Z, not sure which shots you are talking about.
I'll use an example using some of my shots what I mean.
Here is an example of a decapitation. However the plane was too big to fit in my lens so I decapitated the nose and the rear tail section. This was taken with a film camera back in DEN in 1996 and is the only picture on a-d that exists of this plane and Aviateca 727-200. I originally had the wrong registration not knowing anything about Mexican registrations and put XA-51J, but found it was XA-SIJ - however no photos or profile existed of this plane so I went and built a profile for it anyway. I would probably keep this plane because its rare on here. However if I did the same to a Southwest 737-300/700 in current c/s (if you have a Southwest 737-200 in old colors that would be different) or an American 757 etc or for the Europeans on here a Ryan Air 737-800 I would definitely delete it.
http://www.airport-data.com/aircraft/XA-SIJ.html
Here is an example of what I mean by a decapitation - this is from the same trip, this case a Frontier 737-200. I chopped off part of its nose, but what is most important about Frontier? The animal on the tail. This was taken in 1996 with a film camera, plane was moving and I was focusing on the tail had no idea I chopped the nose. If I was at DEN today and a Frontier A319 was about to taxi under that bridge and I chopped its nose I could look on my LCD screen and see I missed it and grab it again
http://www.airport-data.com/aircraft/N212US.html
There are only 3 shots of this air frame on here - I have the only pictures of it in Frontier colors, someone else has it in US Air colors so again it isn't common. However if this was a Southwest 737-700 in the current scheme I would definitely delete it.
I would call the below an intentional decapitation and it was taken by a digital camera. I was trying to zoom in on the lady nose art on a Virgin Atlantic 747, I have several similar shots of different Virgin 747s. What I did BAD here was the editing, and I don't have the original since it got lost on my old computer. While the intention was to decapitate the rest of the plane to get a close up on the nose art, I left too much blue sky on the right side:
http://www.airport-data.com/aircraft/photo/387118.html
I should have made it look like this instead -
http://www.airport-data.com/aircraft/photo/306741.html
Although I still could have centered it better because look at the open sky above it.
http://www.airport-data.com/aircraft/photo/536164.html
This would be more even other than a little open sky between the nose and edge of picture
I know I probably too have some common aircraft that are really bad shots on here, but with 36,000 pictures to go through, it will take a while before I find all of them. A lot of the unacceptable shots I have will be between 2002-and 2006, when the only camera I had from 2002-early 2005 were disposable cameras I bought at Walgreens when something special was coming in to the airport or if I went on a little trip and I was grabbing planes out the airport window - all before I posted anything online but later scanned on here. Then from early 2005 to June 2006 I owned a junk Nikon point and shoot - took decent pictures up close but distant or flying shots sucked.
Those would be candidates for replacement
Along with "dark shots" of common aircraft - ie a Southwest 737 that I have 20 pics of on here where the sun is in front of a cloud - I know I have a bunch of those. I will keep the pics though for more unusual aircraft.