Officially a civil IL-18W, but a special one. STP was a calibration plane of the East German government. Dresden, August 1990. Two months later STP changed its registration to D-AOAQ.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/109661044@N07">Rob Schleiffert</a> from Holland
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/109661044@N07/14175474199/">IL-18 East Germany</a>