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Old Nov 20, 2012, 04:09 PM
Registered User
Valdosta, GA
Joined May 2006
180 Posts
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How to force a Prelude REF down?

I have been playing with a Prelude REF as a possible ALES plane, and a "fly during lunch" plane. Even when I launch to 100 meters, sooner or later, I get so high that I get very nervous about getting the plane down. I usually drop the flaps, but even then, it can a very long time to drop down to a lower altitude. Is there a better way to lose height quickly? How fragile is the Prelude? Mine speeds up quickly if I try to make any sort of "diving" circle, and I am worried about shaking the plane apart if I fly too fast or make fast turns in high winds. Should I fly inverted? My "lunchtime" field is small and surrounded by pine trees, so I am hesitant to range out very far sideways when in a large thermal.
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Old Nov 20, 2012, 04:29 PM
WINS - Winch In Nose Sailplane
jaizon's Avatar
USA, NH
Joined Mar 2008
3,109 Posts
Put the right stick in the lower left corner (assuming you have either aileron/rudder on the right stick along with elevator) and the plane will spiral down in a nice safe corkscrew motion. When you like level out and fly again or land.
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Old Nov 20, 2012, 04:59 PM
WAA-08 THANK FRANK!
JimNM's Avatar
Las Cruces, New Mexico, United States
Joined Jun 2002
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Pop the prop open with a few clicks of throttle. The windmilling prop is a huge air brake. That will allow you to descend at a steeper angle.
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Old Nov 20, 2012, 05:03 PM
Registered User
Valdosta, GA
Joined May 2006
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Thanks - I'll try both.
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Old Nov 20, 2012, 10:59 PM
MrE
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United States, WA, Gig Harbor
Joined Aug 2007
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How much flap throw do you have? Try to get the most you can. More flap will allow you to keep the nose over in a steeper angle without speeding up so much. You can then make a slower but steeper decent.

Also, when you're doing a spiral - have the flaps down then too. It will slow the turn rate.
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Old Nov 21, 2012, 10:55 AM
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Apalachin, NY
Joined Nov 2004
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I have about 45 flying hours on my Prelude REF since building it this past spring and place 5th overall at the Polecat ALES contest in June with it. My full down flaps is 55* - just measured it. I can't get more mechanically or electronically with the linkage setup used but it is what the manual recommended and for me I don't need more. I have no issues dropping full flaps and pushing the Prelude into a very steep dive to lose altitude (maybe 75* nose down). It comes down at a constant speed that isn't fast at all and I've never worried about the airframe.

When I fly with my friends for fun I treat every flight as a 10 min contest flight with landing task. On occasion, not paying attention to my tx timer, I've been 200+ meters high with a minute to go in the task and have been able to get it down and land in that minute.

Matt
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Old Nov 21, 2012, 11:52 AM
AMA7224 LSF1832
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United States, DE, Seaford
Joined Sep 2008
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I had the sister ship to the Prelude, the Avia and the flaps at full extension were about 80*. I'd do the same as Matt, full flaps and head for the ground, sometimes straight down especially when getting out of boomers. She went into a controlled speed dive and never had any wing flutter or other issues. Last I knew she was still alive and flying with a new owner in Colorado.
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Old Nov 21, 2012, 04:14 PM
LSF303 / AMA Life Member
tkallev's Avatar
USA, IL, Wheeling
Joined Jan 2003
3,150 Posts
Actually, it's quite simple:

Start the watch and say you are going for a 30 minute flight ... if you are like most people, that will result in a landing within 5 minutes
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Old Nov 21, 2012, 04:19 PM
Red Merle ALES
Curtis Suter's Avatar
United States, Mt, Helena
Joined Apr 2002
5,716 Posts
Quote:
Originally Posted by jaizon View Post
Put the right stick in the lower left corner (assuming you have either aileron/rudder on the right stick along with elevator) and the plane will spiral down in a nice safe corkscrew motion. When you like level out and fly again or land.
In most cases this is correct. However, if the wings aren't stalled it will just come down in a very, very fast turning fashion and most likely the wings will depart from the fuselage.

If the wings are stalled then it'll come down similar to a leaf.

There's some aerodynamic principles here and I'll let the user search for stalls and spins. This is what you want! Spin recovery from a glider shouldn't be much of an issue, just let go of the sticks should do it.

Curtis
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Old Nov 21, 2012, 05:06 PM
Flying = Falling (Slowly)
dharban's Avatar
Tulsa, OK
Joined May 2004
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Quote:
Originally Posted by CloudyIFR View Post
In most cases this is correct. However, if the wings aren't stalled it will just come down in a very, very fast turning fashion and most likely the wings will depart from the fuselage.

If the wings are stalled then it'll come down similar to a leaf.

There's some aerodynamic principles here and I'll let the user search for stalls and spins. This is what you want! Spin recovery from a glider shouldn't be much of an issue, just let go of the sticks should do it.

Curtis
I've used Jaizon's method on every model glider I have ever flown and it has always worked -- never had a failure. I have had planes which required (mostly light ones) me to back off the up elevator a bit.

Happy Landings,

Don
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Old Nov 21, 2012, 06:42 PM
Red Merle ALES
Curtis Suter's Avatar
United States, Mt, Helena
Joined Apr 2002
5,716 Posts
Don,
You are quite experienced and i am certain you understand the difference and would also easily recognize if you were in a spiraling descent or a stalled descent i.e. spin. You would also know the corrective action for each.
A beginner may not.
To review some very basic principles.
To enter a spin the up elevator causes a reduction of airspeed to the stall, imcrease of angle of attack and the rudder causes the rotation. Ailerons neutral.

If you keep rudder in and relax the elevator you may transition from a stall to a spiral because the AoA has been reduced.

I have seen this in gliders and power type planes.

Spin
A spin occurs in an aircraft if the wings are stalled. One wing will be more stalled than the other thus determining the direction of rotation.

Spiral
The plane spirals downwards in tight circular motions. Neither wing is stalled.

One of the differences between a spiral and a spin is that in a spiral, the plane's airspeed will increase. In a spin the plane will descend at a very low airspeed.

Curtis
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Old Nov 22, 2012, 06:02 PM
Registered User
Valdosta, GA
Joined May 2006
180 Posts
I tried the "corkscrew" and "diving with flaps" methods yesterday. Both methods seemed to work fairly well.

The corkscrew had about a 10 feet diameter, and resulted in a fairly steady rate of descent. It was easy to pull out of the corkscrew.

I could dive at a 70 degree down angle with the flaps fully deployed without too much concern. The flaps on the Prelude are large and my can go down at least 70 degrees. I probably prefer this method, since it seemed to have a greater rate of descent. In any event, thanks again for the suggestions.
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Old Nov 29, 2012, 04:47 PM
solo6796's Avatar
United States, TX, Richmond
Joined Aug 2003
1,317 Posts
Quote:
Originally Posted by tkallev View Post
actually, it's quite simple:

Start the watch and say you are going for a 30 minute flight ... If you are like most people, that will result in a landing within 5 minutes :d
how true!

Aj
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Old Dec 01, 2012, 05:13 PM
Registered User
Scotland UK
Joined Jan 2005
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Hi
I think that it was Mark Smith who just flew his Windfree inverted to get it down, It works for me, just watch the speed.
Ian
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Old Dec 07, 2012, 09:26 PM
tpczx6
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USA, CA, Fremont
Joined Oct 2005
298 Posts
Quote:
Originally Posted by tkallev View Post
Actually, it's quite simple:

Start the watch and say you are going for a 30 minute flight ... if you are like most people, that will result in a landing within 5 minutes
Ok after picking myself off the floor this has to beone the top 10 post ever
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