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 na me. 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 b y the Continuin g Airworthiness Division ( AARDG ) , National Aircraft Certification Branch, Trans p ort Canada, Ottawa, tele p hone 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 Communicat ions 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
2 4-0022 ( 01-2005 ) 1/2 No

. CF-2012-09 Issue Date 15 February 2012

Number: CF-2012-09 Subject: Loss of the 400Hz Fixed Frequency System Due To Multiple Inverter Failures Effective: 27 February 2012 Applicability: Bombardier Inc. DHC-8 Aeroplan e Models 102, 103, 106, 201, 202, 301, 311, 314 and 315, Serial Numbers 002 through 672 Compliance: As indicated below, unless already accomplished. Background: There have been several reported occurrences of the loss of the 400Hz Fixed Frequency System, leading to the loss of power to t he Left 115VAC bus, the Right 115VAC bus, the Left 26VAC bus, the Right 26VAC bus and all sy stems serviced by these four electrical buses. The loss of the 400Hz Fixed Frequency Sy stem has been attributed to a failure of one or two static inverters, which resulted in the loss of the remaining inverters. The loss of systems serviced by the four fixed frequency electric al buses creates an unsafe condition due to the loss of a number of the p ilot’s and co-pilot’s flight instruments, in addition to the other avionics systems. This Airworthiness Directive (AD) mandates the wiring modification to untie the 400Hz inverters and additional Airworthiness Limitation tasks introduced as a result of this modification. Corrective Actions: Part I - Wiring Modifications Within 6000 hours air time or 36 months, whichever occurs first, from the effective date of this AD, incorporate the wiring modifications in accordance with Bombardier Service Bulletin (SB) 8-24-87, Revision A, dated 5 Oc tober 2011, or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada. Incorporation of SB 8-24-87, Initial I ssue, dated 26 May 2011, also meets the requirements of Part I of this AD. Part II - Amendment to the Maintenance Schedule Within 30 days from the effective date of this AD, revise the Transport Canada approved maintenance schedule to incorporate Airworthiness Limitation task 2420/13 as introduced by the applicable Temporary Revi sions (TR) of the Dash-8 Maintenance Program Manual – Airworthiness Limitations List:No. N ° CF-2012-09 2/2

Dash 8 Series TR Number Date

Series 100 TR AWL-117 08 April 2011 Series 200 TR AWL 2-48 08 April 2011 Series 300 TR AWL 3-118 08 April 2011

Authorization: For the Minister of Transport, Infrastructure and Communities


### ORIGINAL SIGNED BY Derek Ferguson Chief, Continuing Airworthiness Contact: Miss Helen Tsai, Continuing Airworthiness, Ottawa, telephone 613-952-4357, facsimile 613-996-9178 or e-mail CAWWEBFeedback@tc.gc.ca or any Transport Canada Centre.