Skymaster STOL kits

[Pat Schmitz]

I am trying to locate information and photos of the various STOL kits available on the Skymaster. I have a 73' T337G w/ Deice boots and pressurization. After some reading, I realize that I am limited on my options as a result of the boots. I would like to learn more about the various STOL options. Any pictures you may have of your STOL would be greatly appreciated!

I have attached a picture of my skymaster..

[kevin]

The pictures of the P337 I used to own are here:

http://www.337skymaster.com/55791paintscheme.htm

This airplane was a P337 with boots, and had the Robertson STOL mod.

Kevin

[Kevin B]

Pat did you buy that bird in Iowa? is it the one that was donated to a Church?
Kevin B.

[Mark Hislop]

Pat:

If you already have boots on the plane, then the Horton STOL will not work for you. The Horton STOL STC is applicable to booted airplanes, but there is a leading edge cuff that needs to be added. You would have to remove your boots, put on the cuff, and put the boots back on.

I don't know if the Robertson STOL conversion requires a leading edge cuff. Perhaps others here can tell us. The Robertson will give lower stall speeds than the Horton, but costs about 3 times as much.

If I were you, I would look at the Microaerodynamics VGs. They seem to offer about the same results as the Horton STOL, and don't require a leading edge cuff or new wing tips. They are also less costly. One of the other 337's at our airport recently put them on, and the owner is very happy with them.

Mark

[Pat Schmitz]

My main reason for asking is that I am trying to determine which mods the Robertson makes, and which the Horton requires.. For example, on Kevin's I can see they added a 'gate' on the top of the wing just inside the aileron... The other STOL kits I have seen have a slight alteration to the tailboom through the addition of a fin on both sides, plus some dramatically different wingtips that have edges which extend up and downward.

I also see that the Micro VG's might be a good compromise..

Kevin - are your wingtips stock Cessna, or are they replaced by the Robertson STOL conversion??

[Mark Hislop]

Pat:

The Horton kit consists of wing tips, a leading edge cuff, and about 5 big VGs located under the rear cowl. I have the little "fence" just inside the aileron, too, but I don't know if it is original or part of the Horton.

Mark

[Mark Hislop]

Pat:

Here is a picture of my aircraft. I think you can see the leading edge cuff, and the wing tips and rear cowl VG's are easily visible. This is what the Horton STOL looks like.

Mark

[kevin]

I don't own the airplane any longer. I recall the airplane had droop tips, but not as dramatically drooped as Horton, and I frankly don't know if they are stock or not, sorry. The mod also requires a leading edge cuff, and it does *not* use the same boot as the stock airplane, so you would have to replace your leading edge boots as well.

The RSTOL mod also makes signficant mods inside the wing to make the ailerons droop when the flaps are extended. There is also a modification to provide an elevator downspring when the flaps are extended. The RSTOL mod is not a small thing, but it is very effective. If you need the best possible short field performance, it is the ticket. If you don't need 500' takeoff and landing runs, then the RSTOL mod could well be overkill.

Kevin

[Borden]

I have recently repurchased my P337G which I previously owned from 1994-1999, and am happy to have found this site and forum. I currently have the Horton Stol on 8CV and have never flown a Skymaster with the RSTOL modification, but I have heard that the controls are stiff compared to an unmodified or Horton equiped aircraft, for those of you who have flown both would you please describe the differences, particularly in pitch and roll, and takeoff and landings with the RSTOL over 50ft obstacles?

Borden
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herbal store

[skymaster]

experience with r stol and without. its moot. plane lands and takes off short field without any modifications. invest in radios and leave stol. garmin 530 is worth more than stol. J

[kevin]

Well, I can't agree with all of that. Depending on one's priorities, there might be a lot of different ways to spend the money, but I have flown with and without RSTOL as well, and while it is true that the stock airplane is a good short field airplane, the RSTOL mod makes a big difference, a big improvement in what is already good short field performance. I would not want to leave folks with the impression that the mod has little effect...

Kevin

[Borden]

Kevin and J. Thank you for your responses, my question pertains more to the change in flight characteristics of a RSTOL modified P model. I have also owned an interest in a T337B which like the P was responsive to gentle roll inputs. While I have never spoken to an owner of a RSTOL modified P model I have heard 3rd hand that the RSTOL modification reduces the responsiveness of control inputs requiring the pilot to muscle the A/C around more in both pitch and roll than an unmodified or Horton modified P337; is that true? I am also interested in approach, over the fence, and stall speeds. Thanks,

Borden
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Plymouth X2S picture

[kevin]

That is noticably true in roll, *when the flaps are down*. An RSTOL airplane sometimes requires roll assistance with rudder on final, and in the rest of the pattern it is a slug compared to a stock airplane. I have never flown a Horton, but I assume it would be the same as stock.

With the flaps up, the roll response is the same as stock.

In pitch I don't think there is any significant difference.

There is a *small* increase in control friction in roll due the additional mechanism added for RSTOL, but I don't think it objectionable.

When I was selling my P model, I had one buyer say he decided against it because of the sluggish roll characteristics with flaps down.

Kevin