SINGAPORE—ST Engineering will start a passenger-to-tanker (P2T) conversion program with U.S.-based firefighting service provider Galactic Holdings to modify Boeing 757s into aerial water bombers.

The work will be carried out at ST Engineering’s facilities in the U.S. The first aircraft is expected to enter service by 2024.

The 757P2T will have a capacity of up to 7,000 gal. of fire retardant, which ST Engineering says will make it one of the most capable aerial firefighting platforms available on the market. It adds that the Boeing 757P2T also is more fuel efficient than the current generation of firefighting platforms, and has the versatility to be deployed to remote locations for firefighting missions. Some legacy converted aerial firefighting platforms include the DC-10, Boeing 737 and Avro RJ85.

The modifications include the installation of two 3,500-gal. tanks on the main deck and lower deck with interlinking channels, and the addition of a forward and aft release doors. Supplemental type certification is expected to take place in 2024 with entry into service the same year. The windows will be plugged with venting functions.

ST Engineering began passenger-to-freighter conversion programs for Boeing 757s in the early 2000s, most notably signing a contract with FedEx for the conversion of 87 757-200s.

Managing member of Galactic Holdings Darrin Henry said in a statement that the 757P2T will deliver “a green and highly innovative firefighting solution” and will rely on ST Engineering’s maintenance, repair and overhaul services for its future fleet. The 757s will be the company’s first jet-powered aircraft.

ST Engineering adds that, although it has the capability to convert aircraft into tankers, it has no plans to develop air-to-air refueling variants for the civilian contractors due to the already mature market dominated by major defense primes.