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Impact Pressure

A

Avanza

Well Known Member
Enclosed is an airspeed impact pressure diagram.
It is correct at sea level and standard temp.
It can be used when working with ASI.
This impact pressure is available for the engine air inlet and
may increase HP and speed at altitude.

Good luck
 

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Seems pretty reasonable correlation to a flight I did just a few minutes ago:

2650 feet, engine off, MP = 27.1
Early TO roll, full throttle, 2700 RPM, MP = 27.7
2650 feet, 212KIAS, 2700 RPM, MP = 29.4
 
This curve is more properly called "dynamic pressure" and is equal to
1/2* (rho) * V^2.

Example: 1" Hg = 0.491 psi + 70.73 psf

Sea level density is 0.002377 slug/ft^3, so V= 243.9 ft/s = 166 mph = 145 kts.
 
Last edited:
scsmith said:
Hopefully 2650.5 ft! ;)
Click to expand...

I figured someone would catch that. 4 miles away from my strip is a nice, flat lakebed that is conveniently about 150 feet below the elevation of my runway. No problem flying in the "same air" and same altitude as my runway, but safely 150 AGL.
 
Toobuilder said:
I figured someone would catch that. 4 miles away from my strip is a nice, flat lakebed that is conveniently about 150 feet below the elevation of my runway. No problem flying in the "same air" and same altitude as my runway, but safely 150 AGL.
Click to expand...

Cool. And probably fewer quail hanging out in the middle of the dry lake too! ;)
 
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