3 ms·

The aircraft was 11 nautical miles away, which is over the horizon.

• Someone 10y ago
  It's only over the horizon if the plane was flying below 200m or so (https://en.wikipedia.org/wiki/Horizon#Distance_to_the_horizon https://en.wikipedia.org/wiki/Horizon#Distance_to_the_horizo...) I can't find conclusive evidence, but I think that's unlikely, given that the planned cruising height was 4300m (https://en.wikipedia.org/wiki/Iran_Air_Flight_655#Shootdown_of_Flight_655 https://en.wikipedia.org/wiki/Iran_Air_Flight_655#Shootdown_...), and it was shot down about halfway through its flight. I'm not sure whether using binoculars at 20km distance makes sense, though. There's quite a size difference, but even if it would be easy to spot the difference from that far away having half a minute or so to find the plane using your binoculars would be challenging (it's about a minute of flight for a passenger plane, but if it were military, you would want to hit it before it had a chance to fire a missile, and according to Wikipedia, the Maverick that they feared an Iranian F14 might carry has a range of over 12 nautical miles)