by Matt Hartman

Coulson Aviation brought their first Boeing 737 Fireliner to California at the end of September for grid testing and certification

Purchased from Southwest airlines this is the first of six Boeing 737-300s which will be converted into air tankers.

This air tanker N137CG (Tanker 137) was delivered to Southwest Airlines in 1995 and retired by the airline in 2017 when it was purchased by Coulson Aviation and converted into the Fireliner. This aircraft has been designed as a multi-use aircraft and has the ability to carry 4000 gallons of retardant or passengers.

The process involves dropping retardant over a grid of thousands of cups intended to measure the volume and consistency of the pattern when it hits the ground. The Interagency AirTanker Board requires   passing this and other certifications before an aircraft can be “carded” as a federal air tanker, which makes it eligible for a contract to fight fires.

The Fireliner was required to make 20 to 25 drops over several days for the test. Firefighting hand crews were hired or borrowed to retrieve the cups after each drop.

The grid testing at Lancaster turned out to be very successful and the Fireliner passed all test and was certified as an Air Tanker. Coulson Aviation have signed a contract with the New South Wales Fire Department and the aircraft will soon be heading down to Australia where it will be based at Richmond Air Force Base.