Date of issue: August 17, 1999

Applicability: Model R44 helicopters, certificated in any category.

Effective date: Upon receipt.

Compliance : Required as indicated in FAA PL AD 99-17-17

99-17-17 ROBINSON HELICOPTER COMPANY: Docket No. 99-SW-46-AD. Issued August 13, 1999.

Applicability: Model R44 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 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 prior to further flight, unless accomplished previously.

To prevent failure of the yoke assembly, which could result in loss of main and tail rotor drive and subsequent loss of control of the helicopter, accomplish the following:

(a) Determine, by inspection, if the yoke assembly, part number (P/N) C908-1C, from Lot No. 36B, 37, or 38 is installed.

NOTE 2: Yoke assemblies, P/N C908-1C, from Lot Nos. 36B, 37, and 38 were installed as original equipment in R44 helicopters, Serial Numbers (S/N) 0219 and 0535 through 0608 (except S/N’s 0565, 0582, and 0592).

(b) Replace any yoke assembly, P/N C908-1C, from Lot No. 36B, 37, or 38, with an airworthy yoke assembly from a lot other than 36B, 37, or 38 in accordance with the compliance procedure, steps 2 through 12, of Robinson Helicopter Company R44 Service Bulletin SB-35, dated July 26, 1999.

(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, 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 3: 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.

(d) Special flight permits will not be issued.

(e) 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.

(f) Emergency Priority Letter AD 99-17-17, issued August 13, 1999, becomes effective upon receipt.

FOR FURTHER INFORMATION CONTACT: Elizabeth Bumann, Aerospace Engineer, FAA, Los Angeles Aircraft Certification Office, Propulsion Branch, 3960 Paramount Blvd., Lakewood, California 90712, telephone (562) 627-5265, fax (562) 627-5210.