June, 1972, Canadian Aviation
Fires may boost the usefulness of large, militarily obsolete seaplanes this year with Canso’s and Martin Mars’s being used as aerial tankers to douse costly summer forest fires across Canada. The 6,000-gallon capacity Martin Mars will be used on British Columbia fires by Forest Industries Flying Tankers Ltd., while the lighter, 800-gallon capacity Canso will be used in Newfoundland by Eastern Provincial Airways, and possibly in Quebec.
One of four bought by Flying Tankers for a total of $350,000, the Mars was converted by Fairey Aviation (Canada) Limited, of Sidney B.C., for approximately $150,000. The first attempt at using the Martin Mars for water bombing ended tragically last summer when the Mariannas Mars – the first to be converted – crashed on a fire run, killing all four crew members. The success of the second Martin Mars will determine whether Flying Tankers’ two remaining giants are to be converted.
The Mars, and ex-U.S. Navy troop carrier, which can operate on nine-foot waves, loads up in 15 seconds through its two scoops, and is airborne after a mile and a quarter run and ready to saturate four acres of fire. With the 6,000 gallons of salt or fresh water weighing 60,000 lbs carried in its four fiberglass, plywood-stiffened tanks, it weighs 162,000 lbs and has a take-off speed of 84 knots. Take-off speed empty is 62 knots. The 120-foot long plane has a 200-foot wingspan and once carried 301 people plus a seven man crew. It is powered by four, Wright 3350 engines, each capable of producing 2,500 hp.
Stop Fires Early
The Mars, like the Canso, is not designed to douse widespread fires. The purpose of the water bomber is to hit incipient fires hard at the outset and retard the spread until ground crews arrive.
The Canso doesn’t have the capacity of the gargantuan Mars, but J. K. Hawkshaw, project engineer for Field Aviation, says that in terms of cents cost per gallon delivered to the fire, the Canso can’t be beat. Two Cansos ordered by Eastern Provincial Airways have recently been converted by Field for water bombardment and both will be operated under contract for the Newfoundland government. Field Aviation also has orders for three more conversions for the Quebec government.
The Canso takes on its 800 gallons in 13 to 17 seconds through a retractable probe while skimming the water at 65 to 70 mph. With good approaches, it is useable on a lake three-quarters of a mile long. For airport landing, fire-fighting chemicals are pumped through two large chutes into the side of the plane. Water is dumped on the fire in a 240 x 120 ft. elliptical pattern through two 27 x 60 in. doors in the hull while the plane is flying over the fire at 95 mph at 150 feet altitude.
If water bombing from the Martin Mars and the Canso proves successful, not only will it preserve Canadian forests, it may also further stimulate the conversion market.
This article originally appeared in the June, 1972 edition of Canadian Aviation magazine. The image of the Canso 777 “Flying Fireman” was taken in Winnipeg in 1985.