"Roy" wrote in message
om...
Many thanks for all the advice and suggestions so far.

Non of the suggestions were for other than standard (old) aircraft
products.

It has been suggested that an RV9 with a big motor (160-200hp) would
be great to do the job.

Anyone else considered this approach?
We are not a commercial operation and dont have to pay our pilots.
There is no insurance problem so this solution has some appeal. ie
new airframe, easy repair & maintenance.

Have a look at this site.
http://www.soarmn.com/soaring_files/...ison_table.jpg
This Towplane table was done in 1994. The calculation are all referenced to
see level and standard temperature. The performances appear high,
but are not, because most of the comments on this group referred to High
temperature and high altitude. All Climb performances are with a fully
loaded
twin Grob. Acceleration on the Ground was not taken into account.
For example if the temperature is 80F and a 1000ft the factor becomes .77
Please note how well the Zenith 300 with a 180 HP does.

I could well imagine Dick VanGrunsven RV 9 with a 180HP would do very well
but
the RV 10 would be a better choice, as the airframe is stronger and designed
to take a bigger engine, the airframe would still be well under 1500lb if it
is a
very basic tow plane. For example the RV 9 with a pilot and fuel and a max
160HP
( allowed only) has a power loading of 10.

The RV10 with the same pilot and fuel would, but 180 HP, would have the
same
power loading as the RV9. The RV 10 has a larger wing area, it would climb
better
at the speeds we tow at. Also the Airframe is designed for up to 260HP.

For a club with a small membership and limited options I would favour a
stripped down
C-170 or 172 with 180HP if Summer temperature and see elevation allow.
Parts and services are readily available and the performance is not bad at
all for 180HP.
Regards
Udo