AD 87-11-06

87-11-06 BELL HELICOPTER TEXTRON, INC.: Amendment 39-5607. Applies to Bell Helicopter Textron, Inc., Model 214ST helicopters, S/N's 28101 through 28159, and Models 214B and 214B-1, S/N's 28001 through 28070, certificated in any category, equipped with upper and lower locking plates, P/N's 214-010-231-101 and 214-010-232-101.

Compliance is required as indicated, unless already accomplished.

(a) To prevent failure of the collective hub locking plate, on the Model 214ST, 214B, and 214B-1 helicopters, replace the P/N 214-010-232-101 lower locking plate and the P/N 214-010-231-101 upper locking plate with locking plate P/N 214-010-569-101 in accordance with Part I of BHTI ASB 214-86-36, dated October 8, 1986, or ASB 214ST-86-37, Rev. A, dated November 3, 1986, within the next 50 hours' time in service or within 30 days after the effective date of this AD, whichever comes first.

(b) Within the next 25 hours' time in service after completing the requirements of paragraph(a) and thereafter at intervals not to exceed 25 hours' time in service from the last inspection, visually inspect the hub and lower hub nut assembly for slippage in accordance with Part II of BHTI ASB 214-86-36, dated October 8, 1986, or ASB 2145T-86-37, Rev. A, dated November 3, 1986.

(c) Within the next 500 hours' time in service after completing the requirements of paragraph (a) and thereafter at intervals not to exceed 500 hours' time in service from the last inspection, perform the following in accordance with Part III of BHTI ASB 214-86-36, dated October 8, 1986, or ASB 214ST-86-37, Rev. A, dated November 3, 1986:

(1) Inspect the hub locking plate, P/N 214-010-569-101, for cracks.

(2) If a crack is found during this inspection, replace the hub locking plate with a serviceable part.

(3) Retorque the lower hub nut and install locking plate, P/N 21 4-010-569- 101, as detailed in paragraph (a).

(d) Installation instructions for the scissors and sleeve may be found in the BHTI- 214ST Maintenance Manual, Chapter 62-21-00, and 214B Maintenance Manual, Chapter 65-20- 00.

(e) Upon compliance with this airworthiness directive, the inspections and actions required by priority letter Airworthiness Directive No. 86-12-01, issued June 6, 1986, may be discontinued.

(f) An alternate method of compliance which provides an equivalent level of safety with this AD may be used when approved by the Manager, Helicopter Certification Branch, Federal Aviation Administration, 4400 Blue Mound Road, Fort Worth, Texas 76106.

The procedure shall be done in accordance with BHT1 ASB 214-86-36, dated October 8, 1986,or ASB 214ST-86-37, Rev. A., dated November 3, 1986.

This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a)(1). Copies may be obtained upon request to Bell Helicopter Textron, Inc., P.O. Box 482, Fort Worth, Texas 76101, Attention: Customer Support.

Copies maybe inspected at the Office of Regional Counsel, FAA, Southwest Region, 4400 Blue Mound Road, Fort Worth, Texas, or at the Office of the Federal Register, 1100 L Street, NW., Room 8401, Washington, D.C.

This amendment becomes effective May 26, 1987.