During the night wildfire the planes should not be involved because earlier in the film they were told never to fly at night.
During the lodge evacuation scene there is a biplane trying to get its engine started so it can take off. The propeller blades on the biplane are obviously pitched in the wrong direction to pull the airplane forward with the engine running and would push it backwards instead.
In the movie, the red and green navigation lights are visible from aircraft in positions where they would not be visible in real life. The red light would be visible only through an arc of 110 degrees from straight ahead to port. The green light would be visible only through an arc of 110 degrees from straight ahead to starboard. This means that you would only see both read and green navigation lights if you were looking head on to the aircraft and would see neither red nor green if within an arc of 140 degrees centred on straight behind (70 degrees either side).
When Blade Ranger and Dusty fight the fire together, Dusty's altimeter shows the 10,000 scale moving incredible fast when it should have been the 100 scale.
Near the end of the film when Dusty's engine seizes due to being redlined, various cockpit instruments and warning lights are shown. During this sequence, a number of gauges are shown failing, including the oil pressure dropping, however, the engine rpm gauge can clearly be seen still at maximum even though the engine has stopped.
The rotating beacon on the water tower at Dusty's home airport is shown as being red and white. Actual civilian airport beacons are green and white.
When the jumpers load into Cabbie, it shows them entering single file, Cabbie is not long enough to hold all the jumpers. Nor is he wide enough to allow them to be parked side by side.
In the lodge is a wood carving, asking the question: "What is the hopping motion observed in deer refered to as?". The word 'referred' is misspelled.