Search results
Results from the WOW.Com Content Network
In flight dynamics, longitudinal stability is the stability of an aircraft in the longitudinal, or pitching, plane. This characteristic is important in determining whether an aircraft pilot will be able to control the aircraft in the pitching plane without requiring excessive attention or excessive strength.
X stability axis is aligned into the direction of the oncoming air in steady flight. (It is projected into the plane made by the X and Z body axes if there is sideslip). Y stability axis is the same as the Y body-fixed axis. Z stability axis is perpendicular to the plane made by the X stability axis and the Y body axis.
Stability is the ability of the aircraft to counteract disturbances to its flight path. According to David P. Davies, there are six types of aircraft stability: speed stability, stick free static longitudinal stability, static lateral stability, directional stability, oscillatory stability, and spiral stability. [5]: 164
If the Dutch roll is very lightly damped or unstable, the yaw damper becomes a safety requirement, rather than a pilot and passenger convenience. Dual yaw dampers are required and a failed yaw damper is cause for limiting flight to low altitudes, and possibly lower Mach numbers, where the Dutch roll stability is improved.
Longitudinal stability and control may be obtained with other wing configurations, including canard, tandem wing and tailless aircraft. Some types of aircraft are stabilized with electronic flight control; in this case, fixed and movable surfaces located anywhere along the aircraft may serve as active motion dampers or stabilizers.
The best-known early flight simulation device was the Link Trainer, produced by Edwin Link in Binghamton, New York, United States, which he started building in 1927. He later patented his design, which was first available for sale in 1929. The Link Trainer was a basic metal frame flight simulator usually painted in its well-known blue color.
The longitudinal modes of a statically stable airplane following a disturbance were shown to consist of a long-period oscillation called the phugoid oscillation, usually with a period in seconds about one-quarter of the airspeed in miles per hour and a short-period oscillation with a period of only a few seconds. The lateral motion had three ...
To ensure stability for safe flight, an LSAS (Longitudinal Stability Augmentation System) was introduced to compensate for the MD-11's rather short horizontal stabilizer and ensure that the aircraft would remain stable. [8] However, there have been incidents in which the MD-11's relaxed stability caused an "inflight upset". [9]