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) 521 Division X. 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), National 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)

1/3 No.

CF-2009-48

Issue Date 

14 December 2009 

In Number: CF-2009-48 

Subject: Air-Driven Generator (ADG) – Non-Conforming Balance Washer Screws 

Effective: 25 January 2010 

Applicability: Bombardier Inc. Models: 

CL-600-2B19, Serial Numbers (S/Ns) 7305 through 7990 and 8000 and subsequent. 

CL-600-2C10, S/Ns 10003 and subsequent. 

CL-600-2D15 and CL-600-2D24, S/Ns 15001 and subsequent. 

Compliance: As indicated below, unless already accomplished. 

Background: Following five reported cases of balance washer screw failure on similar ADGs/ram air 

turbines installed on other aircraft types, investigation by Hamilton Sundstrand 

determined that a specific batch of the screws had a metallographic non-conformity that 

increased their susceptibility to brittle fracture. Subsequently, it was established that 152 

“dry” ADGs [Hamilton Sundstrand Part Numbers (P/Ns) in the 761339 series and 

1711405; see Note] either had non-conforming screws installed during production or 

may possibly have had non-conforming screws installed during maintenance or repair at 

Hamilton Sundstrand repair stations. 

Failure of a balance washer screw can result in loss of the related balance washer, with 

consequent turbine imbalance. Such imbalance could potentially result in ADG structural 

failure (including blade failure), loss of ADG electrical power and structural damage to 

the aircraft and, if deployment was activated by a dual engine shutdown, could also 

result in loss of hydraulic power for the flight controls. 

This directive mandates checking the ADG and replacing the balance washer screws, if 

required. It also prohibits future installation of unmodified ADGs. 

Note: ADGs with Hamilton Sundstrand P/Ns in the 761339 series and 1711405 are 

installed on the aircraft models listed in the Applicability section above in addition 

to Bombardier Inc. Model CL-600-2B16. The latter model is covered in a separate 

directive. 

Corrective 

Actions: 

Part I - Identification Check 

Applicable to: 

CL-600-2B19 aircraft, S/Ns 7305 through 7990 and 8000 through 8105, 

CL-600-2C10 aircraft, S/Ns 10003 through 10297, and 

CL-600-2D15 and CL-600-2D24 aircraft, S/Ns 15001 through 15248. 

Prior to the next in-flight or on-ground functional/operational check of the ADG, after the 

effective date of this directive, check the S/N of the installed ADG: 
No.

 N° CF-2009-48 2/3 

A. If the ADG S/N is not listed in paragraph 1.A. of the applicable Bombardier 

Aerospace Service Bulletin (SB) detailed below, or later revision approved by the 

Chief, Continuing Airworthiness, Transport Canada, no further action is required 

and compliance with this directive is complete. 

Service Bulletin Issue Date

601R-24-127 Original 23 October 2009 

670BA-24-026 Original 23 October 2009 

 

B. If the ADG S/N is listed in paragraph 1.A. of the applicable Bombardier Aerospace 

SB detailed below, or later revision approved by the Chief, Continuing 

Airworthiness, Transport Canada, inspect the ADG identification plate. 

Service Bulletin Issue Date

601R-24-127 Original 23 October 2009 

670BA-24-026 Original 23 October 2009 

1) If symbol “24-5” is marked on the ADG identification plate, the balance washer 

screws have already been replaced. No further action is required and compliance 

with this directive is complete. 

2) If symbol “24-5” is not marked on the ADG identification plate, replacement of 

the balance washer screws is required. Proceed to Part II of this directive.

Note: Part I of this directive may be conducted visually, which requires the ADG to be 

lowered, or by checking the delivery and maintenance records. 

Part II: Replacement of the Balance Washer Screws and Identification of the ADG 

Applicable to: 

CL-600-2B19 aircraft, S/Ns 7305 through 7990 and 8000 through 8105, 

CL-600-2C10 aircraft, S/Ns 10003 through 10297, and 

CL-600-2D15 and CL-600-2D24 aircraft, S/Ns 15001 through 15248. 

Prior to the next in-flight or on-ground functional/operational check of the ADG, after the 

effective date of this directive: 

Replace all of the balance washer screws, and mark the ADG identification plate with 

symbol “24-5”, in accordance with the Accomplishment Instructions in the applicable 

Bombardier Aerospace SB detailed below, or later revision approved by the Chief, 

Continuing Airworthiness, Transport Canada. 

Service Bulletin Issue Date

601R-24-127 Original 23 October 2009 

670BA-24-026 Original 23 October 2009 

Note: Part II is only applicable if required by Part I, Paragraph B.2. of this directive. 

Part III: Replacement Parts 

Applicable to: 

CL-600-2B19 aircraft, S/Ns 7305 through 7990 and 8000 and subsequent, 

CL-600-2C10 aircraft, S/Ns 10003 and subsequent, and 

CL-600-2D15 and CL-600-2D24 aircraft, S/Ns 15001 and subsequent. 
No.

 N° CF-2009-48 3/3 

After the effective date of this directive: 

It is not permitted to install a replacement/spare ADG [Hamilton Sundstrand P/N in the 

761339 series or 1711405] that has one of the S/Ns listed in paragraph 1.A of the 

applicable Bombardier Aerospace SB detailed below, or later revision approved by the 

Chief, Continuing Airworthiness, Transport Canada, unless it is identified with the 

symbol “24-5” on the identification plate. 

Service Bulletin Issue Date

601R-24-127 Original 23 October 2009 

670BA-24-026 Original 23 October 2009 

Authorization: For Minister of Transport, Infrastructure and Communities 

ORIGINAL SIGNED BY

Derek Ferguson, 

Chief, Continuing Airworthiness 

Contact: Mr. Richard Topham, Continuing Airworthiness, Ottawa, telephone 613-952-4357, 

facsimile 613-996-9178 or e-mail CAW Web Feedback@tc.gc.ca or any Transport 

Canada Centre.