# .+. Transport Canada Transports

Canada No. CF~2009·35 Issue Dale TP 7245E 

# I 1/3 

# AIRWORTHINESS 31 August 2009 

# DIRECTIVE

Number: Subject:

Effective: Applicability:

Compliance: Background:

Corrective Actions: CF· 2009-35

Angle of Attack Transducer
- Heating Element Degradation and Inaccurate Calibration 16 September 2009 All Bombardier Inc. Model CL-BOO-2C10,CL..£OO-2D15and CL-600-2D24 aircraft equipped with Thales Angle of Attack (ADA) transducers, Part Number (PIN) C16258AA. As indicated unless already accomplished, The healing capability of several ADA transducer heating elements removed from in-service aircraft has been found to be below the minimum requirement. Also, jt was discovered that a large number of AOA transducers repaired in an approved maintenance facilitywere notcalibrated accurately. Inaccurate calibration of the ADA transducer andlor degraded AOA transducer heating elements can result in early or late activation ofthe stall warning, stick shaker and stick pusher bythe Stall Protection Computer(SPC), This directive mandales a periodic inspection of the inrush current to verify the ADA heating capability and replacementofthe inaccuratelycalibratedAOAtransducers, 1. Angle of Attack Transducers Calibration Part Number (PIN) C16258AA 1.1 Within 6 000 hours airtime from the effective date ofthis directive, perform the following in accordance with the Accomplishment Instructions of Bombardier Service Bulletin (S8) 670BA-27-053, dated 14 May 2009 or later revisions approved bythe Chief, ContinuingAirworthiness, Transport Canada: Inspect the part number and the serial number (SIN) of each of the ADA transducers PIN C16258AAinstalledon the aircraft. 111 Ifthe SIN is not listed in paragraph 1 A.(1} of SB670BA-27-053, dated 14 May 2009 or later revisions approved by the Chief. Continuing Airworthiness, Transport Canada, or if a different part number is installed, nofurther action is required. 1.1.2 If the PIN and the SIN are listed in paragraph 1.A.(1) of S8 670BA-27-053, dated 14 May2009 or later revisions approved bythe Chief, ContinuingAirworthiness, Transport Canada, and the serial number has a suffix "A" (reference: Thales S8 C16258A-27-002), nofurtheraction is required.

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# I~. CF·2009·35

1.1.3 If the PIN and the SIN are listed in paragraph 1.A.(1) of the SB 670BA·27..Q53,

dated 14 May2009 or later revisions approved bythe Chief, ContinuingAirworthiness. Transport canada. replace the AOA transducer in accordance with the Accomplishment Instructions, Part 2 Paragraph 8.(2) ofthe above mentioned S8 or its later revisionsapproved by the Chief, Continuing Airworthiness, Transport Canada. 1.2 As of the effective date of this directive, no person shall install a replacement ADA Transducer PIN C16258AA with a SIN listed in paragraph 1.A(1) of Bombardier SB 670BA-27-0s3, dated 14 May 2009 or later revisions approved by the Chief, Continuing Airworthiness. Transport Canada, unless the serial number hasthesuffix "A" (reference:Thales S8 C16258A-27-002). 2. Angle of Attack Transducers Heating Element Degradation PIN C16258AA 2.1 Inspectionfor InrushCurrent In accordance with the schedule in Table 1 below, measure the inrush current of the installed AOA transducers in accordance with the Accomplishment Instructions, Part A, of Bombardier SB 670BA-27-0s1, dated 14 May 2009 or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada. Table 1 Accumulated Angle of Attack Compliance Schedule for Initial Inrush transducer Hours Air Time on the Current Inspection Effective Date of this directive. Lessthan 6 500 hours airtime Before the ADA transducer has 7 500 hours airtime More than or equal to 6 500 but not Within 500 hours air time from the effective greaterthan 7 500 hoursairtime date ofthis directive but no laterthan 8 000 hours airtime More than or equal to 7 500 hours air Within 250 hours airtime from the effective time date ofthis directive

2.2 Replacement and Repeat Inspection Requirements: 2.2.1 Ifthe installedADA transducers inspected as perTable 1 have an inrush current less than 1.60 Amps, before further flight, replace them in accordance with the Accomplishment Instructions, Paragraph 2. Part C, of Bombardier SB 670BA-27-051. dated 14 May 2009 or later revisions approved by the Chief, Continuing Airworthiness, Transport Canada. Repeat the inspection of the newly installed transducers in accordance with theschedule inTable2 ofthis directive. 2.2.2 Ifthe ADA transducers inspected as perTable 1 have an inrush current more than or equal to 1.60 Amps, repeat the inspection of the transducers in accordancewiththe schedule inTable 2 ofthis directive

# I~· CF-2009-35 

# I~

Authorization;

Contact: Table 2

last Angle of Attack Inrush Current Compliance Schedule 

### 1o, Repeat Measurement (Amps) Inspection Morethan orequal to 1.90 Within 2 000 hours air lime after the last measurement. More than or equal to 1.80 but less than Within 1 500 hours air time after the last 1.90 measurement. More than or equal to 1.70 bulless than Within 1 000 hours air time after the last 1.80 measurement. More than or equal to 1.60 bul less than Within 500 hours air time after the lasl 1.70 measurement. NewADA Transducer Within 2 000 hours air time after the installationdate.
ForMinisterofTransport, Infrastructureand Communities

Derek Ferguson Chief, Continuing Airworthiness Mr. Gordanko Jeremic, 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.