AIRWORTHINESS DIRECTIVE

CAA-AD-031/2002

Date of issue: March 05, 2002

HELICOPTER– K-FLEX DRIVE SHAFT – INSPECTION

Applicability: Bell Helicopter Textron Canada (BHTC)Models 206L-4, 407 and 427 helicopters.

Effective date: Upon receipt

Compliance : Required as indicated in TC AD CF-2002-03.

Remarks:. The compliance of this AD must be recorded in Aircraft Logbook, where applicable the requirements of this AD must be integrated into Aircraft Technical Documentation. Address inquiries concerning this AD to: Civil Aviation Authority, Airworthiness Division, Ruzyne Airport, 160 08 Prague 6, Czech Republic, tel: 420 2 33320922, fax: 420 2 20562270

Ing. Pavel MATOUŠEK
Director of Airworthiness Division
CAA CZ

TC AD CF-2002-03

Subject: Bell Models 206L-4, 407 and 427 – K-Flex Drive Shaft

Effective: 28 February 2002

Applicability: Bell Helicopter Textron Canada (BHTC)Models 206L-4, 407 and 427 helicopters.

Compliance: As indicated, but no later then 31 January 2002, unless already accomplished.

Background: During flight, the engine-to-transmision drive shaft assembly P/N 206-340-300-105 (K-flex shaft) failed, causing a forced landing. Three additional incidents of a cracked flex frame on the forward end of the drive shaft on Model 407 have been reported. As a precautionary measure, a one-time visual inspection for any obvious discrepancy of the shaft was mandated on Model 407 by CF-2001-24.

It has been determined that the K-flex shaft on Model 407 helicopter is experiencing higher loads than on other helicopter models.

Since the K-flex shaft P/N 206-340-300-105 can also be installed on Models 206L-4 and 427, this directive requires a component review to determine if this K-flex shaft was previously installed on Model 407.

Corrective Actions: Part 1. Models 206L-4 and 427

Review the Historical Service Record of the K-flex shaft to determine if it was ever installed on a Bell Model 407 helicopter.

(a) If the K-flex shaft has never been installed on a Bell Model 407 helicopter, then annotate the helicopter log book as follows: “P/N 206-340-300-105 K-flex shaft has not been installed on a Bell 407, AD CF-2002-03 accomplished.”

(b) If the K-flex shaft P/N 206-340-300-105 has been previously installed for any length of time on a Bell 407 helicopter, remove from service as per the applicable schedule published in BHTC Alert Service Bulletin: 206L-01-123 or 427-01-45, both dated 12 October 2001, or later revisions approved by the Director, Aircraft Certification, Transport Canada.

Part 2. Model 407

Remove shaft P/N 206-340-300-105 as per the compliance schedule provided in BHTC Alert Service Bulletin 407-01-45 Rev “A” dated 21 November 2001, or later revisions approved by the Director, Aircraft Certification Transport Canada.

Authorization: For Minister of Transport

B. Goyaniuk

Chief, Continuing Airworthiness

Contact: Mr. Bogdan Gajewski, Continuing Airworthiness, Ottawa, telephone (613) 952-4450, facsimile (613) 996-9178 or e-mail gajewsb@tc.gc.ca or any Transport Canada Centre.