The model in the background looks like a Gulfstream. Probably a
Gulfstream II ? The horizontal elliptical windows sure look like the
Gulfstream trademark to me. I guess they installed the turboprop on
the jet powered aircraft to study effects of tailplane icing on a
turboprop aircraft, but with jet engines as extra safety items (?)
Maybe the jets would provide not only extra thrust but also some "de-
icing" power???

Ray Lovinggood
Carrboro, North Carolina, USA