Charlie:
We used the system for several years on our 2 Pawnees and finally got away from it. I found that it was a useful system for situations of limited operations - particularly where the pilot wants to do a tow and then carry on to a new destination ( like a cross country retrieve) without landing to drop the rope. It also had all of the expected advantages of not landing with a rope hanging behind you. But - we also found a few very significant disadvantages:

1) The system uses an electric motor that is operated by a manual switch. The tow pilot has a mirror that is focused on the tail cone so she or he can shut off the switch when the rope is fully retracted. The system depends on the tow pilot looking in the mirror at exactly the time & place where they need to be looking for traffic, checking cool down, etc. As a tow pilot I did not like that.

2) The system is non compliant with FAR 91.309(a) since it uses only one weak link (the FAR requires 2: one at each end) and there is no way to use a weak link at the towplane end. In a towing accident that could be an issue.

3) The system can't be used in cold weather. If the rope gets wet it freezes on the reel. If you switch over to use the manual Tost release you have to disconnect the guillotine cable and connect it to the Tost release. This is dangerous because if the reel is now used - the guillotine is disconnected. That happened to us twice and we had to tape over the housing to prevent a reoccurrence.

4) It is possible for the reel to get tangled so that the rope stops close to the end - but the glider load is on the reel (and not on the airplane airframe). The reel is not designed to take that load.

5) Tangles are frequent - and a PITA. Checking the portion of the rope that is hidden behind the guillotine is also a PITA. Changing the rope is a PITA.

6) The system is expensive and parts are expensive. We had lots of rope breaks (almost never at the Tost weak link) and that weak link unit is expensive, we lost several tail cones (also expensive) and had a motor burn out (really expensive and a long wait).

7) We had incidents were the tow plane "slack out" process was interrupted and the tow pilot didn't realize that reel was not fully played out. Then when the tow started it whiplashed the glider.

8) A&Ps are not familiar with the system and some were reluctant to work on it.

Bottom line - it's a complex system that makes sense in an operation where cost is not important, the same people are using it, and obstacle clearance is important. But in a busy club or commercial environment a simple rope/release system works better - I was happy to see it go.

Roy B.(GBSC Chief Pilot)