static RPM

static RPM

The maximum RPM of a reciprocating engine when it is not moving through the air. The static RPM is lower than when the aircraft is moving, as forward movement rams air into the carburetor inlet, increases manifold pressure, and, hence, increases the power. The propeller has a decreased angle of attack and, thus, decreased drag.
References in periodicals archive ?
Static rpm checks falling within approved parameters for aircraft with fixed-pitch propellers can verify the engine and propeller are functioning properly.
At each annual or 100-hour inspection, check that the tachometer installed on the aircraft is properly calibrated, and verify that fixed-pitch propeller/engine combinations are approved and operate within static rpm limits at full power.
One owner told us that the static RPM increase on his 172 at nearly sea level demonstrated an increase in four HP using traditional horsepower versus RPM change calculations.
Static RPM (piston craft) must be at or above the expected number or abort.
A calibrated tachometer should be used to compare required static rpm listed on type certificate data sheets to the specified minimum or maximum full throttle rpm.
For a fixed-pitch prop, you should see full static RPM. That varies with the aircraft and condition, but for a typical single with a 2600-RPM redline it might be 2300 RPM when the aircraft is stationary or barely rolling.
Several sent in detailed before and after results, including static RPM readings, fuel flow, time-to-climb and full-throttle cruise speeds.
I found that my static RPM had gone from the low end of the allowable range to the high end, an increase of 150 RPM.
For example, a Cessna 172 Skyhawk with a cruise prop likely will have a lower static rpm and reduced takeoff and climb performance.
The letters stand for: RPM-ensure it's full-rated RPM, or expected static RPM for a fixed-pitch prop; Engine gauges in the green; Airspeed is alive; Centerline of the runway ('cause you've been looking down for a couple seconds, you should make sure you're not about to abscond with a runway light); Takeoff (rotation) speed will be achieved before a preselected abort point.