On Jun 8, 1:43 pm, "J. Severyn" wrote:
"Dallas" wrote in message

...







Am I reading this graph incorrectly?

http://img.photobucket.com/albums/v1...RangeProfileCh...

At the 45% power setting, the best range for a Cessna 150M would be
achieved by flying anywhere from sea level to a maximum of 1,800 feet?

At 75% power the gain is about 2.5 NM of range by flying at 7,000 feet vs.
1,000 feet.

This pretty much trashes my fundamental belief that higher altitudes give
greater range. What am I missing?

--
Dallas

If you stay at 45%, the climb to altitude takes a looooong time, and you are
moving slowly, so the range suffers.

I think most CAFE folks have figured out the best thing to do is climb at
max power, get to a high altitude quickly, then throttle back at the high
altitude to get the max fuel economy. YMMV.

Regards,
John Severyn
KLVK- Hide quoted text -

- Show quoted text -

Climb time is not built into that chart because there is no assumption
about field elevation. It is simply a cruise performance chart *after*
you have climbed to altitude. The reduction in range comes from
reduced propeller efficiency at higher altitudes for the same output
power.