Issued in Renton, Washington, on May 1, 

2009. 

Stephen P. Boyd, 

Acting Manager, Transport Airplane 

Directorate, Aircraft Certification Service. 

[FR Doc. E9–10935 Filed 5–12–09; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2008–1131; Directorate 

Identifier 2008–NE–37–AD; Amendment 39– 

15903; AD 2009–10–08] 

RIN 2120–AA64 

Airworthiness Directives; Pratt & 

Whitney Models PW2037, PW2037(M), 

and PW2040 Turbofan Engines 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: The FAA is adopting a new 

airworthiness directive (AD) for Pratt & 

Whitney models PW2037, PW2037(M), 

and PW2040 turbofan engines with 

high-pressure turbine (HPT) 2nd stage 

hubs that have previously been exposed 

to Pratt & Whitney cleaning procedure 

SPOP 10 or SPOP 9 or equivalent 

procedure. This AD requires a onetime 

optical comparator inspection (OCI) of 

the blade retention slots of the affected 

HPT 2nd stage hubs at the next HPT 

overhaul after the effective date of the 

AD. This AD results from an 

uncontained release of HPT 2nd stage 

blades and blade retention lugs. We are 

issuing this AD to remove 

nonconforming HPT 2nd stage hubs, 

which could result in an uncontained 

release of turbine blades and blade 

retention lugs, and damage to the 

airplane. 

DATES: This AD becomes effective June 

17, 2009. 

ADDRESSES: You can get the service 

information identified in this AD from 

Pratt & Whitney, 400 Main Street, East 

Hartford, CT 06108. 

The Docket Operations office is 

located at Docket Management Facility, 

U.S. Department of Transportation, 1200 

New Jersey Avenue SE., West Building 

Ground Floor, Room W12–140, 

Washington, DC 20590–0001. 

FOR FURTHER INFORMATION CONTACT: 

Mark Riley, Aerospace Engineer, Engine 

Certification Office, FAA, Engine and 

Propeller Directorate, 12 New England 

Executive Park, Burlington, MA 01803; 

e-mail: mark.riley@faa.gov; telephone 

(781) 238–7758, fax (781) 238–7199. 

SUPPLEMENTARY INFORMATION: The FAA 

proposed to amend 14 CFR part 39 with 

a proposed AD. The proposed AD 

applies to PW models PW2037, 

PW2037(M), and PW2040 turbofan 

engines. We published the proposed AD 

in the Federal Register on November 14, 

2008 (73 FR 67427). That action 

proposed to require inspecting all HPT 

2nd stage hubs at the next HPT overhaul 

after the effective date of the AD. 

Examining the AD Docket 

You may examine the AD docket on 

the Internet at http:// 

www.regulations.gov; or in person at the 

Docket Operations office between 9 a.m. 

and 5 p.m., Monday through Friday, 

except Federal holidays. The AD docket 

contains this AD, the regulatory 

evaluation, any comments received, and 

other information. The street address for 

the Docket Operations office (telephone 

(800) 647–5527) is provided in the 

ADDRESSES section. Comments will be 

available in the AD docket shortly after 

receipt. 

Comments 

We provided the public the 

opportunity to participate in the 

development of this AD. We have 

considered the comments received. 

Recommend Referring to the Inspection 

as ‘‘Special Dimensional Inspection’’ 

Pratt & Whitney recommends that the 

inspection in the proposed AD be 

referred to as a ‘‘Special Dimensional 

Inspection’’ per Pratt & Whitney Alert 

Service Bulletin (ASB) PW2000 72–734, 

which is approved by the FAA. The 

proposed AD currently specifies an 

Optical Comparator Inspection (OCI). 

Use of the term ‘‘Special Dimensional 

Inspection’’ instead of OCI will provide 

better alignment with the inspection 

procedures that Pratt & Whitney is 

presently developing and for which it 

will seek FAA approval, to use as an 

alternative to OCI. 

We do not agree. The inspection is an 

OCI. Therefore, identifying the type of 

inspection the AD requires by its name 

is proper. We did not change the AD. 

Request To Revise the Estimated Cost 

Pratt & Whitney and two air carriers 

request that we revise the estimated cost 

to perform an OCI. Pratt & Whitney 

states that the cost is higher than 

previously anticipated and we should 

add about $4,000 to the cost of each disk 

overhaul. Delta Air Lines states that the 

total cost is actually closer to $8,000 and 

it should include shipping ($1,000), 

vendor charges ($5,900), and should 

take into account additional inventory 

required ($180,000 per hub) due to outof-service time required to support the 

off-site inspection. 

We partially agree. We agree that the 

cost estimate in the proposed AD is not 

accurate. We do not agree that it should 

consider shipping charges or additional 

inventory requirements unique to each 

operator. We changed the cost to 

perform the OCI to $4,000 for each HPT 

stage 2 hub as quoted by Pratt & 

Whitney and updated the total to 

$3,048,000. 

Request for Clarification of the 

Inspection Being a Onetime Inspection 

Pratt & Whitney and two air carriers 

request clarification in the AD to state 

that the inspection is a onetime 

inspection. Also, Delta Air Lines 

comments that repetitive inspections 

should be required unless the cause of 

the hub out-of-tolerance condition is 

addressed. They also stated that the 

cause of the hub out-of-tolerance 

condition is not known and repetitive 

inspections are therefore required. 

We partially agree. We agree that we 

need to clarify that the OCI is a onetime 

inspection requirement. We changed the 

AD to clarify that the OCI is a onetime 

inspection requirement. We do not agree 

that the AD should require repetitive 

inspections. If we determine at a later 

date that repetitive inspections are 

required, we may issue an AD to require 

them. 

Proposal To Eliminate the Fluorescent 

Penetrant Inspection 

Pratt & Whitney and United Airlines 

propose that we eliminate the 

fluorescent penetrant inspection (FPI) 

requirement for the HPT 2nd stage hub. 

FPI of the HPT 2nd stage hub is 

redundant, since it is already mandated 

per FAA AD 2005–18–03. 

We agree. We changed the AD to only 

require a onetime OCI of the HPT 2nd 

stage hub after the fluorescent penetrant 

Federal Register / Vol. 74, No. 91 / Wednesday, May 13, 2009 / Rules and Regulations 22427 

inspection and all shop cleaning 

processes have been completed. 

Proposal To Reduce the Affected 

Population of HPT 2nd Stage Hubs 

Pratt & Whitney proposes that we 

reduce the affected population of HPT 

2nd stage hubs to only those that have 

been exposed to Pratt & Whitney 

cleaning procedure SPOP 10 or SPOP 9 

(cleaning processes that have similar 

abrasive characteristics) during their 

shop overhaul history. Based on recent 

findings from the NTSB-led 

investigation, the blade slot dimensional 

variations on the event hub and on other 

inspected hubs resulted from a specific 

process used during the cleaning of 

hubs during the normal overhaul 

process. 

We agree. We changed the AD 

applicability to state that this AD 

applies to Pratt & Whitney models 

PW2037, PW2037(M), and PW2040 

turbofan engines with HPT 2nd stage 

hubs that have previously been exposed 

to Pratt & Whitney cleaning procedure 

SPOP 10 or SPOP 9 or equivalent 

procedure. 

Proposal To Delay Issuance of AD 

United Airlines proposes that we 

delay issuance of the AD, because initial 

OCI results are showing a 25% reject 

rate. This suggests that the proposed 

inspections will not detect the problem 

that led to the one industry failure. 

Otherwise, the industry failure rate 

would be higher. Consequently, issuing 

the AD would be premature, as the 

failure mechanism is not understood, 

and it is not clear that the proposed 

inspections will prevent future failures. 

We do not agree. The investigation 

identified that an out-of-tolerance 

condition of the HPT 2nd stage hub 

blade slots is the cause of the failure 

event. However, the root cause of the 

out-of-tolerance condition is still under 

investigation, but is believed to have 

been caused by aggressive cleaning with 

an abrasive media blast. Inspection of 

the HPT 2nd stage hub blade slots is 

required to identify hubs that are out-oftolerance, to minimize the risk of future 

failures. Pratt & Whitney is reviewing 

the current acceptance criteria for the 

OCI of HPT 2nd stage hub blade slots, 

and if appropriate, may revise these 

limits to reduce the current reject rate. 

We did not change the AD. 

Proposal To Remove the Reporting 

Requirement From the AD 

Three air carriers propose that we 

remove the requirement for operators to 

be responsible for reporting HPT 2nd 

stage hub OCI results within 72 hours of 

the inspection. Delta Air Lines also asks 

if they are required to report OCI results 

after the 6-month period, since not all 

of their HPT 2nd stage hubs will go 

through overhaul within 6 months. The 

three air carriers state that it will be 

extremely difficult for operators to 

comply with the reporting requirements 

of the proposed rule, because it will not 

be the operators performing the 

inspections. The sole source that 

performs the inspections, (Pratt & 

Whitney), should be responsible for 

reporting to the FAA. 

We agree. We removed the reporting 

requirement from the AD. 

Request That an Alternate Inspection 

Be Developed That Is Not SourceApproved 

Two air carriers request that an 

alternate inspection method be 

developed that is not source-approved 

and will permit all overhaul shops the 

capability to perform the inspection. 

They state that Pratt & Whitney is 

currently the only source-approved 

vendor for the OCI. Operators are 

experiencing turn times in excess of 30 

days, which is a hardship to them. 

We agree that an alternate inspection 

procedure that can be performed by all 

overhaul facilities is preferred. 

However, we are unaware of any that 

may exist. We will evaluate any 

proposed alternative inspection an 

operator may submit as an alternative 

method of compliance. We did not 

change the AD. 

Compliance Time Should Be Revised 

The National Transportation Safety 

Board (NTSB), states that the 

compliance time should be revised to 

reflect the recommended compliance 

time in the NTSB Urgent Safety 

Recommendation A–08–85. That 

compliance time requires removal of all 

PW2037 2nd stage turbine hubs for 

inspection when they have accumulated 

significantly fewer hours and/or cycles 

than the incident engine (10,880 hours 

and/or 4,392 cycles). The 10,880 hours 

and 4,392 cycles referenced in A–08–85 

were based on the time and cycles that 

the incident engine had accumulated 

from the last overhaul until engine 

failure. Metallurgical examination of the 

failed hub was not able to discern any 

fatigue striations, so it is unknown how 

long it took those fatigue cracks to 

progress to failure. Typically, when the 

cause of the failure, or length of time for 

a crack to progress to failure is 

unknown, the time and/or cycles, 

whichever is less, since the part was 

new or overhauled until failure, is 

divided by a factor of two or three to 

establish a compliance schedule. 

We do not agree. The field 

management plan defined in the 

proposed AD is based on a risk analysis 

performed by Pratt &Whitney, which we 

reviewed and concluded is adequate. 

Further, additional field data received 

to-date has not indicated any increased 

risk, or that a more restrictive field plan 

is required. We did not change the AD. 

Proposed OCI Procedure Should Be 

Revised 

The NTSB states that the proposed 

OCI procedure should be revised to also 

require that the blade slots be measured 

using a coordinate measuring machine 

(CMM) or another dimensional 

inspection device capable of measuring 

deviations in the center of the blade 

slots. The OCI procedure is limited to 

only measure the blade slot profile on 

the forward and aft ends of the blade 

slot. The current procedure does not 

measure the center portion of the blade 

slot. 

We partially agree. We agree that the 

current OCI procedure is limited such 

that it cannot measure the center 

portion of the blade slot. However, we 

disagree that the OCI procedure is not 

an acceptable inspection method to 

identify non-conforming hubs. We 

verified that the OCI procedure can 

identify HPT 2nd stage hubs with nonconforming blade retention slots. We 

established limits for OCI that ensured 

that no parts with non-conformances 

similar to the event hub would be 

released into service. We continue to 

work with Pratt & Whitney to identify 

other improved inspection methods that 

can be used as an alternate to OCI. We 

did not change the AD. 

AD Compliance Should Also Include 

Inspection of the HPT 2nd Stage Blade 

Root Serrations for Uneven Contact 

Wear 

The NTSB states that the AD 

compliance should also include 

inspection of the HPT 2nd stage blade 

root serrations for uneven contact wear, 

as defined in the PW2000 Engine 

Manual, Task 72–52–17–200–014, 

Inspection/Check 14. The AD should 

also specify an action to take with the 

HPT 2nd stage hubs if any HPT 2nd 

stage blades are detected with uneven 

wear. The HPT 2nd stage blades 

removed from the incident engine 

showed evidence of uneven contact 

wear on the blade root serrations. The 

AD should therefore also include 

inspection of the HPT 2nd stage blades 

and include an action to take with the 

hub if blades are detected to have root 

serrations with uneven wear. 

We do not agree. Inspection of the 

HPT 2nd stage blade root serrations was 

22428 Federal Register / Vol. 74, No. 91 / Wednesday, May 13, 2009 / Rules and Regulations 

incorporated in the PW2000 Engine 

Manual to address a non-conformance 

issue for the blades and is performed 

during normal inspection. All blades 

that are identified with uneven wear on 

the root serrations are rejected and 

removed from service. The cause of 

failure of the incident engine was due 

to a nonconformance of the HPT 2nd 

stage hub blade retention slots. All HPT 

2nd stage hubs that have previously 

been exposed to Pratt & Whitney 

cleaning procedure SPOP 10 or SPOP 9 

or equivalent procedure will require 

OCI per the AD. All non-conforming 

hubs will be identified by OCI and 

removed from service. We did not 

change the AD. 

AD Should Mandate That All of the 

HPT 2nd Stage Hub Blade Slots Be 

Inspected Using OCI 

The NTSB states that the AD should 

mandate that all of the HPT 2nd stage 

hub blade slots be inspected using OCI. 

The current procedure only requires 

that every fourth blade retaining slot in 

the hub be inspected. The incident 

engine had cracks in several adjacent 

blade retaining lugs that resulted in the 

simultaneous release of multiple blades 

that exceeded the turbine case’s 

containment capability. If only every 

fourth slot in the hub is inspected, then 

two adjacent nonconforming blade slots 

could slip through the inspection and 

result in an uncontained engine failure. 

We do not agree. Inspecting every 

fourth blade retaining slot will identify 

all non-conforming hubs. HPT 2nd stage 

hubs that are aggressively cleaned using 

a grit blast procedure will typically have 

a high number of non-conforming slots. 

Field inspection data to-date indicates 

that this assumption currently remains 

valid. We did not change the AD. 

Conclusion 

We have carefully reviewed the 

available data, including the comments 

received, and determined that air safety 

and the public interest require adopting 

the AD with the changes described 

previously. We have determined that 

these changes will neither increase the 

economic burden on any operator nor 

increase the scope of the AD. 

Costs of Compliance 

We estimate that this AD will affect 

762 engines installed on airplanes of 

U.S. registry. We also estimate that it 

will take about 50 work-hours per 

engine to perform the actions, and that 

the average labor rate is $80 per workhour. No parts are required. Based on 

these figures, we estimate the total cost 

of the AD to U.S. operators to be 

$3,048,000. 

Authority for This Rulemaking 

Title 49 of the United States Code 

specifies the FAA’s authority to issue 

rules on aviation safety. Subtitle I, 

Section 106, describes the authority of 

the FAA Administrator. Subtitle VII, 

Aviation Programs, describes in more 

detail the scope of the Agency’s 

authority. 

We are issuing this rulemaking under 

the authority described in Subtitle VII, 

Part A, Subpart III, Section 44701, 

‘‘General requirements.’’ Under that 

section, Congress charges the FAA with 

promoting safe flight of civil aircraft in 

air commerce by prescribing regulations 

for practices, methods, and procedures 

the Administrator finds necessary for 

safety in air commerce. This regulation 

is within the scope of that authority 

because it addresses an unsafe condition 

that is likely to exist or develop on 

products identified in this rulemaking 

action. 

Regulatory Findings 

We have determined that this AD will 

not have federalism implications under 

Executive Order 13132. This AD 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. 

For the reasons discussed above, I 

certify that this AD: 

(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. 

We prepared a summary of the costs 

to comply with this AD and placed it in 

the AD Docket. You may get a copy of 

this summary at the address listed 

under ADDRESSES. 

List of Subjects in 14 CFR Part 39 

Air transportation, Aircraft, Aviation 

safety, Safety. 

Adoption of the Amendment 

■ Accordingly, under the authority 

delegated to me by the Administrator, 

the Federal Aviation Administration 

amends 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. The FAA amends § 39.13 by adding 

the following new airworthiness 

directive: 

2009–10–08 Pratt & Whitney: Amendment 

39–15903. Docket No. FAA–2008–1131; 

Directorate Identifier 2008–NE–37–AD. 

Effective Date 

(a) This airworthiness directive (AD) 

becomes effective June 17, 2009. 

Affected ADs 

(b) None. 

Applicability 

(c) This AD applies to Pratt & Whitney 

models PW2037, PW2037(M), and PW2040 

turbofan engines with high-pressure turbine 

(HPT) 2nd stage hubs that have previously 

been exposed to Pratt & Whitney cleaning 

procedure SPOP 10 or SPOP 9 or equivalent 

procedure. These engines are installed on, 

but not limited to, Boeing 757–200 and 757– 

300 airplanes. 

Unsafe Condition 

(d) This AD results from an uncontained 

release of HPT 2nd stage blades and blade 

retention lugs. We are issuing this AD to 

remove nonconforming HPT 2nd stage hubs, 

which could result in an uncontained release 

of turbine blades and blade retention lugs, 

and damage to the airplane. 

Compliance 

(e) You are responsible for having the 

actions required by this AD performed at the 

next HPT overhaul, unless the actions have 

already been done. 

Onetime Optical Comparator Inspection 

(OCI) of HPT 2nd Stage Hubs 

(f) Perform a onetime optical comparator 

inspection of the HPT 2nd stage hubs after 

a fluorescent penetrant inspection and all 

shop cleaning processes have been 

completed. Pratt & Whitney Alert Service 

Bulletin No. PW2000 A72–734, dated 

November 3, 2008, contains information 

about the optical comparator inspection. 

(g) Remove from service any hubs that fail 

the optical comparator inspection. 

Definition 

(h) This AD defines an HPT overhaul as 

when the HPT is at its piece-part level. 

Alternative Methods of Compliance 

(i) The Manager, Engine Certification 

Office, has the authority to approve 

alternative methods of compliance for this 

AD if requested using the procedures found 

in 14 CFR 39.19. 

Related Information 

(j) Contact Mark Riley, Aerospace Engineer, 

Engine Certification Office, FAA, Engine and 

Propeller Directorate, 12 New England 

Executive Park, Burlington, MA 01803; 

e-mail: mark.riley@faa.gov; telephone (781) 

238–7758, fax (781) 238–7199, for more 

information about this AD. 

(k) Pratt & Whitney Alert Service Bulletin 

No. PW2000 A72–734, dated November 3, 

2008, contains information about the optical 

comparator inspection. 

Federal Register / Vol. 74, No. 91 / Wednesday, May 13, 2009 / Rules and Regulations 22429 

Material Incorporated by Reference 

(l) None. 

Issued in Burlington, Massachusetts, on 

May 4, 2009. 

Peter A. White, 

Assistant Manager, Engine and Propeller 

Directorate, Aircraft Certification Service. 

[FR Doc. E9–10953 Filed 5–12–09; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2007–27747; Directorate 

Identifier 2007–CE–030–AD; Amendment 

39–15904; AD 2009–10–09] 

RIN 2120–AA64 

Airworthiness Directives; Cessna 

Aircraft Company 150 and 152 Series 

Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: The FAA is adopting a new 

airworthiness directive (AD) for Cessna 

Aircraft Company (Cessna) 150 and 152 

series airplanes. This AD requires you to 

either install a placard prohibiting spins 

and other acrobatic maneuvers in the 

airplane or to replace the rudder stop, 

rudder stop bumper, and attachment 

hardware with a new rudder stop 

modification kit and replace the safety 

wire with jamnuts. This AD results from 

follow-on investigations of two 

accidents where the rudder was found 

in the over-travel position with the stop 

plate hooked over the stop bolt heads. 

While neither of the accident aircraft 

met type design, investigations revealed 

that aircraft in full conformity with type 

design can exceed the travel limits set 

by the rudder stops. We are issuing this 

AD to prevent the rudder from traveling 

past the normal travel limit. Operation 

in this non-certificated control position 

is unacceptable and could cause 

undesirable consequences, such as 

contact between the rudder and the 

elevator. 

DATES: This AD becomes effective on 

June 17, 2009. 

On June 17, 2009, the Director of the 

Federal Register approved the 

incorporation by reference of certain 

publications listed in this AD. 

ADDRESSES: To get the service 

information identified in this AD, 

contact Cessna Aircraft Company, 

Product Support, P.O. Box 7706, 

Wichita, KS 67277; telephone: (316) 

517–5800; fax: (316) 517–7271; Internet: 

http://www.cessna.com. 

To view the AD docket, go to U.S. 

Department of Transportation, Docket 

Operations, M–30, West Building 

Ground Floor, Room W12–140, 1200 

New Jersey Avenue, SE., Washington, 

DC 20590, or on the Internet at http:// 

www.regulations.gov. The docket 

number is FAA–2007–27747; 

Directorate Identifier 2007–CE–030–AD. 

FOR FURTHER INFORMATION CONTACT: Ann 

Johnson, Aerospace Engineer, FAA, 

Wichita Aircraft Certification Office, 

1801 Airport Road, Room 100, Wichita, 

Kansas 67209; telephone: (316) 946– 

4105; fax: (316) 946–4107. 

SUPPLEMENTARY INFORMATION: 

Discussion 

On April 10, 2007, we issued a 

proposal to amend part 39 of the Federal 

Aviation Regulations (14 CFR part 39) to 

include an AD that would apply to 

certain Cessna Aircraft Company 

(Cessna) 150 and 152 series airplanes. 

This proposal was published in the 

Federal Register as a notice of proposed 

rulemaking (NPRM) on April 16, 2007 

(72 FR 18925). The NPRM proposed to 

require replacement of the rudder stop, 

rudder stop bumper, and attachment 

hardware with a new rudder stop 

modification kit and replacement of the 

safety wire with jamnuts. 

Comments 

We provided the public the 

opportunity to participate in developing 

this AD. The following presents the 

comments received on the proposal and 

FAA’s response to each comment: 

Comment Issue No. 1: SAIB Instead of 

NPRM 

Joseph Morales, Gary Iverson, Sr., Al 

Roesner, Gerald D. Clark, Al Dyer, Neal 

Trullson, McBride Aircraft Group, 

Matthew M. Gosslein, Samuel K. 

McCauley, Robert E. Hackman from the 

Aircraft Owners and Pilots Association 

(AOPA), and Tom Carr from the Cessna 

Pilots Association (CPA) comment that 

the FAA should withdraw the NPRM 

and issue a special airworthiness 

information bulletin (SAIB). The 

commenters state that if the aircraft is 

properly maintained and rigged, then no 

problems exist; problems should easily 

be detected visually during routine 

maintenance; and a rudder system that 

is built and installed correctly is 

virtually impossible to jam. The 

commenters state adequate regulations 

and requirements are in place to assure 

the inspection of the rudder system is 

completed during annual or 100-hour 

inspections in 14 CFR part 43, 

Appendix D and in the Cessna service 

publication. In addition, the 

commenters point out the following: 

• Two service difficulty reports were 

found but none for a jammed rudder. 

• In the Ohio accident, the rudder 

stop was installed inverted, and the 

functionality of the stop configuration 

was compromised. 

• If you remove the right rudder 

return spring and disconnect the right 

rudder control cable, then the left 

locked rudder event from the Canadian 

accident could be duplicated. 

• The two accident airplanes were 

not airworthy prior to flight. 

The commenters further state that 

requiring replacement of the rudder 

stop, rudder stop bumper, attachment 

hardware, and substituting safety wire 

with jamnuts is an overreaction. The 

commenters request that the FAA 

withdraw the NPRM and issue an SAIB 

since the problem is with a very limited 

number of airplanes, specifically the 

Cessna Model 152, and improper 

maintenance was cited as the cause of 

the two previously mentioned 

accidents. The commenters state the 

airplanes have flown for 51 years and 

thousands of hours with no previous 

problems, and installing the original 

equipment manufacturer (OEM) kit on 

17,090 domestic airplanes would put 

the airplanes at risk. 

We do not agree that this action 

should be an SAIB instead of an AD. 

While the two accident aircraft were not 

airworthy, the issue that needs to be 

corrected is a design issue, not a 

maintenance issue. Follow-on 

investigations did reveal that rudders on 

aircraft in full conformity with type 

design can exceed the travel limits set 

by the rudder stops. Operation in this 

non-certificated control position is 

unacceptable and could cause 

undesirable consequences. Markings on 

one accident aircraft correspond with 

previous contact between the rudder 

and elevator, and similar markings were 

noted on several in-service airplanes. 

We will change the final rule AD to 

provide another option in lieu of the 

actions in the proposed AD. For the new 

option, the limitations section in the 

airplane flight manual (AFM) and the 

pilots operating handbook (POH) must 

be changed to prohibit acrobatics. A 

placard would be displayed on the 

instrument panel in clear view of the 

pilot with the words ‘‘INTENTIONAL 

SPINS AND OTHER ACROBATIC/ 

AEROBATIC MANEUVERS 

PROHIBITED PER AD 2009–10–09.’’ 

We retain as an option the actions 

complying with the service information 

as specified in the proposed AD. After 

such action is done, the specified