Applicability: Model R44 helicopters, serial numbers 0002 through 0420, 0425, 0426, and 0427, with a C056-1 Rev. A through G spring assembly installed, certificated in any category.

Effective date: February 27, 1998

Compliance : Required as indicated in FAA PL AD 98-04-12.

Remarks: Where applicable, the requirements of this AD must be integrated into the Aircraft´s Logbook(s). Address inquiries concerning this AD to: Civil Aviation Authority, Airworthiness Division, Ruzyne Airport, 160 08 Prague 6, Czech Republic, tel: 420 2 324086, fax: 420 2 364112. FOR A COPY OF FIGURE, CALL CAA CZ AT (420) (2) 2011 2521.

Priority Letter issued on February 4, 1998. Docket No. 98-SW-08-AD.

Applicability: Model R44 helicopters, serial numbers 0002 through 0420, 0425, 0426, and 0427, with a C056-1 Rev. A through G spring assembly 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 (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 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 detect excessive wear on the lateral cyclic trim spring shaft (shaft), which could allow the shaft to move from its lower mount and interfere with lateral cyclic control resulting in loss of control of the helicopter, accomplish the following:

(a) Within 10 hours time-in-service (TIS), and thereafter at intervals not to exceed 20 hours TIS, measure the diameter of the shaft in accordance with the Compliance Procedure contained in Robinson Helicopter Company R44 Service Bulletin SB-26, dated January 31, 1998 (SB-26).

(b) If the shaft diameter varies more than 0.004 inch in any 0.50 inch of length, in the measurement area shown in Figure 1 of SB-26, replace the C056-1 Rev. A through G spring assembly with a C056-1 Rev. H spring assembly before further flight.

(c) Replacing the C056-1 Rev. A through G spring assembly with a C056-1 Rev. H spring assembly in accordance with the service bulletin is considered terminating action for the requirements of 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, Los Angeles Aircraft Certification Office, FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Los Angeles 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 Los Angeles Aircraft Certification Office.

(e) Special flight permits will not be issued.

(f) Copies of the applicable service information may be obtained from Robinson Helicopter Company, 2901 Airport Drive, Torrance, California 90505. This information may be examined at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas.

(g) Priority Letter AD 98-04-12, issued February 4, 1998, becomes effective upon receipt.

FOR FURTHER INFORMATION CONTACT: Mr. Fredrick A. Guerin, Aerospace Engineer, FAA, Los Angeles Aircraft Certification Office, Airframe Branch, 3960 Paramount Blvd., Lakewood, California 90712, telephone (562)