[Federal Register Volume 62, Number 41 (Monday, March 3, 1997)]
[Rules and Regulations]
[Pages 9361-9363]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-4951]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-SW-17-AD; Amendment 39-9950; AD 97-05-06]
RIN 2120-AA64


Airworthiness Directives; Schweizer Aircraft Corporation and 
Hughes Helicopters, Inc. Model 269A, 269A-1, 269B, and TH-55A 
Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to Schweizer Aircraft Corporation and Hughes 
Helicopters, Inc. Model 269A, 269A-1, 269A-2, and 269B helicopters, 
that currently requires initial and repetitive inspections of the main 
rotor thrust bearing (bearing) for bearing rotational roughness, 
corrosion, inadequate lubrication, physical damage, or excessive zinc 
chromate paste or moisture. This amendment requires the same initial 
and repetitive inspections required by the existing AD, but would 
extend the retirement life for certain bearings, and would remove the 
Model 269A-2 helicopter from, and add the Model TH-55A helicopters to 
the applicability of this AD. This amendment is prompted by an FAA 
analysis of service information issued by the manufacturer that extends 
the retirement life for certain bearings. The actions specified by this 
AD are intended to prevent failure of the bearing, loss of the main 
rotor, and subsequent loss of control of the helicopter.

DATES: Effective April 7, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of April 7, 1997.

ADDRESSES: The service information referenced in this AD may be 
obtained from Schweizer Aircraft Corporation, P.O. Box 147, Elmira, New 
York 14902. This information may be examined at the FAA, Office of the 
Assistant Chief Counsel, Room 663, 2601 Meacham Blvd., Fort Worth, 
Texas; or at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Mr. Ray O'Neill, Aerospace Engineer, 
Airframe and Propulsion Branch, New York Aircraft Certification Office, 
FAA, New England Region, 10 5th Street, Valley Stream, New York 11581, 
telephone (516) 256-7505, fax (516) 568-2716.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 68-21-05, 
Amendment 39-672 (33 FR 15543, October 19, 1968), which is applicable 
to Model 269A helicopters, serial numbers (S/N) 0011 through 0979 
(except Model TH-55A helicopters), Model 269A-1 helicopters, S/N 0001 
through 0041, Model 269A-2 helicopter, S/N 0001, and Model 269B, S/N 
0001 through 0370, as revised by Amendment 39-1055 (35 FR 12532, August 
6, 1970), was published in the Federal Register on June 17, 1996 (61 FR 
30548). That action proposed to require the same initial and repetitive 
inspections required by the existing AD (inspections of the main rotor 
thrust bearing (bearing) for bearing rotational roughness, corrosion, 
inadequate lubrication, physical damage, or excessive zinc chromate 
paste or moisture), but would extend the retirement life for certain 
bearings, and would remove the Model 269A-2 helicopter from, and add 
the Model TH-55A helicopters to the applicability of this AD.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were received on the 
proposal or the FAA's determination of the cost to the public. The FAA 
has determined that air safety and the public interest require the 
adoption of the rule as proposed, except for editorial changes and 
changes to paragraph (a) that more specifically state the actions that 
are required for those bearings having less than 300 hours time-in-
service. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor expand the scope of 
the AD.
    The FAA estimates that 500 helicopters of U.S. registry will be 
affected by this AD, that it will take approximately 8 work hours per 
helicopter to accomplish the required

[[Page 9362]]

actions, and that the average labor rate is $60 per work hour. Required 
parts will cost approximately $1,890 per helicopter. Based on these 
figures, the total cost impact of the AD on U.S. operators is estimated 
to be $1,185,000.
    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. 106(g), 40113, and 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing Amendment 39-1055 (35 FR 
12532, August 6, 1970), and Amendment 39-672 (33 FR 15543, October 19, 
1968) and by adding a new airworthiness directive (AD), Amendment 39-
9950, to read as follows:

AD 97-05-06 SCHWEIZER AIRCRAFT CORPORATION AND HUGHES HELICOPTERS, 
INC.: Amendment 39-9950. Docket No. 94-SW-17-AD. Supersedes AD 68-
21-05, Amendment 39-1055 and Amendment 39-672.

    Applicability: Model 269A helicopters, serial numbers (S/N) 0011 
through 1109, Model 269A-1 helicopters, S/N 0001 through 0041, Model 
269B, S/N 0001 through 0444, and Model TH-55A, with main rotor 
thrust bearing, part number (P/N) 269A5050-50, -51, or -73, 
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 
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 (g) 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 helicopter from the applicability of this AD.

    Compliance: Required within 25 hours time-in-service (TIS) after 
the effective date of this AD, unless accomplished previously.
    To prevent failure of the main rotor thrust bearing (bearing), 
loss of the main rotor, and subsequent loss of control of the 
helicopter, accomplish the following:
    (a) From available helicopter records, determine the TIS of the 
appropriate bearing, part number (P/N) 269A5050-50, P/N 269A5050-51, 
or P/N 269A5050-73.
    (1) If the TIS on the bearing, P/N 269A5050-50 or -51, equals or 
exceeds 300 hours TIS, replace the bearing with an airworthy bearing 
before further flight.
    (2) If the TIS on the bearing, P/N 269A5050-50 or -51, equals or 
exceeds 275 hours TIS, and is less than 300 hours TIS, replace the 
bearing with an airworthy bearing within the next 25 hours TIS.
    (3) If the TIS on the bearing, P/N 269A5050-50 or -51, is less 
than 275 hours TIS, replace the bearing with an airworthy bearing on 
or before 300 hours TIS.
    (b) Inspect bearing, P/N 269A5050-50 or -51, for rotational 
roughness, corrosion, inadequate lubrication, physical damage, 
moisture or inadequate drainage due to build-up of zinc chromate 
paste in accordance with Step II, paragraph b of Schweizer Service 
Notice (SSN) No. N-59, dated October 9, 1968.
    (1) If bearing rotational roughness, corrosion, inadequate 
lubrication, physical damage, moisture or inadequate drainage due to 
build-up of zinc chromate paste is found, replace the bearing with 
an airworthy bearing.
    (2) If no bearing rotational roughness, corrosion, lack of 
lubrication, physical damage, moisture or inadequate drainage due to 
build-up of zinc chromate paste is found, thereafter, inspect the 
bearing in accordance with this paragraph upon attaining an 
additional 150 hours TIS.
    (3) For replacement bearings, inspect in accordance with this 
paragraph upon attaining 150 hours TIS, unless the bearing reaches 
its 300 hour TIS retirement life limit prior to this inspection.
    (c) For bearing, P/N 269A5050-73:
    (1) Inspect the bearing for corrosion, rust, freedom of 
rotation, looseness, binding, nicks, burrs, cracks and lubrication. 
Thereafter, inspect the bearing at intervals not to exceed 600 hours 
TIS.
    (2) As necessary, repack the bearing cavity in accordance with 
Schweizer Aircraft Corporation CKP-C-41 ``Installation Instructions 
For 269 Series Helicopters, SA-269K-057-1 Main Rotor Thrust Bearing 
Kit,'' dated June 9, 1994.
    (d) This AD establishes a retirement life of 300 hours TIS for 
bearings, P/Ns 269A5050-50 and -51 and a retirement life of 3,000 
hours TIS for bearing, P/N 2695050-73. However, bearings, P/Ns 
269A5050-50 and -51, with at least 275 hours TIS but less than 300 
hours TIS, need not be retired until or before the accumulation of 
an additional 25 hours TIS.
    (e) Inspect the thrust bearing nut (nut), P/N 269A1306-5, for 
corrosion and physical damage and determine whether the nut has been 
modified in accordance with Step III of SSN No. N-59, dated October 
9, 1968.
    (1) If corrosion or physical damage is found, replace the nut 
with an airworthy nut that has been modified in accordance with Step 
III of SSN No. N-59, dated October 9, 1968.
    (2) If the nut has not been modified, modify the nut in 
accordance with Step III of SSN No. N-59, dated October 9, 1968.
    (f) Inspect the interior of the main rotor mast (mast) for 
corrosion, physical damage, foreign materials, moisture or 
inadequate drainage due to a buildup of zinc chromate paste and 
determine whether the mast has been modified in accordance with Step 
II of SSN No. N-59, dated October 9, 1968 to install a drain hole.
    (1) If corrosion or physical damage is found, replace the mast 
with an airworthy mast that has been modified in accordance with 
Step III of SSN No. N-59, dated October 9, 1968.
    (2) If the interior of the mast has foreign materials, moisture 
or inadequate drainage due to a buildup of zinc chromate paste, 
clean the area with a suitable solvent in accordance with Step II of 
SSN No. N-59, dated October 9, 1968.
    (3) If the mast has not been modified, modify the mast in 
accordance with Step III of SSN No. N-59, dated October 9, 1968.
    (g) 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 Aircraft Certification 
Office. Operators shall submit their requests through an FAA 
Principal Maintenance Inspector, who may concur or comment and then 
send it to the

[[Page 9363]]

Manager, New York Aircraft Certification Office.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the New York Aircraft Certification Office.

    (h) 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 helicopter to a location where 
the requirements of this AD can be accomplished.
    (i) The inspections, modifications, and replacements shall be 
done in accordance with Schweizer Service Notice No. N-59, dated 
October 9, 1968 and Schweizer Aircraft Corporation CKP-C-41 
``Installation Instructions For 269 Series Helicopters, SA-269K-057-
1 Main Rotor Thrust Bearing Kit,'' dated June 9, 1994. 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 Schweizer Aircraft Corporation, P.O. 
Box 147, Elmira, New York 14902. Copies may be inspected at the FAA, 
Office of the Assistant Chief Counsel, Room 663, 2601 Meacham Blvd., 
Fort Worth, Texas; or at the Office of the Federal Register, 800 
North Capitol Street, NW., suite 700, Washington, DC.
    (j) This amendment becomes effective on April 7, 1997.

    Issued in Fort Worth, Texas, on February 20, 1997.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 97-4951 Filed 2-28-97; 8:45 am]
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