STALL WARNING SYSTEMS
A stall warning system for airplanes is a mechanism that alerts the pilot in advance of the stall. The requirement for a Stall Warning System will be found under the aviation regulations for the State of Manufacture and the State of the Operator for any given aircraft, as is the case with most safety-related equipment. The weight, capacity, and purpose of the aircraft, as well as the rules under which the aircraft Type Certificate was obtained, will all have an impact on the required operational parameters of the stall warning system on that specific aircraft.
Our Services
The following specifications are part of the regulations for a stall warning system for aircraft other than transport category aircraft:
- When flying straight or turning, with the flaps and landing gear in any standard position, there must be a noticeable and distinct stall warning.
- The aircraft's intrinsic aerodynamic characteristics or a technology that will provide obvious, unmistakable indicators under the anticipated flight conditions may provide the stall warning. By itself, a visual stall warning mechanism demanding the crew's attention in the cockpit is unacceptable.
- The stall warning must start at a speed that is at least 5 knots higher than the stalling speed (Vs) during a wings level, decelerating condition in any normal configuration, and must persist until the stall occurs.
- The stall warning must start far enough ahead of the stall during a turn or in the case of a turning accelerated stall to allow the pilot to avoid the stall by taking the necessary action.
The regulatory requirements for a Transport Category Aircraft are a little more rigorous and the regulations themselves are more normative as follows:
- The stall warning in each normal configuration shall start at a speed (Vsw) that exceeds the stall speed by at least five knots or by five percent of the calibrated airspeed, whichever is larger when the speed is reduced at rates not exceeding one knot per second. The stall warning must persist after it has started until the angle of attack is about equal to where it started.
- The stall warning margin must be enough to allow the pilot to avoid stalling when the recovery is started not less than one second after the stall warning first appears during decelerating turns with a load factor of at least 1.5g and airspeed reductions of at least two knots per second with flaps and gear in any normal position.
- The stall warning must be supplied in all aberrant configurations of the high-lift devices that are anticipated to be deployed in the case of a system failure, including all configurations covered by AFM protocols.
A stall warning system is something of a last resort. By the time it inadvertently activates, one has already disregarded a number of warning signs that the airplane is about to stall. They have permitted the aircraft to become overly sluggish, with an excessive angle of attack, and/or loaded with extra G forces. Then, they disregarded the controls becoming sluggish as well as maybe the aerodynamic signals of the aircraft itself, such as a burble or buffet. A stall warning system of some form is installed in the majority of personal aircraft as a last-ditch effort to catch the pilot's attention.
