Status: Optical Illusion
Barry Bland snapped a photograph of two airplanes apparently narrowly avoiding colliding in the sky over London. However, Civil Aviation Authorities are dismissing the photograph as an optical illusion, pointing out that none of their safety systems indicated that the two planes were close to each other.
The BBC reports:
British Air Line Pilots Association chairman Captain Mervyn Granshaw described it as a "fluke photograph". He explained how visual factors conspire to make the planes could look closer together, but safety measures meant they could not be in such proximity. While the lower plane was a A300, a smaller freight plane, the one behind was a JAL A330 - a larger, passenger plane. The difference in size, angle of the photograph and the distance it was taken from - the ground to two planes at high altitude - would exaggerate the effect, he said.
I'm inclined to agree that it's just an optical illusion, since I've seen these kinds of "near miss" photos before. (For instance, there's this
phony near miss over San Francisco.) The lack of visual reference points in the sky can really play tricks on your eyes. (Thanks to Charlie Wright for the link.)
Comments
There are some really neat optical illusions on this sight as well, you may be able to spend hours there, if you like planes...
For someone to get this photo, they must have been within a very narrow cone of vision to the incident. Given that the JAL plane is meant to be about 40% bigger than the A300 (again, according to reports. I haven't checked this out), it should be possible to work out the distances involved.
Photographer must have taken a series of photos with the planes in roughly the same orientation for a bit.
If we assume that the photographer was looking very nearly straight up (i.e. altitude = distance from observer);
A300, length = 54m, alt = 2700m,
B777, length = 74m, alt = 3000m,
The larger aircraft should appear to be (74/3000)/(54/2700) = 1.233 times the size of the smaller.
Looking at the picture the images of the planes are around 54-56 and 68-70 pixels across; i.e the ratio's between 1.214 and 1.296.
Hence within my margin for error, the planes might easily be 1000 feet apart and are almost certainly more than 500 feet apart.
As this would mean 1.118 times the size "only".
With this it would be not surely more than 1000feet apart?
PS: picture series of this at
http://www.sky.com/skynews/picture_gallery/picture_gallery/0,,70141-1210748-1,00.html
Airbus A300 dimensions:
Wingspan: 44.8 m
Length: 54.1 m
Boeing 777 dimensions:
Wingspan: 60.9 m
Length: 63.7 m
Boeing 777-300 dimensions:
Wingspan: 60.9 m
Length: 73.9 m
I can't tell what model of Boeing 777 it is.