Airworthiness Directive · Amendment 39-21226 · Fuel control/turbine engines
Pratt & Whitney Canada Corp. Turboshaft Engines
This AD applies to Pratt & Whitney Canada Corp. (P&WC) PT6B-37A model turboshaft engines with engine serial number PCE-PU0289 and earlier, which do not have an installed fuel control unit (FCU) that incorporates a stainless steel air adapter using P&WC Service Bulletin (SB) No. PT6B-72-39107, Revision No. 1, dated December 13, 2017.
The FAA is adopting a new airworthiness directive (AD) for all Pratt & Whitney Canada Corp. (P&WC) PT6B-37A model turboshaft engines with engine serial number PCE-PU0289 and earlier. This AD was prompted by a report of contamination from galvanic corrosion between the fuel control unit (FCU) aluminum body and the steel union fitting causing the loss of engine control, resulting in an engine over-speed condition and subsequent in-flight shutdown (IFSD). This AD requires replacing the FCU with a part eligible for installation. The FAA is issuing this AD to address the unsafe condition on these products.
Within the compliance time identified in Table 1 to paragraph (g) of this AD, replace the FCU with an FCU that incorporates the stainless steel air adapter using the Accomplishment Instruments, paragraphs 3.A. and 3.C., of P&WC SB No. PT6B-72-39107, Revision No. 1, dated December 13, 2017.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
