Transport Transports 

Canada Canada

 TP 7245E

 

AIRWORTHINESS DIRECTIVE The following airworthiness directive (AD) may be applicable to an aircraft which our records indicate is registered in your name. ADs are issued pursuant to Canadian 

Aviation Regulation (CAR) 593. Pursuant to CAR 605.84 and the further details of CAR Standard 625, Appendix H, the continuing airworthiness of a Canadian registered aircraft is contingent upon compliance with all applicable ADs. Failure to comply with the requirements of an AD may invalidate the flight authorization of the aircraft. Alternative means of compliance shall be applied for in accordance with CAR 605.84 and the above-referenced Standard. 

This AD has been issued by the Continuing Airworthiness Division (AARDG), Aircraft Certification Branch, Transport Canada, Ottawa, telephone 613 952-4357.

Pursuant to CAR 202.51 the registered owner of a Canadian aircraft shall, within seven days, notify the Minister in writing of any change of his or her name or address. 

To request a change of address, contact the Civil Aviation Communications Centre (AARC) at Place de Ville, Ottawa, Ontario K1A 0N8, or 1-800-305-2059, or www.tc.gc.ca/civilaviation/communications/centre/ address.asp 

24-0022 (01-2005)

1/1 No.

CF-2005-28R1

Issue Date 

14 June 2007 

Number: CF-2005-28R1 

Subject: Power Turbine RPM Steady State Operation Avoidance

Effective: 14 June 2007 

Revision: Supersedes Airworthiness Directive CF-2005-28, August 2005. 

Applicability: Bell Helicopter Textron Canada (BHTC) Model 206L-3 serial numbers 51001 through 

51612, and 206L-4 helicopters serial numbers 52001 through 52313. 

Helicopters fitted with two 250-C20R engines as per Supplementary Type Certificate 

(STC) SR00036SE are excluded. 

Compliance: As indicated. 

Background: Transport Canada has been advised of multiple reports of failure of the third stage 

turbine wheel used in both the Rolls-Royce 250-C30S and 250-C47B engines. There 

have been eight in-flight failures reported. Rolls-Royce has determined that detrimental 

vibrations can occur within a particular range of turbine speed as a potential contributing 

factor to these failures. BHTC revised their rotorcraft flight manual and provided a decal 

to inform pilots to avoid steady state operations at these engine turbine speeds. 

This revision is issued to exclude helicopters having the 250-C20R engines installed per 

STC SR00036SE (twin engine conversion) 

Corrective 

Actions: 

Part A: Rotorcraft Flight Manual Amendment 

Within 10 calendar days after the effective date of this directive, insert into the 

appropriate flight manual revision BHT-206L3-FM-1, Revision 6, dated 26 April 2005, 

BHT-206L4-FM--1, Revision 6, dated 26 April 2005, or later revisions approved by Chief, 

Continuing Airworthiness, Transport Canada into the rotorcraft flight manual and advise 

the pilot of this change. 

Part B: Installation of Decal 

In conjunction with Part A above, install the decal as per Alert Service Bulletin 

206L-05-134, dated 8 June 2005, or later revisions approved by Chief, Continuing 

Airworthiness, Transport Canada. 

Authorization: For Minister of Transport, Infrastructure and Communities 

Bohdan 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.