RE: TCCA CF-2013-21

Durrani, A K 

 to: Robert C Morlath 12/17/2013 11:49 AM

Hello Robert,

As discussed, please see attached herewith the message on the subject issue that was 

provided to MR. Frederick Zink.

Regards,

A.K. Durrani

Senior Engineer / Ingénieur principal 

Corrective Action - Powerplants | Action Corrective - Groupe moteurs,

Continuing Airworthiness / Maintien de la Navigabilité aérienne

(613) 952-5385, facsimile / télécopieur (613) 996-9178 <mailto:ak.durrani@tc.gc.ca> 

Transport Canada,Place de Ville (AARDG), Ottawa, Ontario K1A 0N5 

Government of Canada / Gouvernement du Canada

From: Robert.C.Morlath@faa.gov [mailto:Robert.C.Morlath@faa.gov] 

Sent: December 16, 2013 10:30 AM

To: Durrani, A K

Cc: Anthony.Cerra@faa.gov

Subject: TCCA CF-2013-21

Hello AK, 

I realize that the investigation into the recent failures of single crystal blades is preliminary at this point but 

do you think that TCCA will revise / modify CF-2013-21 due to the recent failures? I ask because the 

comment period for the FAA AD closes on December 30th and we have an opportunity to modify the AD 

requirements at that point if need be. 

Let me know what you think. 

Robert C. Morlath

Aerospace Engineer

Engine Certification Office

Federal Aviation Administration 

PH: 781-238-7154

----- Message from "Durrani, A K" <ak.durrani@tc.gc.ca> on Wed, 20 Nov 2013 16:01:15 -0500 -----

To: "'Frederick.Zink@faa.gov'" 

<Frederick.Zink@faa.gov>

cc: "Lau, Robin" <robin.lau@tc.gc.ca>

Subject

:

RE: 2013-21R1 13ne26 NPRM

Hello Mr. ZinK,
Thank you for this opportunity to review the proposed FAA AD on the subject issue.

Yes! In principle, it meets the requirements of AD cF-2013-21R1. However, with reference to corrective 

action compliance scope and time there are definitely some differences.

FAA’s proposed AD mandates replacement of CT blades during next HSI, whereas Canadian AD 

CF-2013-21R1 mandates two blade sample metallurgical inspection (Destructive testing) and if the 

sample blades fail the subject inspection only then it requires blade set replacement. Note that FAA‘s 

proposed AD does not require the subject metallurgical inspection.

Also it is not clear as to whether the proposed FAA requirement for affected blade replacement during 

next HSI is a onetime compliance or a repeat requirement for each HSI.

If the proposed CT blade replacement requirement during next HSI is in lieu of the metallurgical 

inspection requirement per AD CF-2013-21R1, then it should be repeated each HSI, otherwise it does 

not meet the basic intent of the AD, which was to detect impending failure of pre SB 1669 configuration 

CT blades as result of “Creep “phenomenon and prevent engine IFSD on single engine powered Cessna 

208 (Caravan.) aircraft. The metallurgical analysis (sample 2 blades) during each HSI was one of the 

primary mitigating action identified by the P&WC for serviceability of existing CT blades until such time 

they are replaced with post SB1669 config. blades that are not prone to the “Creep” phenomenon.

Moreover FAA’s proposed AD does not mandate replacement of all affected CT blades with post SB 

1669 configuration blades within a specified time period, as mandated by AD CF-2013-21R1 . Note that 

the engine OEM, P&WC has only committed to provide financial incentives for the post SB 1669 

configured CT blades within the AD compliance time period.

New subject:

As discussed earlier, I am attaching herewith a final draft copy of AD CF-2005-11 Rev 1, which is 

expected to be released by the end of this week. Subject AD CF-2005-11 is revised to include new fuel 

nozzle adapter P/N, introduced by the SB 21841.

Please feel free to contact this office for any further assistance in these matters.

Regards,

A.K. Durrani

Senior Engineer / Ingénieur principal 

Corrective Action - Powerplants | Action Corrective - Groupe moteurs,

Continuing Airworthiness / Maintien de la Navigabilité aérienne

(613) 952-5385, facsimile / télécopieur (613) 996-9178 <mailto:ak.durrani@tc.gc.ca> 

Transport Canada,Place de Ville (AARDG), Ottawa, Ontario K1A 0N5 

Government of Canada / Gouvernement du Canada 

-----Original Message-----

From: Frederick.Zink@faa.gov [mailto:Frederick.Zink@faa.gov] 

Sent: November 6, 2013 12:48 PM

To: Durrani, A K

Subject: 2013-21R1 13ne26 NPRM

Hello Mr. Durrani, it was good talking to you Below is the PT6A-114 AD, please read it over and verify for 

me that it meets the requirements of you revised AD

Thank you very much

Sincerely,
Frederick Zink

Aerospace Engineer

Engine Certification Office. ANE-142

Tel. 781-238-7779

http://www.faa.gov/about/office_org/headquarters_offices/avs/stakeholder_feedback/air/field/

----- Forwarded by Frederick Zink/ANE/FAA on 11/06/2013 11:15 AM -----

From: Drexel Ace/ANE/FAA

 ANE-110, Standards Staff

To: Frederick Zink/ANE/FAA@FAA,

Date: 11/06/2013 10:51 AM

Subject: Final version 13ne26 NPRM

(See attached file: 13ne26n.doc)

Also, in Federal Register:

https://www.federalregister.gov/articles/2013/10/29/2013-25460/airworthiness-directives-pratt-and-whitne

y-canada-corp-turboprop-engines

Drexel Ace

Technical Writer-Editor

Federal Aviation Administration

Air Certification Service

Engine & Propeller Directorate Standards Staff, ANE-110 Burlington, MA

Phone: 781-238-7197

To send us your feedback, click here!RDIMS-#8793364-v4-AD_CF-2005-11R1.DOC