Airworthiness Directive · Amendment 39-19479 · Fuel control/turbine engines
Pratt & Whitney Turbofan Engines
This AD applies to all Pratt & Whitney (PW) PW2037, PW2037M, and PW2040 turbofan engines with JFC104-1 fuel control units (FCUs) with serial numbers listed in the Accomplishment Instructions, FCU Serial Number List, of PW Alert Service Bulletin PW2000 A73-172, dated October 16, 2017.
We are adopting a new airworthiness directive (AD) for all Pratt & Whitney (PW) PW2037, PW2037M, and PW2040 turbofan engines. This AD was prompted by an uncommanded high thrust event that occurred during approach on January 16, 2016, and during landing on April 6, 2016. This AD requires removal of the metering valve pilot valve (MVPV) within certain fuel control units (FCUs) and the MVPV's replacement with a part eligible for installation. We are issuing this AD to address the unsafe condition on these products.
Remove from service the MVPV from the FCU at the next FCU shop visit after the effective date of the AD and replace the MVPV with a part eligible for installation.
(1) For the purpose of this AD, an FCU shop visit is defined as the removal of the FCU from the engine and induction of the FCU into a FCU shop that can perform these procedures regardless of the scheduled maintenance action or the reason for the FCU removal.
(2) For the purpose of this AD, a part eligible for installation is one of the following:
(i) A zero time since new MVPV, or
(ii) An MVPV repaired by a method approved by FAA that includes an end plug with tamper proof features. A tamper proof feature is a feature that goes beyond the original equipment manufacturer design of only using epoxy retention and threads to prevent end cap maintenance tampering and loosening.
After the effective date of this AD, do not install any MVPV removed in accordance with paragraph (g) unless it meets the definition of a part eligible for installation per paragraph (h)(2) of this AD.
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.
