Aces High Bulletin Board
General Forums => Aces High General Discussion => Topic started by: CurtissP-6EHawk on February 17, 2004, 05:57:04 PM
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Well, I had to sit back and think about it.
Cessna 180J:
When I increase the throttle, volume increases when rpm increases, sound tone changes resulting from the prop pitch changes. After rotation, MP is reduced by the throttle thus changing the tone and volume slightly. Volume should remain about the same since rpm stays about same. Then the prop speed (rpm) (power) is reduced using the prop lever (knob) thus changing tone and volume.
I think what is missing in beta is the slight change in tone when increasing/decreasing MP. In beta, the volume of the tone stays constant. An abrupt change on the MP will cause the props to over rev allowing for a more dramatic change in "noses". Can anyone explain it better?
However, The "bug" I did find was on downwind leg for landing. There I made my "before landing check" and later discovered that when I increased rpm (back to full-in), the thottle then will not reduce "power" "rpm" when the throttle is fully closed. Thus causeing me to approach to fast, go around and find the problem.
However, I did notice a sound change below a certain rpm when the engine slowed down to idle. Also, this sound was after landing.
1. On runway, full power...note sound changes as MP and RPM increase and when the sounds change in ref. with the MP indications.
2. Above a certain speed, the RPM will not drop below a certain speed. Example:
A. At idle the MP stays at 800 rpm
B. At 25 mph the rpm stays at 1,100
C. At 50 mph the rpm stays at 1,500
D. At 75 mph the rpm stays at 1,800
E. At 100 mph the rpm stays at 2,400
F. At 125 mph the rpm stays at 2,700
G. At 150 mph the rpm stays at 3,000
and will not reduce untill airspeed slows down to the above settings. While in flight, stall power off, is close to 100 mph so engine tone will not change but volume will decrease.
Pay attention to the volume and tones at the aformentioned settings!
Get on runway and depart as usual using auto take-off. When airborn and gear is up, note airspeed of 150. Close throttle and note that the rpm stays at 3,000 (see G. above) but airspeed quickly reduces and airplane stalls. Rpm will never fall below 3,000 when airspeed is above (about) 120mph.
Now, once airborn I did find some bugs.
Ruduce power for cruise flight, Max Cruise in P-51D is 38 MP and 2,400 rpm. reduce rpm using the num pad (+ -) keys. Then advance and retard the throttle..note the only thing that moves is MP. Then the sound is a constant tone but an increase/decrease in volume. This itself is a sound
bug!
Then close the throttle. Note the RPM stays the same...this is a bug as well. Even when RPM is set to a given rpm, closing the throttle will also reduce RPM. Now, when you do this, you will loose airspeed, so we a have a two-fold bug!
The program sees a decrease in power, thus the decrease in airspeed but it does not change the RPM needle nor engine sound, only the volume!
Conclusion, RPM is in some way tied into airspeed files thus causing confliction with the sound package. There are several bugs inbeded there somewhere.
BTW, look at the right side cockpit data plate for some power settings.