Feb 19, 2015
The Secretive "Rat 55" - Boeing NT-43A, a heavily-modified 737-200
Modified from a T-43A around the turn of the century, Rat-55 (Radar Aircraft Testbed) has radomes on the nose and tail for use in testing the low-visibility/stealth features of new aircraft under realistic flight conditions. Rat-55 primarily operates in restricted airspace during testing. leading to there being very little public information about the testbed.
via Foxtrot Alpha