737-300 Fireliner Air Tanker

Specialist firefighting company Coulson Aviation of Canada has converted six ex-Southwest 737-300s into aerial firefighters, known as "Fireliners". The aircraft have a 4,000-gallon capacity.

The air tanker is a multi-use aircraft with the ability to carry passengers. Coulson said, “With a full retardant load and 4.5 hours of fuel we are so far under max gross weight we are going to leave the full interior and galleys in even when just in airtanker mode.”

Conversion of the first aircraft (N617SW) began in 2017, it was then repainted at Spokane in May 2017. The gravity-based tanks of the retardant system were complete in December 2017. The first conversion was done by Coulson Aircrane Canada. The second aircraft, Tanker 138, arrived April 2018 at the Port Alberni Facility and was converted with the RADS XXL tanking system for aerial firefighting.

On 13 July 2018 air tanker T-137 made its first drops while flying out of San Bernardino, California. Britt Coulson said, “The 4,000 USG RADS-XXL/2 performed perfectly as did the airplane. Our flight crew couldn’t have been happier with the handling characteristics and our split tank worked as designed with no CG shift during the drop.” Next week they will finish flight testing with the FAA, and will soon begin static tests of the tank system. They are working with the Forest Service to schedule the grid test. Mr. Coulson expects Tanker 137 will be ready to fight fire in August.

In 2019 the Australian NSW Rural Fire Service has leased a Fireliner, known as 'Gaia' for around $2.5 million a year. The type is known as "Large Air Tanker" in Australia. The aircraft is also named "Marie Bashir" as a tribute to the first female governor.