The U.S. Navy on Jan. 28 published the final request for proposals (RFP) to build a replacement for its fleet of TH-57 training helicopters.

Industry hopefuls have until April 2 to submit proposals for the Advanced Helicopter Training System (AHTS) TH-XX. The instrument flight rules (IFR)-certified TH-XX aircraft will replace the legacy TH-57B/C Sea Rangers used by the U.S. Navy, Marine Corps and Coast Guard for advanced helicopter training for undergraduate pilots.

Naval Air Systems Command (NAVAIR) anticipates awarding a single firm-fixed-price contract for a total procurement of 130 commercial aircraft through a base and up to four options, according to the RFP. Contract award is anticipated in the first quarter of fiscal year 2020.

Numerous TH-57 Sea Ranger Helicopters sit on the flight line at Millington Municipal Airport, Tenn. U.S. Navy photo by Photographer’s Mate 3rd Class Joseph M. Buliavac (RELEASED)

As a training system, AHTS includes the TH-XX aircraft and its associated Ground Based Training System (GBTS) to train contact, basic and radio instruments, basic formation, and tactical events including use of night vision devices, low level navigation, external load, search and rescue (SAR), hoist, shipboard operations and tactical formation, according to the RFP.

Proposals likely will come from three companies that are publicly competing for the work: Italy’s Leonardo with its TH119 single-engine trainer, Airbus Helicopters with its H135 light twin and incumbent TH-57 Sea Ranger manufacturer Bell, which is offering the 407GXi. Airbus Helicopters is part of Europe’s Airbus Group and Bell is a division of Textron [TXT].

The manufacturers were working off a draft RFP published in November. This RFP finalizes the specifications for the aircraft and anticipated delivery schedule for a commercially available, FAA-certified, IFR-capable training aircraft. Plans are to start buying new trainers in fiscal 2020 and have the entire TH-57 fleet divested by 2023.

Final specifications for the TH-XX aircraft require that it is capable of continuous operations in temperatures ranging from -2 to 102 degrees Fahrenheit at the Navy’s rotorcraft training base at Naval Air Station Whiting Field in Florida.

It will fly at 115 knots true cruise airspeed during daytime operations and 80 knots true airspeed with the doors removed with a service ceiling of at least 15,000 feet, according to the RFP. It will be able to hover out of ground effect at maximum gross takeoff weight at sea level and have two and a half hours of endurance with “mission fuel equal to endurance fuel.”

The Navy is also mandating a digital health and usage monitoring system (HUMS) for ground-based display of information to aid in predictive maintenance and reduce sustainability cost. The HUMS system should store data generated from 24 continuous flying hours and provide diagnostics and health monitoring of drivetrain components, rotor components, engines and engine performance, absorbers, hydraulic systems, electrical systems, hydro-mechanical and electro-mechanical systems, and for structural usage monitoring/regime recognition, according to the RFP.