Federal Register / Vol. 74, No. 165 / Thursday, August 27, 2009 / Rules and Regulations 43629 

TABLE 4—DOCUMENTS INCORPORATED BY REFERENCE FOR ACTIONS REQUIRED BY THIS AD 

Service bulletin Date 

Fokker Service Bulletin SBF50–24–031 .................................................................................................................................. January 29, 2008. 

Fokker Service Bulletin SBF100–24–041 ................................................................................................................................ January 29, 2008. 

Goodrich Power Systems Service Bulletin SG02206–24–01 ................................................................................................. March 4, 2008. 

TABLE 5—DOCUMENTS INCORPORATED BY REFERENCE FOR OPTIONAL ACTIONS SPECIFIED IN THIS AD 

Service bulletin Date 

Fokker Service Bulletin SBF50–24–030 including the drawings identified in Table 2 of this AD .......................................... November 6, 2003. 

Fokker Service Bulletin SBF100–24–037, including Manual Change Notification—Maintenance Documentation MCNM 

F100–076, dated October 2, 2003, and including the drawings identified in Table 3 of this AD.

October 2, 2003. 

Issued in Renton, Washington, on August 

17, 2009. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. E9–20576 Filed 8–26–09; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2009–0477; Directorate 

Identifier 2008–NM–191–AD; Amendment 

39–16003; AD 2009–18–07] 

RIN 2120–AA64 

Airworthiness Directives; Boeing 

Model 747–100, –100B, –100B SUD, 

–200B, and –300 Series Airplanes; and 

Model 747SP and 747SR Series 

Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), Department of 

Transportation (DOT). 

ACTION: Final rule. 

SUMMARY: The FAA is superseding an 

existing airworthiness directive (AD), 

which applies to certain Boeing Model 

747 series airplanes. That AD currently 

requires repetitive inspections to detect 

cracks in various areas of the fuselage 

internal structure, and related 

investigative/corrective actions if 

necessary. This new AD requires 

additional repetitive inspections for 

cracking of certain fuselage structure, 

and related investigative/corrective 

actions if necessary. This AD results 

from fatigue tests and analysis by 

Boeing that identified areas of the 

fuselage where fatigue cracks can occur. 

We are issuing this AD to prevent the 

loss of the structural integrity of the 

fuselage, which could result in rapid 

depressurization of the airplane. 

DATES: This AD becomes effective 

October 1, 2009. 

The Director of the Federal Register 

approved the incorporation by reference 

of a certain publication listed in the AD 

as of October 1, 2009. 

ADDRESSES: For service information 

identified in this AD, contact Boeing 

Commercial Airplanes, Attention: Data 

& Services 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. 

Examining the AD Docket 

You may examine the AD docket on 

the Internet at http:// 

www.regulations.gov; or in person at the 

Docket Management Facility 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 address for the 

Docket Office (telephone 800–647–5527) 

is the Document Management Facility, 

U.S. Department of Transportation, 

Docket Operations, M–30, West 

Building Ground Floor, Room W12–140, 

1200 New Jersey Avenue, SE., 

Washington, DC 20590. 

FOR FURTHER INFORMATION CONTACT: Ivan 

Li, Aerospace Engineer, Airframe 

Branch, ANM–120S, FAA, Seattle 

Aircraft Certification Office, 1601 Lind 

Avenue, SW., Renton, Washington 

98057–3356; telephone (425) 917–6437; 

fax (425) 917–6590. 

SUPPLEMENTARY INFORMATION: 

Discussion 

The FAA issued a notice of proposed 

rulemaking (NPRM) to amend 14 CFR 

part 39 to include an AD that 

supersedes AD 2005–20–30, amendment 

39–14327 (70 FR 59252, October 12, 

2005). The existing AD applies to 

certain Boeing Model 747 series 

airplanes. That NPRM was published in 

the Federal Register on May 26, 2009 

(74 FR 24712). That NPRM proposed to 

continue to require repetitive 

inspections to detect cracks in various 

areas of the fuselage internal structure, 

and related investigative/corrective 

actions if necessary. That NPRM also 

proposed to require additional repetitive 

inspections for cracking of certain 

fuselage structure, and related 

investigative/corrective actions if 

necessary. 

Comments 

We provided the public the 

opportunity to participate in the 

development of this AD. We have 

considered the comment that has been 

received on the NPRM. Boeing concurs 

with the NPRM. 

Conclusion 

We have carefully reviewed the 

available data, including the comment 

that has been received, and determined 

that air safety and the public interest 

require adopting the AD as proposed. 

Costs of Compliance 

There are about 209 airplanes of the 

affected design in the worldwide fleet. 

The following table provides the 

estimated costs for U.S. operators to 

comply with this AD. The average labor 

rate is $80 per work hour. 


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TABLE—ESTIMATED COSTS

Action Work 

hours 

Cost per airplane, per inspection cycle Number of 

U.S.-registered 

airplanes 

Fleet cost 

Inspections (required by AD 2005–20–30) .......................................................................... 130 $10,400 69 $717,600 

Additional inspections in Area 1 (new action) ..................................................................... 6 480 69 33,120 

Additional inspections in Area 6 (new action) ..................................................................... 1 80 69 5,520

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 regulatory evaluation 

of the estimated costs to comply with 

this AD and placed it in the AD docket. 

See the ADDRESSES section for a location 

to examine the regulatory evaluation. 

List of Subjects in 14 CFR Part 39 

Air transportation, Aircraft, Aviation 

safety, Incorporation by reference, 

Safety. 

Adoption of the Amendment 

■ Accordingly, under the authority 

delegated to me by the Administrator, 

the FAA 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 Federal Aviation 

Administration (FAA) amends § 39.13 

by removing amendment 39–14327 (70 

FR 59252, October 12, 2005) and by 

adding the following new airworthiness 

directive (AD): 

2009–18–07 Boeing: Amendment 39–16003. 

Docket No. FAA–2009–0477; Directorate 

Identifier 2008–NM–191–AD. 

Effective Date 

(a) This AD becomes effective October 1, 

2009. 

Affected ADs 

(b) This AD supersedes AD 2005–20–30. 

Applicability 

(c) This AD applies to Boeing Model 747– 

100, 747–100B, 747–100B SUD, 747–200B, 

747–300, 747SP, and 747SR series airplanes; 

certificated in any category; identified in 

Boeing Service Bulletin 747–53A2349, 

Revision 3, dated October 2, 2008. 

Subject 

(d) Air Transport Association (ATA) of 

America Code 53: Fuselage. 

Unsafe Condition 

(e) This AD results from fatigue tests and 

analysis by Boeing that identified areas of the 

fuselage where fatigue cracks can occur. We 

are issuing this AD to prevent the loss of the 

structural integrity of the fuselage, which 

could result in rapid depressurization of the 

airplane. 

Compliance 

(f) You are responsible for having the 

actions required by this AD performed within 

the compliance times specified, unless the 

actions have already been done. 

Restatement of Requirements of AD 2002– 

10–10 With Revised Service Information 

(Excluding Upper Deck Floor Beams) 

Repetitive Inspections 

(g) Prior to the accumulation of 22,000 total 

flight cycles, or within 1,000 flight cycles 

after June 11, 1993 (the effective date of AD 

93–08–12, amendment 39–8559, which was 

superseded by AD 2002–10–10), whichever 

occurs later, unless accomplished previously 

within the last 2,000 flight cycles; and 

thereafter at intervals not to exceed 3,000 

flight cycles: Perform an internal detailed 

inspection to detect cracks in the areas of the 

fuselage internal structure specified in 

paragraphs (g)(1) through (g)(6) of this AD; in 

accordance with Boeing Service Bulletin 

747–53–2349, dated June 27, 1991; Boeing 

Alert Service Bulletin 747–53A2349, 

Revision 1, dated October 12, 2000; Boeing 

Service Bulletin 747–53A2349, Revision 2, 

dated April 3, 2003; or Boeing Alert Service 

Bulletin 747–53A2349, Revision 3, dated 

October 2, 2008. After the effective date of 

this AD, only Revision 3 of Boeing Alert 

Service Bulletin 747–53A2349 may be used. 

Continue doing the inspections until the 

inspections required by paragraph (j) of this 

AD are done. 

(1) Section 42 upper lobe frames. 

(2) Section 46 lower lobe frames. 

(3) Section 42 lower lobe frames. 

(4) Main entry door cutouts. 

(5) Section 41 body station 260, 340, and 

400 bulkheads. 

(6) Main entry doors. 

Note 1: For the purposes of this AD, a 

detailed inspection is: ‘‘An intensive 

examination of a specific item, installation, 

or assembly to detect damage, failure, or 

irregularity. Available lighting is normally 

supplemented with a direct source of good 

lighting at an intensity deemed appropriate. 

Inspection aids such as mirror, magnifying 

lenses, etc., may be necessary. Surface 

cleaning and elaborate procedures may be 

required.’’ 

(h) Prior to the accumulation of 25,000 

total flight cycles, or within 1,000 flight 

cycles after June 11, 1993, whichever is later, 

unless already done within the last 2,000 

flight cycles; and thereafter at intervals not to 

exceed 3,000 flight cycles: Do an internal 

detailed inspection to detect cracks in the 

Section 46 upper lobe frames, in accordance 

with Boeing Service Bulletin 747–53–2349, 

dated June 27, 1991; Boeing Alert Service 

Bulletin 747–53A2349, Revision 1, dated 

October 12, 2000; Boeing Service Bulletin 

747–53A2349, Revision 2, dated April 3, 

2003; or Boeing Alert Service Bulletin 747– 

53A2349, Revision 3, dated October 2, 2008. 

After the effective date of this AD, only 


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Federal Register / Vol. 74, No. 165 / Thursday, August 27, 2009 / Rules and Regulations 43631 

Revision 3 of Boeing Alert Service Bulletin 

747–53A2349 may be used. 

Repair of Cracks Detected During Paragraph 

(g) or (h) Inspections 

(i) Before further flight, repair any cracks 

detected during the inspections done per 

paragraph (g) or (h) of this AD by doing the 

actions specified in paragraph (i)(1) or (i)(2) 

of this AD, as applicable. 

(1) Repair in accordance with a method 

approved by the Manager, Seattle Aircraft 

Certification Office (ACO), FAA; or using a 

method approved in accordance with 

paragraph (p) of this AD. 

(2) Repair in accordance with Boeing 

Service Bulletin 747–53A2349, Revision 2, 

dated April 3, 2003; or Boeing Alert Service 

Bulletin 747–53A2349, Revision 3, dated 

October 2, 2008. After the effective date of 

this AD, only Revision 3 of Boeing Alert 

Service Bulletin 747–53A2349 may be used. 

Where either revision of the service bulletin 

specifies to contact Boeing for repair 

instructions, repair in accordance with a 

method approved by the Manager, Seattle 

ACO; or use a method approved in 

accordance with paragraph (p) of this AD. 

Restatement of Requirements of AD 2005– 

20–30 With Revised Service Information 

Repetitive Inspections 

(j) Do an internal detailed inspection to 

detect cracking in the areas of the fuselage 

internal structure specified in paragraphs 

(j)(1), (j)(2), and (j)(3) of this AD, and internal 

and external detailed inspections of the areas 

specified in paragraphs (j)(4), (j)(5), (j)(6), and 

(j)(7) of this AD. Do the inspections in 

accordance with Boeing Service Bulletin 

747–53A2349, Revision 2, dated April 3, 

2003; or Boeing Alert Service Bulletin 747– 

53A2349, Revision 3, dated October 2, 2008. 

After the effective date of this AD, only 

Revision 3 of Boeing Alert Service Bulletin 

747–53A2349 may be used. Do the 

inspections at the applicable time specified 

in paragraph (k) of this AD. Accomplishment 

of these inspections terminates the 

requirements of paragraph (g) of this AD. 

(1) Section 42 upper lobe frames. 

(2) Section 46 lower lobe frames. 

(3) Section 42 lower lobe frames. 

(4) Main entry door cutouts. 

(5) Nose wheel well bulkheads, sidewall 

panels, and station (STA) 360 and 380 floor 

beams. These areas include Section 41 body 

station 260, 340, and 400 bulkheads. 

(6) Main entry doors. 

(7) Main electronics bay access door 

cutout. 

(k) Do the inspections required by 

paragraph (j) of this AD at the applicable time 

specified in paragraph (k)(1), (k)(2), or (k)(3) 

of this AD. Repeat the inspections thereafter 

at intervals not to exceed 3,000 flight cycles. 

(1) For airplanes on which the inspections 

required by paragraphs (g)(1), (g)(2), (g)(3), 

(g)(4), and (g)(6) of this AD have been done 

before November 16, 2005 (the effective date 

of AD 2005–20–30), but the inspections 

required by paragraphs (j)(5) and (j)(7) of this 

AD have not been done: Within 3,000 flight 

cycles since accomplishment of the most 

recent inspection required by paragraphs 

(g)(1), (g)(2), (g)(3), (g)(4), and (g)(6) of this 

AD, except that the inspections specified in 

paragraphs (j)(5) and (j)(7) of this AD may be 

done within 3,000 flight cycles since 

accomplishment of the most recent 

inspection required by paragraphs (g)(1), 

(g)(2), (g)(3), (g)(4), and (g)(6) of this AD, or 

within 1,000 flight cycles after November 16, 

2005, whichever is later. 

(2) For airplanes on which the inspections 

required by paragraphs (j)(5) and (j)(7) have 

been done before November 16, 2005: Within 

3,000 flight cycles since accomplishment of 

the most recent inspection required by 

paragraphs (j)(5) and (j)(7) of this AD, or 

within 1,000 flight cycles after November 16, 

2005, whichever is later. 

(3) For airplanes on which the inspections 

required by paragraph (g) of this AD have not 

been done before November 16, 2005: Prior 

to the accumulation of 22,000 total flight 

cycles, or within 1,000 flight cycles after 

November 16, 2005, whichever is later. 

Repair of Cracks Detected During Paragraph 

(j) Inspection 

(l) Before further flight, repair any cracking 

found during any inspection required by 

paragraph (j) of this AD in accordance with 

Boeing Service Bulletin 747–53A2349, 

Revision 2, dated April 3, 2003; or Boeing 

Alert Service Bulletin 747–53A2349, 

Revision 3, dated October 2, 2008. After the 

effective date of this AD, only Revision 3 of 

Boeing Alert Service Bulletin 747–53A2349 

may be used. Where any revision of the 

service bulletin specifies to contact Boeing 

for repair instructions, repair in accordance 

with a method approved by the Manager, 

Seattle ACO; or use a method approved in 

accordance with paragraph (p) of this AD. 

New Requirements of This AD 

Inspections and Repair 

(m) Do initial and repetitive detailed 

inspections for cracking in the areas specified 

in Table 1 of this AD using applicable 

internal and external detailed inspection 

methods; and repair all cracks, by doing all 

the applicable actions in accordance with the 

Accomplishment Instructions of Boeing Alert 

Service Bulletin 747–53A2349, Revision 3, 

dated October 2, 2008, except as required by 

paragraph (n) of this AD. Do the initial and 

repetitive inspections at the times specified 

in paragraph 1.E., ‘‘Compliance,’’ of the 

service bulletin, except as required by 

paragraph (o) of this AD. Repair all cracks 

before further flight after detection. 

TABLE 1—ADDITIONAL INSPECTIONS

Inspect the addition portion of area 1 and area 6 as specified in Boeing Alert Service Bulletin 747– 

53A2349, Revision 3, dated October 2, 2008 (‘‘the service bulletin’’)— 

For airplanes identified as these groups 

in the service bulletin— 

In Area 1: Fuselage frames at body stations 260–520 in areas where the upper deck floor beams are 

attached (Figure 11 of the Accomplishments Instructions of the service bulletin).

1 through 7 inclusive. 

In Area 6: Fuselage frames at body stations 400–500 in areas above the Main Entry Door 1 cutouts, 

from the upper chord of the upper deck floor beams to Stringer 8 (Figure 12 of the Accomplishment 

Instructions of the service bulletin).

6 and 7. 

Exceptions to Certain Procedures 

(n) If any crack is found during any 

inspection required by paragraph (m) of this 

AD, and Boeing Alert Service Bulletin 747– 

53A2349, Revision 3, dated October 2, 2008, 

specifies to contact Boeing for appropriate 

action: Before further flight, repair the crack 

using a method approved in accordance with 

the procedures specified in paragraph (p) of 

this AD. 

(o) Where Boeing Alert Service Bulletin 

747–53A2349, Revision 3, dated October 2, 

2008, specifies a compliance time after the 

date on Boeing Alert Service Bulletin 747– 

53A2349, Revision 3, dated October 2, 2008, 

this AD requires compliance within the 

specified compliance time after the effective 

date of this AD. 

Alternative Methods of Compliance 

(AMOCs) 

(p)(1) The Manager, Seattle ACO, FAA, has 

the authority to approve AMOCs for this AD, 

if requested using the procedures found in 14 

CFR 39.19. Send information to ATTN: Ivan 

Li, Aerospace Engineer, Airframe Branch, 

ANM–120S, FAA, Seattle Aircraft 

Certification Office, 1601 Lind Avenue, SW., 

Renton, Washington 98057–3356; telephone 

(425) 917–6437; fax (425) 917–6590. Or, email information to 9-ANM-Seattle-ACOAMOC-Requests@faa.gov. 

(2) To request a different method of 

compliance or a different compliance time 

for this AD, follow the procedures in 14 CFR 

39.19. Before using any approved AMOC on 

any airplane to which the AMOC applies, 

notify your principal maintenance inspector 

(PMI) or principal avionics inspector (PAI), 

as appropriate, or lacking a principal 

inspector, your local Flight Standards District 

Office. The AMOC approval letter must 

specifically reference this AD. 

(3) AMOCs approved previously in 

accordance with AD 2005–20–30 are 

approved as AMOCs with the corresponding 

provisions of this AD. 

(4) An AMOC that provides an acceptable 

level of safety may be used for any repair 


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43632 Federal Register / Vol. 74, No. 165 / Thursday, August 27, 2009 / Rules and Regulations 

required by this AD, if it is approved by an 

Authorized Representative for the Boeing 

Commercial Airplanes Delegation Option 

Authorization Organization who has been 

authorized by the Manager, Seattle ACO, to 

make those findings. For a repair method to 

be approved, the repair must meet the 

certification basis of the airplane, and the 

approval must specifically refer to this AD. 

Material Incorporated by Reference 

(q) You must use Boeing Alert Service 

Bulletin 747–53A2349, Revision 3, dated 

October 2, 2008, as applicable, to do the 

actions required by this AD, unless the AD 

specifies otherwise. 

(1) The Director of the Federal Register 

approved the incorporation by reference of 

this service information under 5 U.S.C. 

552(a) and 1 CFR part 51. 

(2) For service information identified in 

this AD, contact Boeing Commercial 

Airplanes, Attention: Data & Services 

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 August 

17, 2009. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. E9–20579 Filed 8–26–09; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2009–0386; Directorate 

Identifier 2008–NM–184–AD; Amendment 

39–16002; AD 2009–18–06] 

RIN 2120–AA64 

Airworthiness Directives; 

Construcciones Aeronauticas, S.A. 

(CASA), Model CN–235, CN–235–100, 

CN–235–200, and CN–235–300 

Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), Department of 

Transportation (DOT). 

ACTION: Final rule. 

SUMMARY: We are adopting a new 

airworthiness directive (AD) for the 

products listed above. This AD results 

from mandatory continuing 

airworthiness information (MCAI) 

originated by an aviation authority of 

another country to identify and correct 

an unsafe condition on an aviation 

product. The MCAI describes the unsafe 

condition as: 

During operation in icing conditions, an 

asymmetric configuration of the de-icing 

boots was detected, occurring during the 

inflation and deflation check of the de-icing 

system. This was found to be due to an 

unexpected failure mode in the pneumatic 

and de-icing system’s control electronic 

logic. This condition, if not corrected, could 

affect the de-icing capabilities of the boots 

installed on the wing and horizontal 

stabilizers, potentially leading to loss of 

control of the aircraft. 

* * * * * 

We are issuing this AD to require 

actions to correct the unsafe condition 

on these products. 

DATES: This AD becomes effective 

October 1, 2009. 

The Director of the Federal Register 

approved the incorporation by reference 

of certain publications listed in this AD 

as of October 1, 2009. 

ADDRESSES: You may examine the AD 

docket on the Internet at http:// 

www.regulations.gov or in person at the 

U.S. Department of Transportation, 

Docket Operations, M–30, West 

Building Ground Floor, Room W12–140, 

1200 New Jersey Avenue, SE., 

Washington, DC. 

FOR FURTHER INFORMATION CONTACT: 

Shahram Daneshmandi, Aerospace 

Engineer, International Branch, ANM– 

116, Transport Airplane Directorate, 

FAA, 1601 Lind Avenue, SW., Renton, 

Washington 98057–3356; telephone 

(425) 227–1112; fax (425) 227–1149. 

SUPPLEMENTARY INFORMATION: 

Discussion 

We issued a notice of proposed 

rulemaking (NPRM) to amend 14 CFR 

part 39 to include an AD that would 

apply to the specified products. That 

NPRM was published in the Federal 

Register on April 29, 2009 (74 FR 

19460). That NPRM proposed to correct 

an unsafe condition for the specified 

products. The MCAI states: 

During operation in icing conditions, an 

asymmetric configuration of the de-icing 

boots was detected, occurring during the 

inflation and deflation check of the de-icing 

system. This was found to be due to an 

unexpected failure mode in the pneumatic 

and de-icing system’s control electronic 

logic. This condition, if not corrected, could 

affect the de-icing capabilities of the boots 

installed on the wing and horizontal 

stabilizers, potentially leading to loss of 

control of the aircraft. 

To address and correct this unsafe 

condition, EADS–CASA developed 

modification 31558, approved by DGAC– 

Spain and incorporated into the Type Design 

Definition through the approval of CN–235– 

300 version AE02, revision 14 of Spanish 

Type Certificate DGAC 01/86, dated 22 

March 2002, and modification 31607, Minor 

Change approved by EADS–CASA under 

their DOA 21J.032 privileges, complementary 

to modification 31558. The entire 

modification package consists of an 

improvement of the de-icing boots electronic 

control system, making it capable of 

detecting all possible boot configurations on 

wings and horizontal stabilizers without 

affecting pneumatic system functions. The 

instructions for the in-service 

accomplishment of this modification have 

been published as CN–235 Service Bulletin 

(SB) 235–30–16 dated 21 January 2005. 

For the reasons described above, this EASA 

AD requires the modification of the De-Icing 

Boots control system in all aircraft that have 

not yet implemented the modification. 

You may obtain further information by 

examining the MCAI in the AD docket. 

Comments 

We gave the public the opportunity to 

participate in developing this AD. We 

received no comments on the NPRM or 

on the determination of the cost to the 

public. 

Change to Parts Cost 

We have revised the parts cost to 

reflect the price of two kits from the 

manufacturer. The revised cost is less 

than the original cost presented in the 

NPRM. 

Conclusion 

We reviewed the available data and 

determined that air safety and the 

public interest require adopting the AD 

as proposed. 

Differences Between This AD and the 

MCAI or Service Information 

We have reviewed the MCAI and 

related service information and, in 

general, agree with their substance. But 

we might have found it necessary to use 

different words from those in the MCAI 

to ensure the AD is clear for U.S. 

operators and is enforceable. In making 

these changes, we do not intend to differ 

substantively from the information 

provided in the MCAI and related 

service information. 

We might also have required different 

actions in this AD from those in the 

MCAI in order to follow our FAA 

policies. Any such differences are 

highlighted in a NOTE within the AD. 

Costs of Compliance 

We estimate that this AD will affect 8 

products of U.S. registry. We also 


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