Airworthiness Directives; Dassault Aviation Model Mystere-Falcon 50 Series Airplanes

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 93-NM-159-AD; Amendment 39-8963; AD 94-14-15]

Airworthiness Directives; Dassault Aviation Model Mystere-Falcon

50 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD),

applicable to certain Dassault Aviation Model Mystere-Falcon 50 series

airplanes, that requires replacement of certain attachment clamps

installed on the engine exhaust ducts with improved clamps. This

amendment is prompted by reports of failures of certain attachment

clamps due to fatigue cracking. The actions specified by this AD are

intended to prevent such failures, which could cause exhaust gas to

leak and, subsequently, could trigger a false engine fire alarm.

DATES: Effective August 5, 1994.

The incorporation by reference of certain publications listed in

the regulations is approved by the Director of the Federal Register as

of August 5, 1994.

ADDRESSES: The service information referenced in this AD may be

obtained from Falcon Jet Corporation, Customer Support Department,

Teterboro Airport, Teterboro, New Jersey 07608. This information may be

examined at the Federal Aviation Administration (FAA), Transport

Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton,

Washington; or at the Office of the Federal Register, 800 North Capitol

Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Stephen Slotte, Aerospace Engineer,

ANM-113, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW.,

Renton, Washington 98055-4056; telephone (206) 227-2797; fax (206) 227-

1320.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39) to include an airworthiness

directive (AD) that is applicable to certain Dassault Aviation Model

Mystere-Falcon 50 series airplanes was published in the Federal

Register on November 22, 1993 (58 FR 61636). That action proposed to

require replacement of certain attachment clamps installed on the

engine exhaust ducts with improved clamps.

Interested persons have been afforded an opportunity to participate

in the making of this amendment. Due consideration has been given to

the comments received.

One commenter requests that paragraph (b) of the rule be revised to

indicate that instructions for verifying that the clamp screw is

straight are contained in Dassault Aviation Service Bulletin F50-229

(F50-54-13), Revision 1, dated July 21, 1993 (which is the service

bulletin cited elsewhere in the proposed rule). The commenter notes

that those instructions indicate that the verification cannot be made

if the clamp is installed; the clamp must be removed from the tail pipe

attachment in order to determine if it is bent or not. The FAA concurs

with the commenter's request and has revised the final rule

accordingly.

After careful review of the available data, including the comments

noted above, the FAA has determined that air safety and the public

interest require the adoption of the rule with the change previously

described. The FAA has determined that this change will neither

increase the economic burden on any operator nor increase the scope of

the AD.

The FAA estimates that 133 airplanes of U.S. registry will be

affected by this AD, that it will take approximately 1 work hour per

airplane to accomplish the required actions, and that the average labor

rate is $55 per work hour. Required parts will be provided by the

manufacturer at no cost to operators. Based on these figures, the total

cost impact of the AD on U.S. operators is estimated to be $7,315, or

$55 per airplane.

The total cost impact figure discussed above is based on

assumptions that no operator has yet accomplished any of the

requirements of this AD action, and that no operator would accomplish

those actions in the future if this AD were not adopted.

The 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.

For the reasons discussed above, I certify that this action (1) is

not a ``significant regulatory action'' under Executive Order 12866;

(2) is not a ``significant rule'' under DOT Regulatory Policies and

Procedures (44 FR 11034, February 26, 1979); and (3) will not have a

significant economic impact, positive or negative, on a substantial

number of small entities under the criteria of the Regulatory

Flexibility Act. A final evaluation has been prepared for this action

and it is contained in the Rules Docket. A copy of it may be obtained

from the Rules Docket at the location provided under the caption

``ADDRESSES.''

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by

reference, Safety.

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the

Administrator, the Federal Aviation Administration amends part 39 of

the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C.

106(g); and 14 CFR 11.89.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

94-14-15 Dassault Aviation: Amendment 39-8963. Docket 93-NM-159-AD.

Applicability: Model Mystere-Falcon 50 series airplanes, serial

numbers 2 through 216, inclusive; equipped with exhaust duct

attachment clamps, part number (P/N) NH1002299-10 or P/N NH1007763-

10; certificated in any category.

Compliance: Required as indicated, unless accomplished

previously.

To prevent failure of attachment clamps installed on the engine

exhaust ducts, which could cause exhaust gas to leak and,

subsequently, could trigger a false engine fire alarm, accomplish

the following:

(a) For airplanes equipped with exhaust duct attachment clamps

having P/N NH1002299-10: Within 300 flight hours after the effective

date of this AD, or within 6 months after the effective date of this

AD, whichever occurs first, replace attachment clamps having P/N

NH1002299-10 with attachment clamps having P/N NH1007763-10, in

accordance with Dassault Aviation Service Bulletin F50-229 (F50-54-

13), Revision 1, dated July 21, 1993.

(b) For airplanes equipped with exhaust duct attachment clamps

having P/N NH1007763-10: Within 1,400 flight hours after the

effective date of this AD, inspect the attachment clamps installed

on the engine exhaust ducts to verify if the clamp screw is straight

(not bent), in accordance with Dassault Aviation Service Bulletin

F50-229 (F50-54-13), Revision 1, dated July 21, 1993.

(1) If the clamp screw is straight, prior to further flight,

verify if the tightening torque value of the screw is marked on the

attachment clamp as follows: ``NORMAL NET TORQUE 100-120 IN-LBS.''

(i) If the marking is as specified in paragraph (b)(1) of this

AD, no further action is required.

(ii) If the marking is not as specified in paragraph (b)(1) of

this AD, prior to further flight, erase the incorrect marking and

replace it with the correct tightening torque value.

(iii) After correcting the marking, prior to further flight,

ensure that the clamp screw is secured to the tightening torque

value specified in paragraph (b)(1) of this AD.

(2) If the clamp screw is bent, prior to further flight, replace

the discrepant attachment clamp with a new attachment clamp having

the same part number, in accordance with the Accomplishment

Instructions of Dassault Aviation Service Bulletin F50-229 (F50-54-

13), Revision 1, dated July 21, 1993.

(c) As of the effective date of this AD, no person shall install

an exhaust duct attachment clamp having P/N NH1007763-10 on any

airplane, unless that attachment clamp is marked ``NORMAL NET TORQUE

100-120 IN-LBS.''

(d) 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.

(e) 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.

(f) The actions shall be done in accordance with Dassault

Aviation Service Bulletin F50-229 (F50-54-13), Revision 1, dated

July 21, 1993. 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 Falcon Jet

Corporation, Customer Support Department, Teterboro Airport,

Teterboro, New Jersey 07608. 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.

(g) This amendment becomes effective on August 5, 1994.

Issued in Renton, Washington, on June 28, 1994.

Darrell M. Pederson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-16157 Filed 7-5-94; 8:45 am]

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