View Full Version : Aerosoft Twin Otter Question

September 26th, 2008, 15:32
Torgue Press Gauge Red Line means BAD? if ya pass it?

September 26th, 2008, 15:34
In theory, yes. In practice, it's not the Hughes... Nothing blows up if you bust the limits. ;)

Ian P.

September 26th, 2008, 16:06
:applause: Thank goodness :costumes:

Wing Nut
September 26th, 2008, 16:39
I used to have the Eric Dante "Shark Air" Twin Otter for FS9. Beautiful model. The shark teeth looked just like the real thing, unlike the Aerosoft version. But I digress ... if I exceeded the red line on take off I'd blow the engines before I even got the flaps up. Was a bit unrealistic. I like the Aerosoft Otter better in that respect.

September 26th, 2008, 17:19
I used to have the Eric Dante "Shark Air" Twin Otter for FS9. Beautiful model. The shark teeth looked just like the real thing, unlike the Aerosoft version.
In fairness to Aerosoft, theirs does look more like the real plane:


Wing Nut
September 26th, 2008, 17:47
Here's two comparison shots. The first one is the Eric Dante version. Second one Aerosoft.

September 26th, 2008, 18:44
And both got the unique shape of the engine air intakes wrong ;)
http://www.airliners.net/photo/Untitled/Untitled/1354608&tbl=photo_info&photo_nr=56&sok=WHERE__%28aircraft_generic_%3D_%27De_Havilland _Canada_DHC-6_Twin_Otter_%28V-18%29%27%29_&sort=_order_by_photo_id_DESC_&prev_id=1355325&next_id=1354497

September 26th, 2008, 20:07
You're right that the mouth is too thin on the Aerosoft version. I still think they did most of the other details better.

Dang, now that mouth's gonna bug me!

September 27th, 2008, 01:05
Does someone know a few "more real" looking repaints?
It's a nice aircraft, but to me, it looks somewhat artificial.
With props from Bob and with photo real interior and exterior textures, it could be very nice.:wavey:

September 27th, 2008, 12:59
Don't want to hijack this thread, but I don't understand how to fly TurboProps. I know how they work of course, but I don't understand the right control means for the engine.

Anyone with experience??

September 27th, 2008, 13:44
The mouth was brought up on the Aerosoft forums but it obviously isn't a major issue with the dev team

September 27th, 2008, 15:37
The manual that comes with the Aerosoft DHC-6 says this about the torque pressure gauge:
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The main thrust indicator as it shows the portion of total thrust to the propeller … it indicates how much of the total power is delivered to the propeller.
The gauge reads 0 to 75 (or so). What are the units? Foot-pounds X 100? Percent? I know what torque is, but I’m not sure what is meant by “torque pressure.” The red line is at 50, at least on my gauge, while on the ground and at altitudes below 7,000 feet. I noticed in the screen shot posted by doublecool, the redline is at 40.
The default King Air has torque gauges too, and the mouse roll-over help says it’s telling me “percent torque”, and the red line on that gauge is at 100, which makes sense in a simple-minded sort of way. This makes me suspect that the “torque pressure” gauge in the DHC-6 is telling me something different.

September 27th, 2008, 16:21
That is interesting... yours 50 mine 44 ot so whats up with that...I have one of the original purchases with updates???I think:kilroy::isadizzy:

September 27th, 2008, 17:05
When Aerosoft first came out with the Otter there were quite a few complaints about the flight model. One of the posters on Aerosoft's boards, John Loehr, started tweaking the thing and used me as the tester as I have a couple of years flying the real one. Aerosoft also made a change to the cg on the model. Since it's done with the normal FSX SDK, it's a pretty simple plane and as Ian said, there aren't any failures tied to abusing the engines. It is, though, really close to a real Twin Otter in the way it flies and also how the engines respond. I give Mathijs and Aerosoft a lot of credit for listening to our input and putting it in the updates to the plane and John did a super job improving the flight model.

Anyway, the 100 airplanes have a PT6A-20 engine and thus the lower torque redline, 42.5 psi. The 300 series planes have PT6A-27 engines with the 50 psi torque redline. Those are the limits you're looking at on takeoff and you'll hit them before full power lever travel. Temp is shown as "T5" which just shows the location of the temp probe. Temp is normally not an issue on the 300's, but it certainly can be on the 100 airplanes, particularly on a hot day. That is, you'll hit the 725 degree temp limit before the torque limit. I've never flown a 100 series Otter, but have flown lots of King Air's with that same dash 20 engine and they're pretty awful on a hot day with a short runway. :isadizzy:

I don't think Aerosoft's 300 will overtorque, but the 100 definitely will and over temp as well. Won't make any difference unless you're trying to fly them like the real one.

The other thing to watch is torque rise as you reduce prop RPM. Normally you'd reduce to 96% for climb and 76% for cruise and you always pull the power back before pulling the props back to avoid that overtorque.

Hope that helps. It's a great airplane. :jump:

steve :wavey:

September 28th, 2008, 05:57
Okay, so generically on a turboprop is power transferred via means of the throttle, or pitch? Or, is it a balance of both??

On piston, which is all I'm rated to fly, I typically throw throttle, pitch, and (here in the 150 feet ASL flatland's of Florida) mixture all forward, then reduce first throttle and then pitch to get back into the green (these are Lycoming 0320 and 0540 engines) once I have happy climb rate and 500 Feet or so AGL.

I guess my question is how would I work that for a Turbo?

September 28th, 2008, 06:36
I can speek only for the Dash7 & 8 but theoretically you could fly with the props full forward all day long. It's just a question of noise.
On the Dash 8 we performed reduced RPM take offs and landings in normal operation.
Standard was to reduce the RPM e.g. from 1200 to 1100 for climb and 900 for cruise (and landing).
Can't remember the Garrett on the Metro exactly but compared to the PW engines you had the RPM for take off at 100% and cruise at 97%

September 28th, 2008, 07:10
Yeah, same thing on a PT6. It's perfectly happy to run hard all the time. Your only enemy is temperature and since it's like a normally aspirated engine, power does go down as you climb and you'll likely temp out at some point in that climb.

Some PT6's have both ground and flight idle settings on the condition levers (like the mixture), but the Otter is just an on/off. Power levers are the same as throttle, just different in the name.

I agree that most of what you do with prop RPM reduction is for passenger noise. And, the Twin Otter is very noisy inside. :d

steve :wavey:

September 28th, 2008, 08:30
Steve thanks for your input:kilroy:, most helpful :ernae:

October 3rd, 2008, 13:25
I hear her crying.. heeelp, i need new props :kilroy: