A -- Implement an NTS software change to NP2000 propeller system

The Naval Air Systems Command (NAVAIR) intends to negotiate a modification to a delivery order with Hamilton Sundstrand, Windsor Locks, CT 06096, to implement a software change to five modules of the Electronic Propeller Control (EPC) on the NP2000 propeller system in an attempt to minimize the likelihood of a decouple event. Decouple is a gearbox safety feature employed to limit the amount of negative torque and prevent excessive drag on the E-2C aircraft, however it imposes a higher degree of difficulty in maintaining aircraft control. The EPC software will implement a decrease pitch rate limit for a short interval following the Negative Torque System (NTS) plunger action and an increase in the NTS gain. The software logic changes will be verified and validated through engine/propeller dynamic software models and closed loop bench simulations. Hamilton Sundstrand is the designer, developer, and sole manufacturer of the 54460 and NP2000 propellers and is, therefore, the only source that possesses the resources and in-depth technical knowledge and technical data necessary to provide these services within the time required to meet USN requirements. See Note 22. NAVAIR synopsis No. 20064-03.