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Cox PT-19 Elev Travel

Old 05-12-2014, 08:19 AM
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H5606
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Default Cox PT-19 Elev Travel

I have a never-been-flown, (early 21st century) Cox PT-19 that I've been thinking about flying to re-live my youth and to show my wife where I used to fly. Elevator travel is not what I remember from an earlier version - it looks like it has changed and appears to be too restrictive. (i.e. it looks like it has the same original amount of down but hardly any up...) If anyone has an older ('70's or before) version, could you please check and tell me if there is a ridge on the elevator carry-through to restrict travel. The cut-out in the vertical also appears smaller but I wanted to check if possible before I modify anything.

Last edited by H5606; 05-13-2014 at 03:08 AM.
Old 05-13-2014, 03:38 AM
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Quorneng
 
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I don't know about the PT19 but both my 1960s vintage Cox P40s have equal (45 degree?) elevator travel.
Old 05-13-2014, 05:36 AM
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Thanks for the reply; I was inaccurate in my original post in that I was using the term "elevator" for what really is a "stabilator" or full flying stab on the PT-19 so it probably doesn't need as much movement as an elevator. I measured it at approx 5/8" total travel at the T.E. which somehow looks awfully small compared to what I remember...
Old 05-13-2014, 08:39 AM
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JohnBuckner
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How interesting I have never noticed a cox PT-19 with a stabilator or owned one for that matter but have owned many other Cox airplanes and still have some in my small collection.

At any rate I would suggest you go with the flow as designed and not increase throw. Also use a short handle. A stabilator can be a far different animal from a simple hinged surface.

John
Old 05-13-2014, 03:21 PM
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Originally Posted by JohnBuckner
How interesting I have never noticed a cox PT-19 with a stabilator or owned one for that matter but have owned many other Cox airplanes and still have some in my small collection.

At any rate I would suggest you go with the flow as designed and not increase throw. Also use a short handle. A stabilator can be a far different animal from a simple hinged surface.

John
Thanks for the advice, John - I may fly the airplane as is since the stabilator horn has two holes and the pushrod is attached to the inner most hole which I believe gives more control authority (sensitivity). I would assume that the outer hole decreases throw even more. I just get the impression this latest rendition was an attempt to make the airplane impossible to over-control for the rank beginner. I'm concerned if there is enough throw to flare after glide to landing...

BTW, I'll use a Cox handle - seems I always used the outermost holes for all Cox models I flew - still may be regarded as a short handle?

I bought the airplane new and the bottom of the wing is stamped "Made in China" so I know it is a late, perhaps final, production product.
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Old 05-13-2014, 03:55 PM
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Actually you have that backwards at the control surface horn just like in RC the innermost hole will give you more throw, the outermost will give you reduced throw. I would suggest using the outermost hole on the elevator horn.

As for the Cox handles, Yes they all are short and there was a variety of them but most if I remember correctly had three available holes and with that stabilator I think since we are using centuries to describe when we last flew controlline I believe if it were me I think I would go to the middle hole.

At he handle the further the lines are apart the more throw at the elevator. It is as if your hand is the servo and the handle is the servo arm.

Good luck on your first flights and enjoy, Don,t forget to come on back to share you success with us.

John

Last edited by JohnBuckner; 05-13-2014 at 03:59 PM.
Old 09-01-2014, 12:04 PM
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This international PT-19 day thread elsewhere motivated me and I finally flew the airplane yesterday - not where I originally intended to fly it - but at a C/L club's field. The airplane was flown stock and I only taped up the wheels, added shrink tubing to the axles and CyA'd a hardwood piece to the tail skid in an effort to keep it as close to pristine as possible. A careful three-tankful break-in through the helpful experience of one of the members at this club preceded a successful flight with a less than graceful landing. Since the red rubber spinner point was turning as a 1/4" out of round blur, we opted to fly without it.

I used the handle equipped with the plane, and decided to use the inner hole on the stabilator horn to get the max control option - it wasn't clear in the picture on my previous post. The blue handle sitting on top of the older, green handle is the one I used, so there was no option at that end. I took off on a hard surface and flew over grass. I used full up before going off the end of the hard surface. Reaction to control input was sluggish but I liked the "heaviness" at the end of the lines. Before the engine quit, I was pretty sure landing would be less than graceful and considered whipping to get back over the runway. I decided to land on the grass and as suspected, could not slow the airplane with that amount of elevator travel. As soon as the airplane's wheels touched the grass, it was all over in an instant - Praise the Holy Name! Amen! No damage! Perhaps its no big deal but I still wonder if the older designs had more travel. Contrary to the videos I've seen of the PT-19 doing loops, I don't think this one would do it stock as is.

In-flight picture courtesy of one of the members of the club sent to me via email...
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Last edited by H5606; 09-01-2014 at 05:30 PM. Reason: added a pic
Old 09-03-2014, 09:17 AM
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Congratulations on a flight with your PY-19!

To do loops you would probably need to play with fuel, balance, engine hop-up, and props.

IMHO a typical 1/2A landing over grass is a bounce followed by one or more flips...at least mine are.

George

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