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 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)

1/2 No.

CF-2011-42

Issue Date 

 09 November 2011 

Number: CF-2011-42 

Subject: Longeron Cracking 

Effective: 21 November 2011 

Applicability: Bell Helicopter Textron Canada (BHTC) helicopters equipped with upper left 

longeron assembly part number 206-031-314-037, 206-031-314-177 or spare 

assembly part number 206-031-314-219B: 

Model 407, Serial Number 53000 through 53900, 53911 thorugh 54061 and 54300. 

Compliance: As indicated below, unless already accomplished. 

Background: It has been determined that the upper left longeron part number (P/N)

206-031-314-037, 206-031-314-177 and spare assembly P/N 206-031-314-219B on 

helicopters with 1200 or more hours air time is prone to cracking. This situation, if not 

corrected, can lead to a serious structural defect and loss of the helicopter. 

This directive mandates corrective action introduced by Bell Helicopter Alert Service 

Bulletin 407-11-95 Rev A, dated 12 August 2011. 

Corrective 

Actions: 

Part I. Initial inspection 

In accordance with the following phase-in schedule: 

A. For aircraft with 1200 or more hours air time since new: within the next 50 hours air 

time from the effective date of this directive, but no later than 30 November 2011, 

and 

B. For aircraft with less than 1200 hours air time since new: prior to reaching 1250

hours air time. Perform the following inspections: 

A general visual inspection for cracks of the aft fuselage top skin in accordance with the

Accomplishment Instructions, Part I of Alert Service Bulletin (ASB) 407-11-95 Rev A 

dated 12 August 2011 or later revisions approved by the Chief, Continuing Airworthiness. 

If the skin is found cracked, remove the skin and replace it with a new skin before the 

next flight.

A general visual inspection of the upper left longeron assembly for general condition and 

cracks in accordance with Part II of the above mentioned ASB or later revisions approved 

by the Chief, Continuing Airworthiness. If the longeron is found cracked, proceed to Part 

III of this directive. If the longeron is found serviceable, proceed to Part II of this directive.
No.

N° CF-2011-42 2/2 

Part II. Repetitive inspection 

Inspect in accordance with Part II of the above mentioned ASB using the following 

schedule: 

A. For the upper left longeron assembly not modified with external strap doublers in 

accordance with Part III of the above mentioned ASB, at intervals not to exceed 

50 hours air time. If the longeron is found cracked proceed to Part III of this directive.

B. For the upper left longeron assembly modified with external strap doublers in 

accordance with Part III of the above mentioned ASB, at intervals not to exceed 

150 hours air time. If the longeron is found cracked proceed to Part III of this 

directive. 

Part III. Repair 

A. If the longeron is found cracked and the crack has not propagated through the 

complete longeron, before further flight, stop drill the longeron and repair in 

accordance with Part IV of the above mentioned ASB, or later revisions approved by 

the Chief, Continuing Airworthiness, or replace with the new longeron assembly 

P/N 206-031-314-237B and install three (3) external CRES strap doublers. 

B. If the longeron is found cracked and the crack has propagated through the complete 

unit, perform a repair of the longeron in accordance with Part IV of above mentioned 

ASB or later revisions approved by the Chief, Continuing Airworthiness, or replace 

with the new longeron assembly P/N 206-031-314-237B and install three (3) external 

CRES strap doublers. 

C. After the completion of the repair, perform a general visual inspection of the repaired 

longeron at intervals not to exceed 50 hours air time for general condition and cracks 

in accordance with Part II of the above mentioned ASB or later revisions approved by 

the Chief, Continuing Airworthiness. 

Part IV. Terminating action 

The terminating action to this directive consists of the installation of a new longeron 

assembly P/N 206-031-314-237B and installation of the three (3) external CRES strap 

doublers as defined in Part III of the above mentioned ASB later revisions approved by 

the Chief, Continuing Airworthiness. 

Authorization: For the Minister of Transport, Infrastructure and Communities 

ORIGINAL SIGNED BY

Derek Ferguson 

Chief, Continuing Airworthiness 

Contact: Bogdan Gajewski, Continuing Airworthiness, Ottawa, telephone 613-952-4357, facsimile 

613-996-9178 or e-mail CAWWEBFeedback@tc.gc.ca or any Transport Canada Centre.