I am an aircraft mechanic, so admittedly I have trouble watching a movie which will undoubtedly abuse reality in terms of physics and aircraft design. I recall seeing previews for this and being stunned at the laughable scenario of an inverted passenger plane. That experience dropped my expectation to essentially zero.
When I watched this film I was surprised in two ways. Firstly, the scenario was more plausible than I had given it credit. Inverted flight is a problem for most planes because of aerodynamics. And while some aircraft are aerodynamically capable of inverted flight (even some passenger planes) it is additionally a problem because hydraulic and engine oil systems are often gravity fed. This means that if a plane is able to fly this way, most of them won't fly for long before systems begin to fail. The film did a reasonable job of portraying this as the plane was just barely able to sustain level flight with a full pitch down elevator position and displayed low engine oil press warnings which led to engine fire. I suspect the roll maneuver would require more altitude than the film suggests...but otherwise it's not far from what could happen in reality if this was actually attempted. Most engine fire T-handles are designed to instantly shut fuel and bleed air valves for an engine...which doesn't seem to happen here, but that was my biggest realism gripe.
My second surprise is that this movie has very little to do with aviation. Aviation seems to be the setting for the story, but the subject itself is substance abuse. The story could have just as easily been set around a bus driver or a ship captain. Given the fact that aviation was merely a setting for the story I have to give credit to the film makers for paying at least some attention to realism.
I thought the story was fascinating. It's the sort of film that requires something of the viewer. You can't watch this without making moral judgements and that process requires each viewer to evaluate how they feel about certain subjects. The story creates just enough moral dilemma to get people thinking and any story that can succeed in that gets a pass from me.