Hi Bodhi,
>It would take extensive mods to the 17 as it's tail is not strong enough to tow a 14000 lb fighter.
Hm, are you sure this would have been a problem?
The Germans had a lot of different setups for towing, and usually the tugs seem to have been able to tow something like 50% of their own weight without extensive modification. (I pulled this number out of my hat, so please don't consider it accurate or reliable :-)
Using the "lifting tow" (Tragschlepp) system, a He 111 was able to launch and tow a Ju 87, for example. The tow gear was monted near the centre of gravity, so the strength of the tail was not an issue.
The well-known Mistel system had the advantage of having the fighter's engine power available for take-off. It was not used for carrying escort fighters, but I believe this idea might have been behind the original conception.
The German even made air-to-air refueling experiments, developing a hose-and-drogue-system, but they only worked out the aerodynamics and never actually got to the actual refilling part :-)
The Russians had their Zveno system, using it to carry up to four fighters into the air on and below one bomber - a TB-3, I believe. They even used that one operationally, with a TB-3 carrying two I-16 fighter bombers to long-range targets.
Regards,
Henning (HoHun)