never-exceed speed

never-exceed speed (VNE)

never-exceed speed (VNE)click for a larger image
A typical VN diagram indicating region of never exceed speed.
The speed beyond which it is not safe to fly an aircraft. It is normally less than the maximum diving speed (VD). As it concerns rotary-wing aircraft, the never-exceed speed, VNE, must be established so that it is (i) not less than 40 knots calibrated air speed; and (ii) not more than 0.9 times the maximum forward speeds established, the maximum speed, or the maximum speed substantiated for advancing blade tip Mach number effects, whichever is the least. The VNE in this case may vary with altitude, RPM, temperature, and weight. The ASI (air speed indicator) is marked with a red radial line at this speed. See also redline condition.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved
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References in periodicals archive ?
* Upper Red Radial: The airplane's never-exceed speed, VNE.
These give the Yankee a never-exceed speed (VNE) of 170 knots compared to the UH-1N which was limited to 130 knots.
Never-exceed speed of the 200A is 208 MPH, and its maximum structural cruising speed is 165 MPH.
Unless specifically stated otherwise, power should be set to idle and the aircraft pitched down for the recommended airspeed, which could be maximal structural cruising speed ([V.sub.NO]), never-exceed speed ([V.sub.NE]), maximum landing gear extended speed ([-V.sub.LE]), or maximum flap extended speed ([V.sub.FE]).
One aspect of the article drew comments and criticism from readers, some of which were published in the Unicom section in our March issue, involved that article's statements referencing a fixed-wing aircraft's never-exceed speed ([V.sub.NE] ) as a true airspeed.
The FAA defines [V.sub.NE] simply as the aircraft's never-exceed speed. It is required to be determined by the manufacturer during certification testing, as described in the regulatory excerpt in the sidebar on the opposite page.
There are many reasons aircraft are certificated with a never-exceed speed, including the prevention of aerodynamic flutter, which can destroy an airframe in seconds.
As this article's main text notes, an aircraft's never-exceed speed ([V.sub.NE]) is expressed as a true airspeed.
The never-exceed speed (V (NE)) is a red radial marked on the airspeed indicator, but it can be a lie waiting to ambush the unwary.
As we also should know, the yellow arc's bottom range begins at the airplane's maximum structural cruising speed--Vno--while its upper limit is the never-exceed speed, Vne.
We've all been warned to watch out whenever our airspeed enters the yellow arc, and we've learned to absolutely stay away from never-exceed speed, [V.sub.NE].