static instability

negative stability

negative stabilityclick for a larger image
A nose-up displacement will aggravate in situation (B). Thus (B) has negative stability.
A condition in which the aircraft tends to move away from its original position when disturbed from its original position even when external force has been removed. This is the feature of most modern combat aircraft where aircraft is unstable instead of naturally stable. This is to ensure greater agility and maneuverability. Also known as negative static stability and static instability.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved
References in periodicals archive ?
This always indicates high static instability, effectively giving us an unstable environment.
Let's take an environment with high static instability. We'll assume the layer extends from 0 to 5000 feet and cools from 90 degrees F at the bottom to 40 degrees at the top, giving us a lapse rate of 10 degrees per 1000 feet.
Now you understand how static instability translates to turbulence, weather, and upward motion.
"Then I said, 'OK, maybe I was wrong.'" Sticking the landing To compensate for its static instability, the researchers' robot relies on some ingenious engineering.
Topics include: two-phase oscillatory thermal-hydraulic instability, oscillatory flow stability boundary, static instability, thermal-acoustic oscillations in heated channels, instability of condensing flows, and cases of flow instability in pipelines.
The budget funds 95 construction projects, consisting of 10 dam safety assurance, seepage control, and static instability correction projects; 20 projects justified on the basis of life-saving benefits; six project completions; two new starts; and 57 other continuing projects.
This means that the spring months bring a drastic increase in the cold-over-warm temperature gradient, in other words, high static instability dominates the spring months.