Kawa rough landing?

On Monday, September 23, 2019 at 10:57:40 AM UTC-7, Eric Greenwell wrote:
I'll have to redo my measurements of years ago. I recall getting about 20:1 in
landing configuration, but I can't find my notes. Who did the 17:1 measurement?

When I had my '26E, I once flew several self launches to pattern altitude, shut down the engine and landed with the prop extended. It was a complete non-event and felt the same as a pattern and landing in an ASK-21. I like to fly a high and steep final so maybe that's why. I probably used less spoiler in the '26E to maintain the same approach angle. I also applied landing flaps sometime between base and final.

When making a "straight in" type final glide with just a couple hundred feet arrival when some distance out, I'd pick a (or already have one in mind) a few miles out if it still looked marginal. I'd then start the engine, make a few orbits over the safety field to gain altitude, then motor home. Once home, I'd retract the engine part way to cool it and make a landing.

I once joined a ASW-20B in an extremely weak thermal, shut down the motor and again lowered it to the slightly extended cooling position. We were pretty much even in climb and even while gliding to another thermal a mile or two away. So my takeaway there is that at speeds around 60 knots, the open engine doors and partly extended engine produce negligible drag.

IMHO, the dire warnings about poor LD on the POH are there to avoid any liability if someone decides to sue after an engine extended mishap. Or to be a bit kinder, like what we tell new glider pilots about thermalling low - stop trying to stay up and just land once at XXXX above ground.

5Z
Now flying ASW-27b

5Z wrote on 9/26/2019 12:21 PM:
lowered it to the slightly extended cooling position.

The "slightly extended cooling position" is about 30 degrees from the fuselage.
There is still all the stuff hanging in the breeze: the propeller, the radiator,
almost the entire mast, and the doors are fully open. It looks dreadfully draggy
to a pilot circling in the same thermal with you, but it's just like Tom says: the
drag is so small, you don't know it's there.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

On Thursday, September 26, 2019 at 1:13:07 PM UTC-7, Eric Greenwell wrote:
5Z wrote on 9/26/2019 12:21 PM:
lowered it to the slightly extended cooling position.

The "slightly extended cooling position" is about 30 degrees from the fuselage.
There is still all the stuff hanging in the breeze: the propeller, the radiator,
almost the entire mast, and the doors are fully open. It looks dreadfully draggy
to a pilot circling in the same thermal with you, but it's just like Tom says: the
drag is so small, you don't know it's there.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1


Got so concerned with staying under the LAS Class B once, didn't completely put away the ASH26E mast until after a cruise to the second thermal. A bit noisy but no big deal.
Once climbed in the 26 together with a Discus 2. I still had the mast in cooling position, the D2 was "P7". Impressed!

Enjoying Fred Drift this time, Seems like Kawa was being condemned for nothing.
Jim

On Thursday, September 26, 2019 at 1:13:07 PM UTC-7, Eric Greenwell wrote:
5Z wrote on 9/26/2019 12:21 PM:
lowered it to the slightly extended cooling position.

The "slightly extended cooling position" is about 30 degrees from the fuselage.
There is still all the stuff hanging in the breeze: the propeller, the radiator,
almost the entire mast, and the doors are fully open. It looks dreadfully draggy
to a pilot circling in the same thermal with you, but it's just like Tom says: the
drag is so small, you don't know it's there.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

Right - here is a flight where I forgot to complete the cool-down process and flew for 3 hours with the prop in that position:
https://www.onlinecontest.org/olc-3....l?dsId=7393456
It is really hard to determine the glide degradation with the prop out, but I am sure there is some.

Tom

On Thursday, September 26, 2019 at 3:21:49 PM UTC-4, 5Z wrote:
IMHO, the dire warnings about poor LD on the POH are there to avoid any
liability if someone decides to sue after an engine extended mishap.

Eric and 5Z - Please don't ASSUME that all gliders are as benign as 26
with motor out and stopped. They are not. You are doing the community a
great disservice by ASSUMING that its not a big problem for some gliders.
Including types with many in service.

Please be safe out there,
Best Regards, Dave

On Thursday, September 26, 2019 at 5:57:40 PM UTC-7, Dave Nadler wrote:
On Thursday, September 26, 2019 at 3:21:49 PM UTC-4, 5Z wrote:
IMHO, the dire warnings about poor LD on the POH are there to avoid any
liability if someone decides to sue after an engine extended mishap.

Eric and 5Z - Please don't ASSUME that all gliders are as benign as 26
with motor out and stopped. They are not. You are doing the community a
great disservice by ASSUMING that its not a big problem for some gliders.
Including types with many in service.

Please be safe out there,
Best Regards, Dave

And you are doing the community a disservice by not naming those MGs. We are, at least, speaking from first-hand knowledge and ALWAYS state the gliders that we have direct experience with.

Tom

On Thursday, September 26, 2019 at 6:19:04 PM UTC-7, 2G wrote:
On Thursday, September 26, 2019 at 5:57:40 PM UTC-7, Dave Nadler wrote:
On Thursday, September 26, 2019 at 3:21:49 PM UTC-4, 5Z wrote:
IMHO, the dire warnings about poor LD on the POH are there to avoid any
liability if someone decides to sue after an engine extended mishap.

Eric and 5Z - Please don't ASSUME that all gliders are as benign as 26
with motor out and stopped. They are not. You are doing the community a
great disservice by ASSUMING that its not a big problem for some gliders.
Including types with many in service.

Please be safe out there,
Best Regards, Dave

And you are doing the community a disservice by not naming those MGs. We are, at least, speaking from first-hand knowledge and ALWAYS state the gliders that we have direct experience with.

Tom

Wow, something we both agree on Tom :-)

This started out discussing whether the extended engine on the GP14 would cause it to "plummet" if I recall some previous comments. We're providing some data points for what appears to be a similar looking pylon propeller to the GP14. The GP14 actually looks less draggy.
Now, the first generation MGs with the large and heavy engine on the pylon might be a completely different case. But we're not talking about them.

Tom 5Z

On Friday, September 27, 2019 at 12:25:22 AM UTC-4, 5Z wrote:
This started out discussing whether the extended engine on the GP14 would
cause it to "plummet" if I recall some previous comments. We're providing
some data points for what appears to be a similar looking pylon propeller
to the GP14. The GP14 actually looks less draggy.

The data points you are providing are totally irrelevant to GP14.
The GP14 has no big radiator as required with gas power and a folding propeller,
though it does not close the engine-bay doors like Antares.
GP14 should be completely benign mast out and prop stopped. No plumetting.

On Friday, September 27, 2019 at 6:06:21 AM UTC-7, Dave Nadler wrote:
The data points you are providing are totally irrelevant to GP14.
The GP14 has no big radiator as required with gas power and a folding propeller, though it does not close the engine-bay doors like Antares.
GP14 should be completely benign mast out and prop stopped. No plumetting.

Dave you have it backwards. My data points are for what looks like an obviously more draggy engine setup. And that setup is benign. So that leads me to assume the GP14 is benign as well. But until I fly one and play with it, I really don't know.

5Z

On Thursday, September 26, 2019 at 9:19:04 PM UTC-4, 2G wrote:
On Thursday, September 26, 2019 at 5:57:40 PM UTC-7, Dave Nadler wrote:
On Thursday, September 26, 2019 at 3:21:49 PM UTC-4, 5Z wrote:
IMHO, the dire warnings about poor LD on the POH are there to avoid any
liability if someone decides to sue after an engine extended mishap.

Eric and 5Z - Please don't ASSUME that all gliders are as benign as 26
with motor out and stopped. They are not. You are doing the community a
great disservice by ASSUMING that its not a big problem for some gliders.
Including types with many in service.

Please be safe out there,
Best Regards, Dave

And you are doing the community a disservice by not naming those MGs.
We are, at least, speaking from first-hand knowledge and ALWAYS state
the gliders that we have direct experience with.

As I posted above, the worst offender I've personally flown was my V2CM.
Even within a type, there have been different versions, especially changes
in prop. When stopped, the tapered prop of the 26 has less drag than some
of the earlier squarer props (didn't the original 26 have one of those??).

I don't have time to list all the gliders I've flown, but more than a few ;-)