I was watching Mayday Varig Flight 254 and at minute 38 it said that some passengers noticed that the plane was flying in the wrong direction. This accident took place in 1989, so my question is: without 'modern' aids like GPS, smartphones, in-flight entertainment system maps etc., can a passenger really notice where the aircraft is heading to?
(I suggest you watch that minute of the video if you have the time. It will help to understand the question.)
can a passenger really notice where the aircraft is heading to?
A wide variety of observable phenomena and general attentiveness can lead to an approximate understanding of which direction the aircraft is heading in.
Passengers can rely on visibly observed phenomena such as stars, moon, sun, ground topology, or major landmarks (interstates, cities, facilities etc.). General familiarity with flight routes and runways, coupled with attentiveness to significant changes in roll, pitch, and yaw can bolster an understanding of the flight's direction.
Items such as a compass (built into Casio calculator watches?) could also be used to get an approximation of direction. They may be affected by other instrumentation and mechanical features along with being really cheap.
Some passengers will be able to note which runway they took off from and a divergence from a typical path. While still ascending they can more easily notice landmarks that are likely familiar, and recognize that no significant change in direction has happened since orienting themselves.
It's possible too that cognitive bias may be another explanation. The media, and documentaries like this, seem to embrace an event as predictive or accurate despite a long history of inaccuracy or patterned behavior. That passenger who makes 98% incorrect assertions of plane direction is only recorded or listened to after the fact and appears to be 100% accurate in their vastly under sampled assertion set. How does it go? A broken clock is right twice a day?
Also, thanks to all the comments, tried to cover most of those notes/ideas here.
Absolutely you can. I have been doing this since the 1980s when I started flying. I love maps and love looking at the earth from 30000 feet up. When I see interesting features I want to know what they are and where they are. Nowadays with google maps it's very easy to do this without getting into a plane but back in 1989 your best opportunity to see the earth from up high was a plane flight. Every trip for me was an opportunity to explore and I'd prepare for the flight by having a look at a map and gaining an understanding of the significant landmarks we'd be flying over and the potential routes.
When you know what to expect and what things generally look like from altitude it's easy to keep track when over land. Working out the exact heading is trivial if you can see the sun or a few key stars. Most plane flights are above any clouds giving you great astro-navigation cues (learning how to determine compass directions from the stars is easy in both hemispheres).
Once you progress to being a frequent flyer you tend to know exactly where you are. I've flown Sydney to Cairns, Auckland and Melbourne enough times now that I can pick out all the cities, towns, rivers, lakes, damns, harbours, bays, open cast mines, wind farms, power stations etc. Over the ocean it's just dead reckoning (ssw for 2.5 hours from Sydney... should see the NZ coast soon. oh yeah there's the entrance to Kaipara harbour).
I would suggest that there is a subset of the passengers on board who know exactly where the plane is currently and where it is heading. They're the ones in the window seat spending the flight staring out the window like they think the view outside is more interesting than the movie....
There is a way to determine North with your wristwatch, if the sun is visible through the windows (see here). This would help to notice if the plane is heading in a completely wrong direction. Many hikers know this trick.
Of course, it is even more obvious if the sun is ascending in the morning on the completely wrong side.
If it is in the night, many people know where the North star is, and some more skilled in astronomy may guess its location even if they see some other piece of the stellar sky.
All this is not likely for a single random chosen individual, but if there are say 500 passengers on a plane, it may a hiker between them, and it may be an astronomer between them because even finding a certified pilot between passengers is not completely unheard of.
