Towplane performance

Our operation has started the hunt for a new towplane.
The main criteria is that from our 2200ft strip at sea level we need
to have a two seater (janus) "over the fence" at 300ft in still air.

What would you recommend?
Dont dwell on purchase cost but rather performance/running costs

We would consider
a) Used
b) New
c) Experimental/anything else.

Thanks for your thorts.

Roy,

You say that you´re looking for a new towplane! What type did you operate so
far?
A 2200ft strip at sea level and 300ft over the fence in still air with a
Janus in the tow sounds like a challlenge!
I was towed by many different towplanes, but there are very few which can do
that reliably!
One, which can do the job is a YAK-55 though....however, not the usual kind
of towplane!
Check this:

http://tinyurl.com/6jcdt

I tow with our clubs Husky and on our 1600ft strip (1950ft above msl) we are
talking more like 50ft "over the fence" (and much less in the summer) with a
DG-1000 in the tow.

Good luk,
Markus

We have a Pawnee 235HP, most common of tow planes.. there are also 260HP
versions.
Also a CalAir tow plane may work.

We operate from a 2833MSL airport, 3500ft long runway.. normally glider
starts from about 500ft, so that leaves 3000ft of runway to go.. on hot
summer days.. with a 2-33 or a Grob 103 in tow at MaxGW.. we can plan on
200ft at the departure end.

Looking for 300ft in the air at departure end, in a Janus (assume two seats
loaded) at max GW take off from a 2200ft long runway is very optimistic.

I'm not sure what the performance would be with the Wilga... but I'm
guessing not much better.

BT

"Markus Feyerabend" wrote in message
...

Our operation has started the hunt for a new towplane.
The main criteria is that from our 2200ft strip at sea level we need
to have a two seater (janus) "over the fence" at 300ft in still air.

What would you recommend?
Dont dwell on purchase cost but rather performance/running costs

We would consider
a) Used
b) New
c) Experimental/anything else.

Thanks for your thorts.

Roy,

You say that you´re looking for a new towplane! What type did you operate
so
far?
A 2200ft strip at sea level and 300ft over the fence in still air with a
Janus in the tow sounds like a challlenge!
I was towed by many different towplanes, but there are very few which can
do
that reliably!
One, which can do the job is a YAK-55 though....however, not the usual
kind
of towplane!
Check this:

http://tinyurl.com/6jcdt

I tow with our clubs Husky and on our 1600ft strip (1950ft above msl) we
are
talking more like 50ft "over the fence" (and much less in the summer) with
a
DG-1000 in the tow.

Good luk,
Markus

In article SPI3e.2906$ZV5.894@fed1read05,
"BTIZ" wrote:

Looking for 300ft in the air at departure end, in a Janus (assume two seats
loaded) at max GW take off from a 2200ft long runway is very optimistic.

Our 260 HP Pawnees normally get around 600 fpm at 65 knots with a Janus
(or Grob Twin for that matter) with two people. That's a climb angle of
about 1:11. OK, so you can get a better angle with a slower speeed, but
not *that* much better.

300 ft AGL after 2200 ft is a climb angle of nearly 1:7. The actual
1:11 a Pawnee gives would give you 200 ft AGL after 2200 ft. And that's
assuming that you *start* with runway already with full flying speed.
In reaily you're going to need about half the runway just to get up to
climb speed. And then you're going to have to climb at about 2000 fpm.

Not going to happen.


I'm not sure what the performance would be with the Wilga... but I'm
guessing not much better.

When we tried a Wilga at our club we found that the tow turnaround was
shorter, but it was because the Wilga came down faster not because it
went up faster.

--
Bruce | 41.1670S | \ spoken | -+-
Hoult | 174.8263E | /\ here. | ----------O----------

Looking for 300ft in the air at departure end, in a Janus (assume two
seats
loaded) at max GW take off from a 2200ft long runway is very optimistic.

Our 260 HP Pawnees normally get around 600 fpm at 65 knots with a Janus
(or Grob Twin for that matter) with two people. That's a climb angle of
about 1:11. OK, so you can get a better angle with a slower speeed, but
not *that* much better.

Great explanations..
Our 235HP Pawnee will average about 400-500fpm with a two up 2-33 or Grob
103.
And we break ground with about 1500ft runway remaining... so.. about 200ft
at departure end.
We are lifting off at about 55KIAS and towing at 60 for a 1-26 and 65 for
the Grob.

BT