Airworthiness Directives; Eurocopter Deutschland Model EC135 P1 and T1 Helicopters

[Federal Register Volume 62, Number 238 (Thursday, December 11, 1997)]
[Rules and Regulations]
[Pages 65198-65201]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-32255]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-SW-46-AD; Amendment 39-10240; AD 97-20-13]
RIN 2120-AA64


Airworthiness Directives; Eurocopter Deutschland Model EC135 P1 
and T1 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) 97-20-13 which was sent 
previously to all known U.S. owners and operators of Eurocopter 
Deutschland Model EC135 P1 and T1 helicopters by individual letters. 
This amendment is prompted by the discovery of cracks on the stator 
blades of the fenestron tail rotor (tail rotor). The actions specified 
by this AD are intended to prevent failure of the tail rotor and 
subsequent loss of control of the helicopter.

DATES: Effective December 29, 1997, to all persons except those persons 
to whom it was made immediately effective by priority letter AD 97-20-
13, issued on September 25, 1997, which contained the requirements of 
this amendment.
    Comments for inclusion in the Rules Docket must be received on or 
before February 9, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 97-SW-46-AD, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137.

FOR FURTHER INFORMATION CONTACT: Mr. Richard Monschke, Aerospace 
Engineer, FAA, Rotorcraft Directorate, Rotorcraft Standards Staff, 2601 
Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5116, (817) 
222-5961.

SUPPLEMENTARY INFORMATION: On September 25, 1997, the FAA issued 
priority letter AD 97-20-13, applicable to Eurocopter Deutschland Model

[[Page 65199]]

EC135 P1 and T1 helicopters, which requires immediate and daily 
repetitive inspections of the stator blades for cracks in the stator 
hub area. If this visual inspection reveals a crack, a dye-penetrant 
inspection is required. Also, within 400 hours time-in-service (TIS) 
after the effective date of this AD, and thereafter, at intervals not 
to exceed 400 hours TIS, a dye-penetrant inspection for cracks is 
required. If any of the inspections reveal cracked stator blades, each 
crack must be stop-drilled. If any of the inspections reveal cracks on 
a stator blade with a total crack length of 15mm or longer, or if 
cracks are found on more than 3 stator blades, the affected blades must 
be replaced with airworthy blades prior to further flight. That action 
was prompted by the discovery of cracks on the stator blades of the 
tail rotor. This condition, if not corrected, could result in failure 
of the tail rotor and subsequent loss of control of the helicopter.
    Since the unsafe condition described is likely to exist or develop 
on other Eurocopter Deutschland Model EC135 P1 and T1 helicopters of 
the same type design, the FAA issued priority letter AD 97-20-13 to 
prevent failure of the tail rotor and subsequent loss of control of the 
helicopter. The AD requires, before further flight, and thereafter, 
before the first flight of each day, visually inspecting the stator 
blades in the stator hub area. If this visual inspection reveals a 
crack, a dye-penetrant inspection is required. Also, within 400 hours 
TIS after the effective date of this AD, and thereafter, at intervals 
not to exceed 400 hours TIS, a dye-penetrant inspection for cracks is 
required. If any of the inspections reveal cracked stator blades, each 
crack must be stop-drilled. If any of the inspections reveal cracks on 
a stator blade with a total crack length of 15mm or longer, or if 
cracks are found on more than 3 stator blades, the affected stator 
blades must be replaced with airworthy stator blades prior to further 
flight.
    Since it was found that immediate corrective action was required, 
notice and opportunity for prior public comment thereon were 
impracticable and contrary to the public interest, and good cause 
existed to make the AD effective immediately by individual letters 
issued on September 25, 1997 to all known U.S. owners and operators of 
Eurocopter Deutschland Model EC135 P1 and T1 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.

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. 97-SW-46-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, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding a new airworthiness directive 
to read as follows:

97-20-13--Eurocopter Deutschland: Amendment 39-10240. Docket No. 97-
SW-46-AD.

    Applicability: Model EC135 P1 and T1 helicopters, certificated 
in any category.

    Note 1: This AD applies to each helicopter 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 helicopters 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 (d) 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 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 helicopter from the applicability 
of this AD.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent failure of the tail rotor and subsequent loss of 
control of the helicopter, accomplish the following:
    (a) Before further flight, and thereafter before the first 
flight of each day, visually inspect all stator blades in the stator 
hub area for cracks (see Figure 1). Inspect the stator blades in the 
areas where they are riveted to

[[Page 65200]]

the stator hub. Pay particular attention to the radius areas where 
the stator blade base attaches to the stator hub.
    (1) If the inspection reveals a crack at the base of a stator 
blade, remove the paint from the area and perform a dye-penetrant 
inspection.
    (2) If the inspection reveals 3 or less cracked stator blades 
and a total crack length per stator blade of less than 15mm, stop-
drill each crack with a 2mm diameter drill.
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[GRAPHIC] [TIFF OMITTED] TR11DE97.000


[[Page 65201]]


    (b) Within 400 hours time-in-service (TIS), and thereafter, at 
intervals not to exceed 400 hours TIS, remove the paint from all 
stator blades in the stator hub area and perform a dye-penetrant 
inspection for cracks.
    (c) If the inspections reveal cracks on any stator blade with a 
total crack length of 15mm or longer, or if more than 3 stator 
blades are cracked, remove the affected stator blades and replace 
them with airworthy stator blades before further flight. The 
inspections required by this AD must continue to be performed on all 
stator blades including replacement stator blades.

    Note 2: Eurocopter Deutschland Alert Service Bulletin No. EC 
135-53A-001, Revision 01, dated August 8, 1997, pertains to this AD.

    (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, Rotorcraft Standards Staff, 
Rotorcraft Directorate, FAA. 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.

    (e) Special flight permits will not be issued.
    (f) This amendment becomes effective on December 29, 1997, to 
all persons except those persons to whom it was made immediately 
effective by Priority Letter AD 97-20-13, issued September 25, 1997, 
which contained the requirements of this amendment.

    Note 4: The subject of this AD is addressed in Luftfahrt-
Bundesamt (Germany) AD 97-249, effective September 25, 1997.

    Issued in Fort Worth, Texas, on December 2, 1997.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 97-32255 Filed 12-10-97; 8:45 am]
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