- The Provincial Air Service set up its field headquarters in Sault Ste. Marie on April 1, 1924.
- Fourteen HS-2L Flying Boats (H-Boats) were purchased. These open-cockpit, five seaters were clumsy but delicate machines. Engine failure and forced landings were common. These aircraft carried a payload of 700 pounds at a speed of 70 mph and were in service for nine years.
- A number of de Havilland Moth aircraft were purchased and became the backbone of the forest fire detection fleet. This aircraft was adaptable to wheels, skis and floats.
- The amphibious Vickers Vedette, four Hamilton mono seaplanes (the air services first all metal aircraft) and four Fairchild 71 cabin monoplanes with folding wings were added to the fleet.
- The Fairchild KR-34 open cockpit biplane was introduced to the Air Service for fire patrol, light transport and communications.
- The Ontario Provincial Air Service built 4 Buhl CA-6 Air Sedans which made the Air Service an aircraft manufacturer.
- In this decade, the Air Service acquired its first aircraft of modern configuration - the Stinson Reliant, one of the top load carriers of Air Service until well into the war years.
- Pilots directly aided Canada's war effort by regularly flying mine personnel and diamond drills to and from mining properties that were sources of metals vitally important to war production.
- The de Havilland Beaver was introduced. Over 40 of these aircraft were to wear the yellow and black over the next 50 plus years.
- Another welcome addition in 1948 was the completion of additional hangar space to the front of the original hangar which added three times the space and allowed most of the entire fleet of aircraft to be housed in one location for winter maintenance.
- Executive Flight Operations, which began in 1951 with a Beechcraft Dove aircraft provides business aircraft to authorized government officials for flights throughout North America.
- In 1952 the Otter was developed (a bigger and better version of the Beaver). A one ton payload, ultra-high-lift wing and powerful engine capabilities made this aircraft the marvel of its time.
- In 1955, the Air Service's Beaver and Otter flying firefighting crews were called upon to battle holocaust after holocaust in one of the worst fire seasons on record: 2,252 forest fires in all. There were no accidents or casualties that season, which attests to the calibre of the pilots, air engineers and all others engaged in forest firefighting.
- In 1957 the Air Service developed and introduced an entirely new approach to fighting forest fires - aerial waterbombing. From floatmounted or underslung rotatable tanks, which filled with water by means of a snorkel as the aircraft skimmed the surface of a lake, pilots were able to attack fire from the air and gives firefighters a chance to get in on the ground, set up their pumps and put a fire out.
- In 1965, as the phasing-out of the standard Beaver began, the Air Service acquired the turbine-powered Turbo-Beaver and Twin Otter aircraft. A total of 28 Turbo Beavers and three Twin Otters were in operation by 1970.
- With the acquisition of the new aircraft, new integral waterbombing systems were developed and installed on the aircraft in the latter half of the decade.
- In 1970, the Air Service purchased a CS2F-1 Grumman Tracker aircraft as a prototype to test a large land based aerial fire fighting tanker. In 1972/73 six additional units were purchased and converted. These aircraft dropped over 800 gallons of water/retardant mixture at speeds much faster than the Twin Otters, Otters and Turbo Beaver aircraft. In a single pass over a forest fire, it could deliver a smothering weight of 5 1/2 tons of chemical mix.
- In 1978/79, two Beachcraft King Air executive transport aircraft were added to the fleet.
- In 1980 three new Twin Otters were introduced into the Air Service. This more than doubled the fleet of the 400-gallon waterbomber.
- In 1981, the provincial and federal governments of Canada purchased 49 CL-215 aircraft for forest fire protection in Canada. Ontario received nine aircraft commencing in 1983 with the final Cl-215 being delivered in 1987.
- The 1980's also introduced the Air Service to a rotary wing fleet of four Bell 206L-1's and a BK-117 twin-engined helicopter.
- With the new Cl-215 aircraft, it became very clear that Aviation Services required a new home to house and maintain these aircraft. In 1991, Aviation Services staff were moving into a 35,000 square foot hangar and office facility.
- The 1990's saw the addition of four new AS350-B2 helicopters.
- In April 1998, MNR's Aviation Services received the first five of nine state-of-the-art CL-415 heavy waterbombers. These aircraft differ from the CL-215's as they are faster, carry more water, have latest technology in electronic flight instrumentation and flight control systems, air conditioning, equipped with turbo-prop engines, and in general require less maintenance to enable these aircraft to spend more time over the fire.