Pratt & Whitney PT6B-37A engines with fuel control units overhauled after December 2016 - Civil Aviation Safety Alerts (CASA) No. 2018-05


Owners, Operators and Maintainers of Pratt & Whitney Canada PT6B-37A Engines

File Classification No. : Z 5000-35
RDIMS No. : 13822633
Document No. : CASA 2018-05
Issue No. : 01
Effective Date: 2018-05-07


The purpose of this Civil Aviation Safety Alert (CASA) is to raise awareness of a quality escape during overhaul of certain fuel control units installed on Pratt & Whitney Canada PT6B-37A engines.


Transport Canada Civil Aviation has been made aware of a quality escape that affects PT6B-37A fuel control units overhauled after December 2016. Some fuel control units may not have been calibrated to specification, and this condition if not corrected can lead to N1 fluctuations, hung starts and the inability to recover power during autorotation training. Pratt & Whitney Canada has issued Service Information Letter (SIL) NO. PT6B-045 concerning this issue.

Recommended action:

Transport Canada recommends that operators of the subject engine familiarize themselves with the Pratt & Whitney Canada SIL PT6B-045 and follow the recommendations therein.

Contact office:

For more information concerning this issue, contact a Transport Canada Centre; or Dean Ciaschini, Continuing Airworthiness in Ottawa, by telephone at 1-888-663-3639, by fax at 613-996-9178 or by e-mail at

Original signed by

Rémy Knoerr
Continuing Airworthiness

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.