They look compressed. Imgur is a pretty bad image host if you want folks to judge image quality. Try using Flickr and linking to the original image (because Flickr also compresses and sharpens the resized images) or use a host that doesn't mess with files, such as minus.com or abload.de
FWIW, Memphis Belle looks okay, and FiFi looks a bit grainy.
Slight compression, so won't comment on the quality, but both would need better crops. The first needs a tighter one, and the second you've cut the tug and props - either crop tighter or wider than what you have.
Crop should be fine for both, but as you mention, not the best light on the B-17, so I see dark (& softness) possibly being issues. Also looks a bit yellow.
Quoting dlowwa (Reply 4): Crop should be fine for both, but as you mention, not the best light on the B-17, so I see dark (& softness) possibly being issues. Also looks a bit yellow.
Might have to try another image from that sequence then. Is the B-29 okay?