Recently i heard an aircraft call in to a nearby field KDCU, N51255,was not available for flight tracking,comes back to General Dynamics Advanced Information Systems,was wondering if anybody knows what it is used for,possibly a test bed of some type.Thanks!!
Not sure what it’s used for, but it’s an old Convair, built back in 1956. Here’s a photo:
Remote sensing and imaging, GD owned portion of the old ERIM.
I worked with them years ago developing methodologies for tracking oil spills in the marine environment from the air when they were still part of UMICH/Willow Run Labs.
Looking at the pictures again, I should have noticed the “pod” on the bottom. 
Thanks for the replies,somebody had mentioned elsewhere maybe a testbed for the P-3.