P&WC PT6B-37A Engines - Compliance with airworthiness directive CF-2019-05 - Civil Aviation Safety Alerts (CASA) No. 2019-04


Owners, operators and maintainers of Pratt & Whitney Canada (P&WC) PT6B-37A engines installed on Leonardo helicopter models A119 and AW119MKII

File Classification No. : Z 5000-35
RDIMS No. : 15389292
Document No. : CASA 2019-04
Issue No. : 01
Effective Date: 2019-07-24


The purpose of this Civil Aviation Safety Alert ( CASA ) is to raise awareness of the upcoming compliance time expiry of Airworthiness Directive ( AD ) CF-2019-05.


Transport Canada ( TC ) issued AD CF-2019-05 on 19 February 2019 mandating the incorporation of P&WC Service Bulletin ( SB ) PT6B-72-39107R1 for the replacement of fuel control units ( FCU ) on certain engines in order to address a potential unsafe condition.

P&WC is tracking the incorporation rate of the above-mentioned SB and estimates that there are still 90  FCUs with more than 6 years in service since new or last overhaul, which must be replaced in accordance with the subject AD by 19 August 2019. P&WC had provisioned for a pool of modified FCUs assuming a constant rate of return of the pre- SB FCUs , however, given that the SB incorporation has been below expected levels, P&WC may not be able to accommodate last-minute requests.

Recommended action:

TC recommends that operators review P&WC Service Information Letters ( SIL ) PT6B-052 and PT6B-055, and follow the recommendations therein.

TC would also like to remind Canadian operators that alternative means of compliance ( AMOC ) with an AD are approved pursuant to Canadian Aviation Regulation ( CAR ) 605.84(4), which requires that the proposed alternative maintains the level of safety as provided for by the compliance time in the AD . Extension to AD compliance times are not considered unless the proposed alternative meets the above-mentioned CAR  605.84(4) requirements.

Contact office:

For more information concerning this issue, contact a Transport Canada Centre; or contact Robert Farinas, Continuing Airworthiness in Ottawa, by telephone at 1-888-663-3639, facsimile 613-996-9178 or by e-mail at cawwebfeedback@tc.gc.ca.

Original signed by

Rémy Knoerr
Chief, Continuing Airworthiness
National Aircraft Certification

The Transport Canada Civil Aviation Safety Alert ( CASA ) is used to convey important safety information and contains recommended action items. The CASA strives to assist the aviation industry's efforts to provide a service with the highest possible degree of safety. The information contained herein is often critical and must be conveyed to the appropriate office in a timely manner. The CASA may be changed or amended should new information become available.