Cheaper tows?

Wrong?

Answer this, did you/others run small engines for close to 2000hrs at full throttle with no rebuilds?
Frankly, not likely.

While most IC aircraft engines are archaic, they spend most time at close to full power for close to 2000 hours.

Herb, while I know you (and you know me, but maybe not remember me), I have to say most automotive engines trying to do what a "lump of an archaic engine" is normally used in US GA gas piston engines,

Rough guess........would you run a car engine at full power for 2000hrs? Quick numbers, 45MPH for 2000 hours, say about 90,000 miles.
Me, no Frikkin way.
You, I have no clue, go for it, not my wallet.

Herb, go rush against other issues, I think you lose on this one.......OK?

At 20:52 17 October 2018, Charlie M. UH & 002 owner/pilot wrote:
Wrong?

Answer this, did you/others run small engines for close to 2000hrs
at full
throttle with no rebuilds?
Frankly, not likely.

While most IC aircraft engines are archaic, they spend most time
at close
to full power for close to 2000 hours.

Herb, while I know you (and you know me, but maybe not
remember me), I have
to say most automotive engines trying to do what a "lump of an
archaic
engine" is normally used in US GA gas piston engines,

Rough guess........would you run a car engine at full power for
2000hrs?
Quick numbers, 45MPH for 2000 hours, say about 90,000 miles.
Me, no Frikkin way.
You, I have no clue, go for it, not my wallet.

Herb, go rush against other issues, I think you lose on this
one.......OK?


You can't compare aero engines with car engines,They are nearer to
boat engines in their usage .And tugs are worse.
To red line ,full throttle, a car you would need to tow a heavy load
up a very long hill for 2000hrs.
A sensible engineer would want to size the engine to run at max for
20 or 30seconds then throttle back to 50%.

Modern Motors are much more robust, but the way we are using
Rotax engines in modern tugs is going to lead to a lot of scared
tuggies making dead stick off field landings.
With a slippy tug like the Dianamic (probably spelled that wrong)
which I saw for the first time last month, with a blown Rotax and a
variable pitch prop you might have a chance .

I spent much of last year in a Duo Discus xlt behind a eurofox tug.
I am not sure who was most scared me or the Tug pilot, but it was
my syndicate partner that decided to give the sport up.

Max power is at max revs, so the prop needs to be set so that you
can reach max revs by lift off, but if that is only 65Kts you have no
choice but to tow at max revs if the glider is heavy like mine (2 fat
men a tank of gas and a fin full of water) ,and that is at a low
British pressure altitude.
I asked the salesman for a rough price for his as yet uncertified
dianamic with a vp prop ,,,about £160,000+tax,
At that price you can put a lot of gas in Pawnees

On Wednesday, October 17, 2018 at 6:00:07 PM UTC-4, Jonathon May wrote:
I spent much of last year in a Duo Discus xlt behind a eurofox tug.

And that was during just one tow!

On Wednesday, October 17, 2018 at 12:40:35 AM UTC-4, Bruce Hoult wrote:
On Tuesday, October 16, 2018 at 4:20:17 PM UTC-7, Martin Gregorie wrote:
On Tue, 16 Oct 2018 13:13:58 -0700, Charlie M. (UH & 002 owner/pilot)
wrote:

To sorta answer this, there is an ongoing push by AOPA and other groups
along with the FAA (in the US) for a suitable unleaded fuel for use in
the older "leaded fuel" engines.
I know we added a supplement to our low lead fuel for our towplanes.
Don't remember the name of it.

Slightly off topic, but how do you guys like this engine conversion?

https://www.youtube.com/watch?v=loy2n8s_l00

The airframe is interesting: it was developed in California as a low-cost
counter-insurgency aircraft, but never caught on. The design was bought
by a NZ outfit and redeveloped as an agricultural plane in, I think, the
early '60s. It originally had 250hp, but was rapidly upgraded to a 400hp
Continental flat 6. Now they either have a 750 shp turbine or, line this
one a big block truck V8. I don't know if its burning petrol or diesel.

You see one or two 750hp turbine derivatives (the PAC750 bush plane)over
here in the hands of jump clubs. They like them because the carry a lot
of jumpers at a time and can manage 2500 fpm descent rates, so the turn-
round time is good.

Back on topic: I've not heard of them being used as tow planes, but I
reckon they'd be a match for the big turbine Zlins at that game.

Anyway, enjoy the video and its V8 sound track !

Yeah, that's video's been in my bookmarks for a few years.

It's hard to find newer footage and in decent quality :-(

Here's a newer model in 720p \o/ in a a two week old upload.

https://www.youtube.com/watch?v=YOTwJ1ASz1c


Oh, here's a two year old 1080p video of a classic 400 HP piston one. Looks like it's made by a model flyer who gets some stick for noise lol

https://www.youtube.com/watch?v=XSGYL3j5EXo

Here's the whole history of this plane called the Fletcher FU-24:
http://all-aero.com/index.php/contac...fletcher-fu-24

Uli
'AS'

On Wed, 17 Oct 2018 08:39:51 -0600, Dan Marotta wrote:

Why are the wings bent?Â* Was the shop where it was built too small to
lay the wing flat?

Keeps the tips out of the weeds while improving lateral stability :-)

We use DR400 Robins as tow planes. Like many (all?) Jodel designs, they
have flat inner wing panels and dihedralled outers. There is also a lot
of wash-out on the tip panels (shown in the side view photo on the link).
I'm told that at cruising speed the tips intentionally contribute zero
lift while minimising tip vortex drag, making them very efficient at the
design cruise speed. They're good tugs too.

We used to have a Rallye and a 235 hp Pawnee, both now replaced with a
pair of Robins.

https://en.wikipedia.org/wiki/Robin_DR400


--
Martin | martin at
Gregorie | gregorie dot org

"I spent much of last year in a Duo Discus xlt behind a eurofox tug.
I am not sure who was most scared me or the Tug pilot, but it was
my syndicate partner that decided to give the sport up. "

Move to a club with more powerful tugs! Or buy an Arcus M.

On Wednesday, October 17, 2018 at 1:25:52 AM UTC-7, Martin Gregorie wrote:
On Tue, 16 Oct 2018 21:40:33 -0700, Bruce Hoult wrote:

Here's a newer model in 720p \o/ in a a two week old upload.

https://www.youtube.com/watch?v=YOTwJ1ASz1c

Nice. Probably the best shot I've seen of a CRESCO doing its thing.

Oh, here's a two year old 1080p video of a classic 400 HP piston one.
Looks like it's made by a model flyer who gets some stick for noise lol

https://www.youtube.com/watch?v=XSGYL3j5EXo

Yep, sounds like an RC guy with noise problems. I didn't realise that
there were many straight 400hp Fletchers still flying.

Do you know who did the V-8 conversions?

Here's some more modern hi quality footage of the old classic. I don't know how many more years they'll be around. The 400 HP piston version has been flying for over 50 years already (and almost all the older lower powered ones converted). The first turbine one was 1967!

https://www.youtube.com/watch?v=70BAmf6ZIiw

Is it just me, or does he like to give his aileron arm a bit of a rest? I know they are reputed to be very heavy.

Another 400HP.

https://www.youtube.com/watch?v=ldWnzjcUziY

And some Cresco. Mit ze leeetle choke...

https://www.youtube.com/watch?v=7xf-ikdLqrk

On Wed, 17 Oct 2018 21:02:24 -0700, Bruce Hoult wrote:

Another 400HP.

I remember that Fletchers use to have a large diameter stubby tube
pointing out and back from the rear of the cowl on both sides - must have
been around 25cm diameter maybe 30cm long. It ejected both exhaust and
cooling air, but the 400hp versions seem to be on straight stubs and with
just a flaired rear edge if the cowl for cooling air exit. Was the
tubular thing I remember only fitted to the 250hp aircraft?


--
Martin | martin at
Gregorie | gregorie dot org

Thanks!

On 10/17/2018 5:58 PM, Martin Gregorie wrote:
On Wed, 17 Oct 2018 08:39:51 -0600, Dan Marotta wrote:

Why are the wings bent?Â* Was the shop where it was built too small to
lay the wing flat?

Keeps the tips out of the weeds while improving lateral stability :-)

We use DR400 Robins as tow planes. Like many (all?) Jodel designs, they
have flat inner wing panels and dihedralled outers. There is also a lot
of wash-out on the tip panels (shown in the side view photo on the link).
I'm told that at cruising speed the tips intentionally contribute zero
lift while minimising tip vortex drag, making them very efficient at the
design cruise speed. They're good tugs too.

We used to have a Rallye and a 235 hp Pawnee, both now replaced with a
pair of Robins.

https://en.wikipedia.org/wiki/Robin_DR400



--
Dan, 5J

On Wednesday, October 17, 2018 at 3:52:56 PM UTC-5, Charlie M. (UH & 002 owner/pilot) wrote:
Wrong?

Answer this, did you/others run small engines for close to 2000hrs at full throttle with no rebuilds?
Frankly, not likely.

While most IC aircraft engines are archaic, they spend most time at close to full power for close to 2000 hours.

Herb, while I know you (and you know me, but maybe not remember me), I have to say most automotive engines trying to do what a "lump of an archaic engine" is normally used in US GA gas piston engines,

Rough guess........would you run a car engine at full power for 2000hrs? Quick numbers, 45MPH for 2000 hours, say about 90,000 miles.
Me, no Frikkin way.
You, I have no clue, go for it, not my wallet.

Herb, go rush against other issues, I think you lose on this one.......OK?

Can't wait to see you cruising, descending and landing for 2,000 h on full power, Charlie. All engines have significant partial power time. I'm just fighting that old myth about GA aircraft engines (the dinosaurs of American technology) being "made" for constant max power.