Airworthiness Directives; Eurocopter Deutschland (Eurocopter) Model EC135 Helicopters

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-SW-38-AD; Amendment 39-11217; AD 99-12-01]

RIN 2120-AA64

Airworthiness Directives; Eurocopter Deutschland (Eurocopter)

Model EC135 Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This document publishes in the Federal Register an amendment

adopting Airworthiness Directive (AD) 99-12-01, which was sent

previously to all known U.S. owners and operators of Eurocopter Model

EC135 helicopters by individual letters. This AD requires initial and

repetitive visual inspections and one dye-penetrant inspection of the

main rotor hub shaft (shaft) for cracks. If a crack is found during any

of the inspections, this AD requires replacing the shaft with an

airworthy shaft before further flight. This amendment is prompted by

the discovery of fatigue cracks on the shaft of a helicopter. The

actions specified by this AD are intended to detect fatigue cracks in

the shaft that could lead to shaft failure and subsequent loss of

control of the helicopter.

DATES: Effective July 16, 1999, to all persons except those persons to

whom it was made immediately effective by Priority Letter AD 99-12-01,

issued on May 27, 1999, which contained the requirements of this

amendment.

Comments for inclusion in the Rules Docket must be received on or

before August 30, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Office of the Regional Counsel, Southwest Region,

Attention: Rules Docket No. 99-SW-38-AD, 2601 Meacham Blvd., Room 663,

Fort Worth, Texas 76137.

FOR FURTHER INFORMATION CONTACT: Mike Mathias, Aerospace Engineer, FAA,

Rotorcraft Directorate, Rotorcraft Standards Staff, 2601 Meacham Blvd.,

Fort Worth, Texas 76137, telephone (817) 222-5123, fax (817) 222-5961.

SUPPLEMENTARY INFORMATION: On May 27, 1999, the FAA issued Priority

Letter AD 99-12-01, applicable to Eurocopter Model EC135 helicopters,

which requires initial and repetitive visual inspections and one dye-

penetrant inspection of the shaft for cracks. If a crack is found

during any of the inspections, the AD requires replacing the shaft with

an airworthy shaft before further flight. That action was prompted by

the discovery of fatigue cracks on the shaft of a helicopter. This

condition, if not corrected, could result in failure of the shaft and

subsequent loss of control of the helicopter.

Eurocopter has issued Eurocopter EC135 Alert Service Bulletin (ASB)

EC 135-62A-004, dated May 5, 1999, which specifies inspecting the shaft

for cracks. The Luftfahrt-Bundesamt (LBA), which is the airworthiness

authority for the Federal Republic of Germany, classified this service

bulletin as mandatory and issued AD 1999-185, dated May 6, 1999, to

assure the continued airworthiness of these helicopters in the Federal

Republic of Germany. Eurocopter later issued ASB EC135-62A-004, Rev. 1,

dated May 7, 1999.

Since the unsafe condition described is likely to exist or develop

on other Eurocopter Model EC135 helicopters of the same type design,

the FAA issued Priority Letter AD 99-12-01 to detect fatigue cracks in

the shaft that could lead to shaft failure and subsequent loss of

control of the helicopter. The AD requires initial and repetitive

visual inspections and one dye-penetrant inspection of the shaft for

cracks. The short compliance time involved is required because the

previously described critical unsafe condition can adversely affect the

structural integrity of the helicopter. Therefore, inspecting the shaft

for cracks is required before further flight and this AD must be issued

immediately.

Since it was found that immediate corrective action was required,

notice and opportunity for prior public comment thereon were

impracticable

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and contrary to the public interest, and good cause existed to make the

AD effective immediately by individual letters issued on May 27, 1999,

to all known U.S. owners and operators of Eurocopter Model EC135

helicopters. These conditions still exist, and the AD is hereby

published in the Federal Register as an amendment to section 39.13 of

the Federal Aviation Regulations (14 CFR 39.13) to make it effective to

all persons.

The FAA estimates that 10 helicopters will be affected by this AD;

that it will take approximately 0.5 work hour per helicopter to perform

the visual inspections, 1 work hour per helicopter to perform the dye-

penetrant inspection, 10 work hours to replace the shaft, if necessary;

and that the average labor rate is $60 per work hour. Required parts

will cost approximately $25,000 per shaft. Based on these figures, the

total cost impact of the AD on U.S. operators is estimated to be

$55,900 per year, assuming the initial inspection, one dye-penetrant

inspection, and 100 visual inspections per year on each helicopter, and

one shaft replacement in the fleet.

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 should 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 No. 99-SW-38-AD.'' The postcard will be date stamped and

returned to the commenter.

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, 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 and 44701.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding a new airworthiness directive

to read as follows:

AD 99-12-01 Eurocopter Deutschland GmbH: Amendment 39-11217. Docket

No. 99-SW-38-AD.

Applicability: Model EC135 helicopter with main rotor hub shaft

(shaft), part number (P/N) L623M100S 101, installed, certificated in

any category.

Note 1: This AD applies to each helicopter 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 helicopters 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 a fatigue crack in the shaft that could lead to shaft

failure and subsequent loss of control of the helicopter, accomplish

the following:

(a) Before further flight, and thereafter, at intervals not to

exceed 15 hours time-in-service (TIS), visually inspect the shaft,

P/N L623M100S 101, for any crack in the area marked in Figure 1.

Clean the shaft before using a bright light source to inspect for

cracks. If any crack is found, replace the shaft with an airworthy

shaft before further flight.

(b) Within 10 hours TIS, conduct a one-time dye-penetrant

inspection of the shaft using the MIL-STD-6866 or ASTM-E-1417

procedure in the area shown in Figure 1. If any crack is found,

replace the shaft with an airworthy shaft before further flight.

Note 2: Eurocopter EC 135 Alert Service Bulletin EC 135-62A-004,

Rev. 1, dated May 7, 1999, pertains to the subject of this AD.

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(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, Rotorcraft Standards Staff, FAA,

Rotorcraft Directorate. Operators shall submit their requests

through an FAA Principal Maintenance Inspector, who may concur or

comment and then send it to the Manager, Rotorcraft Standards Staff.

Note 3: Information concerning the existence of approved

alternative methods of compliance with this AD, if any, may be

obtained from the Rotorcraft Standards Staff.

(d) Special flight permits will not be issued.

(e) This amendment becomes effective on July 16, 1999, to all

persons except those persons to whom it was made immediately

effective by Priority Letter AD 99-12-01, issued May 27, 1999, which

contained the requirements of this amendment.

Note 4: The subject of this AD is addressed in Luftfahrt-

Bundesamt (Federal Republic of Germany) AD 1999-185, dated May 6,

1999.

Issued in Fort Worth, Texas, on June 23, 1999.

Henry A. Armstrong,

Manager, Rotorcraft Directorate, Aircraft Certification Service.

[FR Doc. 99-16591 Filed 6-30-99; 8:45 am]

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