Federal Register / Vol. 60, No. 11 / Wednesday, January 18, 1995 / Proposed Rules 3581

14 CFR Part 39

[Docket No. 94–NM–107–AD]

Airworthiness Directives; British

Aerospace Model ATP Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes the

supersedure of an existing airworthiness

directive (AD), applicable to all British

Aerospace Model ATP series airplanes,

that currently requires inspections to

detect cracking of the aft end of the

wing rib boom angles on the left and

right engine, and repair or replacement

of the wing rib boom angle assemblies,

if necessary. That AD was prompted by

the detection of cracks in the engine

outboard rib boom angles at the main

landing gear (MLG) actuator attachment

point. The actions specified by that AD

are intended to prevent structural

failure of the actuator attachment point,

which could lead to collapse of the

MLG. This action would limit the

applicability of the rule to only a certain

number of airplanes; revise the initial

inspection threshold, depending on

whether or not certain modifications

have been accomplished on the boom

angles; and would require that modified

boom angles be installed whenever

replacement is necessary.

DATES: Comments must be received by

February 22, 1995.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–103,

Attention: Rules Docket No. 94–NM–

107–AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055–4056.

Comments may be inspected at this

location between 9:00 a.m. and 3:00

p.m., Monday through Friday, except

Federal holidays.

The service information referenced in

the proposed rule may be obtained from

Jetstream Aircraft, Inc., P.O. Box 16029,

Dulles International Airport,

Washington, DC 20041–6029. This

information may be examined at the

FAA, Transport Airplane Directorate,

1601 Lind Avenue, SW., Renton,

Washington.

FOR FURTHER INFORMATION CONTACT:

William Schroeder, Aerospace Engineer,

Standardization Branch, ANM–113,

FAA, Transport Airplane Directorate,

1601 Lind Avenue, SW., Renton,

Washington 98055–4056; telephone

(206) 227–2148; fax (206) 227–1320.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to

participate in the making of the

proposed 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 above. All communications

received on or before the closing date

for comments, specified above, will be

considered before taking action on the

proposed rule. The proposals contained

in this notice may be changed in light

of the comments received.

Comments are specifically invited on

the overall regulatory, economic,

environmental, and energy aspects of

the proposed 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

summarizing each FAA-public contact

concerned with the substance of this

proposal will be filed in the Rules

Docket.

Commenters wishing the FAA to

acknowledge receipt of their comments

submitted in response to this notice

must submit a self-addressed, stamped

postcard on which the following

statement is made: ‘‘Comments to

Docket Number 94–NM–107–AD.’’ The

postcard will be date stamped and

returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this

NPRM by submitting a request to the

FAA, Transport Airplane Directorate,

ANM–103, Attention: Rules Docket No.

94–NM–107–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

On July 14, 1993, the FAA issued AD

93–14–08, amendment 39–8632 (58 FR

42194, August 9, 1993), applicable to all

British Aerospace Model ATP series

airplanes, to require inspections to

detect cracking of the aft end of the

wing rib boom angles at the left and

right engine, and repair or replacement

of the wing rib boom angle assemblies,

if necessary. The initial inspection is

required within 400 hours time-inservice after the effective date of the AD,

or within 12 months since airplane

manufacture, whichever is later. If no

cracks are detected, the inspection is

required to be repeated at intervals of

3,000 landings or 12 months, whichever

occurs sooner. If cracks are detected, the

boom angle(s) must be repaired or

replaced; or, if cracking is within certain

limits, the area may be reinspected for

a period of time until the boom angle is

repaired or replaced.

The issuance of AD 93–14–08 was

prompted by the detection of cracks in

the engine outboard rib boom angles at

the main landing gear (MLG) actuator

attachment point. The requirements of

that AD are intended to prevent

structural failure of the actuator

attachment point, which could lead to

collapse of the MLG.

Since the issuance of that AD, the

Civil Aviation Authority (CAA), which

is the airworthiness authority for the

United Kingdom, has advised the FAA

that airplanes on which modified engine

rib boom angles have been installed may

be less susceptible to the subject

cracking problems initially. The

modified boom angles are of a

configuration that has improved

resistance to cracking. Therefore, for

airplanes on which this modification is

installed, the CAA advises that the

initial inspection for cracking may be

extended beyond that which is currently

required.

British Aerospace has issued Service

Bulletin ATP–57–13, Revision 5, dated

June 3, 1994. This revision is essentially

the same as Revision 1, which was

specified in AD 93–14–08 as the

appropriate source of service

information. Like Revision 1, new

Revision 5 describes procedures for

repetitive detailed visual inspection to

detect cracking of the aft end of the

engine outboard rib boom angles under

the wing rib immediately outboard of

the left and right engine; and describes

procedures for replacement of cracked

rib boom angle assemblies. Revision 5

differs from Revision 1 in that it

recommends that the initial inspection

of airplanes that are equipped with

modified engine rib boom angles

(Modification 10313A) be postponed

until the modified boom angles have

accumulated 30,000 landings. The CAA

has classified this service bulletin as

mandatory.

British Aerospace also has issued

Service Bulletin ATP 57–16–10313A,

Revision 1, dated July 2, 1994 (as

corrected by Errata No. 2, dated August

30, 1994), which describes procedures

for installing Modification 10313A. This

modification entails installation of new

outboard and inboard rib boom angles

on the left wing and right wing that are

less susceptible to cracking. The CAA

classified this service bulletin as

‘‘optional.’’

In light of this, the FAA has

determined that AD 93–14–08 must be

amended to allow airplanes on which

Modification 10313A is installed to be

inspected at a compliance threshold that

is extended beyond that which is
3582 Federal Register / Vol. 60, No. 11 / Wednesday, January 18, 1995 / Proposed Rules

currently required. Additionally, the

FAA has determined that cracked boom

angles must be replaced with modified

boom angles in order to increase the

time-in-service prior to the onset of

cracking, and to reduce the reliance on

repetitive inspections in order to assure

safety over a long period of time.

This airplane model is manufactured

in the United Kingdom and is 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, the CAA has

kept the FAA informed of the situation

described above. The FAA has

examined the findings of the CAA,

reviewed all available information, and

determined that AD action is necessary

for products of this type design that are

certificated for operation in the United

States.

The proposed AD would supersede

AD 93–14–08 to continue to require

repetitive visual inspections to detect

cracking of the aft end of the wing rib

boom angles on the wing rib outboard

of the left and right engine, and repair

or replacement of cracked rib boom

angle assemblies. This proposal would

revise the compliance time for the

initial inspection of airplanes on which

Modification 10313A has been

accomplished. The inspection actions

would be required to be accomplished

in accordance with Service Bulletin

ATP–57–13, Revision 1, dated January

15, 1993, or Revision 5, dated June 3,

1994.

This proposal would require that any

cracked boom angle that is replaced,

must be replaced with a modified boom

angle in accordance with British

Aerospace Service Bulletin ATP–51–16–

10313A, Revision 1, dated June 3 1994.

Any cracked boom angle that is

repaired, must be repaired in

accordance with a method approved by

the FAA.

Additionally, this proposal would

limit the applicability of the rule to only

Model ATP airplanes having serial

numbers 2002 to 2063, inclusive.

Airplanes that are produced subsequent

to serial number 2063 will be modified

in production to include the equivalent

of Modification 10313A, and will

contain in their Manufacturer’s

Recommended Maintenance Program

the inspections and inspection intervals

that would be required by this AD. The

FAA has determined that these

inspections must be mandated (via this

proposed AD) for in-service airplanes

having serial numbers 2002 through

2063 on which Modification 10313A

has been installed (post-production),

since the Manufacturer’s Recommended

Maintenance Program currently

applicable to these airplanes does not

adequately address inspections of the

modified boom angles.

Additionally, this proposed

superseding AD has been reformatted to

simplify and clarify the required

actions.

The FAA estimates that 10 airplanes

of U.S. registry would be affected by this

proposed AD. The inspections that are

currently required by AD 93–14–08 take

approximately 2 work hours per

airplane to accomplish. The average

labor rate is $60 per work hour. Based

on these figures, the total cost impact of

the current inspection requirements AD

on U.S. operators is estimated to be

$1,200, or $120 per airplane, per

inspection cycle.

The total cost impact figure discussed

above is based on assumptions that no

operator has yet accomplished any of

the proposed requirements of this AD

action, and that no operator would

accomplish those actions in the future if

this AD were not adopted. However,

since AD 93–14–08 became effective on

September 3, 1993, the FAA assumes

that at least the initial inspection

already has been performed on several

of the affected airplanes. Thus, the total

cost impact of this proposed AD may be

reduced by the amount of the costs

associated with those inspections that

have already been accomplished.

Additionally, since this proposed AD

would extend the compliance time for

the initial inspection of some airplanes,

it has the effect of reducing the

economic burden for operators of those

airplanes, since it would preclude

scheduling an airplane for inspections

at a time earlier than is necessary.

Should replacement of the boom

angles with modified boom angles be

necessary, it would require

approximately 150 work hours to

accomplish, at an average labor charge

of $60 per work hour. Required parts

would cost approximately $3,800 per

airplane.

The regulations proposed herein

would 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

proposal would not have sufficient

federalism implications to warrant the

preparation of a Federalism Assessment.

For the reasons discussed above, I

certify that this proposed regulation (1)

is not a ‘‘significant regulatory action’’

under Executive Order 12866; (2) is not

a ‘‘significant rule’’ under the DOT

Regulatory Policies and Procedures (44

FR 11034, February 26, 1979); and (3) if

promulgated, 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 copy of the draft

regulatory evaluation prepared for this

action is contained in the Rules Docket.

A copy of it may be obtained by

contacting the Rules Docket at the

location provided under the caption

ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation

safety, Safety.

The Proposed Amendment

Accordingly, pursuant to the

authority delegated to me by the

Administrator, the Federal Aviation

Administration proposes to amend 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. App. 1354(a), 1421

and 1423; 49 U.S.C. 106(g); and 14 CFR

11.89.

§ 39.13 [Amended]

2. Section 39.13 is amended by

removing amendment 39–8632 (58 FR

42194, August 9, 1993), and by adding

a new airworthiness directive (AD), to

read as follows:

British Aerospace: Docket 94–NM–107–AD.

Supersedes AD 93–14–08, Amendment

39–8632.

Applicability: Model ATP series airplanes;

serial numbers 2002 through 2063, 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 use the authority

provided in paragraph (j) to request approval

from the FAA. This approval may address

either no action, if the current configuration

eliminates the unsafe condition; or different

actions necessary to address the unsafe

condition described in this AD. Such a

request should include an assessment of the

effect of the changed configuration on the

unsafe condition addressed by this AD. In no

case does the presence of any modification,

alteration, or repair remove any airplane from

the applicability of this AD.

Compliance: Required as indicated, unless

accomplished previously.
Federal Register / Vol. 60, No. 11 / Wednesday, January 18, 1995 / Proposed Rules 3583

To prevent structural failure of the actuator

attachment point, which could lead to

collapse of the main landing gear (MLG),

accomplish the following:

(a) Conduct a detailed visual inspection to

detect cracking of the aft end of the engine

outboard rib boom angles under the wing rib

outboard of the left and right engine, in

accordance with British Aerospace Service

Bulletin ATP–57–13, Revision 1, dated

January 15, 1993; or Revision 5, dated June

3, 1994; at the applicable time indicated

below.

(1) For airplanes on which Modification

10313A (reference British Aerospace Service

Bulletin ATP–56–16–1013A, Revision 1,

dated July 2, 1994) has not been

accomplished: Conduct the initial inspection

within 400 hours time-in-service after

September 8, 1993 (the effective date of AD

93–14–08, amendment 39–8632), or within

12 months since airplane manufacture,

whichever occurs later.

(2) For airplanes on which Modification

10313A has been accomplished (modified

inboard and outboard boom angles on both

the left wing and right wing): Conduct the

initial inspection prior to the accumulation

of 30,000 landings on the boom angle

assembly or within 12 months after the

effective date of this AD, whichever occurs

later.

(b) For the purposes of compliance with

this AD, the following apply:

(1) Repair of cracked rib boom angles shall

be accomplished in accordance with a

method approved by the Manager,

Standardization Branch, ANM–113, FAA,

Transport Airplane Directorate.

(2) Replacement of cracked rib boom angle

assemblies with modified assemblies shall be

accomplished in accordance with British

Aerospace Service Bulletin ATP–57–16–

10313A, Revision 1, dated July 2, 1994 (as

corrected by Erratum 2, dated August 30,

1994). Prior to the accumulation of 30,000

landings on the replaced (modified) boom

angle assembly, repeat the inspection in

accordance with paragraph (a) of this AD.

(c) If no crack is detected: Repeat the

detailed visual inspection at intervals not to

exceed 3,000 landings or 12 months,

whichever occurs first.

(d) If any crack is detected on only one rib

boom angle, and that crack does not extend

beyond bolt hole X: Repeat the detailed

visual inspection of the rib boom angle for

additional crack propagation at intervals not

to exceed 300 hours time-in-service.

(1) If no additional crack propagation is

detected during any of the repetitive

inspections: Within 6 months after discovery

of the crack, either repair the rib boom angle

or replace the rib boom angle assembly in

accordance with paragraph (b) of this AD.

(2) If any of the repetitive inspections

reveal that crack propagation has reached or

extends beyond bolt hole Y or into bolt hole

A: Prior to further flight, either repair the rib

boom angle or replace the rib boom assembly

in accordance with paragraph (b) of this AD.

(e) If any crack is detected on only one rib

boom angle, and that crack extends beyond

bolt hole X, but not beyond bolt hole Y or

down towards bolt hole A: Repeat the

detailed visual inspection of the rib boom

angle for additional crack propagation at

intervals not to exceed 100 hours time-inservice.

(1) If no additional crack propagation is

detected during any of the repetitive

inspections: Within 3 months after discovery

of the crack, either repair the rib boom angle

or replace the rib boom angle assembly in

accordance with paragraph (b) of this AD.

(2) If any of the repetitive inspections

reveal that crack propagation has reached or

extends beyond bolt hole Y or into bolt hole

A: Prior to further flight, either repair the rib

boom angle or replace the rib boom angle

assembly in accordance with paragraph (b) of

this AD.

(f) If any crack is detected on only one rib

boom angle, and that crack extends beyond

bolt hole Y or into bolt hole A: Repeat the

detailed visual inspection of the rib boom

angle for additional crack propagation at

intervals not to exceed 50 hours time-inservice.

(1) If no additional crack propagation is

detected during any of the repetitive

inspections: Within 1 month after discovery

of the crack, either repair the rib boom angle

or replace the rib boom angle assembly in

accordance with paragraph (b) of this AD.

(2) If any of the repetitive inspections

reveal that crack propagation has reached or

extends beyond bolt hole Y or into bolt hole

A: Prior to further flight, either repair the rib

boom angle or replace the rib boom angle

assembly in accordance with paragraph (b) of

this AD.

(g) If any crack is detected on both rib

boom angles, and cracks do not extend

beyond bolt hole X: Repeat the detailed

visual inspection of the rib boom angles for

additional crack propagation at intervals not

to exceed 100 hours time-in-service.

(1) If no additional crack propagation is

detected during any of the repetitive

inspections: Within 3 months after discovery

of the cracks, either repair the rib boom

angles or replace the rib boom angle

assembly in accordance with paragraph (b) of

this AD.

(2) If any of the repetitive inspections

reveal that crack propagation has reached or

extends beyond bolt hole Y or into bolt hole

A: Prior to further flight, either repair the rib

boom angles or replace the rib boom angle

assembly in accordance with paragraph (b) of

this AD.

(h) If any crack is detected on both rib

boom angles, and cracks extend beyond bolt

hole X, but not beyond bolt hole Y or down

towards bolt hole A: Repeat the detailed

visual inspection of the rib boom angles for

additional crack propagation at intervals not

to exceed 50 hours time-in-service.

(1) If no additional crack propagation is

detected during any of the repetitive

inspections: Within 1 month after discovery

of the cracks, either repair the rib boom

angles or replace the rib boom angle

assembly in accordance with paragraph (b) of

this AD.

(2) If any of the repetitive inspections

reveal that crack propagation has reached or

extends beyond bolt hole Y or into bolt hole

A: Prior to further flight, either repair the rib

boom angles or replace the rib boom angle

assembly in accordance with paragraph (b) of

this AD.

(i) If any crack is detected on both rib boom

angles, and cracks extend beyond bolt hole

Y or into bolt hole A: Prior to further flight,

either repair the rib boom angles or replace

the rib boom angle assembly in accordance

with paragraph (b) of this AD.

(j) 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,

Standardization Branch, ANM–113, 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, Standardization

Branch, ANM–113.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Standardization Branch,

ANM–113.

(k) 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.

Issued in Renton, Washington, on January

11, 1995.

Darrell M. Pederson,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 95–1131 Filed 1–17–95; 8:45 am]

BILLING CODE 4910–13–U

14 CFR Part 39

[Docket No. 94–NM–200–AD]

Airworthiness Directives; Dassault

Aviation Model Mystere-Falcon 900

Series Airplanes Equipped With

Fairchild Model F800 Flight Data

Recorders, Installed in Accordance

With Supplemental Type Certificate

(STC) SA7255SW–D

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes the

adoption of a new airworthiness

directive (AD) that is applicable to

certain Dassault Aviation Model

Mystere-Falcon 900 series airplanes.

This proposal would require

modification of the electrical power

installation of the flight data recorder,

replacement of the currently installed

socket box for ground power with a

modified socket box, and performance

of checks and tests. This proposal is

prompted by reports of the generators

shutting down due to an intermittent

relay failure of the flight data recorders.

The actions specified by the proposed

AD are intended to prevent loss of