61436 Federal Register / Vol. 62, No. 222 / Tuesday, November 18, 1997 / Rules and Regulations

17, 1997: Within 3,000 flight hours after

replacement of the bushings, and thereafter at

intervals not to exceed 300 flight hours,

inspect the new bushings in accordance with

paragraph (c) of this AD.

(f) An alternative method of compliance or

adjustment of the compliance time that

provides an acceptable level of safety may be

used if approved by the Manager,

International Branch, ANM–116, FAA,

Transport Airplane Directorate. Operators

shall submit their requests through an

appropriate FAA Principal Maintenance

Inspector, who may add comments and then

send it to the Manager, International Branch,

ANM–116.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the International Branch,

ANM–116.

(g) Special flight permits may be issued in

accordance with sections 21.197 and 21.199

of the Federal Aviation Regulations (14 CFR

21.197 and 21.199) to operate the airplane to

a location where the requirements of this AD

can be accomplished.

(h) The inspection and replacement shall

be done in accordance with Dornier Alert

Service Bulletin ASB–328–32–019, dated

September 17, 1997. This incorporation by

reference was approved by the Director of the

Federal Register in accordance with 5 U.S.C.

552(a) and 1 CFR part 51. Copies may be

obtained from Dornier Deutsche Aerospace,

P.O. Box 1103, D–82230 Wessling, Federal

Republic of Germany. 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.

(i) This amendment becomes effective on

December 3, 1997.

Issued in Renton, Washington, on

November 10, 1997.

Darrell M. Pederson,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 97–30103 Filed 11–17–97; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97–NM–285–AD; Amendment

39–10209; AD 97–24–02]

RIN 2120–AA64

Airworthiness Directives; Bombardier

Model CL–600–1A11, –2A12, and

–2B16 Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule; request for

comments.

SUMMARY: This amendment adopts a

new airworthiness directive (AD) that is

applicable to certain Bombardier Model

CL–600–1A11, –2A12, and –2B16 series

airplanes. This action requires repetitive

inspections to detect cracks of a certain

bulkhead web of the fuselage at certain

locations, and repair, if necessary. This

amendment is prompted by issuance of

mandatory continuing airworthiness

information by a foreign civil

airworthiness authority. The actions

specified in this AD are intended to

detect and correct cracking in the

pressure bulkhead at frame station (FS)

409.00, which could result in

uncontrolled depressurization of the

airplane and/or reduced structural

integrity of the fuselage.

DATES: Effective December 3, 1997.

The incorporation by reference of

certain publications listed in the

regulations is approved by the Director

of the Federal Register as of December

3, 1997.

Comments for inclusion in the Rules

Docket must be received on or before

December 18, 1997.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–103,

Attention: Rules Docket No. 97–NM–

285–AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055–4056.

The service information referenced in

this AD may be obtained from

Bombardier, Inc., Canadair, Aerospace

Group, P.O. Box 6087, Station

Centreville, Montreal, Quebec H3C 3G9,

Canada. This information may be

examined at the FAA, Transport

Airplane Directorate, 1601 Lind

Avenue, SW., Renton, Washington; or at

the FAA, Engine and Propeller

Directorate, New York Aircraft

Certification Office, 10 Fifth Street,

Third Floor, Valley Stream, New York;

or at the Office of the Federal Register,

800 North Capitol Street, NW., suite

700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Franco Pieri, Aerospace Engineer,

Airframe and Propulsion Branch, ANE–

171, FAA, Engine and Propeller

Directorate, New York Aircraft

Certification Office, 10 Fifth Street,

Third Floor, Valley Stream, New York

11581; telephone (516) 256–7526; fax

(516) 568–2716.

SUPPLEMENTARY INFORMATION: Transport

Canada Aviation (TCA), which is the

airworthiness authority for Canada,

recently notified the FAA that an unsafe

condition may exist on certain

Bombardier Model CL–600–1A11,

–2A12, and –2B16 series airplanes. TCA

advises that the structural configuration

of these airplanes at frame station (FS)

409.00 is similar to that of Bombardier

Model CL–600–2B19 (Regional Jet

Series 100 and 200) series airplanes,

which was shown to have a

pressurization problem caused by

fatigue cracking in the underfloor

pressure bulkhead of the fuselage. TCA

has received several reports of cracking

at this same location on Bombardier

Model CL–600–1A11, –2A12, and

–2B16 series airplanes. This condition,

if not corrected, could result in

uncontrolled depressurization of the

airplane and/or reduced structural

integrity of the fuselage.

Other Relevant Rules

The FAA previously issued AD 97–

14–11, amendment 39–10082 (62 FR

38206, July 17, 1997), which requires

repetitive inspections to detect cracks of

a certain bulkhead web of the fuselage

at certain locations, and repair, if

necessary. That AD applies to certain

Bombardier Model CL–600–2B19

(Regional Jet Series 100 and 200) series

airplanes.

Explanation of Relevant Service

Information

The manufacturer has issued Canadair

Challenger Service Bulletin 601–0501,

dated September 12, 1997 [for Model

CL–600–2A12 (CL–601) and CL–600–

2B16 (CL–601–3A/–3R) series

airplanes]; Service Bulletin 604–53–007,

dated September 30, 1997 [for Model

CL–600–2B16 (CL–604) series

airplanes]; and Service Bulletin 600–

0679, dated September 12, 1997 [for

Model CL–600–1A11 (CL–600) series

airplanes]. These service bulletins

describe procedures for repetitive

detailed visual inspections to detect

fatigue cracking of the underfloor

pressure bulkhead at FS 409.00, and

repair, if necessary. TCA classified these

service bulletins as mandatory and

issued Canadian airworthiness directive

CF–97–16, dated September 25, 1997, in

order to assure the continued

airworthiness of these airplanes in

Canada.

FAA’s Conclusions

These airplane models are

manufactured in Canada and are type

certificated for operation in the United

States under the provisions of section

21.29 of the Federal Aviation

Regulations (14 CFR 21.29) and the

applicable bilateral airworthiness

agreement. Pursuant to this bilateral

airworthiness agreement, TCA has kept

the FAA informed of the situation

described above. The FAA has

examined the findings of TCA, reviewed

all available information, and

determined that AD action is necessary

for products of this type design that are
Federal Register / Vol. 62, No. 222 / Tuesday, November 18, 1997 / Rules and Regulations 61437

certificated for operation in the United

States.

Explanation of Requirements of Rule

Since an unsafe condition has been

identified that is likely to exist or

develop on other airplanes of the same

type design registered in the United

States, this AD requires accomplishment

of the inspections specified in the

service bulletins described previously.

In addition, this AD requires repair, if

necessary, in accordance with a method

approved by the FAA.

Operators should note that, while it is

not the FAA’s normal policy to allow

flight with known cracks, this AD does

permit further flight with cracking

within certain limits. The results of a

review, conducted by the manufacturer,

revealed that cracking in the underfloor

pressure bulkhead of the fuselage will

not result in rapid decompression of the

airplane. Therefore, according to the

review, if the crack size limits are

strictly observed and if repetitive

inspections are performed at the

required intervals, cracks that grow

beyond the limits will be detected, and

corrective action taken, before they can

grow to a size that would create an

unacceptable risk of structural failure.

Transport Canada Aviation concurs

with the findings of this review. In

consideration of these findings and

based on the FAA’s criteria for flight

with known cracking, the FAA has

determined that further flight with

cracking within certain limits in the

center pressure bulkhead is permissible

for an interim period.

This is considered to be interim

action. The manufacturer has advised

that it currently is developing a

modification that will positively address

the unsafe condition addressed by this

AD. Once this modification is

developed, approved, and available, the

FAA may consider additional

rulemaking.

Determination of Rule’s Effective Date

Since a situation exists that requires

the immediate adoption of this

regulation, it is found that notice and

opportunity for prior public comment

hereon are impracticable, and that good

cause exists for making this amendment

effective in less than 15 days.

Comments Invited

Although this action is in the form of

a final rule that involves requirements

affecting flight safety and, thus, was not

preceded by notice and an opportunity

for public comment, comments are

invited on this rule. Interested persons

are invited to comment on this rule by

submitting such written data, views, or

arguments as they may desire.

Communications shall identify the

Rules Docket number and be submitted

in triplicate to the address specified

under the caption ADDRESSES. All

communications received on or before

the closing date for comments will be

considered, and this rule may be

amended in light of the comments

received. Factual information that

supports the commenter’s ideas and

suggestions is extremely helpful in

evaluating the effectiveness of the AD

action and determining whether

additional rulemaking action would be

needed.

Comments are specifically invited on

the overall regulatory, economic,

environmental, and energy aspects of

the rule that might suggest a need to

modify the rule. All comments

submitted will be available, both before

and after the closing date for comments,

in the Rules Docket for examination by

interested persons. A report that

summarizes each FAA-public contact

concerned with the substance of this AD

will be filed in the Rules Docket.

Commenters wishing the FAA to

acknowledge receipt of their comments

submitted in response to this rule must

submit a self-addressed, stamped

postcard on which the following

statement is made: ‘‘Comments to

Docket Number 97–NM–285–AD.’’ The

postcard will be date stamped and

returned to the commenter.

Regulatory Impact

The regulations adopted herein will

not have substantial direct effects on the

States, on the relationship between the

national government and the States, or

on the distribution of power and

responsibilities among the various

levels of government. Therefore, in

accordance with Executive Order 12612,

it is determined that this final rule does

not have sufficient federalism

implications to warrant the preparation

of a Federalism Assessment.

The FAA has determined that this

regulation is an emergency regulation

that must be issued immediately to

correct an unsafe condition in aircraft,

and that it is not a ‘‘significant

regulatory action’’ under Executive

Order 12866. It has been determined

further that this action involves an

emergency regulation under DOT

Regulatory Policies and Procedures (44

FR 11034, February 26, 1979). If it is

determined that this emergency

regulation otherwise would be

significant under DOT Regulatory

Policies and Procedures, a final

regulatory evaluation will be prepared

and placed in the Rules Docket. A copy

of it, if filed, 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

adding the following new airworthiness

directive:

97–24–02 Bombardier, Inc.: Amendment

39–10209. Docket 97–NM–285–AD.

Applicability: Model CL–600–1A11 (CL–

600) series airplanes, serial numbers 1004

through 1085 inclusive; Model CL–600–2A12

(CL–601) series airplanes, serial numbers

3001 through 3066 inclusive; Model CL–600–

2B16 (CL–601–3A/–3R) series airplanes,

serial numbers 5001 through 5194 inclusive;

Model CL–600–2B16 (CL–604) series

airplanes, serial numbers 5301 through 5352

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

otherwise modified, altered, or repaired in

the area subject to the requirements of this

AD. For airplanes that have been modified,

altered, or repaired so that the performance

of the requirements of this AD is affected, the

owner/operator must request approval for an

alternative method of compliance in

accordance with paragraph (c) of this AD.

The request should include an assessment of

the effect of the modification, alteration, or

repair on the unsafe condition addressed by

this AD; and, if the unsafe condition has not

been eliminated, the request should include

specific proposed actions to address it.

Compliance: Required as indicated, unless

accomplished previously.

To detect and correct fatigue cracking in

the underfloor pressure bulkhead of the

fuselage, which could result in uncontrolled

depressurization of the airplane and/or

reduced structural integrity of the fuselage,

accomplish the following:

(a) For Model CL–600–1A11 (CL–600)

airplanes: Prior to the accumulation of 1,900

total landings, or within 100 landings after

the effective date of this AD, whichever

occurs later, perform a detailed visual

inspection to detect cracks at frame station

(FS) 409 of the bulkhead web [part number

(P/N) 600–32014–71/–95/–105], in

accordance with Canadair Challenger Service
61438 Federal Register / Vol. 62, No. 222 / Tuesday, November 18, 1997 / Rules and Regulations

Bulletin 600–0679, dated September 12,

1997.

(1) If no crack is detected, repeat the

detailed visual inspection thereafter at

intervals not to exceed 600 landings.

(2) If any crack is detected and if all three

of the conditions specified in paragraphs

(a)(2)(i), (a)(2)(ii), and (a)(2)(iii) of this AD are

met, within 600 landings or 12 months after

the crack is detected, whichever occurs first,

repair the cracking in accordance with a

method approved by the Manager, New York

Aircraft Certification Office (ACO), FAA,

Engine and Propeller Directorate. Until the

repair is accomplished, repeat the detailed

visual inspection at intervals not to exceed

100 landings.

(i) No more than one crack exists at each

corner radius, as specified in the service

bulletin; and

(ii) No crack extends under the angles

having P/N 600–32014–13 and P/N 600–

32014–15 on the aft side of the bulkhead

web; and

(iii) No crack exists in angles having P/N

600–32014–13 and P/N 600–32014–15 on the

aft side of the bulkhead web.

(3) If any cracking other than that

identified in paragraph (a)(2) of this AD is

detected, prior to further flight, repair it in

accordance with a method approved by the

Manager, New York ACO.

(b) For Model CL–600–2A12 (CL–601), CL–

600–2B16 (CL–601–3A/–3R), and CL–600–

2B16 (CL–604) series airplanes: Prior to the

accumulation of 1,100 total landings, or

within 100 landings after the effective date of

this AD, whichever occurs later, perform a

detailed visual inspection to detect cracks at

FS 409 of the bulkhead web (P/N 600–32014–

105/–137), in accordance with Canadair

Challenger Service Bulletin 601–0501, dated

September 12, 1997 [for Model CL–600–2A12

(CL–601) and CL–600–2B16 (CL–601–3A/–

3R) series airplanes); or Canadair Challenger

Service Bulletin 604–53–007, dated

September 30, 1997 [for Model CL–600–2B16

(CL–604) series airplanes]; as applicable.

(1) If no crack is detected, repeat the

detailed visual inspection thereafter at

intervals not to exceed 600 landings.

(2) If any crack is detected and if all three

of the conditions specified in paragraphs

(b)(2)(i), (b)(2)(ii), and (b)(2)(iii) of this AD

are met, within 600 landings or 12 months

after the crack is detected, whichever occurs

first, repair the cracking in accordance with

a method approved by the Manager, New

York ACO. Until the repair is accomplished,

repeat the detailed visual inspection at

intervals not to exceed 100 landings.

(i) No more than one crack exists at each

corner radius, as specified in the service

bulletin; and

(ii) No crack extends under the angles

having P/N 600–32014–113 and P/N 600–

32014–115 on the aft side of the bulkhead

web; and

(iii) No crack exists in angles having P/N

600–32014–113 and P/N 600–32014–115 on

the aft side of the bulkhead web.

(3) If any cracking other than that

identified in paragraph (b)(2) of this AD is

detected, prior to further flight, repair it in

accordance with a method approved by the

Manager, New York ACO.

(c) An alternative method of compliance or

adjustment of the compliance time that

provides an acceptable level of safety may be

used if approved by the Manager, New York

ACO. Operators shall submit their requests

through an appropriate FAA Principal

Maintenance Inspector, who may add

comments and then send it to the Manager,

New York ACO.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the New York ACO.

(d) Special flight permits may be issued in

accordance with sections 21.197 and 21.199

of the Federal Aviation Regulations (14 CFR

21.197 and 21.199) to operate the airplane to

a location where the requirements of this AD

can be accomplished.

(e) The inspections shall be done in

accordance with Canadair Challenger Service

Bulletin 600–0679, dated September 12,

1997; Canadair Challenger Service Bulletin

601–0501, dated September 12, 1997; or

Canadair Challenger Service Bulletin 604–

53–007, dated September 30, 1997; as

applicable. This incorporation by reference

was approved by the Director of the Federal

Register in accordance with 5 U.S.C. 552(a)

and 1 CFR part 51. Copies may be obtained

from Bombardier, Inc., Canadair, Aerospace

Group, P.O. Box 6087, Station Centre-ville,

Montreal, Quebec H3C 3G9, Canada. Copies

may be inspected at the FAA, Transport

Airplane Directorate, 1601 Lind Avenue,

SW., Renton, Washington; or at the FAA,

Engine and Propeller Directorate, New York

Aircraft Certification Office, 10 Fifth Street,

Third Floor, Valley Stream, New York; or at

the Office of the Federal Register, 800 North

Capitol Street, NW., suite 700, Washington,

DC.

Note 3: The subject of this AD is addressed

in Canadian airworthiness directive CF–97–

16, dated September 25, 1997.

(f) This amendment becomes effective on

December 3, 1997.

Issued in Renton, Washington, on

November 10, 1997.

Darrell M. Pederson,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 97–30104 Filed 11–17–97; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97–ANE–40–AD; Amendment

39–10162; AD 97–21–09]

RIN 2120–AA64

Airworthiness Directives; Allison

Engine Company Model 250–C47B

Turboshaft Engines

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule; request for

comments.

SUMMARY: This amendment supersedes

existing airworthiness directive (AD)

96–24–09, applicable to Allison Engine

Company Model 250–C47B turboshaft

engines, that currently requires

replacing the engine main electrical

harness assembly with an improved

assembly, disabling the overspeed

solenoid, inspecting the engine control

unit (ECU) internal PW10 voltage to

determine electrical noise

characteristics, and replacing units not

considered serviceable. In addition, the

existing AD requires adding a placard to

the helicopter instrument panel

notifying the pilot that the overspeed

protection system is disabled and

removes a placard which was required

by priority letter AD 96–21–12; revises

the Bell Helicopter Textron, A Division

of Textron Canada Ltd. (BHTC) Model

407 Rotorcraft Flight Manual (RFM);

and requires maintenance actions to

clear the ECU of faults prior to each

flight. This amendment continues to

require replacing the engine main

electrical harness assembly with an

improved assembly, but adds the

requirements to install a new

hydromechanical unit (HMU) and ECU,

removing the placard notifying the pilot

that the overspeed protection system is

disabled, and revises the BHTC Model

407 RFM. This amendment is prompted

by the development of overspeed

protection system modifications to

reactivate the overspeed solenoid in

conjunction with raising the power

turbine overspeed trip point and

revising the overspeed system to default

to a minimum fuel flow in the event of

its activation. The actions specified by

this AD are intended to prevent

uncommanded inflight engine

shutdowns, which can result in

autorotation, forced landing, and

possible loss of the helicopter.

DATES: Effective December 3, 1997.

The incorporation by reference of

certain publications listed in the

regulations is approved by the Director

of the Federal Register as of December

3, 1997.

Comments for inclusion in the Rules

Docket must be received on or before

January 20, 1998.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), New England

Region, Office of the Assistant Chief

Counsel, Attention: Rules Docket No.

97–ANE–40–AD, 12 New England

Executive Park, Burlington, MA 01803–

5299. Comments may also be sent via

the Internet using the following address:

‘‘9-ad-engineprop@faa.dot.gov’’.