Given the Ruhrstahl/Kramer X-4 was wire guided I wonder if some sort of prop guard would be required?
After weapons testing with the X-4 wire-guided missile the Ar-234 was converted to pusher turboprops, which, coincidentally, led to the ability to carry a second pair of X-4's inboard of the engines & to the outer missiles being able to be brought closer in, thus reducing the loading on the outer wing sections! ![Wink ;)](http://beyondthesprues.com/Forum/Smileys/clabIcons/wink.gif)
The engineer in me wonders if those would be gearbox driven propellers as on Allison's propfan design or exhaust-driven propellers like the aft fans on the CF700 and CJ805-23 or the aft propfans on GE's GE36 unducted fan engine. Personally, I think the gearbox driven approach would be more feasible for the times.
The BMW concepts used a gearbox, the first design being a contra-prop with planetary gearing in a
ducted spinner, second contra-props with a long spinner, short annular intake and gear drive moved
aft to in front of the compressor.
![](https://i.imgur.com/UOKy9QO.jpg)