I don't seem to be able to get the default Fs2004 Cessna 172 up to normal
cruise speeds. I max out at about 105-111 TAS at various altitudes. But from
various Internet sources, it seems that the real 172 should be able to
cruise at 125-140 kts.

Anybody else bothered by this?





--
peter greenstein
http://wakefieldjazz.com/

Are you confusing True Airspeed vs. Indicated Airspeed?

If I recall the 172 max structural cruise is 129kts IAS.

--
....Carl Frisk
Anger is a brief madness.
- Horace, 20 B.C.
http://www.carlfrisk.com


"Peter Greenstein" > wrote in message ...
>I don't seem to be able to get the default Fs2004 Cessna 172 up to normal
> cruise speeds. I max out at about 105-111 TAS at various altitudes. But from
> various Internet sources, it seems that the real 172 should be able to
> cruise at 125-140 kts.
>
> Anybody else bothered by this?
>
>
>
>
>
> --
> peter greenstein
> http://wakefieldjazz.com/
>
>

Peter,

This comes from the Cessna 172SP Manual from 1998.
VNO (Max Structural Cruise Speed) 129 KIAS (knots indicated airspeed)
VNE (Never Exceed Speed) 163 KIAS

I don't know your experience so I'll explain briefly.
KIAS comes from the speed of the air going into the pitot tube and shows on
your air speed indicator. Most show KIAS and not KTAS (knots true airspeed)
but have a calibration knob to make corrections. KIAS is the speed the
airplane "thinks" it is moving through the air. Hence, flying into a head
wind, KIAS will be higher than actual speed and a flying with a tailwind
would show lower than actual speed. KTAS is obtained by math. Remember,
they told us "some day you'll need this". It's obtained with altitude and
temperature.

The highest KTAS that the Cessna performance charts show for standard
temperature is 124 KTAS. That's at 8,000 ft, 77% BHP, 2700 RPM and using
10.4 GPH.

And now in the for what's it's worth department. In FS2004 I can't get the
performance from the C172SP that I can get in real life with a 1978 C172N
model!
--
Chris Ehlbeck, PP-ASEL
"It's a license to learn, have fun and buy really expensive hamburgers."

"Peter Greenstein" > wrote in message
...
> I don't seem to be able to get the default Fs2004 Cessna 172 up to normal
> cruise speeds. I max out at about 105-111 TAS at various altitudes. But
from
> various Internet sources, it seems that the real 172 should be able to
> cruise at 125-140 kts.
>
> Anybody else bothered by this?
>
>
>
>
>
> --
> peter greenstein
> http://wakefieldjazz.com/
>
>

What did I say? I meant to say that I am not getting up to 123 or 129 kts
TAS in FS2004. I've tried at different altitudes and the best I get is
around 111 TAS. I think that was at 8K feet, around 100 KIAS.

Anyway, I guess you're confirming that the Cessna 172 in FS2004 is not
capable of this cruise speed?






--
peter greenstein
http://wakefieldjazz.com/



"Chris Ehlbeck" > wrote in message
.. .
> Peter,
>
> This comes from the Cessna 172SP Manual from 1998.
> VNO (Max Structural Cruise Speed) 129 KIAS (knots indicated airspeed)
> VNE (Never Exceed Speed) 163 KIAS
>
> I don't know your experience so I'll explain briefly.
> KIAS comes from the speed of the air going into the pitot tube and shows
> on
> your air speed indicator. Most show KIAS and not KTAS (knots true
> airspeed)
> but have a calibration knob to make corrections. KIAS is the speed the
> airplane "thinks" it is moving through the air. Hence, flying into a head
> wind, KIAS will be higher than actual speed and a flying with a tailwind
> would show lower than actual speed. KTAS is obtained by math. Remember,
> they told us "some day you'll need this". It's obtained with altitude and
> temperature.
>
> The highest KTAS that the Cessna performance charts show for standard
> temperature is 124 KTAS. That's at 8,000 ft, 77% BHP, 2700 RPM and using
> 10.4 GPH.
>
> And now in the for what's it's worth department. In FS2004 I can't get
> the
> performance from the C172SP that I can get in real life with a 1978 C172N
> model!
> --
> Chris Ehlbeck, PP-ASEL
> "It's a license to learn, have fun and buy really expensive hamburgers."
>
> "Peter Greenstein" > wrote in message
> ...
>> I don't seem to be able to get the default Fs2004 Cessna 172 up to normal
>> cruise speeds. I max out at about 105-111 TAS at various altitudes. But
> from
>> various Internet sources, it seems that the real 172 should be able to
>> cruise at 125-140 kts.
>>
>> Anybody else bothered by this?
>>
>>
>>
>>
>>
>> --
>> peter greenstein
>> http://wakefieldjazz.com/
>>
>>
>
>

>I don't know your experience so I'll explain briefly.
>KIAS comes from the speed of the air going into the pitot tube and shows on
>your air speed indicator. Most show KIAS and not KTAS (knots true airspeed)
>but have a calibration knob to make corrections. KIAS is the speed the
>airplane "thinks" it is moving through the air. Hence, flying into a head
>wind, KIAS will be higher than actual speed and a flying with a tailwind
>would show lower than actual speed. KTAS is obtained by math. Remember,
>they told us "some day you'll need this". It's obtained with altitude and
>temperature.
>

Actually KIAS is measured by comparing the air pressure inside the pitot tube
and comparing it to the pressure of non moving air outside the pitot tube.
Strictly speaking TAS needs barometric pressure as well in the calculation.
Aerial navigators used to navigate by pressure patterns comparing TAS vatiation
over a period of time to known meteorological conditons. Not an exact science
but good for another data point. The comment about KIAS and headwind/tailwind
applies to groundspeed not TAS. The relationship between IAS and TAS is the
same no matter the winds.