The Canberra is a lot bigger than a U-2 (crew of 2-3 instead of 1, has a large bomb bay that got repurposed for instruments/recon payloads, etc). Also, there ar

The Canberra is a lot bigger than a U-2 (crew of 2-3 instead of 1, has a large bomb bay that got repurposed for instruments/recon payloads, etc). Also, there are probably a lot more spare parts kicking around -- over a thousand were built, and it only went out of front-line service (last operator: the Indian Air Force) in 2007. The SR-71 is monstrously expensive to operate and flies in an utterly different regime -- high supersonic/low hypersonic flight, at higher altitude. And, again, it has a smaller payload. It's kind of amazing that an aircraft specc'ed in 1944 as an emergency wartime replacement for the de Havilland Mosquito is still flying in anything other than an air show display role. https://en.wikipedia.org/wiki/De_Havilland_Mosquito https://en.wikipedia.org/wiki/De_Havilland_Mosquito