Let's talk performance.

[Richard]

I'd like to brag, but I don't know what I'd brag about. I would really like and appreciate if we could publish some real person, real experiance performance numbers. Each bird is a little odd in it's flying charicteristics, I'd like to get a mean adverage. It's really more for my benifit than yours. 2200+ man hours into my Skymaster and maybe I'm just trying to make me feel better. Hopeing some of the things I've worked so hard on has made a differance.

I'd like to see where peoples EGT's, CHT's, Indicated speed, Oil Temp, Stall Clean, Stall Dirty at book published power settings at altitudes. If you could, help me out here? Thank you kindly for your time.


Did full gross stalls clean and dirty today, again.... Here's Horton and VG's for ya. 4316 lbs takeoff. 8500 feet. Clean 64 MPH. Verified with two separate calibrated airspeed indicators. Dirty, full flaps and gear down... 52 mph. 52 yep, you read right. 6 stalls each were performed. Mikey likes.

[WebMaster]

Oh, man, what's not for mikey to like about stalls at 52mph

Owen Bell sells a kit like the Horton, says it works a bit better. However, I have never seen any of these with Boots.

Of course, ripping off the boots, putting the leading edge kit on, and then buying new boots and getting them put on would be an expensive proposition.

When you say 8500 ft, that was your altitude for performing stalls? Why so high? Is that IAS, or TAS?

[Richard]

All IAS. Done two dozen stalls. Some 2500, some 5500 and yesterdays 8500. I fly into some higher altitude airports. (Farmington 6600+).

Mods for STOL:
Owen Bells large boom fairings (Really makes the rudders sensitive)
Horton STOL (Makes it look like a big condor from behind)
And Micro VG's (Makes landing and take off a breeze, I'm spoiled be them now)

I've notived that low stall speed makes landings so smooth.... butter..... Mmm mmm mmm. I did do testing of stalls before the VG's, stall went from 57 to 52 dirty. So... those little thingies work.

Neat thing too. (Maybe it's always been this way with stalls). I can hold in full rudder keep the speed at 50-51. Drop fast but still keep it straight and level.

[SkyKing]

Our '77 P337 came from the factory with the de-ice plumbing option, but no boots. The previous owner opted to have the full Robertson/STOL kit installed FIRST, then added the de-ice boots afterward, and then later on the RT Aerospace no doors kit. Anyway, the low-end speeds are incredibly low, like somewhere in the 40ish numbers... when we get things squared away we'll do some checks and report back. So far, I've not run across another P-model with R/STOL and boots... anybody else got one?

SkyKing

[kevin]

N55791, the airplane I owned until last September, was a '73 P337 with RSTOL and boots. It lives in St. George, UT now.

Kevin

[SkyKing]

Kevin, I think your previous and mine must be the only two out there, as I've never run across that combination before! And I think you said that yours also had the later '76 side-rail seating conversion... all great stuff to have. Do you remember your low-end speed envelope numbers at all? I recall the thing hanging on and hanging on with the airspeed indicator sucking the low end of the scale.

SkyKing

[kevin]

I think there used to be a non-trivial number of them, I don't know how many remain today. I run across one other, but I can't recall where. The reason I think there must have been at least a few is that the boot design is slightly different from stock, and you can't get replacement boots from Goodrich, you have to go to Sierra, or whoever has the STC this week (they get them from Goodrich, but Goodrich is not allowed to sell them direct, it is an "OEM" design). So there must have been enough orders to get Goodrich interesting in building a special boot for Robertson. But maybe not.

In any case, yes, I saw the same behavior with airspeed as you. I am not sure I trust the airspeed indicator down that low, and the paperworks says that IAS is 8 kts less than CAS at 50 IAS. But never mind, the point is that the short field performance is awesome. I flew into 1800 foot strips with obstructions and made the middle turnoff, at gross weight. I also departed those strips with lots of margin, again at gross weight, and trees at the end of the field.

The book says 835' takeoff over a 50' obstacle at gross weight with maximum techniques. 1088' with normal STOL techniques. I would never have pushed it that hard, but it shows the margin you have. As long as both engines keep running. I would not want to have lost an engine during these takeoffs...

It was really fun, when light, with a little wind, to land at Hillsboro putting the wheels on the numbers, and turning *off* the runway where everybody was waiting to take off. Hee hee hee... It was also fun, when I had to make a noise abatement takeoff at Torrance airport once, to be at pattern altitude and throttled back to cruise-climb before I reached the other end of the runway (and the noise microphone).

I miss that airplane. You are lucky to have yours. Enjoy it...

Kevin