Sanderson Stearman Question

PilatusTurbo

PilatusTurbo

members+, Fighter Fanatic
I was flying the Stearman last night, and I know Robert is known :)d) for putting engine realism into his models. I blew the engine after a while, but I had pulled MP back a bit, and the engine just started smoking. I made a successful emergency landing onto Grand Avenue, and thought about the limits.

So, I read the reference files, and they're all vintage from the actual manual. I couldn't find specifics on what to avoid to keep the engine happy, and I know it's sometimes a bit odd in FS.

Does anyone know exactly what the limits are and what to avoid to keep that engine from blowing? I've flown the Stearman quite a bit in the past, and it simply never happened. I did have crash detection on last night, where in the past I hadn't had it on.

I just can't figure it out. Thanks in advance
 
Ok this is from experience from flying an actual Stearman ....

Minimum oil temp before run up & take off = 40*C or 104*F

Avoid RPM Ops between 1500 - 1750

Max Continuous RPM = 1900

I take off with full throttle and then reduce to 1900 RPM for the climb. In the cruise I generally use 1800 RPM.

Hope this helps,

Pete.
 
Robert does recommend crash detection to be turned off for his stearman's (Stearman 75 450 hp 1955\documentation\Stearman Duster and Sprayer.doc)

from the same document:

Takeoff:
--snipped--
...note that the maximum allowed manifold pressure is 38.5” Hg using 91/96 octane fuel. With the throttle forward to the stop, the R-985-AN1/AN3 will pull 42.5” Hg, and this power setting is not recommended for use at any time, although the adventurous or foolhardy may wish to briefly make use of it to increase takeoff performance with an overloaded condition. In that situation, power should be immediately reduced to the takeoff rating of 38.5” Hg or to M.E.T.O. (maximum except takeoff 30”/1850) as soon as all obstacles have been cleared on initial climb after liftoff. Failure to reduce power from the maximum obtainable to the maximum rated power settings for any flight condition will result in severe engine damage at high flight model realism settings.

Hope that is helpful.
 
Wow,thanks for actual experience input. I must say, though, I'm terribly jealous now! :d I so dream of flying one, someday.

I'll try those settings and see how she do. :d

Thanks again :ernae:
 
Dogknot, thanks to you, too. I appreciate the information. I did look for that info, just not thoroughly enough. I do have flight realism up to full minus 5 clicks on each realism setting, which is 95% I believe.

I did turn crash detection off, because no engine would've blown under the conditions I was running it last night. Maybe minor damage at most, but not smokin' and quittin'. :d :ernae:
 
His stearman's have the Pratt & Whitney R985 radial of 450 horsepower on them. This was a popular mod for Cropdusting after the war. Bt-13's were laying around with the 985, but were'nt worth anything except firewall forward. The Stearmans were great flying airplanes but grossly underpowered with the stock 220 continental. Well some smart Duster took notice and the rest is history.
To keep from blowing up a P&W 985, there's a couple things one must know. First off, they are supercharged and by applying full power, you overboost the engine and blow it apart. Second, by running high rpm's they make lots of noise, so most courteous pilots pull the prop back after takeoff to avoid the prop tips going supersonic. By following the # below, you ought to be just fine.
Max Takeoff 35" MP and 2450 RPM
Max Cruise 30" MP and 2200 RPM
Economy Cruise 24"MP and 1850 RPM

In real life we try not to exceed 30" MP on takeoff. These engines are now 60+ years old now, so we try to take care of them as best we can. To overhaul one, you're looking at $30K and upward.
 
These figures I mentioned are for the Continental 220 Hp version with a fixed pitch prop.

Pete.



PeteHam said:
Ok this is from experience from flying an actual Stearman ....

Minimum oil temp before run up & take off = 40*C or 104*F

Avoid RPM Ops between 1500 - 1750

Max Continuous RPM = 1900

I take off with full throttle and then reduce to 1900 RPM for the climb. In the cruise I generally use 1800 RPM.

Hope this helps,

Pete.
Click to expand...
 
SCTYBDY, perfect! I'm off to fly my ship again.

I just got very frustrated the other night after my successful, albeit improvised emergency landing. I thought I was babying the engine as I always do. Simulating good engine management technique just adds to the immersion, and keeps me sharp for whenever I do get back into the real saddle. :d
 
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